Faculty Bibliography

Purpose: Multi-isocentric treatment delivery for CSI and TBI poses specific challenges for treatment delivery. We have developed a software tool to streamline all aspects of delivery for therapists and physicists at the machine, as well as to inform attending physicians of setup variability and image residuals at different locations.
Method(s): Our institution delivers VMAT-based CSI and TBI with up to 3 and 7 isocenters, respectively. A software tool was developed to assist with treatment delivery including initial patient setup, patient imaging, automatic calculation of the optimal global shift based on each isocenter's ideal shift, and automatic calculation of each isocenter's couch coordinates. Initial treatment couch coordinates are queried via the Eclipse scripting API. The global shift was calculated prioritizing the head isocenter for CSI treatments and the chest isocenter for TBI treatments by first maximizing residual tolerance at any other location prior to accepting any residual deviation at these locations. Maximum residuals tolerance was determined based on target margins, plan uncertainty and as per physician instructions. Delivery parameters are reported to a document uploaded to ARIA via API.
Result(s): The developed tool was employed for 11 cases. The software tool replaced the need for plan shift comments or instructions for therapists. In particular, its use eliminated the need to provide isocenter shifts to therapists by directly providing final couch parameters for treatment, greatly reducing the risk of delivery errors. The software effectively informed the therapists if any expected tolerance was surpassed, triggering a patient setup evaluation.
Conclusion(s): The described software tool is a core component to our multi-isocenter treatment programs and has streamlined delivery of these complex techniques that would otherwise require complicated instructions, including multiple shifts and on-the-fly calculations of optimal image alignment based on multiple imaging locations. This has substantially reduced the possibility of delivery errors

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.

Purpose: Patients receiving myeloablative total body irradiation (TBI) doses >= 12Gy are at risk of developing interstitial pneumonitis. At our institution, TBI transitioned from extended distance opposed Laterals to image-guided VMAT, in an effort to improve coverage while sparing lungs and kidneys. This work presents a dosimetric comparison between 3D Laterals and VMAT.
Method(s): Nine patients were treated with VMAT as part of an ongoing phase II single-arm clinical trial. VMAT patients were CT-simulated supine, with thermoplastic masks for head/neck, chest/abdomen/pelvis and feet. VMAT planning (12Gy (n=6) or 13.2Gy (n=3) in 8-BID fractions) utilizes 6MV multi-isocentric arcs and AP/PA beams to treat the upper and lower body, respectively. Ten 3D Lateral patients were CT-simulated supine with arms positioned/immobilized for lung shielding, with rice compensation between legs/feet. Laterals plan (12Gy in 8-BID fractions) uses 15MV, beam spoiler, head compensation, and subfields to maintain coverage and mean-lungs dose <10.5Gy. Target (Body-5mm, extending 3mm into lungs and kidneys for VMAT; Body-2cm for Laterals) coverage was evaluated at V100%, and D98% (percentage of Rx). Absolute dose to lungs and kidneys were reportedResults: Median Target V100% and D98% for VMAT was 93.2% (Range: 95.6% to 92.1%) and 90.2% (94.3% to 88.3%), whereas for Laterals V100% and D98% was 57.3% (66.5% to 46.3%) and 80.6% (75.5% to 84%). The median Lung mean dose was 7.6Gy (7.3Gy to 7.9Gy) for VMAT. The median mean dose to kidney was 10.4Gy (10.1Gy to 10.7Gy) for VMAT, and 12.5Gy (11.9Gy to 13.5Gy) for Laterals.
Conclusion(s): We have established a VMAT-TBI program for patients requiring myeloablative irradiation. Improvement in target coverage is demonstrated by V100% and D98%, while reducing the mean dose to the lungs significantly from 10.5Gy to 8Gy

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: In-vivo dosimetry for conventional total body irradiation (TBI) utilize point detectors placed along the patient surface to confirm the delivered dose matches prescription dose. However, in the volumetrically modulated arc therapy (VMAT) approach to TBI, the electronic portal imager device (EPID) can be utilized to acquire a 2-dimensional transmission fluence plane. This work explores the relationship between patient setup accuracy with transit in-vivo dosimetry.
Method(s): A total of 192 fields were investigated. Each VMAT plan consisted of four isocenters: head, chest, abdomen, and pelvis. Prior to treatment, the patient was imaged at the head, pelvis, and chest. Optimal couch shifts were determined for each isocenter under image guidance. The optimal IGRT shifts were determined using an inhouse application that minimized dose deviation using criteria established through plan uncertainty analysis performed in Eclipse. Translational couch residuals were recorded and defined as the difference in the global shift calculated and the optimal couch position with shifts. Transit dosimetry was measured per arc, and analyzed using SNC PerFRACTION with a gamma criteria of 10%/5mm, 5%/5mm, and 5%/7mm.
Result(s): Based on plan uncertainty analysis, clinical threshold for couch residuals were set to 7 mm (5 mm for chest isocenter) as there would be minimal impact on target coverage and organ sparing at those levels. Transit dosimetry showed that the average pass rate across all fields was 99.6%, 97.0%, and 99.2% for 10%/5mm, 5%/5mm, and 5%/7mm gamma criteria, respectively. Pearson correlation tests showed that there was weak correlation between gamma criteria and couch residuals. At stringent 3%/5mm gamma criteria, moderate correlation was found between lateral couch residuals for the head and chest and the head and chest arc analysis.
Conclusion(s): Transit dosimetry showed high pass rates using our couch residual tolerances, which confirmed the plan uncertainty analysis performed during treatment planning

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.

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.

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/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.

INTRODUCTION/BACKGROUND:Treatment for early-stage Hodgkin lymphoma (HL) involves radiotherapy (RT), chemotherapy, or combined modality therapy (CMT). We analyzed reduction of RT dose in CMT, particularly in the context of German Hodgkin Study Group (GHSG) HD10 randomized trial results of 2010. PATIENTS AND METHODS/METHODS:The National Cancer Data Base was queried for patients with stage I-II HL receiving CMT. RT dose and associated characteristics were analyzed. Stage I and absence of B symptoms were used as a surrogate for early-stage favorable disease. RESULTS:Of 31,301 patients with stage I-II HL, 11,457 received CMT between 2004 and 2015. Using the surrogate defined above, 1955 patients (17.1%) were classified as having favorable disease. The majority (61.6%) received 30-36 Gy, while 7.0% received 20 Gy. The provision of 20 Gy was more common in stage I patients (12.3% vs. 5.4% in stage II) and at academic facilities (10.8% vs. 6.3%-8.9% at other facilities). Use of 20 Gy (vs. 30-36 Gy) was less likely with thorax site (odds ratio [OR] 0.43 vs. head and neck), stage II disease (OR 0.41), and B symptoms (OR 0.33). Notably, the use of 20 Gy increased dramatically after 2010 (the year of publication of GHSG HD10 trial results), with rates of 12.3% in 2010-2015 versus 0.1% in 2004-2009 (OR 6.3, P < .001). This was even more pronounced in cases of favorable early-stage disease, with 25.5% after 2010 versus 2.8% before 2010 (OR 13.2, P < .001). The use of doses > 36 Gy decreased over a corresponding time period (OR 0.44, P < .001). CONCLUSION/CONCLUSIONS:Analysis of CMT for patients with early-stage HL demonstrates variability in RT dose, including increasing use of 20 Gy and decreasing use of high doses > 36 Gy.