PV QA 1 - Poster Viewing Q&A 1
SU_30_2306 - Long Term Results of Cs-131 Monotherapy as Definitive Therapy in a Prospectively-Followed Group of Low Risk Localized Prostate Cancer Patients
Sunday, October 21
1:15 PM - 2:45 PM
Location: Innovation Hub, Exhibit Hall 3
Long Term Results of Cs-131 Monotherapy as Definitive Therapy in a Prospectively-Followed Group of Low Risk Localized Prostate Cancer Patients
B. J. Moran Jr, and M. H. Braccioforte; Prostate Cancer Foundation of Chicago, Westmont, IL
Purpose/Objective(s): Cesium-131 has been available as a permanently implantable brachytherapy source since 2005. Published long-term biochemical control rates for the earlier available Iodine-125 and Palladium-103 sources in the treatment of localized prostate cancer have been available prior to the introduction of Cesium-131. As a result, some question remains as to the long-term performance of Cesium-131 in establishing biochemical control in the localized prostate cancer patient relative to the other two radio-isotopes.
Materials/Methods: A large prospective database maintained since 2000 was queried for low risk prostate cancer patients treated with Cesium-131 monotherapy prior to 2010 and for whom PSA follow-up data was available. “Low risk” was defined per NCCN guidelines as Gleason 3+3 or less disease at diagnostic biopsy, diagnostic serum PSA <= 10 ng/ml and clinical stage T2a or less.
Results: A total of 261 patients were available for analysis per the query criteria. Mean/median diagnostic PSA were 5.6 / 5.4 ng/ml, respectively. 99% of patients were graded as Gleason 3+3, and clinical stage was T1c in 91%. Median follow-up for the group was 66.9 months. A total of 2,847 follow-up PSA measurements were analyzed for the group, an average of 10.9 per patient. Eighteen (18) patients (7%) underwent three months of hormonal therapy prior to implant for the purpose of gland downsizing. The Phoenix definition was used to score each patient as a failure or censored observation. Failure time was determined at call and no further follow-up data was considered for failed patients. Patients who exhibited no rises or exhibited a “bounce” (a rise above nadir where subsequent PSA profile showed a downward trend) were censored at last follow-up. 10 patients (3.8%) were scored as failures. Kaplan-Meier functions returned BRFS rates of 97% at 5 years (155 at risk); 94% at 8 years (75 at risk); 93% at 9 years (47 at risk), and 90% at 10 years (19 at risk).
Conclusion: This analysis represents the longest followed series of Cesium-131 patients reported to-date. The closely followed and mature nature of this large prospective group of uniformly low risk patients provides strong evidence for the efficacy of Cesium-131 monotherapy in this setting per biochemical endpoint analysis.
Author Disclosure: B.J. Moran: None. M.H. Braccioforte: None.