Super-selective intra-arterial platinum-based chemotherapy concurrent with low-dose-rate plaque brachytherapy in the treatment of retinoblastoma: A simulation study.

Abstract

Retinoblastoma is the most common cancer among children under 5 years of age. The common conventional methods for the treatment of retinoblastoma include chemotherapy and brachytherapy (BT). This study investigated the concurrent use of BT with 125I and 103Pd sources and chemotherapy with platinum-based chemotherapy drugs for retinoblastoma. The absorbed doses in different parts of the eye were measured with and without platinum. Platinum concentrations of 5, 7.5, 10, and 15 mg/g were evaluated, and the dose enhancement factors (DEFs) were calculated for different cases. For the 125I source, the DEFs at the tumor apex were 1.49, 1.67, 1.81, and 1.97 at concentrations of 5, 7.5, 10, and 15 mg/g, respectively. The DEF decreased dramatically beyond the apex at 0.85 cm from tumor base and was 0.87, 0.82, 0.76, and 0.63 for the abovementioned concentrations, respectively. For the 103Pd source, the DEFs were 1.15, 1.24, 1.21, and 1.07, respectively, at the apex and 0.76, 0.65, 0.56, and 0.39, respectively, beyond the apex. Our results showed that the concurrent use of low-dose-rate plaque BT and platinum-based chemotherapy significantly increased the tumor-absorbed dose and decreased the absorbed dose in areas outside the tumor and the treatment time.