Standardization and automation of quality assurance for high-dose-rate brachytherapy planning with application programming interface

Abstract

Purpose: To standardize and automate the high-dose-rate (HDR) brachytherapy planning quality assurance (QA) process utilizing scripting with application programming interface (API) in a commercially available treatment planning system (TPS).

Methods and materials: Site- and applicator-dependent plan quality (PQ) evaluation criteria and plan integrity (PI) checklists were established based on published guidelines, clinical protocols, and institutional experience. User designed C# programs ("scripts") were created and executed through the API to access planning information in TPS. A set of standardized quality control reports, focusing on PQ evaluations and PI checks, were automatically generated. Information derived from the TPS was compared against predetermined QA metrics with color-coded pass/fail indicators to aid and enhance the efficiency of plan evaluation. Five independent, blinded observers reviewed mock plans with simulated errors to validate the scripts and to quantify the improvement of plan review efficiency.

Results: Scripts were developed for HDR prostate and breast. Forty-one parameters were reported/checked in the PI report; the PQ report returned dose-volume indices and an independent check of dwell time. All simulated errors were detected by the PI scripts with appropriate warning messages displayed, and any values failing to meet the planning constraints were red-flagged successfully in the PQ report. An average time reduction of 16 min for plan review was observed when using the scripts.

Conclusions: API scripting-based automated planning QA for HDR brachytherapy including PI checks and PQ evaluations was designed and implemented. The simulated error study showed promising results in terms of error catching and efficiency improvement.

Keywords: Application programming interface (API); HDR brachytherapy; Planning quality assurance.