Long‐term outcomes after treatment with brachytherapy and supplemental conformal radiation for prostate cancer patients having intermediate and high‐risk features

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Abstract
BACKGROUND.: This study summarizes long‐term outcomes from treatment of prostate cancer with increased risk of extracapsular cancer extension (ECE) using brachytherapy‐based treatment.METHODS.: A total of 282 consecutive patients were treated from 1992–1996 by 1 author (M.D.). Two hundred forty‐three patients had at least 1 higher risk feature for ECE including Gleason Score 7–10 (172), prostate‐specific antigen (PSA) above 10 (166), and clinical stages T2c (109) and T3 (107). Using National Comprehensive Cancer Network (NCCN) guidelines, 119 patients had intermediate‐risk disease and 124 had high‐risk disease. Patients received pelvic 3‐dimensional conformal external beam radiation followed by a palladium (Pd)‐103 boost. Generous brachytherapy margins were utilized. Biochemical failure was defined using ASTRO Consensus Definition, nadir +2 and PSA >0.2 ng/mL at last follow‐up. The nonfailing patient follow‐up period was 1–14 years (median, 9.5 years). Biochemical data and original biopsy slides were independently re‐reviewed at the University of Washington (by K.W. and L.T., respectively).RESULTS.: Overall actuarial freedom from biochemical progression at 14 years was 81%, including 87% and 72% having intermediate and high‐risk disease, respectively. Absolute risk of failure decreased progressively, falling to 1% beyond 6 years after treatment. All failing patients had prostate biopsies without evidence of local recurrence. The strongest predictor of failure was Gleason score (P = .03) followed by PSA (P = .041). Treatment morbidity was limited to temporary RTOG grade 1–2 urinary and gastrointestinal symptoms.CONCLUSIONS.: High tumor control rates are possible with beam radiation followed by Pd‐103 brachytherapy. Despite perceptions that brachytherapy is inappropriate for patients at higher risk for ECE, this series strengthens the rationale that brachytherapy‐based treatment may be a desirable modality for such patients. Cancer 2007. © 2007 American Cancer Society.