Single Institutional Experience of Stereotactic Radiosurgery Alone for First Brain Metastatic Event and Salvage of Second Brain Metastatic Event in a Community Setting with Review of the Literature.

PURPOSE: To document survival for patients treated with stereotactic radiosurgery (SRS) alone for brain metastases either at initial presentation or for salvage in conjunction with other known prognostic factors in a single institutional community setting with comparison to current literature. METHODS: All patients treated for brain metastases with SRS between October 2006 and October 2013 were reviewed. We identified 91 patients treated with SRS alone for first brain metastatic event (FBME) and 87 patients treated with SRS for second brain metastatic event (SBME). We excluded the 14 patients treated with SRS for both FBME and SBME to satisfy the independence assumption for comparison of groups. Patient demographics, including age, gender, primary cancer type, presence of extracranial metastases, number of brain metastases, initial site of metastases (brain vs. other), recursive partitioning analysis (RPA), and Karnofsky Performance status (KPS) were documented. RESULTS: There were no significant differences in overall survival for patients treated with SRS for FBME compared with SBME (log-rank p = 0.9347). Univariate and multivariable Cox regression modeling revealed KPS (p = 0.0003) and RPA (p = 0.0143) were the only independent prognostic factors for survival. Specifically, patients with RPA 1 had a 61% decreased risk of death compared to those with RPA 3. Patients with RPA 2 had a 33% decreased risk of death compared to those with RPA 3. The 1-year survival rate was 36.5% for patients with RPA1, 33.3% for those with RPA 2, and 17.1% for those with RPA 3. Patients with KPS 90-100 had a 62% decreased risk of death compared to those with KPS < 70. The 1-year survival rate for patients KPS 90-100, 70-80, and <70 were 60.7, 24.6, and 16.7%, respectively. CONCLUSION: No difference in survival was noted for FBME and SBME with performance status, the single most important prognostic factor following SRS. Aggressive treatment should be considered for patients with good performance status regardless if presenting with FBME or SBME. Our results are consistent with single, multi-institutional, and randomized trials after literature review.

SBRT for the Primary Treatment of Localized Prostate Cancer: The Effect of Gleason Score, Dose and Heterogeneity of Intermediate Risk on Outcome Utilizing 2.2014 NCCN Risk Stratification Guidelines.

PURPOSE: To report an update of our previous experience using stereotactic body radiation therapy (SBRT) for the primary treatment of prostate cancer, risk stratified by the updated National Comprehensive Cancer Network (NCCN) version 2.2014, reporting efficacy and toxicity in a community hospital setting. METHODS: From 2007 to 2012, 142 localized prostate cancer patients were treated with SBRT using CyberKnife. NCCN guidelines Version 2.2014 risk groups analyzed included very low (20%), low (23%), intermediate (35%), and high (22%) risk. To further explore group heterogeneity and to comply with new guidelines, we separated our prior intermediate risk group into favorable intermediate and unfavorable intermediate groups depending on how many intermediate risk factors were present (one vs. > one). The unfavorable intermediate group was further analyzed in combination with the high risk group as per NCCN guidelines Version 2.2014. Various dose levels were used over the years of treatment, and have been categorized into low dose (35 Gy, n = 5 or 36.25 Gy, n = 107) and high dose (37.5 Gy, n = 30). All treatments were delivered in five fractions. Toxicity was assessed using radiation therapy oncology group criteria. RESULTS: Five-year actuarial freedom from biochemical failure (FFBF) was 100, 91.7, 95.2, 90.0, and 86.7% for very low, low, intermediate and high risk patients, respectively. A significant difference in 5 year FFBF was noted for patients with Gleason score (GS) ≥8 vs. 7 vs. 5/6 (p = 0.03) and low vs. high dose (p = 0.05). T-stage, pretreatment PSA, age, risk stratification group, and use of ADT did not affect 5-year FFBF. Multivariate analysis revealed GS and dose to be the most predictive factors for 5-year FFBF. CONCLUSION: Our experience with SBRT for the primary treatment of localized prostate cancer demonstrates favorable efficacy and toxicity comparable to the results reported for IMRT in literature. GS remains the single most important pretreatment predictor of outcome.