A MC‐based anthropomorphic test case for commissioning model‐based dose calculation in interstitial breast 192‐Ir HDR brachytherapy

Abstract

Purpose To provide the first clinical test case for commissioning of 192Ir brachytherapy model‐based dose calculation algorithms (MBDCAs) according to the AAPM TG‐186 report workflow. Acquisition and Validation Methods A computational patient phantom model was generated from a clinical multi‐catheter 192Ir HDR breast brachytherapy case. Regions of interest (ROIs) were contoured and digitized on the patient CT images and the model was written to a series of DICOM CT images using MATLAB. The model was imported into two commercial treatment planning systems (TPSs) currently incorporating an MBDCA. Identical treatment plans were prepared using a generic 192Ir HDR source and the TG‐43‐based algorithm of each TPS. This was followed by dose to medium in medium calculations using the MBDCA option of each TPS. Monte Carlo (MC) simulation was performed in the model using three different codes and information parsed from the treatment plan exported in DICOM radiation therapy (RT) format. Results were found to agree within statistical uncertainty and the dataset with the lowest uncertainty was assigned as the reference MC dose distribution. Data Format and Usage Notes The dataset is available online at http://irochouston.mdanderson.org/rpc/BrachySeeds/BrachySeeds/index.html,https://doi.org/10.52519/00005. Files include the treatment plan for each TPS in DICOM RT format, reference MC dose data in RT Dose format, as well as a guide for database users and all files necessary to repeat the MC simulations. Potential Applications The dataset facilitates the commissioning of brachytherapy MBDCAs using TPS embedded tools and establishes a methodology for the development of future clinical test cases. It is also useful to non‐MBDCA adopters for intercomparing MBDCAs and exploring their benefits and limitations, as well as to brachytherapy researchers in need of a dosimetric and/or a DICOM RT information parsing benchmark. Limitations include specificity in terms of radionuclide, source model, clinical scenario, and MBDCA version used for its preparation.

A Monte Carlo dose recalculation pipeline for durable datasets: an I-125 LDR prostate brachytherapy use case

“…With this level of agreement, it can be concluded that the Monte Carlo dose recalculation pipeline can produce consistent TG186 simulations across both MC codes. To ensure the validity of the dose distributions following the TG186 commissioning recommendations, it would require a consensus test case similar to work published by Peppa et al (2023) for HDR brachytherapy, which was not yet available for LDR brachytherapy at the time of publication.…”

AAPM WGDCAB Report 372: A joint AAPM, ESTRO, ABG, and ABS report on commissioning of model‐based dose calculation algorithms in brachytherapy

“…The WGDCAB is currently developing new clinically relevant test cases (GYN, head and neck, breast, and prostate) for the existing MBDCA TPS as well as some low-energy test cases for TPSs in development. A good example of such a clinically oriented test case for breast brachytherapy is based on the geometry published by Peppa et al 42 These will all be added to the Registry once available and fully tested. This report does not address certain other key issues raised in the TG-186 report.…”