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.

Aging a Decade in a Day: Age Cutoff Bias in Adjuvant Therapy Allocation for Early-Stage Breast Cancer.

PURPOSE: Physicians may expedite interpretation of data presented as a continuous variable by binning the data into "high" and "low" subgroups (cutoff heuristic). Use of this cognitive shortcut with age may lead to fewer nuanced or inappropriate decisions. We hypothesized an age cutoff heuristic may lead to non-evidence-based adjuvant treatment allocation among patients with early-stage breast cancer. METHODS AND MATERIALS: Two cohorts with strong indications for adjuvant treatment regardless of age that underwent lumpectomy for early-stage breast cancer between 2004 and 2017 were identified in the National Cancer Database. Cohort 1 had higher-risk features (estrogen receptor negative, endocrine therapy not planned, final margins positive, or size >3 cm; n = 160,990) and was appropriate for radiation. Cohort 2 had hormone receptor positivity with tumors >5 mm (n = 394,946) and was appropriate for endocrine therapy. Multivariable logistic regressions with odds ratios (ORs) and 99.8% confidence intervals (CIs) were performed to determine whether any single year-over-year age difference was independently associated with a difference in likelihood of adjuvant therapy recommendation. RESULTS: In cohort 1, radiation recommendation decreased sharply at age 70, ranging from 90% to 92% between the ages of 50 and 69 years to 81% for those aged 70 years. Multivariable logistic regressions showed year-over-year age difference was an independent predictor for adjuvant radiation recommendation at only age 70 versus 69 (OR, 0.47; CI, 0.39-0.57; P < .001). For cohort 2, endocrine therapy recommendation showed a small decline at age 70, and year-over-year age difference was a predictor of endocrine therapy recommendation at only age 70 versus 69 (OR, 0.86; CI, 0.74-0.99; P = .001). CONCLUSIONS: We observed a unique decline in appropriate adjuvant therapy recommendation between ages 69 and 70. This suggests use of an age cutoff heuristic to process patient age in this population as a categorical, binary variable. This is a previously undescribed phenomenon in early-stage breast cancer.

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.

Characteristics of the Association of Residents in Radiation Oncology Educator of the Year Award Recipients.

PURPOSE: The Association of Residents in Radiation Oncology (ARRO) presents the Educator of the Year Award to outstanding faculty members at each participating institution every year. The aim of this study was to characterize the recipients of this award. METHODS AND MATERIALS: The recipients of the annual ARRO Educator of the Year Award were identified from the years 2008 to 2019. Publicly available website domains were accessed to obtain data regarding clinical treatment site, number of sites treated, whether they were at the same institution where they trained, academic rank, sex, American Society for Radiation Oncology fellow status, repeat awardee status during the period, and number of years since board certification. H- and m-indices were obtained from Scopus and calculated based on the time of the award. General workforce data were obtained from American Society for Radiation Oncology and recently published articles. The authors performed correlative analyses stratified by sex and logistic regression to determine predictors of repeat awardee status. RESULTS: There were a total of 607 ARRO educator awards from the years 2008 to 2019. The majority of recipients were male (77.6%) and assistant professors (39.0%). The median number of years from board certification was 7 (interquartile range, 3-17) and the median h- and m-indices were 14 and 1, respectively. When stratified by sex, publication metrics were significantly higher for men (P < .05), and men were more likely to be repeat awardees (P < .001) and have higher academic rank (P = .007). On multivariate analysis, those of higher rank were more likely to be repeat awardees (associate odds ratio [OR], 3.55; P < .001; full professor OR, 2.04; P = .046) and less likely to be women (OR, 0.41; P = .002), and h- and m-indices were not associated with repeat awardee status. CONCLUSIONS: Recipients of the ARRO educator award appear to be diverse in rank and experience; however, associate professor rank and sex were associated with continued recognition of educational excellence.

Hazardous Attitudes: Physician Decision Making in Radiation Oncology.

Purpose: The Federal Aviation Administration quantifies hazardous attitudes (HAs) among pilots using a scale. HAs have been linked to aviation risk. We assessed the influence of HAs and other factors in treatment decision making in radiation oncology (RO). Methods and Materials: An anonymous survey was sent to 809 radiation oncologists in US cities housing the top 25 cancer centers. The survey included an HA scale adapted for RO and presented 9 cases assessing risk-tolerant radiation therapy prescribing habits and compliance with the American Society for Radiation Oncology's Choosing Wisely recommendations. Demographic and treatment decision data were dichotomized to identify factors associated with prescribing habits using univariable and multivariable (MVA) logistic regression analyses. Results: A total of 139 responses (17.1%) were received, and 103 were eligible for analysis. Among respondents, 40% were female, ages were evenly distributed, and 83% were in academics. Median scores for all attitudes (macho, anti-authority, worry, resignation, and impulsivity) were below the aviation thresholds for hazard and data from surgical specialties. On MVA, responders >50 years old with >5 years' experience were 4.45 times more likely to recommend risk-tolerant radiation (P = .016). Macho attitude was negatively associated with Choosing Wisely compliant treatments (odds ratio [OR], 0.12; P = .001). Physicians who reported having previously retreated the supraclavicular fossa without complication were more likely to recommend retreatment in medically unfit patients if they felt the complication was avoided owing to careful planning (OR, 5.2; P = .008). Conclusions: To our knowledge, this represents the first study analyzing physician attitudes in RO and their effect on self-reported treatment decisions. This work suggests that attitude may be among the factors that influence risk-tolerant prescribing practices and compliance with Choosing Wisely recommendations.

Self-Reported COVID-19 Infections and Social Mixing Behavior at Oncology Meetings.

PURPOSE: The COVID-19 pandemic largely suspended in-person scientific meetings because of risk of disease spread. In the era of vaccination and social distancing practices, meetings have begun returning to in-person formats. We surveyed attendees and potential attendees of 2 oncology meetings in the United States to identify rates of mixing behavior and the subsequent rate of self-reported COVID-19 infection. METHODS AND MATERIALS: We collected via survey reported social mixing behavior and COVID-19 positivity (within 21 days of meeting conclusion) of actual and potential in-person attendees of the American Society of Clinical Oncology (ASCO) Quality Care Symposium held September 24 to 25, 2021, and the American Society for Radiation Oncology (ASTRO) Annual Meeting held October 24 to 27, 2021. Conference speakers and other participants were identified through publicly available meeting materials and targeted via e-mail when possible. Recruitment of additional attendees and potential attendees was also conducted through a sharable link promoted via oncology newsletters and social media. Descriptive statistics alone were performed owing to low COVID-19 event rates. RESULTS: Response rates from targeted conference participants with publicly available e-mails were 27.4% for the ASCO and 14.3% for the ASTRO meetings. The ASCO survey produced 94 responses (48 in-person attendees). The ASTRO survey produced 370 responses (267 in-person attendees). Across both meetings, 3 of 308 (1.0%) in-person attendees versus 2 of 141 (1.4%) nonattendees tested positive for COVID-19. Low COVID-19 positivity rates were reported among in-person attendees spending more (>20) versus fewer (≤20) hours attending live sessions (2.2% vs 0%) and among indoor social event participants versus nonparticipants (0.8% vs 1.9%). Attendees largely felt comfortable attending additional in-person meetings after experiencing ASCO (87.5%) or ASTRO (91.9%) and felt mask compliance was good or excellent at ASCO (100%) and ASTRO (94.6%) meetings. CONCLUSIONS: In-person meetings do not seem to be contributing to high rates of new COVID-19 infections in the setting of vaccine and social distancing mandates, supporting paths forward for at least partially in-person conferences as COVID-19 becomes endemic.

Benefit of Deep Inspiratory Breath Hold for Right Breast Cancer When Regional Lymph Nodes Are Irradiated.

BACKGROUND: Although deep inspiratory breath-hold (DIBH) is routinely used for left-sided breast cancers, its benefits for right-sided breast cancer (rBC) have yet to be established. We compared free-breathing (FB) and DIBH treatment plans for a cohort of rBC undergoing regional nodal irradiation (RNI) to determine its potential benefits. METHODS AND MATERIALS: rBC patients considered for RNI (internal mammary nodal chains, supraclavicular field, with or without axilla) from October 2017 to May 2020 were included in this analysis. For each patient, FB versus DIBH plans were generated and dose volume histograms evaluated the following parameters: mean lung dose, ipsilateral lung V20/V5 (volumes of lung receiving 20 Gy and 5 Gy, respectively); mean heart dose and heart V5 (volumes of heart receiving 5 Gy); liver V20 absolute /V30 absolute (absolute volume of liver receiving 20 Gy and 30 Gy, respectively), liver Dmax, and total liver volume irradiated (TVIliver). The dosimetric parameters were compared using Wilcoxon signed-rank testing. RESULTS: Fifty-four patients were eligible for analysis, comparing 108 FB and DIBH plans. DIBH significantly decreased all lung and liver parameters: mean lung dose (19.7 Gy-16.2 Gy, P < .001), lung V20 (40.7%-31.7%, P < .001), lung V5 (61.2%-54.5%, P < .001), TVIliver (1446 cc vs 1264 cc; P = .006) liver Dmax (50.2 Gy vs 48.9 Gy; P = .023), liver V20 (78.8-23.9 cc, P < .001), and liver V30 (58.1-14.6 cc, P < .001) compared with FB. DIBH use did not significantly improve heart parameters, although the V5Heart trended on significance (1.25-0.6, P = .067). CONCLUSIONS: This is the largest cohort to date analyzing DIBH for RNI-rBC. Our findings demonstrate significant improvement in all lung and liver parameters with DIBH, supporting its routine consideration for rBC patients undergoing comprehensive RNI.

An Evaluation of Health Numeracy among Radiation Therapists and Dosimetrists.

PURPOSE: Medical errors in radiation oncology sometimes involve tasks reliant on practitioners' grasp of numeracy. Numeracy has been shown to be suboptimal across various health care professionals. Herein, we assess health numeracy among American Society of Radiologic Technologists (ASRT) members. METHODS AND MATERIALS: The Numeracy Understanding for Medicine instrument (NUMi), an instrument to measure numeracy in the general population, was adapted to oncology for this study and distributed to ASRT members (n = 14,228) in 2017. Per NUMi scoring, health numeracy scores were categorized as low (0-7), low average (8-12), high average (13-17), or high (18-20). The impact of cGy versus Gy on numeracy performance was investigated. Spearman's rho and a Wilcox-Mann-Whitney test were used for comparisons between the different groups. RESULTS: A total of 662 eligible participants completed the instrument and identified as radiation oncology professionals. In the cGy and Gy NUMi scores, approximately 2% of respondents scored low-average, approximately 40% scored high-average, and approximately 58% scored high, with a median score of 18.0. Although the optimum NUMi score for ASRT members is unknown, one might expect our cohort to have numeracy skills at least as high as college freshmen. Roughly one-sixth of our study group scored at or below the average score of college freshmen (NUMi = 15). In the subset analysis of NUMi questions pertaining to radiation dose unit (cGy vs Gy), respondents performed better with cGy (mean score: 2.94; range, 2-3) versus Gy (mean: 2.91; range, 0-3; P = .011). CONCLUSIONS: In this study of limited sample size, overall numeracy is quite good compared with the general population. However, the range of scores is wide, and some respondents have lower scores that may be concerning, suggesting that numeracy may be an issue that requires improvement for a subset of the studied cohort. Performance was superior with the unit cGy; thus, the adoption of cGy as the standard unit is reasonable.

Physician trajectories of abandoning long-course breast radiotherapy and their cost impact.

OBJECTIVE: To examine variation in trajectories of abandoning conventionally fractionated whole-breast irradiation (CF-WBI) for adjuvant breast radiotherapy among physician peer groups and the associated cost implications. DATA SOURCES: Medicare claims data were obtained from the Chronic Conditions Data Warehouse for fee-for-service beneficiaries with breast cancer in 2011-2014. STUDY DESIGN: We used social network methods to identify peer groups of physicians that shared patients. For each physician peer group in each time period (T1 = 2011-2012 and T2 = 2013-2014), we calculated a risk-adjusted rate of CF-WBI use among eligible women, after adjusting for patient clinical characteristics. We applied a latent class growth analysis to these risk-adjusted rates to identify distinct trajectories of CF-WBI use among physician peer groups. We further estimated potential savings to the Medicare program by accelerating abandonment of CF-WBI in T2 using a simulation model. DATA COLLECTION/EXTRACTION METHODS: Use of conventionally fractionated whole-breast irradiation was determined from Medicare claims among women ≥ 66 years of age who underwent adjuvant radiotherapy after breast conserving surgery. PRINCIPAL FINDINGS: Among 215 physician peer groups caring for 16 988 patients, there were four distinct trajectories of abandoning CF-WBI: (a) persistent high use (mean risk-adjusted utilization rate: T1 = 94.3%, T2 = 90.6%); (b) decreased high use (T1 = 81.3%, T2 = 65.3%); (c) decreased medium use (T1 = 60.1%, T2 = 44.0%); and (d) decreased low use (T1 = 31.6%, T2 = 23.6%). Peer groups with a smaller proportion of patients treated at free-standing radiation facilities and a larger proportion of physicians that were surgeons tended to follow trajectories with lower use of CF-WBI. If all physician peer groups had practice patterns in T2 similar to those in the "decreased low use" trajectory, the Medicare program could save $83.3 million (95% confidence interval: $58.5 million-$112.2 million). CONCLUSIONS: Physician peer groups had distinct trajectories of abandoning CF-WBI. Physician composition and setting of radiotherapy were associated with the different trajectories. Distinct practice patterns across the trajectories had important cost implications.

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.

Resident attitudes and benefits of mock oral board examinations in radiation oncology.

BACKGROUND: Presently, educational programming is not standardized across radiation oncology (RO) training programs. Specifically, there are limited materials through national organizations or structured practice exams for residents preparing for the American Board of Radiology (ABR) oral board examination. We present our 2019 experience implementing a formalized program of early mock oral board examinations (MOBE) for residents in post-graduate years (PGY) 3-5. METHODS: A mixed-methods survey regarding MOBE perception and self-reported comfort across five clinical domains were administered to PGY2-5 residents. MOBEs and a post-intervention survey were implemented for the PGY3-5. The pre and post-intervention score across clinical domains were compared using t-tests. Faculty and residents were asked for post-intervention comments. RESULTS: A total of 14 PGY2-5 residents completed the pre-intervention survey; 9 residents participated in the MOBE (5/14 residents were PGY2s) and post-intervention survey. This was the first mock oral radiation oncology examination experience for 65% of residents. 100% of residents felt the MOBE increased their clinical knowledge and comfort with clinical reasoning. Overall, there was a trend towards improved resident confidence giving planning dose parameters and (p = 0.08). There was also unanimous request for more MOBE experiences from residents and faculty, but time was identified as a significant barrier. CONCLUSIONS: Future directions for this MOBE program are inclusion of more disease sites, better emulation of the exam, the creation of a more rigorous consolidated format testing all sites at once, and consideration for grading of these sessions for future correlation with certifying oral board examination (OBE) performance.

Visiting Professorship in Academic Radiation Oncology.

PURPOSE: Visiting professorship is an enjoyable activity that is also influential in academic promotional processes as evidence of the invitee's national reputation. Little is known, however, about the factors considered when selecting visiting professors (VPs) or whether this practice reflects objective criteria. We sought to characterize the process and diversity of participants in visiting professorships within academic radiation oncology (RO) to determine whether opportunities are equitably distributed. METHODS AND MATERIALS: Surveys were distributed to program directors (PDs) of every 2018 RO residency program accredited by the Accreditation Council for Graduate Medical Education. PDs were asked to identify all VPs over the past 2 years and to describe their departments' decision-making processes. Publicly available demographic and academic characteristics were obtained for each VP, and results were compared by VP gender and hosting program (HP) 2019 Doximity rank using the χ2 test for categorical data and t test for continuous data. RESULTS: The PD response rate was 60 of 93 (65%); 6 surveys were ≥50% incomplete and were excluded. Over a 2-year timeframe, 51 of 54 departments hosted 233 VPs, of whom 29% were women. The mean number of hosted VPs (5; range, 1-19) and gender distribution (35% women; range, 0-100%) did not significantly differ by HP rank (P = .17 and 0.65, respectively), nor did the selection criteria by which VPs were primarily chosen (subject matter expertise, teaching reputation, and resident interest). Women received significantly lower honoraria amounts than men (P = .035) despite no significant differences by gender in academic rank (P = .71), VP department rank (0.19), or M-index (0.83). CONCLUSION: Although sample size is limited, this study suggests that academic RO programs have a relatively equitable approach to selecting VPs that emphasizes trainee education and reflects the gender diversity of RO faculty more generally. Care should be taken to ensure that these similarly qualified women are offered the same monetary amount of honoraria as their male colleagues.

"Radiotherapy for older women (ROW)": A risk calculator for women with early-stage breast cancer.

OBJECTIVE: Among older adult women with early-stage breast cancer who undergo lumpectomy, the benefits of radiotherapy vary according to tumor characteristics and life expectancy. We aimed to develop a risk calculator to predict individualized probability of long-term survival and local recurrence, accounting for these factors. METHODS: We developed a simulation model to estimate an individual patient's risk of local recurrence and all-cause mortality according to age, comorbidities, functional status, tumor characteristics, and radiotherapy status. We integrated two existing prediction models, the Early Breast Cancer Trialist's Collaborative Group prediction model for breast cancer specific outcomes and ePrognosis for life expectancy. An online risk calculator "Radiotherapy for Older Women (ROW)" was developed through an iterative multi-stage process, that included individual consultation and group meetings with an advisory committee (AC) comprised of patients, advocates, clinicians, and researchers. RESULTS: We developed the tool over 40 months and had 15 group meetings. The risk calculator developed as a simulation model with 16 factors (5 tumor-related, 3 demographic, 4 comorbidities, and 4 functional statuses). Across 56,700 simulated scenarios, the benefit of RT in terms of absolute 10-year local recurrence reduction, ranged from 0% to 34%, depending on individual characteristics. Based on feedback from the AC, overall survival and local recurrence were chosen as the output for ROW, with these outcomes displayed numerically (percentages and natural frequencies) and graphically (pictographs). CONCLUSIONS: This tool "ROW" could facilitate shared decision making regarding receipt of radiotherapy for older women with early breast cancer. Additional studies to examine usability testing are underway.

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.

Standard Tangential Radiation Fields Do Not Provide Incidental Coverage to the Internal Mammary Nodes.

PURPOSE: The purpose of the study was to evaluate the incidental dose delivered to the internal mammary nodes (IMNs) in patients treated with tangential 3-dimensional conformal radiation therapy and to identify potential parameters that may affect the IMN mean dose. METHODS AND MATERIALS: The study cohort consisted of 362 consecutively treated patients with breast cancer in our center between January 2015 and July 2017 who had received adjuvant whole-breast radiation therapy or postmastectomy radiation with or without a supraclavicular ± axillary field and without intentional inclusion of the IMN chain. The clinical target volume (CTV) for the IMNs was contoured per the Radiation Therapy Oncology Group 3509/3510 protocol and was then divided into 3 subregions: upper, mid, and lower thirds. The planning target volume for the IMNs was generated by adding 5 mm to the CTV. The primary endpoint was to assess the V40 (volume receiving 40 Gy) to the IMN planning target volume and its potential influencing parameters using a linear regression model. RESULTS: The mean (±standard deviation) dose to the CTV IMN chain was 36% ± 28.7%. The Kruskal-Wallis test demonstrated significant differences in the median dose delivered to each level: upper third (7.2%), mid third (21.5%), and lower third (41.7%) (P < .001). The mean V40 IMN planning target volume was 14.2% (standard deviation, 18.7%). Presternal fat thickness (regression coefficient [RC] = -16.4; P < .001), postmastectomy radiation (RC = 24; P < .001), reconstruction after mastectomy (RC = -22.4; P < .001), and the addition of a supraclavicular field (RC = 8.8; P = .03) were all significantly associated with IMN mean dose. CONCLUSIONS: For patients receiving standard breast/chest wall tangential radiation fields, the IMN chain is not incidentally covered with therapeutic doses in the vast majority of cases. Therefore, if regional nodal radiation is intended to include the IMNs, contouring and careful plan review are necessary to ensure adequate therapeutic coverage.

Association between perceived benefits and receipt of radiotherapy among older breast cancer patients.

While radiotherapy can be safely omitted in many older women with early-stage breast cancer after lumpectomy, approximately two-thirds of eligible women still undergo this treatment. We surveyed 63 older women with stage I (T1N0M0), estrogen-receptor-positive breast cancer who underwent lumpectomy, and were considering/receiving radiotherapy. Participants perceived that radiotherapy would reduce their 10-year risk of local recurrence by an average of 18.7%, which is significantly higher than the 8% risk reduction reported in literature. Multivariate analyses demonstrated that participants who reported a large perceived benefit were significantly more likely to undergo radiotherapy treatment (odds ratio 10.34; 95% confidence interval: 1.66-66.35).