Calibration of the MKD-04 Scintillation Dosimeter for γ Radiation from a 192Ir Source

We present here a scintillation detector based on a polystyrene scintillator with light guides, solid-state photo-electron converters, and computer control for the MKD-04 multichannel dosimeter for in vivo dosimetry during brachytherapy. The external diameter of the detector and light guide was decreased from 4.0 to 3.2 mm, which improved its geometric characteristics for intracavity measurements. The detector was calibrated for the γ radiation of a 192Ir brachytherapy source in a PMMA phantom (including auxiliary calibration in a 200-kV X-ray beam). A correction factor $$ {k}_{Q,{Q}_0}^{SC} $$ = 1.059 ± 0.020 for 192Ir was obtained relative to calibration in a 60Co γ beam.