Optimasi Dosis Terapi Kanker Payudara Menggunakan Program Phits V 3.35 dengan Metode Boron Neutron Capture Terapy

Abstract

Breast cancer is one of the most prevalent malignancies and remains a leading cause of cancer-related mortality among women worldwide. Among the emerging treatment modalities, Boron Neutron Capture Therapy (BNCT) has attracted considerable attention due to its ability to selectively eradicate tumor cells through the neutron capture reaction of the 10B isotope, which generates high-linear energy transfer particles with a short path length, thereby minimizing damage to surrounding healthy tissues. The optimization of boron concentration and irradiation geometry in breast cancer BNCT was investigated using PHITS version 3.35. The simulation was performed based on clinical data from a female patient diagnosed with right-sided breast cancer, with a Gross Tumor Volume (GTV) of 1.1 cm³, a Clinical Target Volume (CTV) of 72.9 cm³, and a Planning Target Volume (PTV) of 104.9 cm³. Boron concentrations of 60, 100, 120, and 140 µg/g were evaluated under two irradiation geometries, namely Anterior–Posterior (AP) and Right–Lateral (RLAT). The assessment included dose distribution, dose rate, equivalent dose, and irradiation time within the target volumes and surrounding organs at risk. The results demonstrated that increasing the boron concentration enhanced both the absorbed dose and dose rate delivered to the target volumes while reducing the irradiation time required to achieve the prescribed therapeutic dose. Furthermore, the AP irradiation geometry yielded higher dose deposition within the tumor volume than the RLAT geometry. Based on the analysis of dose distribution, equivalent dose, and irradiation time, a boron concentration of 140 µg/g was identified as the most favorable treatment condition, providing the highest dose rate to the tumor while maintaining doses to normal tissues below the established tolerance limits. These findings indicate that BNCT possesses significant potential as an effective and safe therapeutic approach for the treatment of breast cancer.