DOI: https://doi.org/10.36347/sasjm.2026.v12i04.024

Pages: 367-373

Dose homogeneity and organ-at-risk (OAR) sparing are essential objectives in breast radiotherapy. Conventional tangential irradiation using dynamic wedges may result in dose inhomogeneity with potential hot spots within the planning target volume (PTV). This study aimed to compare multileaf collimator (MLC)-based conformal planning with conventional dynamic wedge-based techniques in terms of PTV dose homogeneity, target coverage, and OAR doses in both breast and chest wall irradiation. Ten cases (five breast in situ and five chest wall) were retrospectively replanned using both techniques. Dosimetric parameters evaluated included homogeneity index (HI), conformity index (CI), mean heart dose (Dmean), and ipsilateral lung dose-volume parameters (V13, V20, and V30). Median values and interquartile ranges were analyzed, and comparisons between techniques were performed. In breast irradiation, MLC-based planning demonstrated improved PTV dose homogeneity compared to wedge-based techniques, with comparable conformity index and no significant differences in mean heart or ipsilateral lung doses. In chest wall irradiation, MLC-based planning did not show a clear dosimetric advantage over conventional wedge-based techniques, with similar PTV coverage and OAR dose distributions observed between both approaches. Overall, MLC-based conformal planning appears to improve dose homogeneity in breast irradiation while maintaining equivalent target coverage and OAR sparing. However, no consistent benefit was observed in chest wall irradiation, suggesting that the dosimetric advantage of MLC-based planning may be site-dependent.