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PurposeThe quality of medical physics education is heterogenous across training programs, despite its importance in radiation oncology (RO) residency training. We present the results of a pilot series of free high-yield physics educational videos covering 4 topics chosen from the American Society for Radiation Oncology core curriculum.Methods and materialsScripting and storyboarding of videos were iterative processes performed by 2 ROs and 6 medical physicists, with animations created by a university broadcasting specialist. Current RO residents and those who had graduated after 2018 were recruited through social media and e-mail with an aim of 60 participants. Two validated surveys were adapted for use and were completed after each video as well as a final overall assessment. Content was released sequentially after completion of the survey instruments for each prior video. All videos were created and released within 1 year of project initiation with a duration of 9 to 11 minutes.ResultsThere were 169 enrollees for the pilot from across the world, 211% of the targeted cohort size. Of these, 154 met eligibility criteria and received the first video. One hundred eight enrollees initiated the series and 85 completed the pilot, resulting in a 78% completion rate. Participants reported improved understanding and confidence applying the knowledge learned in the videos (median score 4 out of 5). All participants reported that the use of graphic animation improved understanding across all videos. Ninety-three percent agreed with a need for additional resources geared specifically toward RO residents and 100% would recommend these videos to other residents. Use metrics revealed the average watch time was 7 minutes (range, 6:17-7:15).ConclusionsThe high-yield educational physics video pilot series was successful in developing videos that were effective in teaching RO physics concepts.

PurposeMotion management of tumors within the lung and abdomen is challenging because it requires balancing tissue sparing with accuracy of hitting the target, while considering treatment delivery efficiency. Physicists can play an important role in analyzing four-dimensional computed tomography (4DCT) data to recommend the optimal respiratory gating parameters for a patient. The goal of this work was to develop a standardized procedure for making recommendations regarding gating parameters and planning margins for lung and gastrointestinal stereotactic body radiotherapy (SBRT) treatments. In doing so, we hoped to simplify decision-making and analysis, and provide a tool for troubleshooting complex cases.MethodsFactors that impact gating decisions and planning target volume (PTV) margins were identified. The gating options included gating on exhale with approximately a 50% duty cycle (Gate3070), exhale gating with a reduced duty cycle (Gate4060), and treating for most of respiration, excluding only extreme inhales and exhales (Gate100). A standard operating procedure was developed, as well as a physics consult document to communicate motion management recommendations to other members of the treatment team. This procedure was implemented clinically for 1 year and results are reported below.ResultsIdentified factors that impact motion management included the magnitude of motion observed on 4DCT, the regularity of breathing and quality of 4DCT data, and ability to observe the target on fluoroscopy. These were collated into two decision tables-one specific to lung tumors and another for gastrointestinal tumors-such that a physicist could answer a series of questions to determine the optimal gating and PTV margin. The procedure was used clinically for 252 sites from 213 patients treated with respiratory-gated SBRT and standardized practice across our 12-member physics team.ConclusionImplementation of a standardized procedure for respiratory gating had a positive impact in our clinic, improving efficiency and ease of 4DCT analysis and standardizing gating decision-making amongst physicists.

BackgroundStereotactic ablative radiotherapy (SAbR) is an emerging therapy for refractory ventricular tachycardia (VT). However, the current workflow is complicated, and the precision and safety in patients with significant cardiorespiratory motion and VT targets near the stomach may be suboptimal.ObjectiveWe hypothesized that automated 12-lead electrocardiogram (ECG) mapping and respiratory-gated therapy may improve the ease and precision of SAbR planning and facilitate safe radiation delivery in patients with refractory VT.MethodsConsecutive patients with refractory VT were studied at 2 hospitals. VT exit sites were localized using a 3-D computational ECG algorithm noninvasively and compared to available prior invasive mapping. Radiotherapy (25 Gy) was delivered at end-expiration when cardiac respiratory motion was ≥0.6 cm or targets were ≤2 cm from the stomach.ResultsIn 6 patients (ejection fraction 29% ± 13%), 4.2 ± 2.3 VT morphologies per patient were mapped. Overall, 7 out of 7 computational ECG mappings (100%) colocalized to the identical cardiac segment when prior invasive electrophysiology study was available. Respiratory gating was associated with smaller planning target volumes compared to nongated volumes (71 ± 7 vs 153 ± 35 cc, P < .01). In 2 patients with inferior wall VT targets close to the stomach (6 mm proximity) or significant respiratory motion (22 mm excursion), no GI complications were observed at 9- and 12-month follow-up. Implantable cardioverter-defibrillator shocks decreased from 23 ± 12 shocks/patient to 0.67 ± 1.0 (P < .001) post-SAbR at 6.0 ± 4.9 months follow-up.ConclusionsA workflow including computational ECG mapping and protocol-guided respiratory gating is feasible, is safe, and may improve the ease of SAbR planning. Studies to validate this workflow in larger populations are required.

Purpose This study aimed to perform a longitudinal analysis of linear accelerator (linac) technical faults reported with a cloud-based Machine Log system in use in a busy academic clinic and derive operational insights related to linac reliability, clinical utilization, and performance. Methods We queried the Machine Log system for the following parameters: linac type, number of reported technical faults, types of fault, number of faults where the linac was disabled, and estimated clinical downtime. The number of fractions treated and monitor units (MU) delivered were obtained from the record and verify system as metrics of linac utilization and to normalize the number of reported linac faults, facilitating inter-comparison. Two Varian TrueBeam C-arm linacs (Varian Medical Systems, Palo Alto, CA), one Varian 21iX C-arm linac (Varian Medical Systems, Palo Alto, CA), and one newly installed Varian Halcyon ring gantry linac (Varian Medical Systems, Palo Alto, CA) were evaluated. The linacs were studied over a 30-month period from September 2017 to March 2020.  Results Over 30 months, comprising 677 clinical days, 1234 faults were reported from all linacs, including 153 "linac down" events requiring rescheduling or cancellation of treatments. The TrueBeam linacs reported nearly twice as many imaging, multileaf collimator (MLC), and beam generation faults per fraction, and MU as the Halcyon. Halcyon experienced fewer beam generation/steering, accessory, and cooling-related faults than the other linacs but reported more computer and networking issues. Although it employs a relatively new MLC design compared to the C-arm linacs and delivers primarily intensity-modulated treatments, Halcyon reported fewer MLC faults than the other linacs. The 21iX linac had the fewest software-related faults but was subject to the most cooling-related faults, which we attributed to extensive use of this linac for treatment techniques with extended beam-on times. Conclusions A longitudinal analysis of a cloud-based Machine Log system yielded operational insights into the utilization, performance, and technical reliability of the linacs in use at our institution. Several trends in linac sub-system reliability were identified and could be attributed to either age, design, clinical use, or operational demands. The results of this analysis will be used as a basis for designing linac quality assurance schedules that reflect actual linac usage and observed sub-system reliability. Such a practice may contribute to a clinic workflow subject to fewer disruptions from linac faults, ultimately improving efficiency and patient safety.

PurposeTo provide insight into the types of questions asked to medical physicists by patients during one-on-one physicist-patient consults at one institution.Materials and methodsMedical physicists trained in patient communication techniques met with patients to provide an overview of the treatment planning and delivery processes, discuss the patient's treatment plan, and answer any technical questions. From August 2016 to December 2019, 152 physicist-patient consults were conducted. In the initial months of the study (August 2016-December 2017), following each physicist-patient consult, all patient questions were documented by the physicists. For the remaining time period (January 2018-December 2019), any newly encountered questions were periodically added to the list. The questions were compiled into a comprehensive list and organized into categories.ResultsThere were a total of 88 unique patient questions. These questions fit into four topical categories. Fifty-four questions (61.4%) were in the "Treatment Planning and Delivery Questions" category, 15 questions (17.1%) were in the "General Radiation Questions or Concerns" category, 13 questions (14.8%) were in the "Safety and Quality Assurance Questions" category, and 6 questions (6.8%) were in the "Medical Questions" category. Overall, patients were primarily concerned about how radiation works, the treatment planning and delivery processes, and what is being done to keep them safe throughout their treatment.ConclusionPhysicist-patient consults provided an opportunity to address the technical aspects of radiation therapy with patients in greater detail. The fact that patient questions could be conveniently grouped into only four topical categories indicates that it may be straightforward for other medical physicists to prepare for effectively addressing technical questions during physicist-patient consults.

ObjectivesTo develop a training program designed to meet the specific needs of medical physicists as they transition into a clinical role with direct patient care responsibilities.Materials and methodsThe training program was designed in collaboration with the faculty at the UC San Diego School of Medicine and incorporates training techniques that have been shown to be effective in improving communication skills. The program emphasizes experiential, practice-based learning over didactic presentations.ResultsThe training program is comprised of 5 components: 1) a 1-day Clinician-Patient Communication Workshop run by the UC San Diego School of Medicine, 2) Communication Strategies for Radiation Oncology, which consists of two, 2-hour sessions designed to provide trainees with patient communication skills that are specific to patient interactions in radiation oncology, 3) Simulated Patient Interactions, in which trainees perform mock physicist-patient consults with trained patient actors, 4) Faculty-Observed Patient Consults, and 5) a Case-Based Treatment Toxicity Course. A competency assessment mechanism was also developed to provide a clear set of objectives and to guide trainer feedback. [Correction added after first online publication on November 7, 2018: The phrase ", which consists of two, 2-hour" was added above.] CONCLUSIONS: The training program that we have developed incorporates an array of established education techniques and provides a comprehensive, accessible, means of improving medical physicists' patient communication skills.