Competency-Based Medical Education in Canadian Radiation Oncology Residency Training: an Institutional Implementation Pilot Study.

Canadian radiation oncology (RO) residency programs transitioned to a competency-based medical education (CBME) training model named Competence by Design (CBD) in July 2019. Prior to this, CBD was piloted in a single RO training program to characterize assessment completion and challenges of implementation. Six residents and seven staff participated in a mixed-methods study and were oriented to CBD. Four Entrustable Professional Activities were assessed over a 4-week-long block and documented using online assessment forms. Anonymized assessments were analyzed to characterize completion. Post-pilot surveys were completed by 4/6 residents and 5/7 staff. Semi-structured post-pilot focus groups were conducted with all residents. Assessments were requested and documented on a weekly basis. Narrative comments were found in 68.1% of assessments, of which 26.7% described specific examples of observed competence or recommendations for improvement. Three of five staff believed that assessments have a negative impact on clinical workflow. Three themes were identified: (1) direct observation is the most challenging aspect of CBD to implement; (2) feedback content can be improved; and (3) staff attitude, clinical workflow, and inaccessibility of assessment forms are the primary barriers to completing assessments. This study demonstrates that CBD assessments can be completed regularly in an outpatient radiation oncology setting and that implementation challenges include improving feedback quality, promoting direct observation, and continuing faculty development to improve perceptions of this assessment model. Further study is required to identify best practices and expectations for the discipline in the era of CBME.

Desmoplastic Small Round Cell Tumor With Ascending Intraspinal Metastasis at Recurrence: Case Report and Review of the Literature.

BACKGROUND: Desmoplastic small round cell tumor (DSRCT) is a rare and aggressive malignancy commonly involving the abdomen and/or pelvic peritoneum. Despite aggressive therapy, the prognosis remains poor. Central nervous system relapse is rare in abdominal/pelvic primary DSRCT. OBSERVATION: We report a case of a 10-year-old female with a large pelvic DSRCT and involvement of the rectosigmoid colon and liver. Following treatment with chemotherapy, and cytoreductive surgery with hyperthermic intraperitoneal chemotherapy an initial response was noted. With progressive lower limb weakness, recurrence with perineural invasion in the lumbosacral nerve root involving the conus was noted 2.5 years from diagnosis. Cerebrospinal fluid showed tumor cells with a molecular confirmation. CONCLUSIONS: Perineural invasion and ascending paralysis secondary to primary abdominal DSRCT has not been previously reported to our knowledge. We recommend a high index of suspicion for early and accurate diagnosis of this rare presentation.

Patterns of MHC-DRB1 polymorphism in a post-glacial island canid, the Newfoundland red fox (Vulpes vulpes deletrix), suggest balancing selection at species and population timescales.

As the only native insular Newfoundland canid between the extinction of the wolf in the 1930s and the recent arrival of coyotes, the red fox (Vulpes vulpes deletrix Bangs 1898) poses interesting questions about genetic distinctiveness and the post-glacial colonization history of the island's depauperate mammalian fauna. Here, we characterized genetic variability at the major histocompatibility complex (MHC) class II DR ß1 domain (DRB1) locus in 28 red foxes from six sampling localities island-wide and compared it with mitochondrial control region (CR) diversity and DRB1 diversity in other canids. Our goals were to describe novel DRB1 alleles in a new canid population and to make inferences about the role of selection in maintaining their diversity. As in numerous studies of vertebrates, we found an order-of-magnitude higher nucleotide diversity at the DRB1 locus compared with the CR and significantly positive nonsynonymous-to-synonymous substitution ratios, indicative of selection in the distant past. Although the evidence is weaker, the Ewens-Watterson test of neutrality and the geographical distribution of variation compared with the CR suggest a role for selection over the evolutionary timescale of populations. We report the first genetic data from the DRB1 locus in the red fox and establish baseline information regarding immunogenetic variation in this island canid population which should inform continued investigations of population demography, adaptive genetic diversity, and wildlife disease in red foxes and related species.

Hypofractionated Stereotactic Radiotherapy for the Treatment of Benign Intracranial Meningiomas: Long-Term Safety and Efficacy.

INTRODUCTION: Hypofractionated stereotactic radiotherapy (hSRT) has emerged as an alternative to single-fraction stereotactic radiosurgery (SRS) and conventionally fractionated radiotherapy for the treatment of intracranial meningiomas (ICMs). However, there is a need for data showing long-term efficacy and complication rates, particularly for larger tumors in sensitive locations. METHODS: A retrospective review was conducted on adult patients with ICMs seen at a tertiary care center. Eligible patients were treated with the CyberKnife platform and had a planned treatment course of 3-5 fractions from 2011-2020. The local control was assessed based on radiographic stability and the late toxicity/radionecrosis rates were recorded. Radiographic progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. RESULTS: In total, 62 patients (age 26-87) with 67 treated tumors were included in this study with a median follow-up of 64.7 months. RT was delivered as the primary treatment in 62.7% of cases and for recurrence in 37.3%. The most common tumor locations were the convexity of the brain and the base of the skull. The tumor sizes ranged from 0.1-51.8 cc and the median planning target volume was 4.9 cc. The most common treatment schedule was 18 Gy in 3 fractions. The five-year PFS and OS were 85.2% and 91.0%, respectively. The late grade III/IV toxicity rate was 3.2% and the radionecrosis rate was 4.8%. CONCLUSIONS: Based on our data, hSRT remains an effective modality to treat low-grade ICMs with acceptable long-term toxicity and radionecrosis rates. hSRT should be offered to patients who are not ideal candidates for SRS while preserving the benefits of hypofractionation.

A pilot study of stereotactic boost for malignant epidural spinal cord compression: clinical significance and initial dosimetric evaluation.

PURPOSE: Metastatic epidural spinal cord compression (MESCC) is a devastating complication of advanced malignancy, which can result in neurologic complications and significant deterioration in overall function and quality of life. Most patients are not candidates for optimal surgical decompression and as a result, receive urgent 3D conformal radiotherapy (3DCRT) to prevent or attempt to reverse neurologic progression. Multiple trials indicate that response and ambulatory rates after 3DCRT are inferior to surgery. The advent of stereotactic body radiation therapy (SBRT) has created a method with which a "radiosurgical decompression" boost may facilitate improve outcomes for MESCC patients. METHODS: We are conducting a pilot study to investigate SBRT boost after urgent 3D CRT for patients with MESCC. The aim of the study is to establish feasibility of this two-phase treatment regimen, and secondarily to characterize post-treatment ambulation status, motor response, pain control, quality of life and survival. DISCUSSION: We describe the study protocol and present a case report of one patient. A quality assurance review was conducted after the first seven patients, and resultant dose-constraints were revised to improve safety and feasibility of planning through more conservative organ at risk constraints. There have been no severe adverse events (grade 3-5) to date. We have illustrated clinical and dosimetric data of an example case, where a patient regained full strength and ambulatory capacity. CONCLUSIONS: Our study aims to determine if SBRT is a feasible option in addition to standard 3DCRT for MESCC patients, with the goal to consider future randomized trials if successful. Having a robust quality assurance process in this study ensures translatability going forward if future trials with multicenter and increased patient representation are to be considered. TRIAL REGISTRATION: clinicaltrials.gov; registration no. NCT03529708; https://clinicaltrials.gov/ct2/show/NCT03529708 ; First posted May 18, 2018.

Endotracheal brachytherapy alone: An effective palliative treatment for tracheal tumors.

BACKGROUND: Tracheal tumors are rare. They are usually unresectable and treated primarily with external beam radiation. The use of palliative endotracheal brachytherapy (ETBT) alone in treating patients with tracheal tumors has not been reported. METHODS: Using a prospective database, demographic, treatment, and outcome data of patients with tracheal tumors treated palliatively with ETBT from 2006 to 2014 were analyzed. Tumor and symptom responses were evaluated based on response evaluation criteria in solid tumors criteria. Survival, in-field disease control, symptom response, and duration of symptom responses were evaluated using descriptive analyses. RESULTS: Sixteen ETBT (median, 2) treatments were delivered to 8 patients. Median age was 63.4 years old. Common symptoms were hemoptysis, cough, and dyspnea. Tracheal lengths of 3.5-11 cm were treated with 5-7 Gy/fraction, using 1-3 fractions. The mean overall survival was 5 months and symptom-free survival was 6.8 months, respectively. After ETBT, 88% of patients experienced symptomatic improvement (hemoptysis [n = 3/3], cough [n = 6/7], and dyspnea [n = 4/4]). One patient developed Grade 1 stenosis that did not require intervention. CONCLUSIONS: This is among the largest series of tracheal tumors treated palliatively with ETBT alone. ETBT provided effective palliation with symptom improvement and minimal toxicity.