Dosimetric comparison of intensity-modulated proton radiotherapy versus intensity-modulated photon-based radiotherapy for breast cancer

Purpose : This study aims to compare the dosimetric differences in intensity-modulated proton therapy (IMPT) using pencil beam scanning technology and photon-based radiotherapy (IMRT) hypofractionated whole-breast irradiation (HF-WBI) find out more beneficial technique. Methods Materials Eight breast cancer (BC) patients with pathological stage T1 ~ 2N0M0 were immobilized underwent 4D-CT used deep inspiration breath-hold (DIBH) technology. The IMPT IMRT plans designed for each patient. two en-face angles. field optimization constraints of types identical. Prescription dose regimen was 40.05 Gy (relative biological effect [RBE])/15 fx a 10 (RBE)/5 boost, five fractions week. A 95% target volume should not be less than prescribed dose. coverage evaluated D1, D2, D50, D95, D98, D99. distribution conformity Conformity index (CI) homogeneity (HI). Organs at risk (OARs) mean (Dmean) maximum (Dmax). Ipsilateral Lung Contralateral additionally V5, V10, V20, V30. Results Heart ( P = 0.012), 0.036), Spinal Cord 0.012) significantly reduced plans. also showed tendency reduce V20 0.05) V30 Lung. But there no significant difference coverage, homogeneity, between Conclusion Compared IMRT, can spare OARs without compromising BC undergoing HF-WBI, which potentially incidence radiation-related adverse effects thus may positively impact long-term survival.