Multiple Sessions vs. Single Session Image-Based Intracavitary Brachytherapy for Locally Advanced Cervical Cancer: A Randomized Control Trial

The objectives of this study are: 1) To compare the acute toxicity caused in the treatment of locally advanced cervical cancer (LACC) treated with weekly multiple applications vs. a single application for image-guided intracavitary High Dose Rate (HDR) brachytherapy (BT) after External Beam Radiation Therapy (EBRT) 2) To compare the loco-regional control of cancer at six months in the two arms MATERIALS/METHODS: In a prospective study, 40 patients with biopsy-proven LACC with FIGO-2018 stage IIB-IIIC1 disease, underwent EBRT to the pelvis at a dose of 50.4 Gy/ 28 fractions over 5.5 weeks with weekly concurrent cisplatin. After completion of EBRT, they were randomized into two arms with 20 patients each. In the Control arm (Arm-A), BT sessions were given with weekly 3 applications whereas, in the experimental arm (Arm-B), all the sessions were given with a single application at 6-12 hours intervals with aim of the high-risk clinical target volume receiving >80 Gy EQD2 and 2 cm3 of the bladder and rectum/sigmoid receiving <85 Gy and <75 Gy, respectively. The OAR contouring was done on CT RESULTS: All 40 patients were treated as per protocol. The mean duration of treatment including EBRT and BT was 73.15 days [95% CI 68.63-77.66] in Arm A and 55.85 days [95% CI 52.11-59.58] in Arm B which was significant. After 6 months, 37 patients came for follow-up, all 19 patients in Arm A had Grade 1 or Grade 2 rectal toxicity. In Arm B as well all 18 patients had Grade 1 or Grade 2 rectal toxicity. Bladder toxicity was Grade 1 or Grade 2 in 18 patients and Grade 3 severity in 1 patient among Arm A. Among 18 patients of Arm B, bladder toxicity of Grade 1 or Grade 2 was seen in 16 patients, and 2 patients had grade 3 toxicity. 2 patients in Arm A and 3 in Arm B complained of Grade 1 urinary incontinence. Moreover, Abdominal pain at 6 months was of Grade 1 in around 6 patients in Arm A but 14 patients had abdominal pain in Arm B which was of Grade 1 in 8, 4 had grade 2 and 2 patients had grade 3 severity abdominal pain. In the monthly analysis of acute toxicity, none of the patients showed Grade 3 or 4 toxicity at the 1st, 2nd, or 3rd month of completion of treatment. When comparing local control in both arms at 6 months, 2 patients had treatment failure in the Experimental Arm compared to only 1 patient in the Control Arm CONCLUSION: Single Application Multiple Fraction Intracavitary Brachytherapy post concurrent CTRT is a safe option for the treatment of locally advanced cervical cancer. When compared to the weekly application arm, single-application ICRT showed a comparable acute toxicity profile and comparable local control rates as well. Some patients in Single Application Arm showed abdominal pain which needs to be investigated with further trials. The overall treatment time in the single application arm is significantly lower than the standard weekly application arm.