Faculty Bibliography

Metastatic castrate-resistant prostate cancer (CRPC) refers to the disease state in which metastatic prostate cancer fails to respond to androgen deprivation therapy (ADT). This can be manifest as a rising PSA, increase in radiographically measurable disease, or progression of clinical disease. Roughly 90 % of men with metastatic prostate cancer have bone metastases, which is a predictor of both morbidity and mortality. Historically, treatment has been palliative, consisting of external beam radiation therapy (EBRT) and pharmacological analgesics for pain control and osteoclast inhibitors, such as bisphosphonates and denosumab to mitigate skeletal-related events. Older radiopharmaceuticals, such as Strontium-89 and Samarium-153, are Beta-emitting agents that were found to provide palliation but were without survival benefit and carried high risks of myelosuppression. Radium-223 is an Alpha-emitting radiopharmaceutical that has demonstrated a significant overall survival benefit in men with metastatic CRPC, delay to symptomatic skeletal events (SSEs), and improvement in pain control, with a favorable toxicity profile compared with placebo. Unlike EBRT, Radium-223 has systemic uptake, with the potential to address several bone metastases concurrently and provides overall survival benefit. It is a simple administration with minimal complexity and shielding requirements in experienced hands. EBRT appears to provide a more rapid and dramatic palliative benefit to any given lesion. Because Radium-223 has limited myelosuppression, the two can be thoughtfully integrated, along with multiple agents, for the treatment of men with CRPC with symptomatic bone metastases. Given its excellent safety profile, there is interest and anecdotal safety combining Radium-223 with therapies, such as abiraterone and enzalutamide. Formal recommendations regarding combination therapies will require clinical trials. The use of Alpha-emitting radiopharmaceuticals in castrate-sensitive disease, in metastatic asymptomatic CRPC, the categorical sequencing amongst other treatments for CRPC, as well as the application to other primary pathologies, such as metastatic breast cancer, is currently evolving.

The adrenal gland is a common site of cancer metastasis. Surgery remains a mainstay of treatment for solitary adrenal metastasis. For patients who cannot undergo surgery, radiation is an alternative option. Stereotactic body radiotherapy (SBRT) is an ablative treatment option allowing larger doses to be delivered over a shorter period of time. In this study, we report on our experience with the use of SBRT to treat adrenal metastases using CyberKnife technology. We retrospectively reviewed the Winthrop University radiation oncology data base to identify 14 patients for whom SBRT was administered to treat malignant adrenal disease. Of the factors examined, the biological equivalent dose (BED) of radiation delivered was found to be the most important predictor of local adrenal tumor control. We conclude that CyberKnife-based SBRT is a safe, non-invasive modality that has broadened the therapeutic options for the treatment of isolated adrenal metastases.

An image-guided robotic stereotactic radiosurgery (SRS) system can be used to deliver curative-intent radiation in either single fraction or hypofractionated doses. Medical records for 19 dogs with nonlymphomatous nasal tumors treated with hypofractionated image-guided robotic stereotactic body radiotherapy (SBRT), either with or without adjunctive treatment, were retrospectively analyzed for survival and prognostic factors. Median survival time (MST) was evaluated using Kaplan-Meier survival curves. Age, breed, tumor type, stage, tumor size, prescribed radiation dose, and heterogeneity index were analyzed for prognostic significance. Dogs were treated with three consecutive-day, 8-12 gray (Gy) fractions of image-guided robotic SBRT. Overall MST was 399 days. No significant prognostic factors were identified. Acute side effects were rare and mild. Late side effects included one dog with an oronasal fistula and six dogs with seizures. In three of six dogs, seizures were a presenting complaint prior to SBRT. The cause of seizures in the remaining three dogs could not be definitively determined due to lack of follow-up computed tomography (CT) imaging. The seizures could have been related to either progression of disease or late radiation effect. Results indicate that image-guided robotic SBRT, either with or without adjunctive therapy, for canine nonlymphomatous nasal tumors provides comparable survival times (STs) to daily fractionated megavoltage radiation with fewer required fractions and fewer acute side effects.

PURPOSE/OBJECTIVE(S)/OBJECTIVE:Stereotactic body radiation therapy (SBRT) has been shown to have increased local control and overall survival relative to conventional external beam radiation therapy in patients with medically inoperable stage I non-small cell lung cancer (NSCLC). Excellent rates of local control have been demonstrated both in clinical trials and in single-center studies at large academic institutions. However, there is limited data on the experiences of small academic hospitals with SBRT for stage I NSCLC. The purpose of this study is to report the local control and overall survival rates in patients treated with SBRT for stage I NSCLC at Winthrop-University Hospital (WUH), a small academic hospital. MATERIALS/METHODS/METHODS:This is a retrospective review of 78 stage I central and peripheral NSCLC tumors treated between December 2006 and July 2012 with SBRT at WUH. Treatment was given utilizing fiducials and a respiratory tracking system. If the fiducials were not trackable, a spine tracking system was used for tumor localization. CT-based planning was performed using the ray trace algorithm. Treatment was delivered over consecutive days to a median dose of 4800 cGy delivered in four fractions. The Kaplan-Meier method was used to calculate local control and overall survival. RESULTS:The median age was 78.5 years. Fifty-four percent of the patient population was female. Sixty seven percent of the tumors were stage IA, and 33% of the tumors were stage IB. Fifty-three percent of the tumors were adenocarcinomas and 29% were squamous cell carcinomas, with the remainder being of unknown histology or NSCLC, not otherwise specified The 2-year local control rate was 87%, and the 2-year overall survival was 68%. CONCLUSION/CONCLUSIONS:Our findings support that local control and overall survival at a small academic hospital are comparable to that of larger academic institutions' published experiences with SBRT for stage I NSCLC.