Acute Toxicity Profile of Hypo fractionated Pelvic Radiotherapy versus Standard Fractionation in Patients with Inoperable Rectal Cancer: A Prospective Comparative Analysis

Open Access

Abstract

Background: Pelvic radiotherapy remains a mainstay of palliative management for inoperable rectal cancer. Although hypo fractionated regimens offer considerable logistical advantages, their acute toxicity profile relative to standard fractionation remains underexplored, particularly in resource-limited settings. Objective: The present study aimed to compare the incidence and severity of acute treatment-related toxicities between hypo fractionated and standard pelvic radiotherapy in patients with inoperable rectal cancer. Methods: This prospective comparative study was conducted in the Promise Hospital, Dhaka, Bangladesh, from January 2024 to December 2025 and enrolled 60 histologically confirmed inoperable rectal cancer patients. Group A (n=30) received hypofractionation (30 Gy/5 fractions); Group B (n=30) received standard fractionation (50.4 Gy/28 fractions). Both groups had gastrointestinal, genitourinary, hematological, and dermatological toxicities graded weekly via CTCAE v5.0. SPSS v23.0 was used in data analysis. Results: Detailed toxicity grade distributions across all four domains. Grade ≥2 gastrointestinal toxicities was significantly higher in Group A than in Group B (43.3% vs. 20.0%; p=0.047). No significant differences emerged for grade ≥2 genitourinary (16.7% vs. 13.3%; p=0.71), hematological (10.0% vs. 13.3%; p=0.69), or dermatological (6.7% vs. 3.3%; p=0.55). No grade 4 events, treatment completion was similar (96.7% vs. 100%), and no mortality occurred. Conclusion: Hypo fractionated pelvic radiotherapy confers higher acute gastrointestinal toxicity versus standard fractionation, whereas genitourinary, hematological, and dermatological toxicities remain comparable. These findings strongly advocate intensified gastrointestinal supportive care when hypo fractionated schedules are used for inoperable rectal cancer.