Ex vivo mechanical and microstructural evaluation of a changing hepatic microstructure.

Background/objectives: Recent advancements in non-invasive imaging of the liver hold significant potential for disease diagnosis and monitoring. However, the influence of different microstructural features on clinically derived mechanical biomarkers in the liver are not fully elucidated. The aim of this study was to investigate the influence of microstructural changes within liver tissue on mechanics.

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

The goal of this report is to assist the clinical medical physicist in assuring that key quality standards and practice considerations are met to ensure safe, reliable, and reproducible high dose rate (HDR) brachytherapy (BT) treatment. This guideline has been developed to provide appropriate minimum standards for such services. The secondary goal is to provide recommendations to the regulatory community from the experts to guide the adoption of regulations in the future.

GEC-ESTRO guidelines for commissioning and quality assurance of TG-43 based brachytherapy treatment planning systems.

This report defines practical guidelines for (a) commissioning a TG-43-based treatment planning system for brachytherapy, and (b) establishing a continuous quality assurance program for the TPS. The main functionalities of the TPS are described, including image import and geometry, source specification, dose calculation, applicator specification and treatment plan data output, and recommended tests are given. For all tests, the frequency and tolerance are summarized in tables.

Enhancing IMRT/VMAT Competencies in LMICs globally within radiation physicists through remote training.

Background And Purpose: High-quality intensity-modulated radiation therapy (IMRT)/volumetric modulated arc therapy (VMAT) is necessary to drive positive patient outcomes, yet gaps in staff training hinder its implementation in low-to-middle-income countries (LMICs). This work aimed to evaluate a large-scale remote training curriculum for medical physicists and clinicians with existing IMRT infrastructure in LMICs.

Materials And Methods: A 15-week free, virtual course with weekly live sessions incorporating didactics and case-based learning led by expert volunteers was conducted.

Injectable bio-absorbable spacers in brachytherapy for gynecological cancers: A scoping review.

Purpose: Insertion of a spacer between tumor and an adjacent organ at risk may improve the therapeutic ratio in gynecological cancer brachytherapy. The purpose of this review was to assess the available literature on the use of injectable bio-absorbable spacers in brachytherapy for gynecological cancers.

Material And Methods: Embase, PubMed, Medline, and Cochrane Central Register of Controlled Trials were searched until March 28, 2024.

Implementation of a programmatic assessment model in radiation oncology medical physics training.

Purpose: In 2019, a formal review and update of the current training program for medical physics residents/registrars in Australasia was conducted. The purpose of this was to ensure the program met current local clinical and technological requirements, to improve standardization of training across Australia and New Zealand and generate a dynamic curriculum and programmatic assessment model.

Methods: A four-phase project was initiated, including a consultant desktop review of the current program and stakeholder consultation.

Developing an educational "hub": impact of a distance-learning curriculum in a multinational cohort.

Purpose: To address a gap in radiation oncology education in low- and middle-income countries (LMICs), we sought to evaluate the effectiveness and generalizability of a refined curriculum on intensity modulated radiotherapy (IMRT) offered to existing radiation therapy (RT) clinics across Africa and Latin America (LATAM) at no cost.

Methods: A curriculum was created based on prior needs assessments and adapted for participating medical physicists, radiation oncologists, radiation therapists, and trainees in LMICs. English-speaking and Spanish-speaking teams of volunteer educators delivered 27 hour-long sessions 1-2 times weekly for 4 months using video conferencing to African and LATAM cohorts, respectively.

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

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.

Impact of High-Dose-Rate Brachytherapy Training via Telehealth in Low- and Middle-Income Countries.

Purpose: Our objective was to demonstrate the efficacy of a telehealth training course on high-dose-rate (HDR) brachytherapy for gynecologic cancer treatment for clinicians in low- and middle-income countries (LMICs).

Methods: A 12-week course consisting of 16 live video sessions was offered to 10 cancer centers in the Middle East, Africa, and Nepal. A total of 46 participants joined the course, and 22 participants, on average, attended each session.

Dosimetric comparison of single-beam multi-arc and 2-beam multi-arc VMAT optimization in the Monaco treatment planning system.

The purpose of this study was to evaluate the dosimetric and practical effects of the Monaco treatment planning system "max arcs-per-beam" optimization parameter in pelvic radiotherapy treatments. We selected for this study a total of 17 previously treated patients with a range of pelvic disease sites including prostate (9), bladder (1), uterus (3), rectum (3), and cervix (1). For each patient, 2 plans were generated, one using an arc-per-beam setting of "1" and another with an arc-per-beam setting of "2" using the volumes and constraints established from the initial clinical treatments.

Intravenous cannula site management.

What was the nature of the CPD activity, practice-related feedback and/or event and/or experience in your practice? The CPD article provided information about safe and effective practice in intravenous cannulation, including indications for cannulation, appropriate cannulation sites, types and sizes of cannula, cannula maintenance, recognising and avoiding complications.

Electron beam energy QA - a note on measurement tolerances.

Monthly QA is recommended to verify the constancy of high-energy electron beams generated for clinical use by linear accelerators. The tolerances are defined as 2%/2 mm in beam penetration according to AAPM task group report 142. The practical implementation is typically achieved by measuring the ratio of readings at two different depths, preferably near the depth of maximum dose and at the depth corresponding to half the dose maximum.

A phantom assessment of achievable contouring concordance across multiple treatment planning systems.

In this paper, the highest level of inter- and intra-observer conformity achievable with different treatment planning systems (TPSs), contouring tools, shapes, and sites have been established for metrics including the Dice similarity coefficient (DICE) and Hausdorff Distance. High conformity values, e.g.

Implications for dosimetric changes when introducing MR-guided brachytherapy for small volume cervix cancer: a comparison of CT and MR-based treatments in a single centre.

To evaluate cervix brachytherapy dosimetry with the introduction of magnetic resonance (MR) based treatment planning and volumetric prescriptions and propose a method for plan evaluation in the transition period. The treatment records of 69 patients were reviewed retrospectively. Forty one patients were treated using computed tomography (CT)-based, Point A-based prescriptions and 28 patients were treated using magnetic resonance (MR)-based, volumetric prescriptions.

Optimal single 3T MR imaging sequence for HDR brachytherapy of cervical cancer.

Purpose: The superior image quality of 3 tesla (3T) magnetic resonance (MR) imaging in cervical cancer offers the potential to use a single image set for brachytherapy. This study aimed to determine a suitable single sequence for contouring tumour and organs at risk, applicator reconstruction, and treatment planning.

Material And Methods: A 3T (Skyra, Siemens Healthcare AG, Germany) MR imaging system with an 18 channel body matrix coil generated HDR cervical cancer brachytherapy planning images on 20 cases using plastic-based treatment applicators.

Dosimetric comparison of optimization methods for multichannel intracavitary brachytherapy for superficial vaginal tumors.

Purpose: Multichannel vaginal applicators allow treatment of a more conformal volume compared with a single, central vaginal channel. There are several optimization methods available for use with multichannel applicators, but no previous comparison of these has been performed in the treatment of superficial vaginal tumors. Accordingly, a feasibility study was completed to compare inverse planning by simulated annealing (IPSA), dose point optimization (DPO), and graphical optimization for high-dose-rate brachytherapy using a multichannel, intracavitary vaginal cylinder.

Lessons learned from a HDR brachytherapy well ionisation chamber calibration error.

The outcomes of a recent brachytherapy well-type ionization chamber calibration error are given in the hope that other brachytherapy treatment centres may better understand the importance of each entry stated in a well chamber calibration certificate. A Nucletron Source Dosimetry System (SDS) PTW well-type ionization chamber was sent for a biennial calibration in September 2010. Upon calibration of the chamber, it was discovered that the previous calibration (in July 2008) contained a +2.

Methodology for commissioning a brachytherapy treatment planning system in the era of 3D planning.

To describe the steps undertaken to commission a 3D high dose rate (HDR) brachytherapy treatment planning system (TPS). Emphasis was placed on validating previously published recommendations, in addition to checking 3D parameters such as treatment optimization and dose volume histogram (DVH) analysis. Commissioning was performed of the brachytherapy module of the Nucletron Oncentra MasterPlan treatment planning system (version 3.