Evaluation of Prostate Cancer Treated with Temporary High Dose Rate Interstitial Brachytherapy and Followed by EBRT

Abstract

Purpose: To evaluate the treatment outcome of patients with localized prostate cancer treated with HDR interstitial brachytherapy followed by EBRT. Materials and Methods: From February 2004 to February 2009, 28 prostate cancer patients with cancer staging of T1~3, N0, M0 were treated with HDR interstitial brachytherapy followed by 3-D EBRT. Patient received 3 consecutive HDR-brachytherapy in 2 days with the brachytherapy median dose of 18 Gy (15~21 Gy). EBRT was given 2~4 weeks after the HDR interstitial brachytherapy with dose ranged from 50 Gy to 70.4 Gy. Results: Three patients were lost during the follow-up period and therefore were excluded from the analysis. The median age was 73 years old, with a range of 48~82 years old. The median pretreatment PSA value was 16.3 ng/ml, with a range of 6.2~85.3 ng/ml; and the median Gleason Score was 6, with a range of 2~9. Twenty patients (80%) received anti-androgenic hormone therapy prior to radiotherapy. The median follow-up period was 30 months (range 12~66 months). The 1 year and 5 years biochemical control rate was 96% and 84% respectively according to Phoenix definition of biochemical failure. The 5 years overall survival rate was 100%. Seven (28%) patients developed grade Ⅱ acute radiation associated side effects. Two (8%) patients had late grade Ⅱ toxicity. No Gr Ⅲ or Gr Ⅳ side effects were observed. Conclusion: Localized prostate cancer treated with HDR interstitial brachytherapy and EBRT has shown excellent result in disease control with well-acceptable complication rate. However, longer follow-up period and more patients are required for more meaningful long term disease control, survival, and side effect evaluation.