Dosimetric evaluation of a new design MOSFET in vivo dosimeter.

A single-use dosimeter, designed for in vivo patient dosimetry, has been evaluated. Key dosimetric characteristics of the dosimetry system have been measured for high-energy photon and electron beams commonly used in external beam therapy. Under the measurement conditions utilized, dose accuracy was within 5% for all data points, and inter-batch uniformity was acceptable, with a standard deviation of 1.7%. Dose linearity was confirmed for doses ranging from 2 to 400 cGy. The dosimeter readings were independent of dose rate for rates ranging from 80 to 480 cGy/min. When used as instructed, the dosimeter readings were accurate across the tested range of energy and modality. These measurements show that the dosimetry system's performance may be acceptable for in vivo dosimetry of entrance d(max) doses.