SS 08 - GU 2 - Long-Term Updates of Prospective Prostate Cancer Clinical Trials
63 - Ten-Year Outcomes and Toxicity With Moderately Hypofractionated (70 Gy in 28 fractions) Intensity-Modulated Radiation Therapy for Localized Prostate Cancer.
Monday, October 22
8:25 AM - 8:35 AM
Location: Room 214 C/D
Ten-Year Outcomes and Toxicity With Moderately Hypofractionated (70 Gy in 28 fractions) Intensity-Modulated Radiation Therapy for Localized Prostate Cancer.
I. Abu-Gheida1, R. Kotecha2, M. A. Weller1, C. S. Shah1, C. A. Reddy1, P. A. Kupelian3, O. Y. Mian1, J. P. Ciezki1, K. L. Stephans1, and R. D. Tendulkar1; 1Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH, 2Department of Radiation Oncology, Miami Cancer Institute, Baptist Health South Florida, Miami, FL, Miami, FL, 3Department of Radiation Oncology, University of California, Los Angeles, Los Angeles, CA
Purpose/Objective(s): Long-term outcomes with hypofractionated radiation therapy for prostate cancer are limited. We report 10-year efficacy and toxicity outcomes of patients treated with intensity modulation radiation therapy (IMRT) for localized prostate cancer with 70 Gy in 28 fractions at 2.5 Gy/fraction.
Materials/Methods: This IRB-approved study included all 854 consecutive patients with localized prostate cancer treated with moderately hypofractionated IMRT at a single institution between 1998 and 2012. The median follow-up was 11.3 years (maximum, 19 years). Patients were grouped into low-risk (LR, n=266); favorable intermediate-risk (FIR), defined as a single National Comprehensive Cancer Network (NCCN) intermediate-risk factor (n=238); unfavorable intermediate-risk (UIR), defined as ≥2 NCCN intermediate-risk factors (n=106), and high-risk (HR, n=244) groups. Biochemical relapse free survival (bRFS; defined as nadir + 2 ng/mL), clinical relapse free survival (cRFS), & overall survival (OS) were analyzed used Kaplan-Meier analysis. Prostate cancer specific mortality (PCSM) was analyzed using Fine and Gray regression. All grade ≥3 genitourinary (GU) and gastrointestinal (GI) toxicities were recorded using CTCAE version 4.03 and cumulative incidence rates of GU and GI toxicity were calculated.
Results: The 10-year bRFS was 71% (95% CI: 67-74%). For patients with LR, FIR, UIR, and HR disease the 10-year bRFS rates were 88%, 78%, 71%, and 42%, respectively (p <0.0001), while the 10-year cRFS rates were 95%, 91%, 85%, and 72%, respectively (p <0.0001). Overall, the 10-year actuarial OS rate was 69% (95% CI: 66-73%) and the 10-year PCSM was 7% (95% CI: 5-9%). For patients with LR, FIR, UIR and HR disease, the 10-year PCSM rates were 2%, 5%, 5% and 15%. Long-term grade ≥3 GU or GI toxicity remained low with 10-year cumulative incidences of 2% and 1%, respectively.
Conclusion: High-dose moderately hypofractionated IMRT for localized prostate cancer continues to show excellent oncological outcome with a low incidence of toxicity over long-term follow up. This fractionation schedule appears to be acceptable for patients across all risk groups.
Author Disclosure: I. Abu-Gheida: None. R. Kotecha: Honoraria; Elsevier Practice Update. M.A. Weller: None. C.S. Shah: Employee; Cleveland Clinic Foundation. Consultant; Impedimed. C.A. Reddy: Statistical Editor; International Journal Radiation Oncology Biology and Physics. P.A. Kupelian: Research Grant; Varian Medical Systems, Inc. Honoraria; Accuray. Consultant; ViewRay. Advisory Board; Accuray, ViewRay. Travel Expenses; Accuray, ViewRay. O.Y. Mian: None. R.D. Tendulkar: None.