Abstract
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.
Highlights
The American Society of Radiation Oncology (ASTRO) model policy update of 2013 [1] acknowledged that stereotactic body radiation therapy (SBRT) is equivalent to standard radiation modalities used to treat prostate cancer such as intensity modulated radiation therapy (IMRT)
A significant difference in 5 year freedom from biochemical failure (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)
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
Summary
The American Society of Radiation Oncology (ASTRO) model policy update of 2013 [1] acknowledged that stereotactic body radiation therapy (SBRT) is equivalent to standard radiation modalities used to treat prostate cancer such as intensity modulated radiation therapy (IMRT). Prognostic factors necessary to guide staging and treatment options for prostate cancer include Gleason score (GS), initial PSA, and T-stage These factors have been used to group patients into risk categories of low, intermediate, and high risk, which www.frontiersin.org. The Memorial Sloane-Kettering group identified high-risk features within the intermediate risk group, which correlated with decreased biochemical freedom from relapse, decreased local control, increased distant metastasis, and increased prostate-specific mortality. They created stratifications of favorable and unfavorable intermediate risk groups, assigning the unfavorable intermediate risk group to patients with primary Gleason pattern of 4, percentage of biopsy positive cores ≥50%, or multiple NCCN-defined intermediate risk factors (cT2b-c, PSA 10–20, or GS 7) [12]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
