(P080) After the Thaw: Prostate IGRT Effectively Treats Cryotherapy Failures

Glen Gejerman, MD, Gene Rosenberg, MD, Vincent Lanteri, MD, Sergey Rome, MD, Kevin Basralian, MD, Daniel Lowe, MD, Mutahar Ahmed, MD, Alberto Zacchino, CMD, Nadia Whittington, MS, Eduard Mullokandov, PhD, Eduard Kagan, MD; Hackensack University Medical Center; New Jersey Urology

Purpose: To retrospectively analyze the efficacy and toxicity of image-guided radiotherapy (IGRT) in the management of prostate cancer (PCA) recurrence after primary cryotherapy.

Methods: Patients with organ-confined PCA who developed biochemical failure after cryotherapy were treated with definitive IGRT. Acute and late genitourinary (GU) and gastrointestinal (GI) side effects were scored every 4 months using the Common Terminology Criteria for Adverse Effects (CTCAE). PSA was measured at 4- to 6-month intervals after IGRT.

Results: From 2011 through 2013, 16 patients (9 low-risk, 5 intermediate-risk, and 2 high-risk) who failed to respond to primary cryotherapy were treated with 7,920 cGy IGRT. Thirty-one percent received a short course of concurrent androgen suppression. The median age was 72 years (range: 47–80 yr); The median precryotherapy PSA was 4 ng/mL (range: 1.6–17 ng/mL); the median interval from cryotherapy to IGRT was 48 months (range: 12–84 mo); and the median pre-IGRT PSA was 3.4 ng/mL (range: 1.2–27 ng/mL). At a median follow-up of 18 months (range: 9–34 mo), biochemical control was achieved in all patients. Fifty-six percent of patients developed grade 2 GU toxicity requiring the use of an alpha-blocker or cholinergic receptor antagonist, and 12% developed grade 2 GI toxicity requiring the use of corticosteroid suppositories. These side effects resolved within 12 months. No grade 3 toxicity was encountered.

Conclusion: Prostate IGRT after cryotherapy failure is well tolerated, and early results show excellent PSA response.