Abstract 20P
Background
The study was conducted with the aim to compare four radiotherapy schedules in terms of overall survival (OS), disease-free survival (DFS), acute & late toxicities in locally advanced cervical cancer.
Methods
A total of 73 patients (ECOG 0-1) with histologically proven cervical cancer, FIGO stage IIB-IVA were included in the study (December 2020 to July 2022). All the patients were treated with 6 MV Linear Accelerator with Volumetric modulated arc therapy (VMAT) to the whole pelvis. This was followed by High dose rate brachytherapy (HDR-BT) with intracavitary (ICRT) or interstitial (ISBT) application. Patients were randomized into four treatment arms: Arm A- EBRT: 45 Gy/ 25 fractions/ 5 weeks; ISBT: 6 Gy / fraction, 4 fractions, twice daily. Arm B- EBRT: 50 Gy/ 25 fractions/ 5 weeks; ISBT: 6 Gy / fraction, 4 fractions, twice daily. Arm C- EBRT: 45 Gy/ 25 fractions/ 5 weeks; ICRT: 7 Gy / fraction, 4 fractions, weekly. Arm D- EBRT: 45 Gy/ 25 fractions/ 5 weeks; ICRT: 7 Gy / fraction, 3 fractions, weekly. Positive lymph nodes were treated with simultaneous integrated boost (SIB) of 55 Gy in 25 fractions and concurrent cisplatin at 40mg/m2 in all four arms. The patients were contoured and planned on CT based planning system. Response assessment was done with functional MRI after completion of EBRT & after 3 months of treatment completion.
Results
The median follow-up of the study was 19.4 months. The mean OS in arms A, B, C & D was 32.3, 15.7, 15.3 & 34.5 months respectively (p= 0.954). The mean DFS in arms A, B, C & D was 31.9, 11.9, 11.0, and 28.8 months respectively (p= 0.562). Grade 3/4 acute hematological toxicity was seen in arm A (18.2%), C (5.6%) & D (17.3%). Grade 3/4 GI toxicity was present in arms C (5.6%) & D (13%). Radiation proctitis was significantly more in the arm A & B (p=0.007).
Conclusions
All the treatment arms were similar in survival outcomes and acute toxicities. However, radiation proctitis was significantly more in patients receiving ISBT.
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.