Dose–response with stereotactic body radiotherapy for prostate cancer: A multi-institutional analysis of prostate-specific antigen kinetics and biochemical control

Rebecca G. Levin-Epstein, Naomi Y. Jiang, Xiaoyan Wang, Shrinivasa K. Upadhyaya, Sean P. Collins, Simeng Suy, Nima Aghdam, Constantine Mantz, Alan J. Katz, Leszek Miszczyk, Aleksandra Napieralska, Agnieszka Namysl-Kaletka, Nicholas Prionas, Hilary Bagshaw, Mark K. Buyyounouski, Minsong Cao, Nzhde Agazaryan, Audrey Dang, Ye Yuan, Patrick A. KupelianNicholas G. Zaorsky, Daniel E. Spratt, Osama Mohamad, Felix Y. Feng, Brandon A. Mahal, Paul C. Boutros, Arun U. Kishan, Jesus Juarez, David Shabsovich, Tommy Jiang, Sartajdeep Kahlon, Ankur Patel, Jay Patel, Nicholas G. Nickols, Michael L. Steinberg, Donald B. Fuller, Amar U. Kishan

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Background and purpose: The optimal dose for prostate stereotactic body radiotherapy (SBRT) is still unknown. This study evaluated the dose–response relationships for prostate-specific antigen (PSA) decay and biochemical recurrence (BCR) among 4 SBRT dose regimens. Materials and methods: In 1908 men with low-risk (50.0%), favorable intermediate-risk (30.9%), and unfavorable intermediate-risk (19.1%) prostate cancer treated with prostate SBRT across 8 institutions from 2003 to 2018, we examined 4 regimens (35 Gy/5 fractions [35/5, n = 265, 13.4%], 36.25 Gy/5 fractions [36.25/5, n = 711, 37.3%], 40 Gy/5 fractions [40/5, n = 684, 35.8%], and 38 Gy/4 fractions [38/4, n = 257, 13.5%]). Between dose groups, we compared PSA decay slope, nadir PSA (nPSA), achievement of nPSA ≤0.2 and ≤0.5 ng/mL, and BCR-free survival (BCRFS). Results: Median follow-up was 72.3 months. Median nPSA was 0.01 ng/mL for 38/4, and 0.17–0.20 ng/mL for 5-fraction regimens (p < 0.0001). The 38/4 cohort demonstrated the steepest PSA decay slope and greater odds of nPSA ≤0.2 ng/mL (both p < 0.0001 vs. all other regimens). BCR occurred in 6.25%, 6.75%, 3.95%, and 8.95% of men treated with 35/5, 36.25/5, 40/5, and 38/4, respectively (p = 0.12), with the highest BCRFS after 40/5 (vs. 35/5 hazard ratio [HR] 0.49, p = 0.026; vs. 36.25/5 HR 0.42, p = 0.0005; vs. 38/4 HR 0.55, p = 0.037) including the entirety of follow-up, but not for 5-year BCRFS (≥93% for all regimens, p ≥ 0.21). Conclusion: Dose-escalation was associated with greater prostate ablation and PSA decay. Dose-escalation to 40/5, but not beyond, was associated with improved BCRFS. Biochemical control remains excellent, and prospective studies will provide clarity on the benefit of dose-escalation.

Original languageEnglish (US)
Pages (from-to)207-213
Number of pages7
JournalRadiotherapy and Oncology
Volume154
DOIs
StatePublished - Jan 2021

All Science Journal Classification (ASJC) codes

  • Hematology
  • Oncology
  • Radiology Nuclear Medicine and imaging

Fingerprint Dive into the research topics of 'Dose–response with stereotactic body radiotherapy for prostate cancer: A multi-institutional analysis of prostate-specific antigen kinetics and biochemical control'. Together they form a unique fingerprint.

Cite this