Planning with electronic brachytherapy in patients with cervical cancer
PD-0561
Abstract
Planning with electronic brachytherapy in patients with cervical cancer
Authors: Sergio Lozares1, Victor Gonzalez2, Santiago Pellejero3, Jose Antonio Font1, Almudena Gandía1, David Villa1, Verónica Alba1, Sara Jiménez1, Javier Díez1, Raquel Castro1, Andrea González1
1H.U. Miguel Servet, Física y P.R., Zaragoza, Spain; 2Fundacion Instituto Valenciano de Oncologia, Física y P.R., Valencia, Spain; 3Complejo Hospitalario de Navarra, Radiofísica y P.R., Pamplona, Spain
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Purpose or Objective
This study presents the dosimetric calculation results with the Axxent electronic brachytherapy
(eBT) system for 56 cervical cancer patients.
Material and Methods
All cases were first calculated and treated with Ir-192 in 3 different hospital centres, then,
retrospectively planned with Axxent and the BrachyCare treatment planning system (with TG-
43 algorithm) specific for Axxent eBT (Técnicas Radiofísicas, Zaragoza-Spain) using CT-study of
each patient.
The patients presented different stages (Table 1) and were contoured following the ESTRO-ABS-
EMBRACE guidelines. Treatment consisted of 50 Gy in 2 weeks of external beam
radiotherapy (EBRT), plus 4 sessions of 7 Gy of intracavitary brachytherapy. The planning
dosimetric targets are those corresponding to the EMBRACE study, the average D90 and
D98of high-risk clinical target volume (HR-CTV) parameters are presented, together with
D2cc, D1cc and D0.1cc of organs at risk (OAR) whose are bladder, rectum, and sigma in terms
of equivalent dose in 2-Gy fractions (EQD2), including the EBRT.
Results
Of all patients calculated, 41 (73%) complied EMBRACE requirements and 15 (27%) did not
complied some of the parameters, either HR-CTV coverage or dose in OARs. The average EQD2
of patients meeting the targets and ensuring a high probability of local control (D90 >90 Gy)
are shown in Table 2.
Conclusion
The main result, 73% of cervical cancer patients studied might be adequately treated with eBT
and based on CT images, is quite important result. Electronic brachytherapy treatments allow
bunker-free treatment of cervical cancer with optimistic results for patients with multiple
stages and significant HR-CTV volumes.
We believe they are a plausible option for LMICs due to their ease of use, portability, and
versatility. At our centre we have extensive experience with this technique in endometrial,
breast, cervical and skin cancer treatments.