In Vivo, Fiberoptic-Coupled Radiation Dose Verification System for Prostate Radiotherapy

摘要

A fiberoptic-coupled patient dose verification system has been successfully developed that provides real-time dose rate and total dose information during radiotherapy treatments. The system has up to seven channels that can simultaneously provide dosimetry data at seven locations inside the body, at and near the prostate. The spatial resolution of the dose measurements is less than a millimeter. The fiberoptic-coupled system utilizes novel, optically stimulated luminescence (OSL) glass fiber dosimeters that permit all- optical readout of the total dose and dose rate. The system has been characterized and its performance evaluated in side by side tests with conventional radiation sensors, such as ionization chambers, Si diodes and MOSFET dosimeters. These comparisons were conducted in phantoms and in clinical trials with patients. The characterization experiments included measurement of the dose response, the resistance to radiation damage, the energy dependence of the response, the angular dependence of the response and the dose rate dependence of the response. In every case the fiberoptic-coupled dosimeter provided the correct measurement, often with accuracy to within 1 % of the accepted values. The fiberoptic-coupled OSL dosimeter will enhance the effectiveness of prostate radiotherapy procedures, reduce negative side effects such as death, incontinence and impotence, and improve the quality of life for prostate cancer survivors.