RESUMEN

Objective:To formulate clinical commissioning procedures, items, and testing method for Flexitron afterloader hardware and software and establish relevant quality control procedures in order to meet national standards and clinical requirements.Methods:Clinical commissioning included hardware, treatment planning system (TPS), and end-to-end (ETE) full-process testing. The radioactive source positioning accuracy was measured using a source position check ruler. The accuracy and linearity of dwell time were evaluated using three method: stopwatch timing, ion chamber measurement, and video analysis. The accuracy of source position simulator, connecting tubes, source position check ruler, and other measuring tools was tested using a high-precision ruler. Films were used for calibration of marker lines and applicators. The electrometer and well chamber were used to calibrate the radioactive source activity. The display and reconstruction accuracies of the TPS were evaluated using physical image data. ETE testing was conducted using a custom-made phantom for scanning, planning, and dose measurement.Results:The accuracy testing result of the commissioning items were within acceptable limits. The deviation in source activity measurements was 0.21%, and the ETE point dose measurement deviation was 2.32%, both of which met the clinical requirements. However, there was a 2 mm difference between the nominal and measured values of the magnetic resonance marker line in the accuracy testing items. Therefore, adjustments were required when using marker line for catheter reconstruction based on magnetic resonance images.Conclusions:By summarizing the clinical commissioning experience of the Flexitron afterloader, this study has developed quality control method and baseline levels of result of afterloader and TPS items, which provides a reference for the commissioning before clinical use.