Comparative study of two different dose fractionations for High Dose Rate Brachytherapy in Locally Advanced

Abstract

Background Cervical cancer is the most common and fatal among other gynecologic malignancies encountered in Low and Middle Income Countries. Brachytherapy holds a central part in the treatment of locally advanced cervical carcinoma. It has been suggested that smaller doses per brachytherapy insertions were safer and more efficient as attempts to brachytherapy hypofractionation. This study compares two different dose fractionations of High Dose Rate brachytherapy, kept at the same total Biologically Effective Dose to point A, and to compare the disease control, toxicity and overall survival at 9 months of follow-up. Materials and Methods The study was a comparative study, including two groups of patients who underwent concurrent external beam radiation therapy and weekly cisplatin followed by HDR intracavitary brachytherapy. External Beam Radiation Therapy was delivered by a Co-60 teletherapy unit to a prescribed dose of 50 Gray with 2 Gray per fraction in 25 fractions over 5 weeks, together with weekly intravenous cisplatin at a dose of 40 mg/m2. The patients were allocated into two groups of either HDR-ICBT dose of either a weekly 8.5Gray x 2 insertions (Test Group – Arm A) or a weekly 6.7 Gray x 3 insertions (Control Group – Arm B). Patients were then followed-up every 3 months for 9 months, with regular check for toxicity and abdomino-pelvic ultrasound to monitor disease control. Independent Chi-Square analysis was used to compare local control and toxicity profiles between the two arms. Kaplan-Meier analysis was run to estimate survival. Results Our preliminary findings were for the first 65 patients, enrolled between April and August 2017, then followed up until May 2018. Median follow-up time was 9.1 months. Analysis was run for 47 patients with complete data. Over a half of our patients were aged between 41-50 years, 93.6% were Squamous Cell Carcinoma, and 46.8% of the patients had stage IIB disease. ix