Dosimetric evaluation of a variable energy superficial x-ray machine with applications for endocavitary radiotherapy techniques

Abstract

This investigation presents the beam characteristics of a newly-marketed variable energy superficial X ray machine for radiotherapy. The X ray system hardware, including a high voltage generator, and console software allow for nine independent operator-selected X ray beams from 10–150 kVp. Filament current values are also independently variable; 1.0–13.0 mA for 90–150 kVp, and 1.0–30.0 mA for 10–90 kVp. The HVL's, effective energies, and radiation outputs for the nine combinations of kVp and mA are presented. In addition, percentage depth dose and beam uniformity results are presented as a function of cone size. Radiation output stability and reproducibility results are included. Discussion of adaption of this X ray system to the Papillon technique for the treatment of rectal cancers is presented.