Evaluating the Acute Toxicities by Using Bolus throughout vs. Alternate Days in Locally Advanced Post-Mastectomy Breast Cancer Patients Receiving Hypo-fractionated Radiotherapy

Abstract

Background: Hypo-fractionated radiotherapy has gained popularity in the management of post-mastectomy breast cancer owing to its reduced treatment duration while maintaining efficacy. However, this approach, particularly when combined with bolus material, raises concerns regarding toxicity and patient outcomes. Objective: The study aimed to compare the toxicity outcomes between bolus used throughout versus alternate day in hypo-fractionated radiotherapy regimen in post-mastectomy breast cancer patients. Methods: The quasi-experimental study took place in the National Institute of Cancer Research and Hospital and Ahsania Mission Cancer & General Hospital in Dhaka, Bangladesh during January 2023 to June 2024. The total participants were 60 in number and they were divided equally into 2 arms; Arm A received bolus throughout the treatment and Arm B received bolus in alternate days during radiotherapy. Their demographic and clinical characteristics; tumor attributes and four types of toxicity were assessed and compared: skin, hematological, pulmonary and cardiac. A follow-up of 36 weeks was also documented. Findings: Among the participants, 86.7% in Arm A and 80.0% in Arm B had invasive ductal carcinoma; 56.6% in Arm A and 50.0% in Arm B had Grade 3 tumors; 53.3% in Arm A and 50.0% of Arm B had Luminal A tumors. After 2nd week of radiotherapy, 26.7% and 16.7% Arm A participants had Grade 2 and Grade 1 skin toxicities respectively compared to 6.7% of Arm B suffering Grade 1 and Grade 2 toxicities (p=0.033). Hematological toxicity outcomes were non-significant in both the arms; after 3rd week of radiotherapy 16.7% in Arm A and 10.0% in Arm B developed Grade 1 anemia. Pulmonary toxicity assessed after 36 weeks revealed 23.3% participants of Arm A suffered Grade 1 toxicity compared to 13.3% cases in Arm B. Lastly, none of the participants exhibited any form of cardiac toxicity outcomes. Conclusion: Evaluation of toxicity outcomes is highly essential for determining the most efficacious and beneficial treatment modality for the patients. This would enhance their survival chances and upgrade their overall quality of life.