Early Breast Cancer Treated with Electronic Intraoperative Radiotherapy
System (IORT): Report of the First Patients Treated in Portugal
Paulo Serafim Costa* • Fleming de Oliveira** • Graça Fonseca* • M. Moutinho Ribeiro** • José Moutinho** • Julieta Mayer da Silva***
Luís Mestre**** • Fernanda Ponte* • Joana Vale* • Gonçalo Martins***** • Diogo Marcos***** • Maria Adelina Costa*
* Departamento de Radioterapia do ICUF – Porto • ** Serviço de Cirurgia do HCUF – Porto • *** Departamento de Radioterapia do HCUF Infante Santo – Lisboa
**** Unidade de Senologia do HCUF Infante Santo – Lisboa • ***** Sociedade Avanço
INTRODUCTION
RESULTS
Intra-Operative Radiation Therapy (IORT) has been effectively employed
for the treatment of early-stage breast cancer. Single-fraction radiation
treatment applied directly to the tumor bed immediately following
lumpectomy reduces the volume and dose of radiation to normal tissue,
shortens treatment time, and makes completion of local therapy more
convenient.
There were no postoperative complications
and the immediate toxicity was low, with no
grade 3/4 acute toxicity or delayed healing.
Two cases of seroma and two cases of
subcutaneous fibrosis were reported. With
a median follow-up of 14 months, there
were no local recurrences. One case of
axillar recurrence occurred one year after
treatment.
The Xoft Axxent Electronic Brachytherapy System (Xoft, Inc., San Jose,
CA, USA) (Fig 1), uses a miniaturized 50 kV x-ray source tube capable
of delivering high dose rate, low energy radiation without the use of
radioactive isotopes. Among the advantages of this equipment are its
portability and low energy photons, allowing for minimal shielding during
radiation therapy.
figure 1
PURPOSE/OBJECTIVES
To describe the initial experience in Portugal, in treating early breast cancer
with intraoperative radiotherapy (IORT) with electronic brachytherapy
system.
figure 2
MATERIAL/METHODS
We retrospectively analyzed the data of 28 women, who underwent
intraoperative irradiation during breast conserving surgery, between
July 2012 and June 2014. The treatment was performed in a single
fraction, using an applicator suitable to the surgical bed (ranging from
3-4 and 4-5cm in diameter – Fig 2 and 3), and the distance to the skin
surface was checked through intraoperative ultrasound monitoring (Fig
4). A dose of 20Gy was delivered to the surgical bed, with a mean
treatment duration of 550 seconds (Fig 5). The protection of the chest
wall was performed with a stainless steel attenuation disk that varied
between 4 and 6cm in diameter (Fig 6). Clinical, surgical and pathologic
parameters, as well as the immediate and late toxicity were evaluated,
using the EORTC score.
figure 3
figure 4
figure 5
figure 6
PATIENT CHARACTERISTICS
CONCLUSION
Age
64 Years (range 41 - 88)
Histology
Invasive Ductal Breast Cancer (93%)
without extensive intraductal component
AJCC Classification
pT1-2 N0 M0
Tumor Size
1.2 cm (range 0.4 - 2.0 cm)
IORT using the electronic brachytherapy system as part of the conservative treatment of breast cancer is safe, with low morbidity. The low
incidence of side effects as well as the short treatment time has led
to a growing interest in using this treatment solution. Following these
patients will allow monitoring any delayed reactions and consequent
cosmetic effect as well as the local control rate and survival.