Clinical test cases for commissioning, QA, and benchmarking of model-based dose calculation algorithms in 192Ir HDR gynecologic tandem and ring brachytherapy

TL;DR

This paper develops and validates clinically relevant test cases for commissioning and benchmarking model-based dose calculation algorithms in HDR gynecologic brachytherapy, using patient models and Monte Carlo simulations.

Contribution

It introduces a standardized framework and datasets for commissioning MBDCAs in HDR brachytherapy, facilitating quality assurance and intercomparison with Monte Carlo methods.

Findings

MC simulations agree within statistical uncertainty

MBDCAs show strengths and limitations compared to MC

Proposed methodology aids in TPS commissioning and benchmarking

Abstract

Purpose: To develop clinically relevant test cases for commissioning Model-Based Dose Calculation Algorithms (MBDCAs) for 192Ir High Dose Rate (HDR) gynecologic brachytherapy following the workflow proposed by the TG-186 report and the WGDCAB report 372. Acquisition and Validation Methods: Two cervical cancer intracavitary HDR brachytherapy patient models were created, using either uniformly structured regions or realistic segmentation. The computed tomography (CT) images of the models were converted to DICOM CT images via MATLAB and imported into two Treatment Planning Systems (TPSs) with MBDCA capability. The clinical segmentation was expanded to include additional organs at risk. The actual clinical treatment plan was generally maintained, with the source replaced by a generic 192Ir HDR source. Dose to medium in medium calculations were performed using the MBDCA option of each TPS, and three different Monte Carlo (MC) simulation codes. MC results agreed within statistical uncertainty, while comparisons between MBDCA and MC dose distributions highlighted both strengths and limitations of the studied MBDCAs, suggesting potential approaches to overcome the challenges. Data Format and Usage Notes: The datasets for the developed cases are available online at http://doi.org/ 10.5281/zenodo.15720996. The DICOM files include the treatment plan for each case, TPS, and the corresponding reference MC dose data. The package also contains a TPS- and case-specific user guide for commissioning the MBDCAs, and files needed to replicate the MC simulations. Potential Applications: The provided datasets and proposed methodology offer a commissioning framework for TPSs using MBDCAs, and serve as a benchmark for brachytherapy researchers using MC methods. They also facilitate intercomparisons of MBDCA performance and provide a quality assurance resource for evaluating future TPS software updates.