Effect of Bolus in Post-Mastectomy Chest-Wall Irradiation: A Retrospective Cross-sectional Study
Authors: Mahmuda Akter4, Md. Fajle Rabby4, Rubel Ahmed4, Md. Motiur Rahman3, Muhammad Adnan Arifeen2, A.Z.M. Sumsuzoha2, AKM Ahsan Habib1
Institution: TMSS Cancer Centre
Introduction
The use of a bolus in post-mastectomy chest-wall irradiation (PMCI) is essential for ensuring adequate radiation dose delivery to the chest wall, particularly in patients with high-risk factors such as skin involvement or positive surgical margins. However, its application can also lead to increased skin toxicity, necessitating a careful balance between tumor control and normal tissue sparing. This study evaluates the dosimetric impact of bolus use in PMCI by comparing treatment plans with and without bolus, focusing on dose distribution, surface dose enhancement, and effects on nearby critical structures.
Methods
This study was conducted in TMSS Cancer Center, Bogura, Bangladesh, including 30 patients, with invasive ductal carcinoma of breast treated with conventional radiotherapy protocol during the last year. 15 patients were treated with first 12 days daily bolus and 15 with alternate days bolus. Daily bolus significantly increased the risk of severe radiation dermatitis, but alternate-day bolus showed a nonsignificant increase for severe radiation dermatitis. The patients were treated with 3DCRT by a linear accelerator and appropriate photon energy.
Results
Key parameters such as target coverage, dose homogeneity, and exposure to organs at risk—including the lungs and heart—are analyzed. The results indicate that while bolus improves tumor bed coverage by increasing surface dose, its routine use may require optimization to reduce unnecessary toxicity.
Conclusion
These findings emphasize the need for a patient-specific approach to bolus application, aiming to maximize therapeutic benefits while minimizing adverse effects.
