AUA 2018: Utilization of Salvage Radiation Therapy for Biochemical Recurrence After Radical Prostatectom

San Francisco, CA ( For men with adverse pathologic features at the time of radical prostatectomy, the role of adjuvant as compared to salvage radiotherapy is hotly debated. While level 1 evidence has shown that adjuvant radiotherapy reduces biochemical recurrence, metastasis and possibly death when compared to a ‘wait and see’ approach, its merits compared to a salvage approach are currently still be evaluated. In a a moderated poster at the American Urologic Association Annual Meeting using the statewide Michigan Urological Surgery Improvement Collaborative (MUSIC), Dr Hawken and colleagues assessed factors associated with the use of salvage radiotherapy (SRT) and the variation in the use of this approach. 

Patients with localized prostate cancer who had undergone radical prostatectomy between 2012-2016 at one of 27 practices participating in MUSIC were identified. For the purpose of this analysis, patients with post-operative biochemical recurrence (defined herein as at least 1 post-operative PSA >=0.1ng/mL) were selected. Logistic regression models were used to identify associations between patient demographic and pathologic characteristics and the receipt of SRT. 

1017 eligible patients who experienced biochemical recurrence following radical prostatectomy were identified. Of these, 29.7% underwent SRT, at varying levels of PSA: 16.7% at 0.1-0.5, 5.2% at 0.5-1.0, 3.3% at 1.0-2.0, and 4.5% at 2.0 ng/mL or higher. After accounting for patient and practice level factors, patients with higher post-RP PSA, those with positive surgical margins, those with higher T-stage, and those with higher pathological grade were more likely to receive SRT, as might be expected. Interestingly, even after accounting for patient demographic and tumor characteristics, there was significant variation in the utilization of SRT, ranging from 3.5% to 74%. This appeared to be driven by a practice-level philosophy regarding SRT, rather than patient-level factors. 

The authors identify significant variation in practice-level utilization of SRT, which cannot be explained by either patient demographics or tumor characteristics. This is not necessarily surprising given the scientific uncertainty regarding the optimal approach to post-operative radiotherapy.  

Presented By: Scott Hawken 
Co-authors: Daniel E Spratt, Ji Qi, Susan M Linsell, Michael L Cher, Kurshid R Ghani, David C Miller, James E Montie, Todd M Morgan, for the Michigan Urological Surgery Improvement Collaborative 

Written by: Christopher J.D. Wallis, Urology Resident, University of Toronto, Twitter: @WallisCJDat the 2018 AUA Annual Meeting - May 18 - 21, 2018 – San Francisco, CA USA