Faculty Bibliography

Purpose: To investigate the effect of patient positioning in Volumetric Modulated Arc Therapy (VMAT) for Total Body Irradiation (TBI) given the use of multiple isocenters, by simulating offsets in patient positioning and evaluating changes to planned dose distributions.
Method(s): VMAT treatment plans for seven TBI patients treated as part of a prospective stage II clinical trial were evaluated. Plan uncertainties were calculated by introducing 5mm and 10mm translational shifts to the plans' isocenters in the lateral (x), vertical (y), and longitudinal (z) directions. Dose distributions were then re-calculated in the treatment planning system (Eclipse), in order to evaluate dosimetric robustness to one global imaging shift at treatment. Differences in target volume (PTV) coverage and doses to organs at risk were evaluated based on four parameters: lung mean dose, PTV-V100%, PTV-D98%, and kidney mean doses.
Result(s): Lung mean dose increased an average of 8.2cGy, 4.4cGy, and 3.3cGy when shifted 5mm in the x, y, z directions (respectively) across seven patients; 33.2CGy, 18.5cGy, 18.3cGy for 10mm shifts in x, y, z. Target coverage V100% decreased an average of 0.3%, 0.03%, 0.1% for 5mm shifts, and 1.1%, 0.8%, 0.4% for 10mm shifts in x, y, z. D98% decreased 0.9%, 0.3%, 0.3% when shifted 5mm; 3.5%, 2.1%, 1.0% when shifted 10mm in x, y, z. Mean dose to the left kidney increased 6.6cGy, 9.7cGy, 2.8cGy for 5mm, and 28.1cGy, 32.7cGy, 18.0cGy for 10mm shifts in x, y, z. Right kidney mean dose increased 11.9cGy, 8.9cGy, 3.1cGy for 5mm, and 36.5, 30.5, 19.8cGy for 10mm.
Conclusion(s): Though small in relation to total dose, the largest increase in mean lung dose and decrease in coverage was seen with lateral shifts as compared to vertical or longitudinal shifts. These results support the use of an approach with preferential alignment to the chest region (lung-sparing), as long as residual imaging alignment outside the chest is kept below 10mm. Jose Teruel has received honorarium from Varian Medical Systems

Purpose/UNASSIGNED:Resident physicians use social media (SM) for many reasons. We sought to characterize current SM use by radiation oncology (RO) trainees for education and professional development. Methods and Materials/UNASSIGNED:An anonymous 40-question survey was sent by e-mail to RO residents in the 2018 to 2019 academic year. SM platform use, time spent on SM, professional use, and opinions regarding SM use were assessed. Descriptive statistics and a univariate logistic regression analysis were performed to identify factors associated with perceptions of SM and spending >25% of SM time for academic or professional purposes. Results/UNASSIGNED:< .001) were more likely to spend >25% of their SM time on professional/academic purposes. The vast majority of respondents agreed that SM exposed them to novel educational content (82%) and was helpful for career development (65%). In addition, 69% agreed that SM can improve clinical skills and knowledge. A substantial minority agreed that SM distracts them from studying (38%) or they felt pressure to have a SM presence (29%). Conclusions/UNASSIGNED:Most RO residents reported that SM provides novel educational content and can help with career development. Potential disadvantages of SM for trainees may include distraction and pressure to maintain a SM presence. SM use by RO trainees merits further research to optimize its potential for education and professional development.

BACKGROUND:Young women with ductal carcinoma in situ (DCIS) represent a unique cohort given considerations for future risk reduction and treatment effects on fertility and quality of life. We evaluated national patterns of care in the treatment of young women and the impact of those treatments on overall survival (OS). METHODS:Women younger than 50 years of age diagnosed with pure DCIS from 2004 to 2016 in the National Cancer Database (NCDB) were identified. Clinical, demographic, and choice of local therapy are summarized and trended over time. OS was analyzed using Cox proportional hazard models. RESULTS:A total of 52,150 women were identified, and the most common surgical treatment was breast-conservation surgery (BCS; 59%). Bilateral mastectomy (BM) increased in frequency from 2004 to 2016 (11-27%; p < 0.001). In women < 40 years of age, BM (39%) surpassed BCS (35%) in 2010 with a continued upward trend. On multivariable analysis, no OS benefit of BM (hazard ratio [HR] 0.99, p = 0.90) or unilateral mastectomy (UM; HR 0.98, p = 0.80) was observed when compared with BCS + radiation therapy (RT). Inferior OS was seen with BCS, Black race, estrogen receptor (ER)-negative, and tumor ≥ 2.5 cm (p ≤ 0.006). In ER+ patients, there was a significant difference in endocrine therapy (ET) use between BM (11%), UM (33%), and BCS (28%) compared with BCS + RT (64%, p < 0.001). CONCLUSION/CONCLUSIONS:The use of BM for DCIS is increasing in younger patients and now exceeds breast-conservation approaches in women < 40 years of age with no evidence of improved OS. Among ER+ patients, the rates of ET are lower in the BM, UM, and BCS-alone groups compared with BCS + RT.

BACKGROUND:) that evaluates recurrence risk has been developed and validated. We evaluated the impact of DCISionRT on clinicians' recommendations for adjuvant RT. METHODS:The PREDICT study is a prospective, multi-institutional, observational registry in which patients underwent DCISionRT testing. The primary endpoint was to identify the percentage of patients where testing led to a change in RT recommendations. RESULTS:Overall, 539 women were included in this study. Pre DCISionRT testing, RT was recommended to 69% of patients; however, post-testing, a change in the RT recommendation was made for 42% of patients compared with the pre-testing recommendation; the percentage of women who were recommended RT decreased by 20%. For women initially recommended not to receive an RT pre-test, 35% had their recommendation changed to add RT following testing, while post-test, 46% of patients had their recommendation changed to omit RT after an initial recommendation for RT. When considered in conjunction with other clinicopathologic factors, the elevated DCISionRT score risk group (DS > 3) had the strongest association with an RT recommendation (odds ratio 43.4) compared with age, grade, size, margin status, and other factors. CONCLUSIONS:DCISionRT provided information that significantly changed the recommendations to add or omit RT. Compared with traditional clinicopathologic features used to determine recommendations for or against RT, the factor most strongly associated with RT recommendations was the DCISionRT result, with other factors of importance being patient preference, tumor size, and grade.

We describe a model case of unplanned pregnancy during radiation therapy to the chest wall and peripheral lymphatics for breast cancer. We use the Morbidity and Mortality Conference format to demonstrate how radiation oncology departments should evaluate and manage this situation.

PURPOSE/OBJECTIVE:Anti-HER2 therapy delivered in the adjuvant setting for breast cancer is given in conjunction with cytotoxic chemotherapy. For HER2-positive (HER2+) patients who cannot tolerate chemotherapy, there is no randomized data regarding the role of anti-HER2 therapy without chemotherapy. METHODS:The National Cancer Database (NCDB) was queried for non-metastatic breast cancer patients with estrogen receptor-positive (ER+) and HER2+ breast cancer who received surgery and endocrine therapy, without chemotherapy from 2013 to 2016. Outcomes were compared between endocrine therapy alone (ET) or endocrine therapy with anti-HER2 therapy (ET + aHER2). Univariate and multivariate Cox-proportional hazards models were used to analyze the association between clinical characteristics and survival outcomes between groups. Propensity score matching (PSM) was performed to account for differences between the two groups. RESULTS:Of all patients with non-metastatic ER+/HER2+ breast cancer, we identified 9458 (20.5%) who did not receive chemotherapy. Of the 6741 patients who received ET, 17.2% also received aHER2 therapy. Median follow-up was 31.7 months (IQR 21.1-42.1). In the aHER2 group (vs. ET), there were more patients with older age, higher stage, node positivity, poorly or undifferentiated disease, lymphovascular invasion, lobular cancer, and Medicare insurance. Compared to the ET cohort, ET + aHER2 was not significantly associated with improved OS on multivariate analysis (HR 0.88 95% CI 0.68-1.15) or after propensity score matching (HR 0.80 95% CI 0.57-1.11). CONCLUSIONS:There is no significant difference in survival with the addition of HER2 therapy to endocrine therapy in ER+/HER2+ non-metastatic breast cancer patients who do not receive chemotherapy. To our knowledge, this is the largest series investigating this question.

The purpose of this work is to establish an automated approach for a multiple isocenter volumetric arc therapy (VMAT)-based TBI treatment planning approach. Five anonymized full-body CT imaging sets were used. A script was developed to automate and standardize the treatment planning process using the Varian Eclipse v15.6 Scripting API. The script generates two treatment plans: a head-first VMAT-based plan for upper body coverage using four isocenters and a total of eight full arcs; and a feet-first AP/PA plan with three isocenters that covers the lower extremities of the patient. PTV was the entire body cropped 5 mm from the patient surface and extended 3 mm into the lungs and kidneys. Two plans were generated for each case: one to a total dose of 1200 cGy in 8 fractions and a second one to a total dose of 1320 cGy in 8 fractions. Plans were calculated using the AAA algorithm and 6 MV photon energy. One plan was created and delivered to an anthropomorphic phantom containing 12 OSLDs for in-vivo dose verification. For the plans prescribed to 1200 cGy total dose the following dosimetric results were achieved: median PTV V100% = 94.5%; median PTV D98% = 89.9%; median lungs Dmean = 763 cGy; median left kidney Dmean = 1058 cGy; and median right kidney Dmean = 1051 cGy. For the plans prescribed to 1320 cGy total dose the following dosimetric results were achieved: median PTV V100% = 95.0%; median PTV D98% = 88.7%; median lungs Dmean = 798 cGy; median left kidney Dmean = 1059 cGy; and median right kidney Dmean = 1064 cGy. Maximum dose objective was met for all cases. The dose deviation between the treatment planning dose and the dose measured by the OSLDs was within ±4%. In summary, we have demonstrated that scripting can produce high-quality plans based on predefined dose objectives and can decrease planning time by automatic target and optimization contours generation, plan creation, field and isocenter placement, and optimization objectives setup.

PURPOSE/OBJECTIVE:Autoimmune connective tissue disease (CTD) has historically represented a relative contraindication to breast conservation (BC) among patients with early stage breast cancer. Controversy exists regarding hypofractionated radiotherapy (RT) among patients with CTDs. We evaluated acute and late toxicity in patients with breast cancer and CTD treated with BC. METHODS AND MATERIALS/METHODS:Of 1983 patients treated with BC from 2012 to 2016, we identified 91 patients with autoimmune disease (AD). Each patient was matched to a control without AD based on age, RT field and fractionation. RT toxicity and clinician-rated cosmesis were compared between cases and controls. Overall survival, disease-free survival, and local recurrence free survival were estimated using the Kaplan-Meier method. RESULTS:Median follow-up was 49.9 months for cases and 53.0 months for controls. 67% of cases and controls were treated with hypofractionated RT. There was no difference in grade 2/3 acute toxicity between cases and controls (26.4% vs. 16.5%, p=0.148, respectively). There was a significantly higher rate of grade 2/3 late toxicity among cases (25.8% vs 12.1%, p=0.049). Active AD at the time of RT increased the rate of grade 2/3 late toxicity compared to controls (41.7% vs. 11.4%, p=0.018). Among patients treated with hypofractionated RT, there was no difference in acute or late grade 2/3 toxicity between cases and controls (acute: 13.1% cases vs. 11.5% controls, p=1; late: 11.9% in cases vs 13.1% in controls, p=1). Rate of good/excellent clinician- rated cosmesis was similar between groups (92.9% vs 98.9%, p=0.142). CONCLUSIONS:In the largest matched case control study of patients with CTD treated with conventional and hypofractionated RT, we demonstrate low rates of radiation toxicity, with good to excellent clinician-rated cosmesis. There was increased late toxicity in cases, especially in patients with active AD at time of RT. There was no increase in acute or late toxicity in the patients treated with hypofractionation.

PROBLEM/OBJECTIVE:Physician-scientists are individuals trained in both clinical practice and scientific research. Often, the goal of physician-scientist training is to address pressing questions in biomedical research. The established pathways to formally train such individuals are, mainly, MD-PhD programs and physician-scientist track residencies. Although graduates of these pathways are well equipped to be physician-scientists, numerous factors, including funding and length of training, discourage application to such programs and impede success rates. APPROACH/METHODS:To address some of the pressing challenges in training and retaining burgeoning physician-scientists, New York University Grossman School of Medicine formed the Accelerated MD-PhD-Residency Pathway in 2016. This pathway builds on the previously established accelerated three-year MD pathway to residency at the same institution. The Accelerated MD-PhD-Residency Pathway conditionally accepts MD-PhD trainees to a residency position at the same institution through the National Resident Matching Program. OUTCOMES/RESULTS:Since its inception, 2 students have joined the Accelerated MD-PhD-Residency Pathway, which provides protected research time in their chosen residency. The pathway reduces the time to earn an MD and PhD by one year and reduces the MD training phase to three years, reducing the cost and lowering socioeconomic barriers. Remaining at the same institution for residency allows for the growth of strong research collaborations and mentoring opportunities, which foster success. NEXT STEPS/UNASSIGNED:The authors and institutional leaders plan to increase the number of trainees that are accepted into the Accelerated MD-PhD-Residency Pathway and track the success of these students through residency and into practice to determine if the pathway is meeting its goal of increasing the number of practicing physician-scientists. The authors hope this model can serve as an example to leaders at other institutions who may wish to adopt this pathway for the training of their MD-PhD students.