Integration of Radiation Oncology Into the Preclinical Curriculum Through Problem-Based Learning.

PURPOSE: Early exposure to oncology care during the preclinical years of medical school may translate to increased student interest in oncology-related fields and improved understanding of oncologic treatment modalities, including radiation oncology. Many schools incorporate problem-based learning (PBL) into the medical school curriculum; this is an opportunity to immerse students in oncologic case management. We describe the effective incorporation of one course into the medical school curriculum that may be replicated at other institutions. METHODS AND MATERIALS: A PBL case regarding pancreatic cancer was created by a radiation oncology resident and faculty member in collaboration with the gastrointestinal course director for first-year medical students at a single institution. Pancreatic cancer was chosen based on curricular needs. Learning objectives were discussed to guide the creation of the case. RESULTS: All 140 first-year medical students participated in the 1-hour small group case focused on oncologic work up, multidisciplinary care, and radiation therapy concepts. Students were provided with a case prompt and resources to review prior to the PBL session. Volunteer radiation oncology facilitators attended a 30-minute educational meeting and were provided a detailed case guide 1 week before the PBL session. During the PBL case, facilitators guided students to achieve desired learning objectives. Among the 76 (54%) medical students who completed an optional post-PBL survey, the majority reported that the case motivated them to learn more about oncology (89%) and radiation oncology (82%). There was an increase in the number of subscribers to the Oncology Interest Group (43% increase from previous year) and preclinical students shadowing in the radiation oncology department. The PBL case was continued in future years for all first-year students and extended to 2 hours to promote additional discussion in response to student and facilitator feedback. CONCLUSIONS: A cancer-specific PBL case facilitated by radiation oncology educators is an effective avenue to integrate radiation oncology into the preclinical curriculum and stimulate interest in oncology among first-year medical students.

Ninety-day mortality following transoral robotic surgery or radiation at Commission on Cancer-accredited facilities.

BACKGROUND: Postoperative mortality for oropharynx squamous cell carcinoma (OPSCC) with transoral robotic surgery (TORS) varies from 0.2% to 6.5% on trials; the real-world rate is unknown. METHODS: NCDB study from 2010 to 2017 for patients with cT1-2N0-2M0 OPSCC with Charleson-Deyo score 0-1. Ninety-day mortality assessed from start and end of treatment at Commission on Cancer-accredited facilities. RESULTS: 3639 patients were treated with TORS and 1937 with radiotherapy. TORS cohort had more women and higher income, was younger, more often treated at academic centers, and more likely to have private insurance (all p < 0.05). Ninety-day mortality was 1.3% with TORS and 0.7% or 1.4% from start or end of radiotherapy, respectively. From end of therapy, there was no significant difference on MVA between treatment modality. CONCLUSIONS: There is minimal difference between 90-day mortality in patients treated with TORS or radiotherapy for early-stage OPSCC. While overall rates are low, for patients with expectation of cure, work is needed to identify optimal treatment.

Development and validation of a prognostic gene expression signature for lower-grade glioma following surgery and adjuvant radiotherapy.

BACKGROUND AND PURPOSE: Standard of care for lower-grade glioma (LGG) is maximal safe resection and risk-adaptive adjuvant therapy. While patients who benefit the most from adjuvant chemotherapy have been elucidated in prospective randomized studies, comparable insights for adjuvant radiotherapy (RT) are lacking. We sought to identify and validate patterns of gene expression that are associated with differential outcomes among LGG patients treated by RT from two large genomics databases. MATERIALS AND METHODS: Patients from The Cancer Genome Atlas (TCGA) with LGG (WHO grade II-III glioma) treated by surgery and adjuvant RT were randomized 1:1 to a discovery cohort or an internal validation cohort. Using the discovery cohort only, associations between tumor RNA-seq expression and progression-free survival (PFS) as well as overall survival (OS) were evaluated with adjustment for clinicopathologic covariates. A Genomic Risk Score (GRS) was then constructed from the expression levels of top genes also screened for involvement in glioma carcinogenesis. The prognostic value of GRS was further assessed in the internal validation cohort of TCGA and a second distinct database, compiled by the Chinese Glioma Genome Association (CGGA). RESULTS: From TCGA, 289 patients with LGG received adjuvant RT alone (38 grade II, 30 grade III) or chemoradiotherapy (CRT) (51 grade II, 170 grade III) between 2009 and 2015. From CGGA, 178 patients with LGG received adjuvant RT alone (40 grade II, 13 grade III) or CRT (41 grade II, 84 grade III) between 2004 and 2016. The genes comprising GRS are involved in MAP kinase activity, T cell chemotaxis, and cell cycle transition: MAP3K15, MAPK10, CCL3, CCL4, and ADAMTS1. High GRS, defined as having a GRS in the top third, was significantly associated with poorer outcomes independent of age, sex, glioma histology, WHO grade, IDH mutation, 1p/19q co-deletion, and chemotherapy status in the discovery cohort (PFS HR 1.61, 95% CI 1.10-2.36, P = 0.014; OS HR 2.74, 95% CI 1.68-4.47, P < 0.001). These findings were replicated in the internal validation cohort (PFS HR 1.58, 95% CI 1.05-2.37, P = 0.027; OS HR 1.84, 95% CI 1.13-3.00, P = 0.015) and the CGGA external validation cohort (OS HR 1.72, 95% CI 1.27-2.34, P < 0.001). Association between GRS and outcomes was observed only among patients who underwent RT, in both TCGA and CGGA. CONCLUSION: This study successfully identified an expression signature of five genes that stratified outcomes among LGG patients who received adjuvant RT, with two rounds of validation leveraging independent genomics databases. Expression levels of the highlighted genes were associated with PFS and OS only among patients whose treatment included RT, but not among those with omission of RT, suggesting that expression of these genes may be predictive of radiation treatment response. While additional prospective studies are warranted, interrogation of these genes may be considered in the multidisciplinary management of LGG.

Serial T2-Weighted Magnetic Resonance Images Acquired on a 1.5 Tesla Magnetic Resonance Linear Accelerator Reveal Radiomic Feature Variation in Organs at Risk: An Exploratory Analysis of Novel Metrics of Tissue Response in Prostate Cancer.

"Delta-radiomics" investigates variations in quantitative image metrics over time and can yield important clinical information. We hypothesized that in patients undergoing active radiation therapy (RT) for prostate cancer (PCa), there would exist observable variation in the quantitative metrics that describe the T2-weighted (T2W) intensity histogram in the prostate and surrounding organs at risk (OAR) over time. We investigated the feasibility of acquisition and subsequent analysis of the delta-radiomic profiles of these regions of interest (ROI) in serial T2W magnetic resonance (MR) images obtained on a 1.5 Tesla (T) Magnetic Resonance Linear Accelerator (MRL). Principally, we sought to illustrate the significance of longitudinal radiomic data acquisition for tissue response monitoring and provide a framework for future hypothesis driven research. Patients with PCa undergoing treatment with RT were compiled from an ongoing prospective observational imaging trial using a 1.5 T MRL (NCT30500081). Contiguous axial slices of prostate parenchyma were contoured and temporally normalized to sections of Sartorius muscle which served as a control. Similarly, contiguous sections of rectal and bladder wall adjacent to the prostate were contoured and temporally normalized to regions of these organs further removed from the planning target volume (PTV). First order statistical descriptors of the T2W intensity histogram were extracted and evaluated for changes over time using linear mixed effects regression modeling and post-hoc contrasts. Benjamini-Hochberg corrections were employed to reduce the effects of multiple testing and control for the false discovery rate (FDR). Four patients with a median age of 69 comprised this exploratory cohort. One patient had low-risk disease, two had intermediate (one favorable, one unfavorable), and one had high risk disease. Three out of four patients underwent definitive radiation to 75.6 Gray (Gy) in 42 fractions and one received hypofractionated therapy to a total dose of 70 Gy over 28 fractions, and all received treatment on a conventional linear accelerator. The most significant acute toxicity event was grade 2 GU dysfunction observed in two patients. Follow up ranged from 1 month to 10 months post treatment, and no long-term complications were reported in patients who completed treatment at least one month prior. Bladder wall adjacent to the prostate demonstrated significant variation in the mean and median metric values after the first week of treatment. In addition, rectal wall adjacent to the prostate exhibited significant variation in the mean, median, and standard deviation metric values by the second week of treatment. No significant variation in any radiomic feature was observed in the Sartorius control. This exploratory study is one of the earliest examining the delta-radiomic characteristics of the T2W intensity histogram in OAR extracted from images acquired on a 1.5 T MRL in patients actively being treated with RT for PCa. We demonstrated a feasible approach to longitudinal radiomic data acquisition providing limitless opportunity for future research. Analysis of the delta-radiomic profiles in OAR revealed significant variation in metrics after only one week of RT in bladder and rectal wall adjacent to the prostate. These findings must be further investigated and validated with expanded data sets with long-term follow up and correlation to clinical outcomes including toxicity and tumor control.