Biochemical outcome after high-dose-rate intensity modulated brachytherapy with external beam radiotherapy: 12 years of experience.

UNLABELLED

Study Type - Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? Biochemical control from series in which radical prostatectomy is performed for patients with unfavorable prostate cancer and/or low dose external beam radiation therapy are given remains suboptimal. The treatment regimen of HDR brachytherapy and external beam radiotherapy is a safe and very effective treatment for patients with high risk localized prostate cancer with excellent biochemical control and low toxicity.

OBJECTIVE

• To investigate the long-term oncological outcome, during the PSA era, of patients with prostate cancer who were treated using high-dose-rate (HDR) brachy therapy (BT) combined with external beam radiation therapy (EBRT).

PATIENTS AND METHODS

• From June 1998 to April 2007, 313 patients with localized prostate cancer were treated with 46 Gy of EBRT to the pelvis with a HDR-BT boost. • The mean (median) follow-up was 71 (68) months. • Toxicity was reported according to the Common Toxicity Criteria for Adverse Event, V.4.

RESULTS

• The 10-year actuarial biochemical control was 100% for patients with no high-risk criteria, 88% for patients with two intermediate-risk criteria, 91% with one high-risk criterion and 79% for patients with two to three high-risk criteria (P= 0.004). • The 10-year cancer-specific survival was 97% (standard deviation ± 1%). • The multivariate Cox regression analyses identified, Gleason score and T stage as independent prognostic factors for biochemical failure. • Gleason score was the only factor to significantly affect distant metastases. • Grade ≥ 3 late toxicity was not detected.

CONCLUSION

• The 10-year results confirm the feasibility and effectiveness of EBRT with conformal HDR-BT boost for patients with localised prostate cancer.