Luciana Cristante Izar Marino
Avaliação dos nódulos tireoidianos na infância por
elastografia: comparação de suas características com a
ultrassonografia convencional
Dissertação apresentada ao Curso de Pós
Graduação da Faculdade de Ciências Médicas da
Santa Casa de São Paulo para obtenção do Titulo
de Mestre em Ciências da Saúde.
SÃO PAULO
2014
Luciana Cristante Izar Marino
Avaliação dos nódulos tireoidianos na infância por
elastografia: comparação de suas características com a
ultrassonografia convencional
Dissertação apresentada ao Curso de Pós
Graduação da Faculdade de Ciências Médicas da
Santa Casa de São Paulo para obtenção do Titulo
de Mestre em Ciências da Saúde
Área de Atuação: Ciências da Saúde
Orientadora: Prof. Doutora Cristiane Kochi
Co-Orientador: Prof. Doutor Eduardo
de Faria Castro Fleury
SÃO PAULO
2014
Versão Corrigida
FICHA CATALOGRÁFICA
Preparada pela Biblioteca Central da
Faculdade de Ciências Médicas da Santa Casa de São Paulo
Marino, Luciana Cristante Izar
Avaliação dos nódulos tireoidianos na infância por elastografia:
comparação de suas características com a ultrassonografia
convencional./ Luciana Cristante Izar Marino. São Paulo, 2014.
Dissertação de Mestrado. Faculdade de Ciências Médicas da
Santa Casa de São Paulo – Curso de Pós-Graduação em Ciências da
Saúde.
Área de Concentração: Ciências da Saúde
Orientadora: Cristiane Kochi
Co-Orientador: Eduardo de Faria Castro Fleury
1. Neoplasias da glândula tireoide 2. Nódulo da glândula tireoide
3. Técnicas de imagem por elasticidade 4. Ultrassonografia 5. Criança
BC-FCMSCSP/27-14
AGRADECIMENTOS
Inicio meus agradecimentos aos meus pais Jorge Luiz Izar e Lucia Helena Cristante Izar; sem
eles, todos os anos dedicados apenas aos estudos não seriam possíveis. Ao meu marido César
Marino Neto pelo constante apoio e incentivo.
Aos meus professores da Endocrinologia Pediátrica Dr. Osmar Monte, Dr. Carlos A. Longui,
Dra. Cristiane Kochi, Dr. Luis Eduardo Calliari, Dr. Mauro Borghi pelo meu conhecimento
em Endocrinologia Pediátrica.
Em especial, à Dra. Cristiane Kochi que me presenteou com o tema elastografia e que me
ajudou a crescer na vida acadêmica com a sua inteligência, atenção e amizade. Ainda, em
especial, ao Dr. Carlos A. Longui que está sempre presente e que me faz buscar a excelência
em tudo o que eu faço.
Ao Dr. Adriano Namo Cury por sua participação dedicada do início ao final do trabalho.
Ao Dr. Eduardo Fleury que tornou esse trabalho possível realizando todos os exames de
ultrassonografia, elastografia, punção aspirativa com agulha fina e que me ensinou e me
incentivou durante esses dois anos, sempre com bom humor e gentileza.
À Dra. Maria do Carmo Assunção Queiroz que realizou todas as avaliações citológicas.
À Selene, secretária do laboratório Locus, que sempre me enviou com rapidez e
responsabilidade todos os resultados da PAAF.
À Maria Helena V. Richtzenhain e ao Thomaz A. Alves da Rocha e Silva pelo carinho e
contribuição durante a realização do trabalho.
À Mirtes e Sônia, funcionárias da pós-graduação da Faculdade de Ciências Médicas da Santa
Casa de São Paulo, por me ajudarem de maneira tão solícita em todos os passos burocráticos
do mestrado.
Às minhas amigas de residência Eliza, Laura e Letícia e “minhas R3” queridas pela amizade,
paciência e apoio nesses dois anos de mestrado.
Aos pacientes e familiares pela confiança e disponibilidade.
Finalmente, à Faculdade de Ciências Médicas da Santa Casa de São Paulo e à Irmandade da
Santa Casa de Misericórdia de São Paulo por tornarem viável a realização deste trabalho.
DEDICATÓRIA
Dedico este trabalho aos meus pais Jorge Luiz Izar e Lucia Helena Cristante Izar, ao meu
marido César Marino Neto e aos meus irmãos Gustavo Cristante Izar e Fernando Cristante
Izar. Pessoas que eu tenho o privilégio de conviver e que me inspiram a querer aprender e
melhorar sempre.
SUMÁRIO:
I.
II.
III.
IV.
V.
VI.
INTRODUÇÃO
OBJETIVOS
ARTIGO
COMENTÁRIOS FINAIS
REFERÊNCIAS BIBLIOGRÁFICAS
ANEXOS
PAG
1
3
4
25
28
33
Introdução:
Nódulos tireoidianos são raros na infância, menos de 1.5%, porém com alta incidência de
malignidade, em torno de 26.4% (1-5).
A incidência de câncer de tireoide é de 1:1.000.000, entre menores de 10 anos, 1:200.000
entre 10-14 anos, e 1:75.000 entre 15-19 anos. Após a puberdade, as meninas têm quatro
vezes maior probabilidade de ter câncer de tireoide do que meninos, enquanto a proporção em
pré-púberes é similar (1:1) (6).
O câncer de tireoide apresenta-se avançado ao diagnóstico em crianças, com
comprometimento de linfonodos em 40-90% dos casos e metástases à distância em 20-30%
(6-16).
O protocolo para diagnóstico de nódulos tireoidianos consiste em: exame físico, exames
laboratoriais, ultrassonografia de tireóide (USG), biópsia por punção aspirativa com agulha
fina (PAAF) (17-21).
A avaliação citológica do material obtido pela PAAF é a melhor maneira para o diagnóstico
diferencial entre nódulos benignos e malignos de tireoide, devido sua alta sensibilidade e
especificidade (22).
Porém, apenas alguns artigos envolvem a PAAF para diagnóstico de nódulos tireoidianos na
infância (23-28). A PAAF deve obter material celular adequado, todavia, em alguns casos, o
rápido influxo de sangue de tumores altamente vascularizados exige mais de uma punção para
diagnóstico, o que pode ser particularmente difícil em crianças. A aplicação de creme
analgésico minimiza uma desvantagem ao método, que é o desconforto durante a punção,
especialmente em crianças pequenas (29-31).
O tamanho do nódulo para indicação de punção permanece em discussão; em adultos a
punção é recomendada para nódulos maiores de 1 cm, mas em crianças, devido à alta
incidência de malignidade, é razoável a punção de nódulos menores, entre 0.5-1 cm (32,33).
Apesar da alta especificidade e sensibilidade da PAAF, cerca de 20 % a 40% dos achados
citológicos não são suficientes para o diagnóstico ou são indeterminados, e o diagnóstico
correto é obtido apenas após avaliação histológica (34).
A USG é a modalidade mais sensível de identificação e avaliação não invasiva de nódulos
tireoidianos (35,36), visto que, algumas características dos nódulos como microcalcificações,
hipoecogenicidade, vascularização central, e ausência de halo, têm sido associadas com maior
risco de malignidade (37-38). A combinação dessas características determina se o médico
deve ou não encaminhar o paciente para punção ou realizar USG de seguimento (39). Porém,
há uma incerteza na acurácia diagnóstica dessas características e os resultados da USG
sozinhos não podem ser aceitos como verdadeiramente positivos em termos de malignidade
(39,40).
2
A elastografia é uma técnica dinâmica que pode aprimorar a avaliação ultrassonográfica dos
nódulos tireoidianos (41-44), utiliza um software acoplado ao aparelho de USG convencional
para estimar a rigidez de um tecido através do seu grau de deformação após aplicação de uma
força externa. Lesões malignas tendem ser mais rígidas do que o tecido benigno ao redor (4145). Estudos in vitro com tumores demonstraram rigidez 10 vezes maior em neoplasias
malignas comparadas com tecido benigno (46). A elastografia foi desenvolvida por Ophir e
colaboradores, em 1991 (University of Texas Medical School, Houston) (47).
A elastografia tem sido usada para diferenciar câncer de lesões benignas em próstata, mamas,
pâncreas e linfonodos (43,44). Porém, existem dúvidas quanto à reprodutibilidade de uma
tecnologia em que a deformação avaliada do tecido depende de uma compressão externa. Não
se observa na literatura consenso quanto a melhor técnica ou classificação para a sua
aplicação clínica (45).
Atualmente existem dois métodos de elastografia para determinação da rigidez do nódulo
tireoidiano: (a) quando uma força é aplicada ao tecido e ocorre uma deformação paralela à
direção da força (Strain), (b) quando a deformação é perpendicular à direção da força (Shear
wave). A deformação do nódulo tireoidiano é mensurada através dos ecos da USG (48).
A primeira técnica necessita de uma força manual sobre o tecido em estudo, a imagem
elastográfica é gerada a partir da deformação do nódulo tireoidiano- nódulos rígidos
apresentam menor deformação- produzindo ecos que são transformados em cores conforme
sua variação elástica (48). A segunda utiliza uma tecnologia patenteada chamada Sonic Touch
para criar uma onda que se propaga perpendicular às ondas ultrassonográficas convencionais.
Quanto mais rígido o tecido, a onda se propaga com maior rapidez, essa velocidade é então
quantificada; essa técnica apresenta limitações como exigir trabalho dedicado, demorado e
equipamentos caros (49-51).
A elastografia tem sido utilizada no estudo de nódulos tireoidianos em adultos com resultados
positivos em relação ao diagnóstico diferencial entre nódulos benignos e malignos (41,52).
Estudo publicado por Azizi e colaboradores (2012), em que a elastografia foi realizada pelo
método de compressão manual em 706 adultos com 912 nódulos, uma correlação significativa
foi encontrada entre a elastografia e malignidade dos nódulos tireoidianos (p=0.0001) (53).
Devido à importância do diagnóstico diferencial entre nódulos tireoidianos benignos e
malignos e a concomitante necessidade de procedimentos diagnósticos menos invasivos na
infância, optamos avaliar o desempenho da elastografia por compressão manual, nessa faixa
etária, como nova técnica diagnóstica.
3
Objetivos
•
•
Avaliar o desempenho da elastografia por pressão manual no diagnóstico diferencial
de nódulos tireoidianos benignos e malignos na infância;
Comparar o desempenho da elastografia com a ultrassonografia convencional no
diagnóstico diferencial de nódulos benignos e malignos na infância.
4
ELASTOGRAPHY FOR THE EVALUATION OF THYROID NODULES IN
CHILDREN
ELASTOGRAPHY OF THYROID NODULES IN CHILDREN
Luciana Cristante Izar Marino, Cristiane Kochi, Ph.D., Adriano Namo Cury, Ph.D., Osmar
Monte, Ph.D., Carlos A. Longui, Ph.D., Eduardo de Faria Castro Fleury, Ph.D.
Faculdade De Ciências Médicas Da Santa Casa De São Paulo, Street Dr. Cesário Mota Jr.,
112, Vila Buarque São Paulo Sp Brazil Postcode 01221-020
Correspondence:
Luciana Cristante Izar Marino
Santa Casa SP – Faculty of Medical Science
Street Dr. Cesário Mota Jr., 112, Vila Buarque São Paulo SP Brazil Postcode 01221-020
Phone number: +55-11-974613777
Email address: [email protected]
Keywords: thyroid cancer, child, thyroid nodules, elastography, ultrasound
Acknowledgements: We are indebted to the patients and families evaluated and to Dr. Maria
do Carmo Assunção Queiroz for her expertise and assistance in all cytological analysis. No
competing financial interests exist.
Word Count: 2463.
5
SUMMARY
Objective: Elastography is a diagnostic technique, performed as part as ultrasound
examination, that evaluates tissue stiffness, which could be an indicator of malignancy of
thyroid nodules (TNs). It was recently shown to be a sensitive, noninvasive tool for the
identification of thyroid cancer in adults. Since the management of TNs in children has
important particularities and the most appropriate investigation(s) of TNs are still debated, we
report our experience with elastography in the diagnostic approach to childhood thyroid
nodules.
Design and Patients: This was a prospective study conducted between September 2012
and August 2013 at the Santa Casa de São Paulo Hospital in Brazil. We performed
elastography, ultrasonography and fine-needle aspiration biopsy (FNAB) on 32 patients aged
between 6 and 18 years of age who had, in total, 38 TNs. Elastography was evaluated using 2
scores, namely E1 for elastic lesions (benign) and E2 for rigid lesions (malignant).
Results: Twelve of the 32 patients with cytological abnormalities concerning for
cancer were referred for surgery, 7 patients were diagnosed with thyroid cancer,
corresponding to a 22% cancer rate. McNemar’s Test showed that the findings of
elastography in relation to histopathological were correct in 78.5% of cases. 92% of benign
TNs were classified as E1. Elastography could have avoided unnecessary thyroidectomy of 3
patients with underterminated biopsy result. Only one malignant thyroid nodule was classified
as E1.
Conclusions: Our findings suggested that high elasticity of a nodule on elastography is
associated with a low risk of thyroid cancer, if further confirmed; elastography may be useful
as a complementary screening test in children who present with TNs.
6
INTRODUCTION
Thyroid nodules (TNs) are rare in children, with an incidence rate of only 1.5%.
However, the risk of malignancy among children with TNs is high, reaching a quarter. 1, 2
The incidence of thyroid cancer is 1:1.000, 000 among children younger than 10 years
of age, 1:200,000 among children 10 to 14 years of age and 1:75,000 among those 15 to 19
years of age. After puberty, girls are 4 times more likely to have thyroid cancer than boys,
while the ratio in the prepubertal period is comparable (1:1). 3
Children are often diagnosed with advanced thyroid cancer, with 40% to 90% of cases
presenting with lymph node involvement and 20% to 30% presenting with distant metastases.
3- 8
Thorough investigation of suspicious nodules that might require surgery is
recommended so as to ensure early identification of malignancy and to avoid unnecessary
thyroidectomy in those with benign nodules. 3, 9
The protocol for the diagnosis of TNs includes physical examination, laboratory tests,
thyroid ultrasonography, and fine needle aspiration biopsy (FNAB). 10, 11 However, the most
appropriate investigation(s) of TNs are still debated. Ultrasonography is considered more
sensitive than physical examination for the detection of TNs, but this technique is not specific
for differentiating between malignant and benign nodules. 12
FNAB is thought to be the most accurate method for diagnosing TNs, but in children,
this procedure is particularly difficult because of the discomfort associated with the biopsy. In
addition, 20-40% of the cytological findings following FNAB are indeterminate or not
sufficient for a definite diagnosis. An accurate diagnosis is often made only after histological
evaluation. 13
7
The nodule size that validates biopsy is still debated. In adults, biopsy is recommended
for nodules larger than 1 cm, and in children, it is advisable to perform biopsy on smaller
nodules, i.e., 0.5 to 1 cm, 14 because of the high incidence of malignancy among children.
Elastography is a promising technique for the ultrasonographic evaluation of TNs. 15, 16
This technique relies on software that is available for conventional ultrasound devices and it
evaluates the different types of tissue, which are visualized ultrasonographically, according to
variations in their stiffness. Elastography is based on the principle that benign lesions are
usually softer than malignant lesions, and these data can facilitate a differential diagnosis in
clinical pathologies, such as TNs. 17
There are 2 general ultrasonographic methods used for determining TN stiffness: (i) a
force is applied to the tissue using manual compression and the tissue deformation is parallel
to the force direction (strain), and (ii) a pushing beam is created and the tissue deformation is
perpendicular to the force direction (shear wave). 18
In children with TNs, a diagnosis that differentiates between benign or malignant
disease is vitally important. We evaluated the usefulness of elastography (using manual
compression) as a diagnostic tool for children who present with TNs.
8
MATERIALS AND METHODS
Subjects:
This was a prospective study conducted between September 2012 and August 2013 at
the Santa Casa de São Paulo Hospital in Brazil. The Ethics and Research Committee of Santa
Casa de São Paulo approved the study (authorization number: 01687412200005479). The
parents/legal guardian of each participant provided informed consent and the participants
provided assent.
We evaluated 35 patients with TNs who had been treated at our
hospital’s pediatric endocrinology service. In total, 42 TNs were identified on physical
examination or with cervical ultrasonography. We excluded 3 patients with a total of 4
nodules. One patient with 2 nodules had inconclusive FNAB results, one patient had thyroid
nodule with apparent muscle invasion but in consecutive evaluations showed regression of the
nodule, and 1 wished to withdraw from the study. Therefore, we enrolled 32 patients with a
total of 38 TNs in our study.
Laboratory evaluations of thyroid function (the circulating levels of thyroid-stimulating
hormone, free thyroxine, thyroid peroxidase antibody, antithyroglobulin antibody, and
calcitonin) were conducted. Patients with euthyroidism were referred to the CTC-Genesis
diagnostic center, São Paulo, Brazil, to undergo ultrasonography, elastography and FNAB.
Examinations were conducted by the same radiologist who, at the time of the study, had had 9
years of experience in thyroid imaging. The specimen obtained by FNAB was send to the
Locus cytological analysis laboratory, São Paulo, Brazil, for evaluation by a cytologist who
has had more than 30 years of experience in cytological analysis.
The Bethesda System of Reporting Thyroid Cytopathology was used to categorize
biopsies as nondiagnostic (I), benign (II), atypia of underterminated significance (III),
suspicious for follicular neoplasm (IV), suspicious for malignancy (V) or malignant (VI).
9
Thyroidectomy was recommended for patients who had possible non-benign cytology
(TNs classified as Bethesda IV, V, or VI).
Equipment:
Ultrasonography and elastography were performed using the Ultrasonix Sonix SP
probe with a multifrequency of 5–14 MHz. For the elastography study, we used special
software [version 3.0.2 (Beta1)], which was developed for the Ultrasonix apparatus
(Ultrasonix Medical Corporation, Vancouver, Canada). The radiologist in charge of the study
obtained the rights to use the software for experimental research during the study period.
Elastography:
Elastography was performed during the US examination, using the same real-time
instrument and the same probe. A box was highlighted by the operator that included the
nodule to be evaluated.
The patient was placed in the supine position with hyperextension of the neck, and the
transducer of the ultrasonography was oriented perpendicular to the area of interest. For
elastography, a slight and continuous manual compression was exerted with the transducer on
the TN(s) until resistance could be felt. When the operator sensed resistance he relaxed the
hand holding the transducer so as to provide spontaneous decompression of the thyroid
nodule. It is important that the level of pressure is maintained constant throughout the
examination. The operator knows that the freehand compression is correct through a green
light that appears to the right of the ultrasound image (Figure 1). The possibility to select the
area of elastography analysis allowed a correct screening, even of the small nodules,
independently from the position of the nodule within the thyroid nodule.
10
The principle of elastography is to acquire two ultrasonic images before and after
tissue compression by the probe and track tissue displacement by assessing the propagation of
the imaging beam. A dedicated software able to provide an accurate measurement of tissue
distortion was used.
This technique is easy to perform. Examination time ranged from 30 seconds to 2
minutes.
All examinations were performed by the same operator who was not aware of the
results of cytology.
The elastography software program provides information in various colors. Each color
represents a level of elasticity. In descending order of elasticity is blue, green, yellow, and
red.
In this study, elastography was evaluated using 2 scores, modified from Azizi et al.’s
classification, 19 namely E1 and E2. Every TN was given a score of E1 or E2. If the TN had a
red coloring of <50% then it was classified as E1 (elastic TNs); when red was present in
>50% of the thyroid nodule then it was classified as E2 (hard TNs) (Figures 2, 3, and 4).
Statistical analysis
McNemar’s test was used to determine the agreement between elastography, whether
benign or malign, with histology.
11
RESULTS
Patients:
We enrolled 32 patients with one or more nodules, referred for suspected nodules
detected by palpation or as incidental radiographic findings. The mean age of patients was
12.9 years (range, 6–18 years) and the female: male ratio was 2.5. The mean age of the girls
(n=23) and boys (n=9) being 13.5 and 11 years, respectively.
Biopsy was offered for all nodules (0.5-4.3cm).
Twelve of the 32 patients with cytological abnormalities concerning for cancer were
referred for surgery – total thyroidectomy. Overall, 7 patients were diagnosed with thyroid
cancer, corresponding to a 22% cancer rate. Their histological diagnoses were 6 with papillary
thyroid carcinoma and 1 with medullary carcinoma.
The patients with cytologically benign nodules agreed to long-term surveillance with
annual neck ultrasonography. FNAB was repeated in the cases of changes in US features. So
far, no changes in the diagnosis of benign nodules occurred.
The mean age of patients with thyroid cancer was 12 years (range, 7–18 years). Six
were female and 1 was male.
Eleven patients tested positive for antibodies, only one among those diagnosed with
thyroid cancer. One patient had elevated calcitonin levels: 3.770 pg/ml (reference value:
<8.4). This patient was diagnosed with medullary thyroid carcinoma.
Thyroid nodules (TNs):
As a result of FNAB, 24 of the 38 TNs (63%) were classified as Bethesda II, 6 (16%)
as Bethesda IV, 7 (18%) as Bethesda V, and 1 (3%) as Bethesda VI.
All TNs classified as Bethesda V and VI were malignant by operative pathology. Five
TNs classified as Bethesda IV were benign, one was malignant.
12
The location of TNs was as follows: 47% (18/38) in the right lobe, 45% (17/38) in the
left lobe, 5% (2/38) in the isthmus and 3% (1/38) were diffuse. The TNs in the isthmus were
benign, whereas the TN with a diffuse appearance was malignant. Four of the TNs in the right
lobe and 4 in left lobe were malignant.
The average size of the malignant and benign TNs was similar, 1.3–1.6 cm.
Elastography features
Among the 14 TNs evaluated by histology, 5 were benign (35.7%) and 9 were
malignant (64.3%).
McNemar’s Test showed that the findings of elastography in relation to
histopathological were correct in 78.5% of cases, i.e., elastography classified 21.4% as benign
and 57.1% as malignant (Table 1).
Elastography was classified as E1 in only one malignant nodule, and in this
particularly case, the patient had high level of calcitonin, one more thyroid nodule which was
Bethesda V, and the histological diagnosis was medullary carcinoma.
Among the 5 benign thyroid nodule, elastography was classified as E1 in 3 thyroid
nodules.
As in much larger adult series, the fact that the vast majority of patients with benign
cytology do not have surgery prevents an absolute assessment of the accuracy of biopsy. But
if we consider the 24 “benign” TNs after FNAB, elastography was classified as E1 in 22 TNs
(92%).
Three patients referred to surgery after FNAB suspicious for follicular neoplasm
(Bethesda IV) had elastography classified as E1 and the histology confirmed the TNs to be
benign.
13
DISCUSSION
The goal of this paper is to report our experience with elastography in the diagnostic
approach to childhood thyroid nodules.
Our findings suggest that high elasticity of a nodule on elastography is associated with
a low risk of thyroid cancer, since, elastography E1 (elastic TNs) was found in 3 of 5 benign
TNs, and if we consider the 24 TNs classified as benign after FNAB, 92% were classified E1.
On top of that, only one malignant thyroid nodule was classified as elastography E1, and it
was a particularly case of a boy with elevated calcitonin and final diagnosis of medullary
thyroid carcinoma.
Among the 6 patients with FNAB suspicious for follicular neoplasm (Bethesda IV), 3
patients had elastography classified as E1 and histology confirmed the TNs to be benign, so,
they were referred unnecessary to thyroidectomy.
McNemar’s Test showed that the findings of elastography in relation to
histopathological were correct in 78.5% of cases.
Elastography was recently introduced as a technique that, by assessing tissue
elasticity, might differentiate malignant (usually hard) from benign lesions. With this
technique, tissue elasticity is evaluated by measuring the local displacement of nodular tissue
being compressed by an external force: the softer the nodule, the larger the displacement and
vice-versa.15
The first study to assess the role of this technique in thyroid nodules was performed in
2007 by Rago et al. They reported a positive predictive value of 100% and a negative
predictive value of 98%. Their conclusion was that elastography was a useful adjunctive tool
for the diagnosis of thyroid cancer. 20
14
Subsequent studies showed similar results, such as Azizi’s et al. They performed
elastography in 706 patients with 912 TNs and found a significant correlation between
elastography and malignancy (p=0.0001). 19
Since the high incidence of malignancy, any thyroid nodule in children should be
viewed with suspicion and the diagnostic approach should be aggressive, but, it is also
important trying to avoid invasive procedures and unnecessary thyroidectomies.
Ultrasound is used to screen TNs but many reports question its reliability. A
systematic review by Brito et al. evaluated the performance of ultrasonography in the
diagnosis of TNs and concluded that individual ultrasonographic features are not accurate
predictors of thyroid cancer. 21
Although presently, FNAB remains the most important procedure for the diagnostic
management of TNs yet a substantial proportion (up to 20%) of cytological specimens
provides indeterminate results, and the distinction between benign and malignant lesions can
only be made on histological criteria. 22
As far as we know, there is no report using elastography for the diagnosis of TNs in
childhood. If larger studies confirm our results elastography might allow children with elastic
TNs to be placed in follow-up without invasive procedures or unnecessary thyroidectomies.
However, the accuracy of elastography is hampered by intra-and interoperator
variability. 23, 24-26
There are ways that may improve the diagnostic accuracy of elastography.
Magri et al, in their study, evaluated the usefulness of elastography in 528 patients
with a total of 661 TNs, identifying a strain index (SI) cutoff with the highest diagnostic
performance. The SI was calculated as a ratio of the nodule strain divided by the strain of the
softest part of the surrounding normal tissue. The elastographic SI had a high sensitivity,
specificity, and negative predictive value for the diagnosis of thyroid malignancy. 27
15
Furthermore, there is a new technique of elastography that estimates tissue stifness in real
time and is quantitative and user independent, shear wave elastography (SWE). Promising
results have been obtained with this technique
28, 29
but it is limited use because it is time
consuming, labor intensive, and requires dedicated, expensive ultrasonography devices.
In this study to minimize interoperator variability, ultrasonography and elastography
by manual compression were performed by a single radiologist with nine years of experience
in elastography and was not aware of the FNAB results.
Although pediatric reports about thyroid cancer may be flawed by their small size, we
thought that is important to improve the investigation of TNs in these young patients. In this
single report about elastography in childhood, the low number of false negative results by
elastography might imply that high elasticity of TNs is associated with benign histology.
In summary, it is easy to incorporate elastography in routine ultrasound examination
and it can be used as a complementary screening test for children who present with TNs.
Larger studies are needed to obtain the diagnostic accuracy of elastography in children.
16
REFERENCES
1. Yip, F.W., Reeve, T.S., Poole, A.G., et al. (1994) Thyroid nodules in childhood and
adolescence. The Australian and New Zealand Journal of Surgery, 64, 676–678.
2. Millman, B. & Pellitteri, P.K. (1997) Nodular thyroid disease in children and
adolescents. Otolaryngology--Head and Neck Surgery: Official Journal of American
Academy of Otolaryngology-Head and Neck Surgery, 116, 604–609.
3. Hogan, A.R., Zhuge, Y., Perez, E.A., et al. (2009) Pediatric thyroid carcinoma: incidence
and outcomes in 1753 patients. Journal of Surgical Research, 156, 167–172.
4. Chaukar, D.A., Rangarajan, V., Nair, N., et al. (2005) Pediatric thyroid cancer. Journal of
Surgical Oncology, 92, 130–133.
5. Okada, T., Sasaki, F., Takahashi, H., et al. (2006) Management of childhood and
adolescent thyroid carcinoma: long-term follow-up and clinical characteristics. European
Journal of Pediatric Surgery : Official Journal of Austrian Association of Pediatric
Surgery ... [Et Al] = Zeitschrift für Kinderchirurgie, 16, 8–13.
6. O'Gorman, C.S., Hamilton, J., Rachmiel, M., et al. (2010) Thyroid cancer in childhood: a
retrospective review of childhood course Thyroid: Official Journal of the American
Thyroid Association, 20, 375–380.
7. Luster, M., Lassmann, M., Freudenberg, L.S., et al. (2007) Thyroid cancer in childhood:
management strategy, including dosimetry and long-term results. Hormones (Athens,
Greece), 6, 269–278.
8. Dinauer, C.A., Breuer, C. & Rivkees, S.A. (2008) Differentiated thyroid cancer in children:
diagnosis and management. Current Opinion in Oncology, 20, 59–65.
9. Ridgway, E.C. (1991) Clinical evaluation of solitary thyroid nodules. In Werner and
Ingbar’s The Thyroid (ed. L.E. Braverman, S.C. Werner, R.D. Utiger, et al.), Lippincott,
Philadelphia, pp. 1197–1203.
17
10. Brito, J.P., Gionfriddo, M.R., Al Nofal, A., et al. (2014) The accuracy of thyroid nodule
ultrasound to predict thyroid cancer: systematic review and meta-analysis. Journal of
Clinical Endocrinology and Metabolism, 99, 1253–1263.
11. Koutras, D.A. (2001) Thyroid nodules in children and adolescents: consequences in adult
life. J. Pediatr. Endocrinol. Metab., 14, 1283–1287.
12. Niedziela, M. & Korman, E. (2002) Thyroid carcinoma in a fourteen-year-old boy with
Graves disease. Medical and Pediatric Oncology, 38, 290–291.
13. Redman, R., Zalaznick, H., Mazzaferri, E.L., et al. (2006) The impact of assessing
specimen adequacy and number of needle passes for fine-needle aspiration biopsy of
thyroid nodules. Thyroid: Official Journal of the American Thyroid Association, 16, 55–
60.
14. Mazzaferri, E.L. & Sipos, J. (2008) Should all patients with subcentimeter thyroid nodules
undergo fine-needle aspiration biopsy and preoperative neck ultrasonography to define the
extent of tumor invasion? Thyroid: Official Journal of the American Thyroid Association,
18, 597–602.
15. Ophir, J., Alam, S.K., Garra, B., et al. (1999) Elastography: ultrasonic estimation and
imaging of the elastic properties of tissues. Proceedings of the Institution of Mechanical
Engineers. Part H, Journal of Engineering in Medicine, 213, 203–233.
16. Cochlin, D.L., Ganatra, R.H. & Griffiths, D.F. (2002) Elastography in the detection of
prostatic cancer. Clinical Radiology, 57, 1014–1020.
17. Fleury, E.deF., Fleury, J.C.V., Oliveira, V.M., et al. (2009) [Proposal for the
systematization of the elastographic study of mammary lesions through ultrasound
scan]. Revista da Associação Médica Brasileira, 55, 192–196.
18. Barr, R.G., Memo, R. & Schaub, C.R. (2012) Shear wave ultrasound elastography of the
prostate: initial results. Ultrasound Quarterly, 28, 13–20.
18
19. Azizi, G., Keller, J., Lewis, M., et al. (2013) Performance of elastography for the
evaluation of thyroid nodules: a prospective study. Thyroid: Official Journal of the
American Thyroid Association, 23, 734–740.
20. Rago T, Santini F, Scutari M, et al. (2007) Elastography: new developments in
ultrasound for predicting malignancy in thyroid nodules. J Clin Endocrinol Metab, 92,
2917–2922.
21. Brito JP, Gionfriddo MR, Nofal AA, et al. (2013) The accuracy of thyroid nodule
ultrasound to predict thyroid cancer: systematic review and meta-analysis. J Clin
Endocrinol Metab, 99, 1253-1263.
22. Redman R, Zalaznick H, Mazzaferri EL, et al. (2006) The impact of assessing specimen
adequacy and number of needle passes for fine-needle aspiration biopsy of thyroid
nodules. Thyroid, 16, 55–60.
23. Moon HJ, Sung JM, Kim EK, et al. (2012) Diagnostic performance of gray-scale US and
elastography in solid thyroid nodules. Radiology, 262, 1002–1013.
24. Hegedüs L. (2010) Can elastography stretch our understanding of thyroid
histomorphology? J Clin Endocrinol Metab, 95, 5213– 5215.
25. Trimboli P, Guglielmi R, Monti S, et al. (2012) Ultrasound sensitivity for thyroid
malignancy is increased by real-time elastography: a prospective multicenter study. J Clin
Endocrinol Metab, 97, 4524–4530.
26. Magri F, Chytiris S, Capelli V, et al.(2012) Shear wave elastography in the diagnosis of
thyroid nodules: feasibility in the case of coexistent chronic autoimmune Hashimoto’s
thyroiditis. Clin Endocrinol (Oxf), 76, 137–141.
27. Magri, F., Chytiris, S., Capelli, V., et al. (2013) Comparison of elastographic strain index
and thyroid fine-needle aspiration cytology in 631 thyroid nodules. Journal of Clinical
Endocrinology and Metabolism, 98, 4790–4797.
19
28. Bercoff, J., Tanter, M. & Fink, M. (2004) Supersonic shear imaging: a new technique for
soft tissue elasticity mapping. IEEE Transactions on Ultrasonics, Ferroelectrics, and
Frequency Control, 51, 396–409.
29. Sebag, F., Vaillant-Lombard, J., Berbis, J., et al. (2010) Shear wave elastography: a new
ultrasound imaging mode for the differential diagnosis of benign and malignant thyroid
nodules. Journal of Clinical Endocrinology and Metabolism, 95, 5281–5288.
20
Figure 1.
Green light that shows to the left of the ultrasound image when the freehand compression is
correct.
21
Figure 2.
Classification of thyroid nodules by elastography:
elastography: A classification E1 indicated an elastic
lesion, which was likely benign and a classification E2 indicated a rigid lesion, which was
likely malignant.
22
Figure 3.
An elastography image with a classification of E1
23
Figure 4.
An elastography image with a classification of E2
24
Table 1. McNemar’s Test for elastography and histopathological results
B
ELASTOGRAPHY
M
TOTAL
COUNT
%
COUNT
%
COUNT
%
B
3
21.4%
2
14.3%
5
35.7%
M
1
7.1%
8
57.1%
9
64.3%
HP
4
28.6%
10
71.4%
14
100%
B: benign; M: malignant; HP: histopathological; %: % of total.
Agreement between elastography and histopathological was 78.6%.
25
Considerações finais:
Os objetivos desse estudo foram: avaliar a elastografia no diagnóstico diferencial de nódulos
benignos e malignos de tireoide na infância e comparar seu desempenho com a
ultrassonografia convencional.
Nossos achados sugerem que nódulos mais elásticos pela elastografia estão associados a um
menor risco de câncer de tireóide, visto que, a elastografia classificou como E1 (nódulos
elásticos) 3 dos 5 nódulos benignos pela histologia e 22 dos demais 24 nódulos considerados
benignos pela PAAF. Além disso, entre os 9 nódulos malignos, a elastografia classificou
como E1 apenas um nódulo. Neste caso, o paciente apresentava calcitonina elevada e a
presença de outro nódulo tireoidiano classificado como E2 pela elastografia e resultado
histológico de carcinoma medular de tireóide. Ainda, dado digno de nota foi que os 3 nódulos
benignos com a classificação E1 pela elastografia pertenciam a 3 pacientes que foram
encaminhados para tireoidectomia desnecessária devido PAAF suspeita de neoplasia folicular
(Bethesda IV).
O teste estatístico McNemar demonstrou concordância entre os resultados da elastografia e os
resultados histológicos de 78.5%.
Em relação à USG convencional, verificamos que o tamanho dos nódulos benignos e
malignos foi semelhante: 1.3 a 1.6 cm. A localização dos nódulos malignos foi: 4 em lobo
direito e 4 em lobo esquerdo da tireoide, 1 nódulo que comprometia difusamente a glândula.
A concordância, entre achados da USG e a histologia foi realizada considerando
hipoecogenicidade, presença de microcalcificações, ausência de halo e presença de
vascularização central como características de malignidade. Encontramos concordância de
71,5%, 57.2%, 28.6% e 42.9% respectivamente.
Ao avaliarmos as tabelas 2 a 5, em relação ao teste estatístico de concordância utilizado nesse
estudo (McNemar), verificamos que entre os 9 nódulos malignos, 6 eram hipoecogênicos, 4
apresentavam microcalcificações, 2 não apresentavam halo, e 2 tinham vascularização central
ao doppler. Esses achados sugerem incerteza na associação dessas características
ultrassonográficas de malignidade isoladas com malignidade do nódulo tireoidiano.
A elastografia foi introduzida recentemente como uma técnica que ao avaliar a elasticidade de
um tecido poderia diferenciar lesões malignas (geralmente rígidas) de benignas. Com essa
técnica, a elasticidade do nódulo tireoidiano é determinada através da medida do
deslocamento que ocorre após uma compressão externa, quanto mais elástica a lesão maior é
o seu deslocamento e vice-versa (42).
O primeiro estudo que avaliou o papel da elastografia no diagnóstico diferencial de nódulos
tireoidianos malignos de benignos foi publicado em 2007 por Rago e colaboradores. Eles
apresentaram como resultados da elastografia um valor preditivo positivo de 100% e um valor
preditivo negativo de 98%. A conclusão do trabalho foi que a elastografia era uma ferramenta
adicional útil para o diagnóstico de câncer de tireóide (54).
26
Estudos posteriores apresentaram resultados semelhantes, como o estudo de Azizi e
colaboradores que realizaram a elastografia por compressão manual em 706 pacientes com
912 nódulos tireoidianos e encontraram uma correlação significativa entre a elastografia e
malignidade (p=0.0001) (53).
Todos os nódulos tireoidianos na infância devem ser avaliados com suspeita, visto a alta
incidência de malignidade e o frequente comprometimento de linfonodos e metástases à
distância ao diagnóstico (1-6); porém, é igualmente importante que procedimentos invasivos e
tireoidectomias desnecessárias não sejam realizados em pacientes pequenos. Não
encontramos na literatura estudos com a utilização da elastografia na avaliação de nódulos
tireoidianos na infância.
A USG é o exame escolhido como triagem dos nódulos tireoidianos por ser um exame não
invasivo e de informações imediatas. Entre muitas características descritas pela USG, a
hipoecogenicidade do nódulo, a presença de microcalcificações, a ausência de halo e a
presença de vascularização central têm sido utilizadas para predizer a malignidade (37,38).
Essas características sozinhas são pouco preditivas de malignidade; juntas, aumentam sua
especificidade, mas perdem em sensibilidade (55). A USG determina se o médico deve ou não
encaminhar o paciente para punção ou realizar USG de seguimento.
A PAAF é o procedimento para diagnóstico diferencial entre nódulos tireoidianos malignos e
benignos de maior acurácia diagnóstica, porém, mais de 20% das amostras avaliadas
apresentam resultados indeterminados, e a distinção entre benignidade e malignidade só é
feito pelo anatomopatológico (34).
Nossos achados, se confirmados por maiores estudos, têm relevância na abordagem de
nódulos tireoidianos na infância, visto que pacientes com nódulos tireoidianos elásticos,
poderiam ser acompanhados por USG e elastografia, sem a necessidade de procedimentos
diagnósticos invasivos ou mesmo tireoidectomias desnecessárias.
Entretanto, a acurácia da elastografia é questionada devido à variabilidade intraobservador e
interobservadores (56,57). Na literatura, existem estudos que demonstram alternativas para
aumentar a acurácia diagnóstica da elastografia.
Uma alternativa é a avaliação semiquantitativa da rigidez do nódulo tireoidiano, em que é
calculado um índice de deformação (strain index), que avalia a rigidez do nódulo tireoidiano
em relação ao tecido ao redor (58). Magri e colaboradores avaliaram a elastografia em 528
pacientes com 661 nódulos tireoidianos pelo cálculo do índice de deformação; nódulos
malignos apresentaram valores significativamente maiores do índice de deformação do que
nódulos benignos. Além disso, nesse estudo foi avaliado o índice de deformação na presença
e ausência de tireoidite e o resultado foi alta sensibilidade, especificidade, e valor preditivo
negativo do índice de deformação da elastografia para o diagnóstico de câncer de tireóide na
presença ou ausência de tireoidite (59).
Outra possibilidade é a avaliação quantitativa da rigidez do nódulo tireoidiano (60,61). Existe
uma nova técnica de elastografia chamada “Shear Wave Elastography” que estima a rigidez
27
de um tecido de maneira quantitativa e é operador independente. Trata-se de uma tecnologia
patenteada chamada Sonic Touch para criar uma onda que se propaga perpendicular às ondas
ultrassonográficas convencionais. Quanto mais rígido o tecido, a onda se propaga com maior
rapidez, essa velocidade é então quantificada (48-51). Resultados promissores com essa
técnica são descritos na literatura (60,62). Porém, seu uso é limitado pelo tempo necessário
para realização, é um método trabalhoso que requer dedicação do operador. Além disso,
requer aparato de ultrassonografia de maior custo.
Nesse estudo, optamos por um observador único com experiência de 9 anos de elastografia
por compressão manual para minimizar a variação interoperadores. Esse operador não sabia
os resultados da PAAF.
Embora estudos na infância de câncer de tireóide possam ser questionados devido à baixa
incidência da doença e assim, amostra pequena de pacientes, consideramos importante os
estudos voltados para essa população. Nesse trabalho único na literatura sobre elastografia na
infância, o número pequeno de falsos negativos da elastografia pode implicar que nódulos
tireoidianos elásticos estão associados à histologia benigna.
Maiores estudos são necessários para encontrarmos a acurácia diagnóstica da elastografia no
diagnóstico de câncer de tireóide na infância. No momento, a avaliação da elasticidade de um
nódulo tireoidiano poderia ser utilizada como ferramenta adicional de diagnóstico diferencial
dos nódulos tireoidianos na infância.
28
Referências bibliográficas:
1. Kirkland RT, Kirkland JL, Rosenberg HS, Harberg FJ, Librik L, Clayton GW 1973 Solitary
thyroid nodules in 30 children and report of a child with a thyroid abscess. Pediatrics
51:85-90.
2. Rallison ML, Dobyns BM, Keating FR Jr, Rall JE, Tyler FH 1975 Thyroid nodularity in
children. JAMA 233:1069-1072.
3. Scott MD, Crawford JD 1976 Solitary thyroid nodules in childhood: is the incidence of
thyroid carcinoma declining? Pediatrics 58:521-525.
4. Yip FW, Reeve TS, Poole AG & Delbridge L 1994 Thyroid nodules in childhood and
adolescence. Aust N Z J Surg 64:676-678.
5. Millman B, Pellitteri PK 1997 Nodular thyroid disease in children and adolescents.
Otolaryngol, Head and Neck Surg 116:604-609.
6. Hogan AR, Zhuge Y, Perez EA, Koniaris LG, Lew JI, Sola JE 2009 Pediatric thyroid
carcinoma: incidence and outcomes in 1753 patients. J Surg Res 156:167-172.
7. Welch Dinauer CA, Tuttle RM, Robie DK, McClellan DR, Svec RL, Adair C, Francis
GL1998 Clinical features associated with metastasis and recurrence of differentiated thyroid
cancer in children, adolescents and young adults. Clin Endocrinol (Oxf) 49:619–628.
8. Reiners C, Demidchik YE 2003 Differentiated thyroid cancer in childhood: pathology,
diagnosis, therapy. Pediatr Endocrinol Rev 1 2:230–235.
9. Chaukar DA, Rangarajan V, Nair N, Dcruz AK, Nadkarni MS, Pai PS, Mistry RC 2005
Pediatric thyroid cancer. J Surg Oncol 92:130–133.
10. Okada T, Sasaki F, Takahashi H, Taguchi K, Takahashi M, Watanabe K, Itoh T, Ota S,
Todo S 2006 Management of childhood and adolescent thyroid carcinoma: long-term followup and clinical characteristics. Eur J Pediatr Surg 16:8–13.
11. Thompson GB, Hay ID 2004 Current strategies for surgical management and adjuvant
treatment of childhood papillary thyroid carcinoma. World J Surg 28:1187–1198.
12. O'Gorman CS, Hamilton J, Rachmiel M, Gupta A, Ngan BY, Daneman D 2010 Thyroid
cancer in childhood: a retrospective review of childhood course. Thyroid 20:375–380.
13. Rachmiel M, Charron M, Gupta A, Hamilton J, Wherrett D, Forte V, Daneman D 2006
Evidence-based review of treatment and follow up of pediatric patients with differentiated
thyroid carcinoma. J Pediatr Endocrinol Metab 19:1377–1393.
14. Luster M, Lassmann M, Freudenberg LS, Reiners C 2007 Thyroid cancer in childhood:
management strategy, including dosimetry and long-term results. Hormones (Athens) 6:269–
278.
15. Dinauer C, Francis GL 2007 Thyroid cancer in children. Endocrinol Metab Clin North
Am 36:779–806.
29
16. Dinauer CA, Breuer C, Rivkees SA 2008 Differentiated thyroid cancer in children:
diagnosis and management. Curr Opin Oncol 20:59–65.
17. Salas M 1995 Thyroid nodules in children and adolescents. Pediatr Endocrinol 3: 415422.
18. Korman E, Niedziela M, Rybakowa M, Dziatkowiak H, Dorant B, Kalicka-Kasperczyk A,
Malecka-Tendera E, Nizankowska-Blaz T, Romer TE, Szewczyk L et al.1999 Thyroid
nodular disease in children - apreliminary Polish multicenter study. Hormone
Research 2:18.
19. Koutras DA 2001 Thyroid nodules in children and adolescents: consequences in adult life.
J Pediatr Endocrinol Metab 14:1283-1287.
20. Wiersinga D 2001 Thyroid cancer in children and adolescents -consequences in later life.
J Pediatr Endocrinol Metab 4:1289-1296.
21. Niedziela M & Korman E 2002 Thyroid carcinoma in a fourteen-year-old boy with
Graves disease. Med Pediatr Oncol 38:290-291.
22. Cooper DS, Doherty GM, Haugen BR, Kloos RT, Lee SL, Mandel SJ, Mazzaferri EL,
McIver B, Sherman SI, Tuttle RM 2006 Management guidelines for patients with thyroid
nodules and differentiated thyroid cancer. Thyroid 16:109–142.
23. Raab SS, Silvermann JF, Elsheikh TM, Thomas PA &Wakely PE 1995 Pediatric thyroid
nodules: disease demographics and clinical management as determined by fine needle
aspiration biopsy. Pediatrics 95:46-49.
24. Degnan BM, McClellan DR & Francis GL 1996 An analysis of fine-needle aspiration
biopsy of the thyroid in children and adolescents. J Pediatr Surg 31:903-907.
25. Lugo-Vicente H, Ortiz VN, Irizarry H, Camps JI, PaganV 1998 Pediatric thyroid nodules:
management in the era of fine-needle aspiration. J Pediatr Surg 33:
302-305.
26. Khurana KK, Truong LD, LiVolsi VA & Baloch ZW 2003 Cytokeratin 19
immunolocalization in cell block preparation of thyroid aspirates. An adjunct to fine-needle
aspiration diagnosis of papillary thyroid carcinoma. Archives of Pathology and Laboratory
Medicine 127:579-583.
27. Al-Shaikh A, Ngan B, Daneman A & Daneman D 2001 Fine-needle aspiration biopsy in
the management of thyroid nodules in children and adolescents. J Pediatr 138:140-142.
28. Amrikachi M, Ponder TB, Wheeler TM, Smith D & Ramzy I 2005 Thyroid fine-needle
aspiration biopsy in children and adolescents: experience with 218 aspirates. Diagnostic
Cytopathology 32:189-192.
30
29. Van Vliet G, Glinoer D, Verelst J, Spehl M, Gompel C &Delange F 1987 Cold thyroid
nodules in childhood: is surgery always necessary? Eur JPediatr
146:378-382.
30. Koch CA,Sarlis NJ 2001 The spectrum of thyroid diseases in childhood and its evolution
during transition to adulthood: Natural history, diagnosis, differential
diagnosis and management. J Endocrinol Investigation 24:659-675.
31. Bettendorf M 2002 Thyroid disorders in children from birth to adolescence. European J
Nucl Med 29:439-S446.
32. Mazzaferri EL, Sipos J. 2008 Should all patients with subcentimeter thyroid nodules
undergo fine-needle aspiration biopsy and preoperative neck ultrasonography to define the
extent of tumor invasion? Thyroid 18:597–602.
33. Cooper DS, Doherty GM, Haugen BR, Kloos RT, Lee SL, Mandel SJ, Mazzaferri EL,
McIver B, Sherman SI, Tuttle RM 2006 Management guidelines for patients with thyroid
nodules and differentiated thyroid cancer. Thyroid 16:109–142.
34. Redman R, Zalaznick H, Mazzaferi EL, Massoll NA 2006 The impact of assessing
specimen adequacy and number of needle passes for fini-needle aspiration biopsy of thyroid
nodules. Thyroid 16:55-60.
35. Baskin HJ 2000 Ultrasound of Thyroid nodules. In: Baskin HJ, ed. Thyroid Ultrasound
and Ultrasound-Guided FNA Biopsy, Kluwer Academic Publishers, Boston, MA, pp 71-86.
36. Solbiati L, Osti V, Cova L, Tonolini M 2001 Ultrasound of Thyroid, parathyroid glands
and neck lymph nodes. Eur Radiol 11:2411-2424.
37. Rago T, Vitti P, Chiovato L, Mazzeo S, De Liberi A, Miccoli P, Vacava P,Bogazzi F,
Martino E, Pinchera A 1998 Role of conventional ultrasonographyand color flow-Doppler
sonography in predicting malignancy in “cold” thyroid nodules. Eur J Endocrinol 138:41–46
38. Papini E, Guglielmi R, Bianchini A, Crescenzi A, Taccagna S, Nardi F,Panunzi C, Rinaldi
R, Toscano V, Pacella CM 2002 Risk of malignancy innonpalpable thyroid nodules:predictive
value of ultrasound and color-Doppler features. J Clin Endocrinol Metab 87:1941–1946.
39. Brito JP, Gionfriddo MR, Nofal AA, Boehmer KR, Leppin AL, Reading C, Callstrom M,
Elraiyah TA, Prokop LJ, Stan MN, Murad MH, Morris JC, Montori VM 2013 The accuracy
of thyroid nodule ultrasound to predict thyroid cancer: systematic review and meta-analysis. J
Clin Endocrinol Metab 99:1253-1263.
40. Niedziela M 2006 Pathogenesis, diagnosis and management of thyroid nodules in
children. Endocrine-Related Cancer 13:427-453.
41. Lerner RM, Huang SR, Parker KJ 1990 Sonoelasticity images derived from ultrasound
signals in mechanically vibrated tissues. Ultrasound Med Biol 16:231–239.
42. Ophir J, Alam SK, Garra B, Kallel F, Knofagou E, Krouskop T, Varghese T 1999
Elastography: ultrasonic estimation and imaging of the elastic properties of tissues. Proc Inst
Mech Eng [H] 213:203–233.
31
43. Garra BS, Cespedes EI, Ophir J, Spratta SR, Zuurbier RA, Magnant CM, Pennaren MF
1997 Elastography of breast lesions: initial clinical results. Radiology 202:79–86.
44. Cochlin DL, Ganatra RH, Griffiths DF 2002 Elastography in the detection of prostatic
cancer. Clin Radiol 57:1014–1020.
45. Fleury EFC, Fleury JCV, Oliveira VM, Rinaldi JF, Piato S, Júnior D R 2009 Proposta de
sistematização do estudo elastográfico de lesões mamárias pela ultrassonografia. Rev. Assoc.
Med. Bras 55:192-196.
46. Asteria C, Giovanardi A, PizzocaroA, Cozzaglio L, Morabito A, Somalvico F, Zoppo A
2008 US-elastohraphy in the differential diagnosis of benign and malignant thyroid nodules.
Thyroid 18:523-532.
47. Ophir J, Cespedes I, Ponnekanti H, Yazdi Y, Li X 1991 Elastography: a quantitative
method for imaging the elasticity of biological tissues. Ultrason Imaging 13:111-134.
48. Barr RG, Memo R, Schaub CR 2012 Shear wave ultrasound elastography of the prostate:
initial results. Ultrasound Q 28:13-20.
49. Lazebnik RS 2008 Siemens Medical Solutions, USA, Inc.,Ultrasound, Mountain View,
CA USA Whitepaper: Tissue Strain Analytics Virtual Touch Tissue Imaging and
Quantification. Available at usa.healthcare.siemens.com/ultrasound/tissue-strainanalytics/esie-touch-elasticity-imaging.
50. Friedrich-Rust M, Romenski O, Meyer G, Dauth N, HolzerK, Gru¨ nwald F, Kriener S,
Herrmann E, Zeuzem S, Bojunga J 2012 Acoustic radiation force impulse-imaging for the
evaluationof the thyroid gland: a limited patient feasibility study. Ultrasonics 52:69–74.
51. Nightingale K, McAleavey S, Trahey G 2003 Shear-wave generation using acoustic
radiation force: in vivo and ex vivo results. Ultrasound Med Biol 29:1715–1723.
52. Lyshchik A, Higashi T, Asato R, Tanaka S, Ito J, Mai J, Pellot-Barakat C, Insana MF,
Brill AB, Saga T, Hiraoka M, TogashiK 2005 Thyroid gland tumor diagnosis at US
elastography. Radiology 237:202–211
53. Azizi G, Keller J, Lewis M, Puett D, Rivenbark K, Malchoff C 2013 Performance of
Elastography for the Evaluation of Thyroid Nodules: A Prospective Study. Thyroid 23:734740.
54. Rago T, Santini F, Scutari M, Pinchera A, Vitti P 2007 Elastography: new developments
in ultrasound for predicting malignancy in thyroid nodules. JClin Endocrinol Metab.
92:2917–2922.
55. Nam-Goong IS, Kim HY, Gong G, Lee HK, Hong SJ, Kim WB, Shong YK 2004
Ultrasonography-guided fine-needle aspiration of thyroid incidentaloma: correlation with
pathological findings. Clin Endocrinol (Oxf) 60:21–28
56. Moon HJ, Sung JM, Kim EK, Yoon JH, Youk JH, Kwak JY 2012 Diagnostic performance
of gray-scale US and elastography in solid thyroid nodules. Radiology 262:1002-1013.
32
57. Hegedüs L 2010 Can elastography stretch our understanding of thyroid histomorphology?
J Clin Endocrinol Metab. 95: 5213– 5215.
58. Rago T, Vitti P. 2008 Role of thyroid ultrasound in the diagnostic evaluation of thyroid
nodules. Best Pract Res Clin Endocrinol Metab. 22: 913–928.
59. Magri F, Chytiris S, Capelli V, Gaiti M, Zerbini F, Carrara R, Malovini A, Rotondi M,
Bellazzi R, Chiovato L 2013 Comparison of Elastography Strain Index and Thyroid FineNeedle Aspiration Cytology in 631 Thyroid Nodules. J Clin Endocrinol Metab 98:4790-4797.
60. Sebag et al 2010 Shear Wave Elastography and Thyroid Nodules. J Clin Endocrinol
Metab, 95(12):5281–5288.
61. Cantisani V, D’Andrea V, Biancari F, et al. 2012 Prospective evaluation of
multiparametric ultrasound and quantitative elastosonography in the differential diagnosis of
benign and malignant thyroid nodules: preliminary experience. Eur J Radiol. 81: 2678–2683.
62. Bercoff, J., Tanter, M. & Fink, M. 2004 Supersonic shear imaging: a new technique for
soft tissue elasticity mapping. IEEE Transactions on Ultrasonics, Ferroelectrics, and
Frequency Control. 51: 396–409.
33
Anexo 1: Tabelas.
Tabela 1. Teste estatístico McNemar para resultados da elastografia e anatomopatológico
B
ELASTOGRAFIA
M
TOTAL
NÚMERO
% TOTAL
NÚMERO
% TOTAL
NÚMERO
% TOTAL
B
3
21.4%
2
14.3%
5
35.7%
M
1
7.1%
8
57.1%
9
64.3%
B: benigno; M: maligno; AP: anatomopatológico
Concordância entre elastografia e anatomopatológico foi de 78.6%
AP
4
28.6%
10
71.4%
14
100%
34
Tabela 2. Teste estatístico McNemar para resultados da ecogenicidade e anatomopatológico
B
ECOGENICIDADE
M
TOTAL
NÚMERO
% TOTAL
NÚMERO
% TOTAL
NÚMERO
% TOTAL
B
4
28.6%
1
7.1%
5
35.7%
M
3
21.4%
6
42.9%
9
64.3%
B: benigno; M: maligno; AP: anatomopatológico
Concordância entre a ecogenicidade e anatomopatológico foi de 71.5%
AP
7
50%
7
50%
14
100%
35
Tabela 3. Teste estatístico McNemar para microcalcificações e anatomopatológico
B
MICROC.
M
TOTAL
NÚMERO
% TOTAL
NÚMERO
% TOTAL
NÚMERO
% TOTAL
B
4
28.6%
1
7.1%
5
35.7%
M
5
35.7%
4
28.6%
9
64.3%
AP
9
64.3%
5
35.7%
14
100%
MICROC. : Microcalcificações; B: benigno; M: maligno; AP: anatomopatológico
Concordância entre microcalcificações e anatomopatológico foi de 57.2%
36
Tabela 4. Teste estatístico McNemar para halo e anatomopatológico
B
HALO
M
TOTAL
NÚMERO
% TOTAL
NÚMERO
% TOTAL
NÚMERO
% TOTAL
B
3
21.4%
2
14.3%
5
35.7%
M
2
14.3%
7
50%
9
64.3%
B: benigno; M: maligno; AP: anatomopatológico
Concordância entre halo e anatomopatológico foi de 71.4%
AP
5
35.7%
9
64.3%
14
100%
37
Tabela 5. Teste estatístico McNemar para vascularização e anatomopatológico
B
VASC.
M
TOTAL
NÚMERO
% TOTAL
NÚMERO
% TOTAL
NÚMERO
% TOTAL
B
4
28.6%
1
7.1%
5
35.7%
M
7
50%
2
14.3%
9
64.3%
AP
11
78.6%
3
21.4%
14
100%
VASC. : Vascularização; B: benigno; M: maligno; AP: anatomopatológico
Concordância entre vascularização e anatomopatológico foi de 42.9%
38
Anexo 2: Dados clínicos dos pacientes e resultados encontrados após avaliação dos nódulos
tireoidianos.
Nódulo: numeração dos nódulos; Paciente: número de identificação do paciente; F:
feminino; M: masculino; LE: lobo esquerdo; LD: lobo direito; Eco: ecogenicidade; Hipo:
hipoecogênico; Hiper: hiperecogênico; Iso: isoecogênico; Calcif.: microcalcificação;
Vasc.: vascularização; Perif.: periférica; C+P: central e periférica presentes; E: escore da
elastografia; PAAF: punção aspirativa por agulha fina; AP: anatomopatológico; CP:
carcinoma papilífero; CM: carcinoma medular.
39
Anexo 2: Dados clínicos dos pacientes e resultados encontrados após avaliação dos nódulos
tireoidianos.
Nódulo: numeração dos nódulos; Paciente: número de identificação do paciente; F:
feminino; M: masculino; LE: lobo esquerdo; LD: lobo direito; Eco: ecogenicidade;
ecogenicidad Hipo:
hipoecogênico; Hiper: hiperecogênico; Iso: isoecogênico; Calcif.: microcalcificação;
Vasc.: vascularização; Perif.: periférica; C+P: central e periférica presentes; E: escore da
elastografia; PAAF: punção aspirativa por agulha fina; AP: anatomopatológico.
anatomopat
40
Anexo 2: Dados clínicos dos pacientes e resultados encontrados após avaliação dos nódulos
tireoidianos.
Nódulo: numeração dos nódulos; Paciente: número de identificação do paciente; F:
feminino; M: masculino; LE: lobo esquerdo; LD: lobo direito; Eco: ecogenicidade; Hipo:
hipoecogênico; Hiper: hiperecogênico; Iso: isoecogênico; Calcif.: microcalcificação;
Vasc.:
c.: vascularização; Perif.: periférica; C+P: central e periférica presentes; E: escore da
elastografia; PAAF: punção aspirativa por agulha fina.
41
Anexo 3. Aprovação do Comitê de Ética e Pesquisa
42
43
Anexo 4: Orientações para submissão Clinical Endocrinology
Clinical Endocrinology
© John Wiley & Sons Ltd
Edited By: J. S. Bevan, S. J. Judd and S. G. Ball
Impact Factor: 3.353
ISI Journal Citation Reports © Ranking: 2013: 53/123 (Endocrinology & Metabolism)
Online ISSN: 1365-2265
Author Guidelines
Clinical Endocrinology encourages the online submission of your manuscripts. Original
articles should be submitted through http://mc.manuscriptcentral.com/cen. Support for online
submission is available by e-mailing to [email protected]. Telephone support is
available at +1-434-817-2040 x 334 (Monday through Friday 3:00 am to 8:30 pm EST). The
editorial office can be contacted at [email protected].
If online submission is not possible, authors should send original papers with a disk to the
appropriate regional editor, as listed here. European authors should submit to the Editorial
Office, again with a disk. All other manuscripts, including reviews and commentaries, should
be administered online or through the Editorial Office.
44
Papers are accepted on the understanding that no substantial part has been, or will be,
published elsewhere. Papers may be subject to editorial revision without notice and remain
the copyright of the journal. The Editors reserve the right to make the final decision whether
or not a paper is accepted. Authors must indicate in the text the way in which they have
complied with the recommendations of the Declaration of Helsinki (British Medical Journal,
1964, ii, 177). Experimental human studies should first have been approved by a local Ethical
Committee, and a statement to this effect should be included.
An Author's Declaration, obtained from the Journal website,
http://mc.manuscriptcentral.com/cen, under 'Instructions and Forms' or from the Editorial
Office of Clinical Endocrinology, must accompany each paper submitted and should be
signed by all authors.
In addition, the Editors request that authors provide them with a statement of any competing
interests, using a similar form as is used for this purpose by the British Medical Journal. An
electronic version of this form is available under 'Instructions and Forms' on the Journal
website. Although the Editors will not reject a paper simply because of a competing interest,
they will publish a statement of declared interests.
Copyright
If your paper is accepted, the author identified as the formal corresponding author for the
paper will receive an email prompting them to login into Author Services; where via the
Wiley Author Licensing Service (WALS) they will be able to complete the license agreement
on behalf of all authors on the paper.
For authors signing the copyright transfer agreement
If the OnlineOpen option is not selected the corresponding author will be presented with the
copyright transfer agreement (CTA) to sign. The terms and conditions of the CTA can be
previewed in the samples associated with the Copyright FAQs below:
CTA Terms and Conditions http://authorservices.wiley.com/bauthor/faqs_copyright.asp
For authors choosing OnlineOpen
If the OnlineOpen option is selected the corresponding author will have a choice of the
following Creative Commons License Open Access Agreements (OAA):
Creative Commons Attribution Non-Commercial License OAA
Creative Commons Attribution Non-Commercial -NoDerivs License OAA
To preview the terms and conditions of these open access agreements please visit the
Copyright FAQs hosted on Wiley Author Services
http://authorservices.wiley.com/bauthor/faqs_copyright.asp and visit
http://www.wileyopenaccess.com/details/content/12f25db4c87/Copyright--License.html.
If you select the OnlineOpen option and your research is funded by The Wellcome Trust and
members of the Research Councils UK (RCUK) you will be given the opportunity to publish
your article under a CC-BY license supporting you in complying with Wellcome Trust and
45
Research Councils UK requirements. For more information on this policy and the Journal’s
compliant self-archiving policy please visit: http://www.wiley.com/go/funderstatement.
For RCUK and Wellcome Trust authors click on the link below to preview the terms and
conditions of this license:
Creative Commons Attribution License OAA
To preview the terms and conditions of these open access agreements please visit the
Copyright FAQs hosted on Wiley Author Services
http://authorservices.wiley.com/bauthor/faqs_copyright.asp and visit
http://www.wileyopenaccess.com/details/content/12f25db4c87/Copyright--License.html
Note to NIH Grantees
Pursuant to NIH mandate, Wiley Blackwell will post the accepted version of contributions
authored by NIH grant-holders to PubMed Central upon acceptance. This accepted version
will be made publicly available 12 months after publication. For further information, see
www.wiley.com/go/nihmandate.
Accepted Articles
'Accepted Articles' have been accepted for publication and undergone full peer review but
have not been through the copyediting, typesetting, pagination and proofreading process.
Accepted Articles are published online a few days after final acceptance, appear in PDF
format only, are given a Digital Object Identifier (DOI), which allows them to be cited and
tracked, and are indexed by PubMed. A completed copyright form is required before a
manuscript can be processed as an Accepted Article.
Early View
Clinical Endocrinology is covered by Wiley Blackwell's Early View service. Early View
articles are complete full-text articles published online in advance of their publication in a
printed issue. Articles are, therefore, available for publication as soon as they are ready, rather
than having to wait for the next scheduled print issue. Early View articles are complete and
final. They have been fully reviewed, revised and edited for publication, and the authors' final
corrections have been incorporated. Because they are in a final form, no changes can be made
after online publication. The nature of Early View articles means that they do not yet have
volume, issue or page numbers, so Early View articles cannot be cited in the traditional way.
They are, therefore given a Digital Object Identifier (DOI), which allows the article to be
cited and tracked before it is allocated to an issue. After print publication, the DOI remains
valid, and can be continued to be used to cite and access the article.
The final version of the hard copy and the file on the disk must be the same. Note the software
used, the type of computer and any special (non-keyboard) characters used.
Access to this journal is available free online within institutions in the developing world
through the HINARI initiative with the WHO. For information, visit
www.healthinternetwork.org
Material storage policy
Please note that unless specifically requested, the Publisher will dispose of all hardcopy or
46
electronic material submitted two months after publication. If you require the return of any
material, please inform the Editorial Office or Production Editor as soon as possible.
Original Articles
Manuscripts must be typewritten (double-spaced) on one side of the paper only. The text must
be preceded by a structured summary of no more than 250 words, to include the following
headings: objective, including a background sentence setting the study in context, design,
patients, measurements, results, conclusions. Word count should be no longer than 3500
words, references no more than 35 and figures / tables no more than 6 in total (word count =
text only, not including the abstract, references, figure legends or table legends).
Only those abbreviations listed below may be used in the summary. A single title page must
give: (1) the title; (2) a short title; (3) the name(s) of the author(s); (4) the department(s) in
which the work was done; and (5) the name, full postal address, fax number and e-mail
address of the author to whom the proofs and requests for offprints should be sent, to be
headed 'Correspondence'; (6) a list of no more than five keywords (MeSH terms) related to
subjects discussed in the paper; (7) an acknowledgement section to include any conflicting
interests, and financial disclosure (if none, put `nothing to declare') in the paper; and (8) a
word count for the manuscript.
Please note that Clinical Endocrinology does not publish papers relating directly to diabetes
care and clinical management.
Rapid Communications
Rapid communications should consist of new data of sufficient importance to warrant
immediate publication. The submitted paper should be self-contained and not a tentative
preliminary communication. It will be refereed very quickly and any revision must be dealt
with promptly.
It is expected that the time interval between the acceptance and subsequent publication of the
manuscript will be approximately 3 months. If the Editors consider the article unsuitable for
publication as a rapid communication it will be processed as a normal paper unless it is
withdrawn by the authors.
Correspondence
Correspondence will be considered for publication if it contains constructive criticism on
published articles, the authors of which will be given the right of reply. Items of topical
interest, including case reports presenting a significant advance in therapy or highlighting
substantial scientific advances in understanding the mechanism(s) of the disease process, will
also be considered under this heading. Correspondence should not exceed 1000 words, have
no more than 5 references and only 1 figure / table.
In line with current Editorial policy, we only accept case reports that are truly exceptional and
provide new insights into endocrine pathogenesis, investigation or treatment. Case report
submissions should be written in line with our correspondence criteria: maximum of 1000
words, either one table or one figure and no more than five relevant references. Please do not
include any abstract or section headings. Case reports should be written in the style of a Letter
to the Editors.
We work together with Wiley’s open access journal, Clinical Case Reports, to enable rapid
publication of good quality case reports that we are unable to accept for publication in our
47
journal. Authors of case reports rejected by our journal will be offered the option of having
their case report, along with any related peer reviews, automatically transferred for
consideration by the Clinical Case Reports editorial team. Authors will not need to reformat
or rewrite their manuscript at this stage, and publication decisions will be made a short time
after the transfer takes place. Clinical Case Reports will consider case reports from every
clinical discipline and may include clinical images or clinical videos. Clinical Case Reports is
an open access journal, and article publication fees apply. For more information please go to
www.clinicalcasesjournal.com.
Review Articles and Commentaries
Review articles are normally commissioned, but we welcome suggestions for review titles and
authors. Review articles in the 'Clinical Practice Update' category should deal with a defined
clinical endocrine topic, and should focus on recent developments in understanding of the
clinical presentation, and in clinical endocrine management. Other review articles may take a
broader view of the topic and focus more on the basic mechanisms of endocrine dysfunction.
Anyone wishing to write a review, clinical practice update or commentary for the journal
should first consult the UK Editor, Professor John Bevan ( [email protected]). Word count
should be no longer than 4500 words, references no more than 70 and figures / tables no more
than 6 in total (word count = text only, not including the abstract, references, figure legends or
table legends.
Clinical Questions
Clinical Question articles are focused answers to specific clinical questions. The content is
similar to that in a typical 'corridor consultation' something that occurs every day between
clinicians, either in person, or by telephone or email. The difference here is that the author
will be able to expand and provide additional background for their answer. The manuscripts
will be written by invitation only with the goal of one 'Clinical Question' article per issue. The
answers to many of these questions rely heavily on clinical experience, and the articles will
likely be highly sought after and potentially frequently referenced. These manuscripts should
be no longer than 1800 words (excluding Summary) and include no more than two figures
and/or tables and 30 references. It is anticipated that most experts will be able to write 90% of
the manuscript in two or three sittings. To enhance the listing in Medline and PubMed, a brief
unstructured summary should be included.
Clinical Trials
Authors should be aware that the International Committee of Medical Journal Editors has
recommended that clinical trials should be prospectively registered, and that papers reporting
results of such trials should indicate that the trial has been registered (http://www.mja.com.au/
public/issues/182_12_200605/van10384_fm.pdf). Authors are advised to consult the Editorial
Office if there is uncertainty about the requirement for the process to be completed.
Papers must be written in clear, concise English. Spelling should follow The Concise Oxford
Dictionary of Current English (Clarendon Press, Oxford). Avoid jargon and neologisms. The
journal is not prepared to undertake major correction of language, which is the responsibility
of the author. Where English is not the first language of the authors, the paper must be
checked by a native Engligh speaker. Authors may suggest the names of suitable referees if
they wish.
Figures and Tables
Digital artwork files for reproduction should preferably be EPS or TIFF and meet our
48
standards, but we may be able to use other formats so please include these (see
http://authorservices.wiley.com/bauthor/illustration.asp). Figures should be included with
online submissions, either as JPEG, GIF, TIFF, BMP, PICT with RTF manuscripts or
embedded in the PDF file. Colour reproductions will incur a charge.
Tables should be typed on separate sheets, numbered (with arabic numbers) and have a title.
Supporting Information
Supporting Information can be a useful way for an author to include important but ancillary
information with the online version of an article. Examples of Supporting Information include
additional tables, data sets, figures, movie files, audio clips, 3D structures, and other related
nonessential multimedia files. Supporting Information should be cited within the article text,
and a descriptive legend should be included. It is published as supplied by the author, and a
proof is not made available prior to publication; for these reasons, authors should provide any
Supporting Information in the desired final format.
For further information on recommended file types and requirements for submission, please
visit: http://authorservices.wiley.com/bauthor/suppinfo.asp
Colour
If there is colour artwork in your manuscript, you will be required to complete and return a
colour work agreement form before your paper can be published. This form can be
downloaded as a PDF here. Once completed, please return the form to:
Customer Services (OPI)
John Wiley & Sons Ltd, European Distribution Centre
New Era Estate
Oldlands Way
Bognor Regis
West Sussex
PO22 9NQ
United Kingdom
Statistics
Special attention must be paid to the appropriate use of statistical methods in both the design
and analysis of the study. Authors are advised to consider the recommendations published in
the British Medical Journal (1983) 286, 1489-1493. Manuscripts may be reviewed by the
Journal's medical statisticians.
Units
SI units should be used throughout, with molar, in preference to mass units wherever possible.
Mass units may, however, be used for peptide hormones (e.g. leptin, ghrelin). Pituitary and
other hormones expressed in units per litre should quote the appropriate standard reference
preparation used in the assay. GH must be expressed in mass units (µg/l) measured against
International Standard 98/574. Concentrations should be expressed per litre, rather than per
mL or dL and laboratory reference ranges quoted as appropriate.
Abbreviations
In general the Journal follows the recommendations in Units, Symbols and Abbreviations
(1988). Royal Society of Medicine, London.
The following abbreviations may be used without definition:
49
ACTH corticotrophin; ADH antidiuretic hormone, vasopressin; AVP arginine vasopressin;
FSH follicle stimulating hormone; GH growth hormone; GnRH gonadotrophin releasing
hormone; HCG human chorionic gonadotrophin; hMG human menopausal gonadotrophin:
hPL human placental lactogen; IGF insulin-like growth factor: IGFBP insulin like growth
factor binding protein; LH luteinizing hormone; OT oxytocin; PRL prolactin; PTH
parathyroid hormone; SHBG sex hormone binding globulin; T4 thyroxine; T3
triiodothyronine; rT3 reverse T3: TRH thyrotrophin releasing hormone; TSH thyrotrophin:
VIP vasoactive intestinal peptide.
The Biochemical Journal (1975) 145, 1011, enumerates abbreviations for certain compounds
and also describes the correct use of chemical names and formulae.
All other abbreviations must be defined where they are introduced.
Chemical symbols and formulae should not be used in the text.
Steroids
Authors should follow the recommendations for steroid nomenclature published in the
Journal of Endocrinology (1980) 84, 3-4.
Amino Acids
Abbreviations may only be used in tables and for representing polymers or sequences in the
text [see Biochemical Journal (1975) 145, 11].
Isotopically Labelled Compounds
See Biochemical Journal (1975) 145,13-14 and the Radiochemical Catalogue (Radiochemical
Centre, Amersham, Bucks).
Solutions
Solutions should be described in terms of molarity (M), not normality (N). For values less
than 0.1 M use mM (50 mM not 0.05 M). Buffers: composition, pH and method of adjustment
should be given, e.g. 0.1 M potassium dihydrogen phosphate adjusted to pH 7.4 with 2 M
sodium hydroxide. Volume ratios - e.g. methanol: water, 8 2 v/v (use 'by vol.' instead of v/v if
more than two substances are involved).
References
These should conform to Vancouver style. List up to three authors and use et al. for
subsequent authors. The references in the text should be numbered consecutively in the order
in which they appear and indicated by superscript numerals. Examples are given below:
Edge. J.A., Matthews, D.R. & Dunger, D.B. (1990) The dawn phenomenon is related to
overnight growth hormone release in adolescent diabetics. Clinical Endocrinology, 33, 729737.
Russell, W.E. & Van Wyk, J.J. (1989) Peptide growth factor. In Endocrinology (ed. L. J. De
Groot), pp. 2504-2524. W. B. Saunders, Philadelphia, pp.2504-2524.
References in Articles
We recommend the use of a tool such as Reference Manager for reference management and
formatting.Reference Manager reference styles can be searched for here:
http://www.refman.com/support/rmstyles.asp
50
Disclaimer
The Publisher, the Society for Endocrinology and Editors cannot be held responsible for
errrors or any consequences arising from the use of information contained in this journal; the
views and opinions expressed do not necessarily reflect those of the publisher, the Society for
Endocrinology and Editors, neither does the publication of advertisments constitute any
endorsement by the advertised.
51
Anexo 5: Comprovante de Submissão no Clinical Endocrinology
52