Risk and Quality in Brachytherapy From a Technical Perspective

Aims: To provide an overview of the history of incidents in brachytherapy and to describe the pillars in place to ensure that medical physicists deliver high-quality brachytherapy. Materials and methods: A review of the literature was carried out to identify reported incidents in brachytherapy, together with an evaluation of the structures and processes in place to ensure that medical physicists deliver high-quality brachytherapy. In particular, the role of education and training, the use of process and technical quality assurance and the role of international guidelines are discussed. Results: There are many human factors in brachytherapy procedures that introduce additional risks into the process. Most of the reported incidents in the literature are related to human factors. Brachytherapy-related education and training initiatives are in place at the societal and departmental level for medical physicists. Additionally, medical physicists have developed process and technical quality assurance procedures, together with international guidelines and protocols. Education and training initiatives, together with quality assurance procedures and international guidelines may reduce the risk of human factors in brachytherapy. Conclusion: Through application of the three pillars (education and training; process control and technical quality assurance; international guidelines), medical physicists will continue to minimise risk and deliver high-quality brachytherapy treatments

Dosimetric impact of a robust optimization approach to mitigate effects from rotational uncertainty in prostate intensity‐modulated brachytherapy

BackgroundIntensity-modulated brachytherapy (IMBT) is an emerging technology for cancer treatment, in which radiation sources are shielded to shape the dose distribution. The rotatable shields provide an additional degree of freedom, but also introduce an additional, directional, type of uncertainty, compared to conventional high-dose-rate brachytherapy (HDR BT). PurposeWe propose and evaluate a robust optimization approach to mitigate the effects of rotational uncertainty in the shields with respect to planning criteria. MethodsA previously suggested prototype for platinum-shielded prostate Yb-169-based dynamic IMBT is considered. We study a retrospective patient data set (anatomical contours and catheter placement) from two clinics, consisting of six patients that had previously undergone conventional Ir-192 HDR BT treatment. The Monte Carlo-based treatment planning software RapidBrachyMCTPS is used for dose calculations. In our computational experiments, we investigate systematic rotational shield errors of +/- 10 degrees and +/- 20 degrees, and the same systematic error is applied to all dwell positions in each scenario. This gives us three scenarios, one nominal and two with errors. The robust optimization approach finds a compromise between the average and worst-case scenario outcomes. ResultsWe compare dose plans obtained from standard models and their robust counterparts. With dwell times obtained from a linear penalty model (LPM), for 10 degrees errors, the dose to urethra (D0.1cc) and rectum (D0.1cc and D1cc) increase with up to 5% and 7%, respectively, in the worst-case scenario, while with the robust counterpart, the corresponding increases were 3% and 3%. For all patients and all evaluated criteria, the worst-case scenario outcome with the robust approach had lower deviation compared to the standard model, without compromising target coverage. We also evaluated shield errors up to 20 degrees and while the deviations increased to a large extent with the standard models, the robust models were capable of handling even such large errors. ConclusionsWe conclude that robust optimization can be used to mitigate the effects from rotational uncertainty and to ensure the treatment plan quality of IMBT.Funding: Vetenskapsradet [VR-NT 2019-05416]; Cancerfonden [CAN 2017/1029]; Canada Research Chairs [252135]; Collaborative health research projects [523394-18]</p

GEC-ESTRO ACROP recommendations on calibration and traceability of HE HDR-PDR photon-emitting brachytherapy sources at the hospital level

The vast majority of radiotherapy departments in Europe using brachytherapy (BT) perform temporary implants of high-or pulsed-dose rate (HDR-PDR) sources with photon energies higher than 50 keV. Such techniques are successfully applied to diverse pathologies and clinical scenarios. These recommen-dations are the result of Working Package 21 (WP-21) initiated within the BRAchytherapy PHYsics Quality Assurance System (BRAPHYQS) GEC-ESTRO working group with a focus on HDR-PDR source cal-ibration. They provide guidance on the calibration of such sources, including practical aspects and issues not specifically accounted for in well-accepted societal recommendations, complementing the BRAPHYQS WP-18 Report dedicated to low energy BT photon emitting sources (seeds). The aim of this report is to provide a European-wide standard in HDR-PDR BT source calibration at the hospital level to maintain high quality patient treatments. (c) 2022 The Authors. Published by Elsevier B.V. Radiotherapy and Oncology 176 (2022) 108-117 This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Funding Agencies|Spanish "Ministerio de Ciencia e Innovacion" (MCIN) - MCIN/AEI [PID2021-125096NB-I00]; "Generalitat Valenciana" (GVA) [PROMETEO/2021/064]</p