Clinical Impact of Intensity-Modulation Radiation Therapy versus 3D Conformal Radiation Therapy in Breast Cancer Patients: Toxicity and Organ Sparing

Abstract

Radiotherapy selection in breast cancer depends on multiple clinical and dosimetric factors, as it influences organs at risk and determines both early and late toxicities that may affect long-term outcomes. This study compared intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3D-CRT) with respect to dosimetric parameters, toxicity profiles, and superficial changes. A retrospective analysis was conducted on 20 patients, with 10 treated using IMRT and 10 using 3D-CRT. Data were analyzed using descriptive statistics; Welch’s t-test and Mann–Whitney U test were applied due to the small sample size, while chi-square and Fisher’s exact tests were used for categorical variables. Results demonstrated that IMRT significantly reduced ipsilateral lung doses (p = 0.0023) and improved planning target volume homogeneity (p < 0.0001) compared with 3D-CRT. Delayed toxicity occurred in 20% of IMRT patients versus 80% of 3D-CRT patients (p = 0.0102). However, IMRT was associated with higher mean cardiac doses (p = 0.0254). These findings highlight the trade-offs between IMRT and 3D-CRT, emphasizing the importance of individualized radiotherapy planning in breast cancer treatment.