Faculty Bibliography

Objective/UNASSIGNED:CT-guided, frameless robotic radiosurgery is a novel radiotherapy technique for the treatment of intracranial arteriovenous malformations (AVMs) that serves as an alternative to traditional catheter-angiography targeted, frame-based methods. Methods/UNASSIGNED:Patients diagnosed with AVMs who completed single fraction frameless robotic radiosurgery at Medstar Georgetown University Hospital between July 20, 2006 - March 11, 2013 were included in the present study. All patients received pre-treatment planning with CT angiogram (CTA) and MRI, and were treated using the CyberKnife radiosurgery platform. Patients were followed for at least four years or until radiographic obliteration of the AVM was observed. Results/UNASSIGNED:Twenty patients were included in the present study. The majority of patients were diagnosed with Spetzler Martin Grade II (35%) or III (35%) AVMs. The AVM median nidus diameter and nidal volume was 1.8 cm and 4.38 cc, respectively. Median stereotactic radiosurgery dose was 1,800 cGy. After a median follow-up of 42 months, the majority of patients (81.3%) had complete obliteration of their AVM. All patients who were treated to a total dose of 1800 cGy demonstrated complete obliteration. One patient treated at a dose of 2,200 cGy developed temporary treatment-related toxicity, and one patient developed post-treatment hemorrhage. Conclusions/UNASSIGNED:Frameless robotic radiosurgery with non-invasive CTA and MRI radiography appears to be a safe and effective radiation modality and serves as a novel alternative to traditional invasive catheter-angiography, frame-based methods for the treatment of intracranial AVMs. Adequate obliteration can be achieved utilizing 1,800 cGy in a single fraction, and minimizes treatment-related side effects.

We describe the utilization of SpaceOAR Vueâ„¢, a new iodinated rectal spacer, during Robotic Stereotactic Body Radiation Therapy (SBRT) for a Prostate Cancer Patient with a contraindication to Magnetic Resonance Imaging. A 69-year-old Caucasian male presented with unfavorable intermediate risk prostate cancer and elected to undergo SBRT. His medical history was significant for atrial fibrillation on Rivaroxaban with a pacemaker. He was felt to be at increased risk of radiation proctitis following SBRT due to the inability to accurately contour the anterior rectal wall at the prostate apex without a treatment planning MRI and an increased risk of late rectal bleeding due to prescribed anticoagulants. In this case report, we discuss the technical aspects of appropriate placement and treatment planning for utilizing SpaceOAR Vueâ„¢ with Robotic SBRT.

STUDY DESIGN/METHODS:A retrospective data review. OBJECTIVE:To evaluate the efficacy of CyberKnife (CK) stereotactic radiosurgery (SRS) for thyroid spinal metastasis (SMs). SUMMARY OF BACKGROUND DATA/BACKGROUND:Thyroid carcinoma is an infrequent cause of SM. The absolute efficacy of SRS generally and CK in particular remains poorly characterized for thyroid SM. The current study is the first to specifically evaluate the efficacy of CK SRS for thyroid SMs. METHODS:A retrospective review of patients at our institution between 2003 and 2013 was done. Details about tumor location, radiographic findings before and after CK SRS, tumor recurrence, prescription isodose level, total and maximum dose, number of fractions, and gross tumor volume coverage were similarly collected. For comparison with other studies, the biologically effective dose and the equivalent total dose in 2 Gy fractions were calculated. Each patient was assessed for survival and local disease control from the time of the first CK session and survival analysis was carried out using the Kaplan-Meier method. Risk factors for local failure were assessed using multivariate logistic regression. RESULTS:A total of 12 patients with 32 spinal metastases from thyroid carcinoma that were treated with CK SRS were identified. Survival for 1, 2, and 3 years was 55%, 44%, and 33%, and local control was 67%, 56%, and 34% respectively. The study found that the single strongest factor associated with local control was prior radiotherapy (β-coefficient -27.72, P = 0.01). No complications occurred in the immediate or late follow-up period. CONCLUSION/CONCLUSIONS:This was the first study to specifically investigate the efficacy of CK for treatment of thyroid SMs. Our findings suggest that CK can be safely used to treat spinal SMs from thyroid cancer and is associated with a high rate of local control. LEVEL OF EVIDENCE/METHODS:4.

PURPOSE/OBJECTIVE:In an effort to better characterize the extent and impact of residency expansion and job placement, the authors conducted a multilevel survey of radiation oncologists exploring the current state of the radiation oncology employment market. METHODS:A multilevel survey was conducted using the Qualtrics platform in the spring of 2017. Survey participants were categorized into five groups within radiation oncology: (1) chairpersons, (2) program directors, (3) new practitioners (at least 1 year out of residency), (4) new residency graduates (radiation oncology postgraduate year 5 graduates with new jobs), and (5) medical students. The Wilcoxon-Mann-Whitney test was used to compare Likert scale scores. RESULTS:A total of 752 participants were surveyed, with an overall response rate among all five groups of 31% and 92% of those completing the entire survey. Chairpersons were more likely to consider expanding their residency programs compared with program directors. Fellowship remained low on the job search, with less than 10% of new graduates and new practitioners interested in fellowship positions. Job satisfaction was high with 85% of new graduates, and 78% of new practitioners moderately to very satisfied with their future or current employment. The vast majority of both new practitioners (85%) and new graduates (81%) was moderately to very satisfied with their location of practice. CONCLUSIONS:Resident job satisfaction remains high, whereas interest in radiation oncology fellowships remains low. Conflicting perception regarding the job market and residency expansion could have downstream impacts, such as deterring potential applicants.