Biochemical Outcome After Radical Prostatectomy, External Beam Radiation Therapy, or Interstitial Radiation Therapy for Clinically Localized Prostate Cancer

ll patients managed with definitive RT were treated using at least 10-MV photons and a conformal shaped 4-field technique. Those patients with AJCC clinical stage T1c, T2a disease who also had a PSA level of 10 ng/mL or less and biopsy Gleason score of 2 to 6 were treated to the prostate only with a 1.5-cm margin. The median prescription dose was 66 Gy (66-70 Gy) and was delivered using 2-Gy fractions. All other patients with clinically localized disease received a median prescription dose of 45 Gy (45-50.4 Gy) in 1.8-Gy fractions to the prostate and seminal vesicles plus a 1.5-cm margin. This was followed by treatment to the prostate alone using a shrinking field technique with a 1.5-cm margin to a median prescription dose of 22 Gy (18-22 Gy) in 1.8- to 2.0-Gy fractions. A 95% normalization was used.

Implant therapy was performed using palladium 103103 Pd) seeds, a perineal template-guided, peripheral-loading technique, and a Bruel & Kjaer 8551 transrectal ultrasound unit (Naerum, Denmark). The minimum peripheral dose to the prostatic capsule was 115 Gy. A transrectal ultrasound probe was used to image the prostate at 5-mm intervals preoperatively to ascertain the optimal number and location of seeds needed to deliver the minimum peripheral dose to the entire prostate gland volume. Individual seed strength ranged from 58 to 61 MBq. The total amount implanted ranged from 1306 to 7189 MBq. Postimplant dosimetry was performed on all patients based on films obtained at 4 weeks after the implant. For the first 143 patients this consisted of orthogonal films, and for the latter 75 patients, computed tomography was used. Of the 218 patients who received implant therapy, 152 (70%) received neoadjuvant androgen deprivation for a median of 3 months (2-10 months). Hormonal therapy consisted of a luteinizing hormone-releasing hormone agonist that was preceded by the use of a nonsteroidal antiandrogen for 7 to 10 days. Ninety-six (63%) of 152 patients received 3 months of neoadjuvant androgen deprivation therapy. The remaining 2 (1.33%), 15 (10%), 14 (9%), 20 (13%), 1 (1%), 2 (1.33%), and 2 (1.33%) received 2, 4, 5, 6, 7, 9, or 10 months of neoadjuvant androgen deprivation therapy, respectively.

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