Toxicity in patients receiving radiotherapy for ultracentral stage I non-small cell lung cancer: A secondary analysis of the LUSTRE randomized trial.

BACKGROUND AND PURPOSE: Stereotactic body radiotherapy (SBRT) carries potentially higher risks for ultracentral (UC) NSCLC with limited prospective data to guide decision making. We conducted a secondary analysis from a randomized trial of SBRT and conventionally hypofractionated radiation (CRT) to assess these risks. MATERIALS AND METHODS: Patients (n = 233) with medically inoperable stage I NSCLC were recruited from 2014 to 2020. Patients with UC targets directly overlapping the proximal bronchial tree (PBT) were identified. The primary objective was the occurrence of related grade 3-5 toxicity > 3 months following radiation. Secondary endpoints included local control, survival, and evaluation of PBT dose and its association with late toxicity. RESULTS: Thirty UC tumors were identified (23 - SBRT 60 Gy/8 fractions, 7 - CRT 60 Gy/15 fractions). Median age was 72 years, and median tumor size was 2.8 cm. Most patients (67 %) had histologically confirmed NSCLC. At a median follow-up of 2.9 years, 3 and 1 patients developed grade 3 and 5 toxicity respectively (all SBRT). 3-year local control was 85 %. Mean PBT dose (converted to 2 Gy dose equivalents) was higher in patients with grade ≥ 3 toxicity, particularly for 4 cc (105.5 vs 51.8 Gy, p = 0.0004), 5 cc (84 vs 46.1 Gy, p = 0.003), and volumetric doses (V65 - V100Gy). The patient with grade 5 toxicity had the highest 5 cc dose (117 Gy), V90Gy (8.2 cc), and V100Gy (7 cc). CONCLUSIONS: SBRT for UC NSCLC provides good local control but carries a high rate of late grade 3-5 toxicity. An apparent association between toxicity and PBT volumetric dose was observed, which should be considered if SBRT is offered.

Evaluation of a National Radiation Oncology Research and Mentorship Program.

PURPOSE: The Canadian Association of Radiation Oncology Annual Scientific Meeting Medical Student Research and Mentorship Award was established in 2020 to support medical students pursuing radiation oncology (RO) research and RO as a career. This study is an evaluation of the effect of this national research and mentorship award on medical students, resident mentors, and research supervisors over 3 iterations. METHODS AND MATERIALS: Three separate surveys were created for medical student mentees, RO resident mentors, and attending research supervisors. These surveys were developed using best practice strategies for medical education surveys and circulated for peer review among experts in oncology medical education. The surveys were sent to the 52 individuals (18 students, 18 residents, 16 supervisors) who participated in 3 cycles of Canadian Association of Radiation Oncology ASM MSRMA (2020-21, 2021-22, 2022-23). After anonymization, quantitative answers were analyzed using descriptive statistics, and narrative responses were evaluated using a grounded theory approach. RESULTS: There was a 90% survey response rate. For medical student mentees, the award maintained (71%) or increased (24%) interest in pursuing an RO career. Students reported receiving helpful tips for residency applications and insight into RO residency, research, and career planning advice. Only the first student cohort currently has matching results for residency, with approximately 50% matching to RO. All resident mentor respondents felt the program either maintained or increased motivation to mentor students in RO. Research project supervisors unanimously enjoyed their role in this program and would recommend and participate in this program again. CONCLUSIONS: A national research and mentorship award for medical students has shown a positive effect on participants. Medical students felt this award program motivated them to continue pursuing oncology research and a potential career in RO. The program also enhanced mentorship skills in residents and research supervisors, which encourages further RO mentorship, teaching, and exposure for future generations of students.

A Qualitative Analysis of Medical Student Reflections Following Participation in a Canadian Radiation Oncology Studentship.

Exposure to radiation oncology in medical school curricula is limited; thus, mentorship and research opportunities like the Dr. Pamela Catton Summer Studentship Program attempt to bridge this gap and stimulate interest in the specialty. In 2021, the studentship was redesigned as virtual research, mentorship, and case-based discussions due to the COVID-19 pandemic. This study explores the impact of COVID-19 on the studentship, on students' perceptions of the program, and on medical training and career choice. Fifteen studentship completion essays during 2021-2022 were obtained and anonymized. Thematic analysis was performed to interpret the essays with NVivo. Two independent reviewers coded the essays. Themes were established by identifying connections between coded excerpts. Consensus was achieved through multiple rounds of discussion and iteratively reviewing each theme. Representative quotes were used to illustrate the themes. The themes confirmed the studentship was feasible during the pandemic. Perceived benefits of the program included mentorship and networking opportunities; gaining practical and fundamental knowledge in radiation oncology; developing clinical and research skills; and creating positive attitudes towards radiation oncology and the humanistic aspect of the field. The studentship supported medical specialty selection by helping define student values, shaping perceptions of the specialty, and promoting self-reflection upon students' personal needs. This study informs future iterations of the studentship to promote radiation oncology in Canadian medical school curricula. It serves as a model for studentships in other specialties that have limited exposure and similar challenges with medical student recruitment.

Supply and Demand for Radiation Oncologists in Canada: Workforce Planning Projections From 2020 to 2040.

PURPOSE: The number of Canadians diagnosed with cancer, and subsequent demand for radiation therapy, are expected to increase over time. This study aimed to update our needs-based workforce planning model to ensure appropriate staffing levels in the future. METHODS AND MATERIALS: The supply of radiation oncologists, by age group, sex, and full-time equivalent status, was projected from 2020 to 2040 using a recursive-aging, input-output model developed with seeding parameters derived from national sources. The demand for radiation oncologists until 2040 was estimated using referral patterns for radiation therapy and consultation workload metrics applied to projected annual cancer incident cases to calculate required full-time equivalent positions. Baseline model parameters were also applied to the 2005-2019 workforce and incident case data to evaluate preprojection supply and demand trends. RESULTS: Preprojection trends for 2005 to 2019 revealed accelerated staffing growth that transitioned from a workforce shortage to a surplus state in 2014 followed by substantial growth slowdown in 2016. The model predicts a transient surplus of radiation oncologists until 2026 followed by a projected deficit in subsequent years. Sensitivity analyses using the plausible range for each parameter continued to favor an undersupply, suggesting a trainee shortage unable to meet workforce expansion needs. Considering possible future declining trends in radiotherapy utilization and workload, calculations to inform corrective efforts in resident numbers resulted in 25 entry positions per year, up from 21 per year currently. Geographic distribution of trainees, relative to workforce and cancer incidence distributions, could be improved with more residency positions in Canadian regions outside Ontario. CONCLUSIONS: Demand for radiation therapy and radiation oncologists in Canada are expected to grow more quickly than future expansion in staffing levels. Our workforce planning model provides evidence for more trainee requirements to inform stakeholders of possible corrective actions to training programs and recruitment. Further research is needed to explore additional strategies to expand capacity and high-quality delivery of radiation therapy to meet the foreseeable increase in Canadian patients with cancer.

The transition in practice to reduce bolus use in post-mastectomy radiotherapy: A dosimetric study of skin and subcutaneous tissue.

To inform clinical practice for women receiving post-mastectomy radiotherapy (PMRT), this study demonstrates the dosimetric impact of removing daily bolus on skin and subcutaneous tissue. Two planning strategies were used: clinical field-based (n = 30) and volume-based planning (n = 10). The clinical field-based plans were created with bolus and recalculated without bolus for comparison. The volume-based plans were created with bolus to ensure a minimum target coverage of the chest wall PTV and recalculated without bolus. In each scenario, the dose to superficial structures, including skin (3 mm and 5 mm) and subcutaneous tissue (a 2 mm layer, 3 mm deep from surface) were reported. Additionally, the difference in the clinically evaluated dosimetry to skin and subcutaneous tissue in volume-based plans were recalculated using Acuros (AXB) and compared to the Anisotropic Analytical Algorithm (AAA) algorithm. For all treatment planning strategies, chest wall coverage (V90%) was maintained. As expected, superficial structures demonstrate significant loss in coverage. The largest difference observed in the most superficial 3 mm where V90% coverage is reduced from a mean (± standard deviation) of 95.1% (± 2.8) to 18.9% (± 5.6) for clinical field-based treatments with and without bolus, respectively. For volume-based planning, the subcutaneous tissue maintains a V90% of 90.5% (± 7.0) compared to the clinical field-based planning coverage of 84.4% (± 8.0). In all skin and subcutaneous tissue, the AAA algorithm underestimates the volume of the 90% isodose. Removing bolus results in minimal dosimetric differences in the chest wall and significantly lower skin dose while dose to the subcutaneous tissue is maintained. Unless the skin has disease involvement, the most superficial 3 mm is not considered part of the target volume. The continued use of the AAA algorithm is supported for the PMRT setting.

Exploring the Perceived Educational Impact of COVID-19 on Postgraduate Training in Oncology.

This study sought to report the degree to which postgraduate trainees in radiation oncology perceive their education has been impacted by the COVID-19 pandemic. A cross-sectional online survey was administered from June to July 2020 to trainee members of the Canadian Association of Radiation Oncology (CARO) (n = 203). Thirty-four trainees responded with a 17% response rate. Just under half of participants indicated that COVID-19 had a negative/very negative impact on training (n = 15; 46%). The majority agreed/strongly agreed that they feared family/loved ones would contract COVID-19 (n = 29, 88%), felt socially isolated from friends and family because of COVID-19 (n = 23, 70%), and had difficulty concentrating on tasks because of concerns about COVID-19 (n = 17, 52%). Changes that had a negative/very negative impact on learning included limitations to travel and networking (n = 31; 91%) and limited patient contact (n = 19; 58%). Virtual follow-ups (n = 25: 76%) and in-patient care activities (n = 12; 36%) increased. Electives were cancelled in province (n = 10; 30%), out-of-province (n = 16; 49%), and internationally (n = 15; 46%). Teaching from staff was moderately reduced to completely suppressed (n = 23, 70%) and teaching to medical students was moderately reduced to completely suppressed (n = 27, 82%). Significant changes to radiation oncology training were wrought by the pandemic, and roughly half of trainees perceive that these changes had a negative impact on training. Innovations in training delivery are needed to adapt to these new changes.

Employment Outcomes for Canadian Radiation Oncology Graduates: 2020 Assessment and Longitudinal Trends.

Purpose: Canadian radiation oncology (RO) trainees have experienced employment challenges after residency training. The present study was conducted to evaluate current employment trends and perform comparisons to prior reported assessments. Methods and Materials: A survey was administered to all 13 Canadian RO program directors requesting the employment status and location of their graduates during the past 3 years, and their perceptions on graduates' employment challenges. Visa trainees were excluded. Findings were compared with surveys performed in 2014, 2016, and 2018. Results: The response rate from RO program directors was 100%. There were 77 graduates identified who completed their residency training between 2017 and 2020. All had known employment status and location. Two (17%) 2020 graduates, 16 (84%) 2019 graduates, 17 (81%) 2018 graduates, and 24 (100%) 2017 graduates had staff employment. Of the 59 graduates with staff positions, 86% were in Canada. Some graduates (28%) obtained staff or locum employment in a province other than their training program. The proportion of graduates obtaining staff positions 1 year after residency increased to 84% from 46%-48% in prior assessments. Most program directors (62%) did not perceive any difficulties with their graduates finding staff employment or trainees transferring to training programs in other disciplines owing to perceived workforce challenges. Conclusions: Compared with 3 prior employment outcome assessments, this study observed a higher proportion of graduates with staff positions in Canada, fewer total graduates, fewer graduates seeking staff employment or in fellowship positions, and a trend for fewer graduates seeking employment or fellowships abroad. These findings support the view that the Canadian RO job market continues to improve. Although employment challenges for newly certified, Canadian-trained radiation oncologists still exist, national corrective measures to regulate resident intake in 2011 appear to have had a positive effect on the employment outcomes of recent Canadian RO graduates.

Acute Care Use by Breast Cancer Patients on Adjuvant Chemotherapy in Alberta: Demonstrating the Importance of Measurement to Improving Quality.

Breast cancer patients receiving adjuvant chemotherapy are at increased risk of acute care use. The incidence of emergency department (ED) visits and hospitalizations (H) have been characterized in other provinces but never in Alberta. We conducted a retrospective population-based cohort study using administrative data of women with stage I-III breast cancer receiving adjuvant chemotherapy. Rates of ED and H use in the 180 days following chemotherapy initiation were determined, and logistic regression was performed to identify risk factors. We found that 47% of women receiving adjuvant chemotherapy experienced ED or H, which compared favourably to other provinces. However, Alberta had the highest rate of febrile neutropenia-related ED visits, and among the highest chemotherapy-related ED visits. The incidence of acute care use increased over time, and there were significant institutional differences despite operating under a single provincial healthcare system. Our study demonstrates the need for systematic measurement and the importance of quality improvement programs to address this gap.

Implementation of high-dose-rate brachytherapy for prostatic carcinoma in an unshielded operating room facility.

PURPOSE: The purpose of the study was to describe our approach towards safe delivery of single-fraction high-dose-rate (HDR) brachytherapy (BT) boost in patients with prostate cancer in the setting of an unshielded operating room (OR). METHODS AND MATERIALS: A total of 95 patients received 15 Gy HDR BT boost. The procedure involved transrectal ultrasound-based catheter insertion and planning in the OR, after which the patient was moved to a shielded treatment room for radiation. This required three vital components: (1) an OR table capable of transporting the patient in lithotomy position, (2) robust motion management checks to ensure reproducibility of prostate and catheter positions in the treatment room before radiation delivery, (3) remote monitoring of patient vitals while under anesthesia, during the radiation. Initial viability of this approach was confirmed by assessing acute toxicities using the Common Terminology Criteria for Adverse Events v4.0 and American Urologic Association symptom scores. RESULTS: We found good stability in prostate and catheter position, with less than 1 mm shifts in each direction due to patient transfer. The median baseline American Urologic Association score was 7 (3-11), which increased to 12 (7-17) at 4 weeks and 9 (5-14) at 3 months (p = 0.003). Common Terminology Criteria for Adverse Events ≥ grade 2 genitourinary and gastrointestinal toxicities were experienced by 7% and 0% patients, respectively, at 3 months posttreatment completion. CONCLUSIONS: Single-fraction HDR prostate BT can be delivered safely in an unshielded OR facility with a distant shielded treatment room using rigorous motion management checks and supplementary procedural equipment.