Self-reported COVID-19 infection, and illness severity associated with a large professional-society meeting of the AAPM in 2022.

BACKGROUND: Many in-person conferences were suspended during the initial stages of the COVID-19 pandemic but have recently begun to return to in-person or hybrid formats. However the incidence and severity of COVID-19 infection during conferences, as well as behaviors at meetings associated with infection, are not well known. PURPOSE: We performed a targeted, systematic survey of self-reported COVID-19 infection and severity rates among in-person attendees and potential attendees of a large national medical conference held in hybrid format during the during the Omicron subvariant wave, to provide guidance for future meeting attendees and organizers on COVID-19 risk. METHODS: A survey was sent to all members of the American Association of Physicists in Medicine (AAPM) as well as all attendees of the AAPM 2022 Annual Meeting (held July 10th-14th 2022 in Washington DC) with hybrid format) (total n = 10,627). The survey assessed relevant respondent demographics, views of COVID-19 and in-person meetings, COVID-19 infection during the meeting or the following 7 days, and any COVID-19 treatment received. Descriptive statistics and multivariable logistic regression with odds ratios (OR) and 95% confidence intervals (CI) were used for analysis. RESULTS: The response rate was 13.7% (n = 1464) among the total invitees. Of respondents, 62.9% (n = 921) attended the meeting in person and 37.1% (n = 543) did not. Among in-person meeting attendees, 82.1% (n = 756) attended indoor social events during the meeting including 67.5% (n = 509) who attended a large, AAPM-coordinated social event. Reported COVID-19 infection rates were higher among in-person attendees (15.3%, n = 141) versus those that did not attend in-person (6.1%, n = 33) (p < 0.001). Of those infected, 97.9% (n = 138) recovered entirely at home, with the remaining 2 (1.4%) undergoing emergency room visit without admission, and 1 (unvaccinated) individual (0.7%) reported hospital admission. On multivariable analysis of reported in-person attendee behaviors, only attendance of the large, AAPM-coordinated social event remained significantly associated with COVID-19 infection (OR 2.8, CI 1.8-4.2, p < 0.001). Among in-person attendees, 74.1% (n = 682) agreed that they would feel comfortable attending in-person conferences in the future, 11.8% (n = 109) disagreed, and 14.0% (n = 129) neither agreed nor disagreed. CONCLUSIONS: Despite higher than previously reported COVID-19 infection rates than prior studies, severity of infection was self-limited with no hospitalizations among vaccinated attendees. In-person attendees showed a willingness to return to large-scale indoor social interaction, with a higher rate of COVID-19 infection noted among those who attended a large conference-affiliated social gathering. Most individuals reported feeling comfortable attending other in-person meetings in the future.

Results of a Multi-Disciplinary and Multi-Institutional Pilot Creating High-Yield Physics Educational Content (Hi-Phy).

Purpose: The 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 materials: Scripting 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. Results: There 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). Conclusions: The high-yield educational physics video pilot series was successful in developing videos that were effective in teaching RO physics concepts.

Lessons Learned From an Educational Pilot: High-Yield Physics Videos for Radiation Oncology Residents.

Radiation oncology is uniquely poised to benefit from the development of remote learning tools, given the need for mastery of often challenging basic science topics, as well as the interprogram heterogeneity of resident educational quality. Our team successfully created and disseminated 4 high-yield animated physics educational videos through the collaboration of radiation oncologists, medical physicists, and a graphic design specialist. This is a unique process requiring significant intellectual, monetary, and time capital. In this article, we describe important lessons learned throughout this process, in hopes that others will learn from our experience, applying the following concepts to their own digital content creation. These lessons include (1) playing to your teammates' strengths and personalizing tasks, rather than equally dividing work; (2) anticipating animations before and during script writing; (3) developing multiple routes of communication and being open to which one works best for your team; and (4) discussing funding up front and collaborating within an affiliated institution or company for graphic design to alleviate the financial stress of such endeavors.

Resource Allocations for Common Radiation Oncology Procedures.

PURPOSE: Radiation Oncology is a complex, resource-intensive discipline. The complexity of the radiation oncology treatment process has increased significantly in recent years with the introduction of more advanced imaging, planning, and treatment delivery technology and enhanced use of multidisciplinary care paths. We conducted a multi-institutional study to estimate the average time by functional unit for a wide range of modern radiation oncology treatment regimens. METHODS AND MATERIALS: Structured process mapping was performed for 24 treatment categories, and average time estimates for 6 functional groups were obtained for each process step through consultation with the full clinical team at each institution. Six geographically dispersed institutions participated in the study. Significant effort was invested in aggregate data analysis and clarification of assumptions. RESULTS: The findings show significant variability in the resources expended for many treatment categories as well as the distribution of workload between functional units. Major factors in the variability include the rate of adoption of hypofractionation in external beam therapy, adoption of automation tools and standardization, and the transition to multimodality image-based planning in brachytherapy. CONCLUSIONS: The data obtained from this study may be useful in designing institution-specific staffing models appropriate to the scope of radiation therapy services provided at each institution.

A Blinded, Prospective Study of Error Detection During Physician Chart Rounds in Radiation Oncology.

PURPOSE: Peer review during physician chart rounds is a major quality assurance and patient safety step in radiation oncology. However, the effectiveness of chart rounds in detecting problematic treatment plans is unknown. We performed a prospective blinded study of error detection at chart rounds to clarify the effectiveness of this quality assurance step. METHODS AND MATERIALS: Radiation Oncology Incident Learning System publications were queried for problematic plans approved for treatment that would be detectable at chart rounds. A resident physician, physicist, and dosimetrist collaboratively generated 20 treatment plans with simulated errors identical in nature to those reported to the Radiation Oncology Incident Learning System. These were inserted randomly into weekly chart rounds over 9 weeks, with a median of 2 problematic plans presented per chart rounds (range, 1-4). Data were collected on detection, attendance, length, and number of cases presented at chart rounds. Data were analyzed using descriptive statistics and univariable logistic regression with odds ratios. RESULTS: The median length of chart rounds over the study period was 60 minutes (range, 42-79); median number of cases presented per chart rounds was 45 (range, 38-50). The overall detection rate was 55% (11 of 20). Detection rates were higher for cases presented earlier in chart rounds: 75% versus 25% of problematic plans were detected within 30 minutes of start of chart rounds versus after 30 minutes (odds ratio, 0.11; 95% confidence interval, 0.01-0.88; P = .037). Detection rates showed a trend toward increase during the study period but this was not significant: 33% in weeks 1 to 5 and 73% during weeks 6 to 9 (5.3; 95% confidence interval, 0.78-36; P = .08). CONCLUSIONS: The detection of clinically significant problematic plans during chart rounds could be significantly improved. Problematic plans are more frequently detected earlier in chart rounds and inserting such plans into chart rounds may enhance detection; however, larger studies are needed to confirm these findings. A multi-institutional study is planned.

Error Types and Associations of Clinically Significant Events Within Food and Drug Administration Recalls of Linear Accelerators and Related Products.

PURPOSE: Medical devices in radiation therapy undergo a complex process of Food and Drug Administration (FDA) approval. Little is known about which processes within the radiation therapy medical device industry are most prone to events involving wrong dose, volume, or targeting in radiation therapy treatment. METHODS AND MATERIALS: We carried out a retrospective analysis of the United States FDA Medical Device Recalls database for recalls of products classified as "Accelerator, Linear, Medical" from 2010 to 2016. Each recall event was classified using a modified Delphi method among 3 experts in safety according to product type, error category, and severity score. Error categories included inconvenience; suboptimal plan or treatment; incorrect dose, volume, or targeting; and nonradiation injury risk. Variables investigated were product type, recall year, FDA-determined cause, and quantity of units recalled. Univariate and multivariate logistic regression were used to identify factors prognostic of incorrect dose, volume, or targeting. RESULTS: We identified a total of 250 recall events between 2010 and 2016, with 165 eligible for analysis. Linear accelerators (LINACs) (28%) and LINAC control software (19%) were the most frequently recalled products. The most common FDA-determined causes for recalls were software design (42%) and device design (26%). On univariate analysis (P < .05), LINAC control software (odds ratio [OR] 5.4) and oncology information system or treatment management system (OR 3.9) versus LINACs and software design (OR 3.4) versus device design were associated with wrong dose, volume, or targeting events. On multivariate analysis, only the association with LINAC control software (OR 3.7) persisted for wrong dose, volume, or targeting events. CONCLUSIONS: Review of these data shows that problems with LINAC control software were associated with incorrect dose delivery at a 4-fold higher rate than errors with LINACs. Manufacturers should focus on improvements in software design to minimize dose- and targeting-related errors to patients.

Stereotactic radiosurgery-radiotherapy: Should Monte Carlo treatment planning be used for all sites?

PURPOSE: To evaluate a Monte Carlo (MC) treatment planning system for CyberKnife treatments of cranial and extracranial lesions and determine whether it is necessary for all treatment sites. Dose distributions are compared to those calculated with a ray-tracing algorithm. Maximum doses and dose-volume histograms for the target and selected critical structures are analyzed. METHODS AND MATERIALS: The CyberKnife is used for stereotactic radiosurgery-radiotherapy of intracranial lesions (91) as well as stereotactic body radiotherapy for lesions in the spine (24), lung (58), and pelvis (36). The Multiplan system is an inverse treatment planning system which uses an effective path length (EPL) algorithm (sometimes referred to as ray-trace) for dose calculations. In addition, an MC algorithm became clinically available in late 2007. RESULTS: The maximum doses calculated by the EPL to targets in the lung were uniformly larger than the doses calculated by MC by up to a factor of 1.32. In addition, large differences in target and critical organs' dose coverage were observed. In general, more beams traversing larger distances through low density lung are associated with larger differences. For other sites such as brain and pelvis targets the differences in maximum doses and tumor coverage were generally less than 5% between the 2 calculation methods. CONCLUSIONS: The MC algorithm should be consistently used for treatment plans of lung lesions and lesions near large air cavities, but the faster EPL algorithm is adequate for treatment sites with less tissue heterogeneity.

Comparison of planned dose distributions calculated by Monte Carlo and Ray-Trace algorithms for the treatment of lung tumors with cyberknife: a preliminary study in 33 patients.

PURPOSE: To compare dose distributions calculated using the Monte Carlo algorithm (MC) and Ray-Trace algorithm (effective path length method, EPL) for CyberKnife treatments of lung tumors. MATERIALS AND METHODS: An acceptable treatment plan is created using Multiplan 2.1 and MC dose calculation. Dose is prescribed to the isodose line encompassing 95% of the planning target volume (PTV) and this is the plan clinically delivered. For comparison, the Ray-Trace algorithm with heterogeneity correction (EPL) is used to recalculate the dose distribution for this plan using the same beams, beam directions, and monitor units (MUs). RESULTS: The maximum doses calculated by the EPL to target PTV are uniformly larger than the MC plans by up to a factor of 1.63. Up to a factor of four larger maximum dose differences are observed for the critical structures in the chest. More beams traversing larger distances through low density lung are associated with larger differences, consistent with the fact that the EPL overestimates doses in low-density structures and this effect is more pronounced as collimator size decreases. CONCLUSIONS: We establish that changing the treatment plan calculation algorithm from EPL to MC can produce large differences in target and critical organs' dose coverage. The observed discrepancies are larger for plans using smaller collimator sizes and have strong dependency on the anatomical relationship of target-critical structures.

Identification and quantitation of sorbitol-based nuclear clarifying agents extracted from common laboratory and consumer plasticware made of polypropylene.

Reported here is the mass spectral identification of sorbitol-based nuclear clarifying agents (NCAs) and the quantitative description of their extractability from common laboratory and household plasticware made of polypropylene. NCAs are frequently added to polypropylene to improve optical clarity, increase performance properties, and aid in the manufacturing process of this plastic. NCA addition makes polypropylene plasticware more aesthetically pleasing to the user and makes the product competitive with other plastic formulations. We show here that several NCAs are readily extracted with either ethanol or water from plastic labware during typical laboratory procedures. Observed levels ranged from a nanogram to micrograms of NCA. NCAs were also detected in extracts from plastic food storage containers; levels ranged from 1 to 10 microg in two of the three brands tested. The electron ionization mass spectra for three sorbitol-based nuclear clarifying agents (1,3:2,4-bis-O-(benzylidene)sorbitol, 1,3:2,4-bis-O-(p-methylbenzylidene)sorbitol, 1,3:2,4-bis-O-(3,4-dimethylbenzylidene)sorbitol) are presented for the native and trimethylsilyl-derivatized compounds together with the collision-induced dissociation mass spectra; gas and liquid chromatographic data are also reported. These NCAs now join other well-known plasticizers such as phthalate esters and bisphenol A as common laboratory contaminants. While the potential toxicity of NCAs in mammalian systems is unknown, the current data provide scientists and consumers the opportunity to make more informed decisions regarding the use of polypropylene plastics.