AAPM medical physics practice guideline 13.a: HDR brachytherapy, part A

PurposeThe purpose of this study was to validate the use of a model‐based dose calculation algorithm (MBDCA), Acuros BV, for high dose rate brachytherapy treatment planning for a community‐based hospital with a Bravos afterloader. Based on published AAPM recommendations, this work details a practical approach for community‐based clinics to complete initial validation of Acuros BV, in order to add a MBDCA to a TG‐43 based brachytherapy treatment planning program.MethodsSource dimensions and materials used in Acuros BV and TG‐43 source models were compared to the physical source. TG‐186 testing was completed with standardized test cases externally calculated with Monte Carlo compared to locally calculated with Acuros BV. Point doses calculated using TG‐43 were compared to those calculated with Acuros BV in water at various dose grid settings. Secondary dose check software was used to evaluate dose distributions resembling clinical patient plans, both in water and on CT datasets representative of patient anatomy.ResultsThe major source of discrepancy of source models was the length of modeled steel cable. TG‐186 testing showed that the largest differences between Monte Carlo and Acuros BV dose distributions were located along the source axis for cases calculated in water, as well as located in regions of high dose gradients and within the applicator for the case calculated with a generic shielded applicator. An audit of point doses calculated with both TG‐43 and Acuros BV in water found that dose grid settings significantly affected agreement. Secondary dose check software indicated that Acuros BV functioned satisfactorily, and a 5% threshold was adopted for secondary dose checks on gynecologic plans.ConclusionThis validation process indicated that Acuros BV met expected standards and affirmed its suitability for integration into this clinical practice's brachytherapy treatment planning.

Section: Introductionmentioning

confidence: 99%

Practical experience with initial quality assurance of a high dose rate brachytherapy grid‐based Boltzmann solver algorithm

Fagerstrom

2024

“…Previous work has shown the importance of acquiring accurate commissioning measurements to characterize each HDR applicator in clinical service. [3][4][5][6]…”

Section: Introductionmentioning

confidence: 99%

“…A suite of MRI‐compatible tandem and ring applicators was purchased for use with the Bravos system, with the intent to use MRI data for treatment planning acquired with the implant in place (denoted here as “MRI‐based” planning 2 ). Previous work has shown the importance of acquiring accurate commissioning measurements to characterize each HDR applicator in clinical service 3–6 . Prior to clinical use, testing was completed to define basic physical characteristics of the applicators.…”

Section: Introductionmentioning

confidence: 99%

Practical experience commissioning MRI‐compatible tandem and ring applicators for use with the Bravos HDR afterloader

Fagerstrom

2023

Five complete MR‐conditionally approved ring sets, including fifteen tandems, and two additional rings, were commissioned at an institution intending to use them in an MRI planning environment with a Bravos HDR brachytherapy remote afterloader. Channel length, radiograph, autoradiograph, ring offset, and treatment interrupt measurements were performed, and applicators were assessed in both CT and MRI. During commissioning, one ring was found to be defective and was returned to the manufacturer for a replacement. The eventual complete applicator suite (including the replacement ring) was found to follow the manufacturer‐provided specifications, including those delineated in vendor‐provided 3D virtual models and those defined within the manufacturer's instructions for use documentation. Based on this work, an offset correction of −0.4 cm will be used for all tested rings using the Bravos system's internal distal dwell position correction feature during treatment preparation. This study reiterated the requirement for careful commissioning of each applicator intended for clinical service considering the intended use and the planned clinical environment and work processes.

AAPM medical physics practice guideline 13.a: HDR brachytherapy, part A

Richardson

Buzurović

Cohen

et al. 2023

The American Association of Physicists in Medicine (AAPM) is a nonprofit professional society whose primary purposes are to advance the science, education, and professional practice of medical physics. The AAPM has more than 8000 members and is the principal organization of medical physicists in the United States. The AAPM will periodically define new practice guidelines for medical physics practice to help advance the science of medical physics and to improve the quality of service to patients throughout the United States. Existing medical physics practice guidelines (MPPGs) will be reviewed for the purpose of revision or renewal, as appropriate, on their fifth anniversary or sooner. Each medical physics practice guideline represents a policy statement by the AAPM, has undergone a thorough consensus process in which it has been subjected to extensive review, and requires the approval of the Professional Council. The medical physics practice guidelines recognize that the safe and effective use of diagnostic and therapeutic radiology requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guidelines and technical standards by those entities not providing these services is not authorized. The following terms are used in the AAPM practice guidelines: Must and must not: Used to indicate that adherence to the recommendation is considered necessary to conform to this practice guideline. Should and should not: Used to indicate a prudent practice to which exceptions may occasionally be made in appropriate circumstances. Approved by AAPM's Executive Committee April 28, 2022.