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.
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.
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).
All the treatment arms were similar in survival outcomes and acute toxicities. However, radiation proctitis was significantly more in patients receiving ISBT.