3367 - Systematic Review of SBRT after Radical Prostatectomy in Prostate Cancer: Current Evidence and Clinical Outcomes in Both Adjuvant and Salvage Scenarios
Presenter(s)
L. Samhouri1, M. Jaradat2, A. Mohammad3, F. Aldalgamouni4, J. Oqaily4, and R. Ababneh4; 1Department of Radiology, jordan university of science and technology, irbid, Jordan, 2Faculty of medicine, Jordan University of Science and Technology, Irbid, Jordan, 3Saudi Center for Radiotherapy, King Abdullah University Hospital, Irbid, Jordan, 4Faculty of medicine, Jordan University of Science and Technology., Irbid, Jordan
Purpose/Objective(s):
Stereotactic body radiotherapy (SBRT) has gained increasing interest in both adjuvant and salvage prostate cancer treatment; however, the potential toxicity and clinical outcomes in postoperative settings remain insufficiently studied. This systematic review was conducted to evaluate the current evidence regarding toxicity and clinical outcomes following SBRT after radical prostatectomy.
Materials/Methods:
In 2025, we conducted a systematic review of studies published across the following databases: PubMed, Embase, Cochrane Library, Scopus, and ClinicalTrials.gov, using the keywords “SBRT,” “adjuvant radiotherapy,” “salvage radiotherapy,” “prostatectomy,” “dose escalation,” and “androgen deprivation therapy.” Studies evaluating SBRT delivered in the adjuvant or salvage setting after radical prostatectomy were included. Outcomes of interest included genitourinary (GU) and gastrointestinal (GI) toxicity and biochemical control.
Results:
We included 17 individual studies in this systematic review, with a total of 780 patients. The median age was 69.45 years, and the median follow-up duration was 20.35 months. SBRT was primarily targeted at macroscopic recurrence, with prescription doses ranging from 30 to 36 Gy, delivered in 5 to 6 fractions. Among the included studies, patients who had received prior radiotherapy were reported in 7 studies before SBRT [n = 256], while the remaining studies included patients without prior radiotherapy [n = 524]. Late GU toxicities were consistently higher in patients with prior radiotherapy, with rates reaching up to 31.3%. GI toxicity remained low across both subgroups. Grade =3 toxicities were rare across nearly all included studies. Overall, modern SBRT demonstrated an acceptable safety profile.
Biochemical endpoints varied across studies (BCR, BC, BRFS) and were most defined using PSA thresholds of 0.2–0.5 ng/mL above nadir. One-year biochemical control or recurrence-free survival ranged from 74–89%, declining to 52–75% at 2 years and 27–41% at 3 years across time-to-event analyses. This variability reflects heterogeneous endpoint definitions, follow-up duration, and prior treatment exposure.
Conclusion:
Using SBRT in the adjuvant or salvage setting demonstrates favorable early biochemical control rates, around 80–88% at the end of the first year, with acceptable toxicity in carefully selected patients. It has also been shown to be a cost-effective option with higher QALY compared to other radiotherapy modalities. However, the heterogeneous reporting of endpoints [BCR, BC, or BRFS] and the short median follow-up of 20.35 months across the reviewed studies remain limitations in interpreting long-term oncologic outcomes.