Failure-free survival following brachytherapy alone or external beam irradiation alone for T1-2 prostate tumors in 2222 patients: Results from a single practice

Purpose: To evaluate failure-free survival (FFS) for brachytherapy (BT) alo ne compared to external beam radiotherapy (EBRT) alone for Stage T1-2 Nx-No Mo patients over the same time period by a single community-based practice in the prostate-specific antigen (PSA) era. Materials and Methods: The database of Arizona Oncology Services (a multiph ysician radiation oncology practice in the Phoenix: metropolitan area) was reviewed for patients meeting the following criteria: (1) T1 or T2 Nx-No Mo prostate cancer; (2) no prior or concurrent therapy including hormones; (3 ) treatment period 12/88-12/95; and (4) treatment with either EBRT alone or BT alone (I-125 or Pd-103). This yielded 1527 EBRT and 695 BT patients; no patients meeting the above criteria were excluded from analysis. Median fo llow-up for EBRT patients was 41.3 months and, for BT patients, 51.3 months . Patients were not randomized to either therapy but rather received EBRT o r BT based upon patient, treating, and/or referring physician preference. P SA failure was defined according to the ASTRO consensus guidelines. The med ian patient age was 74 years for both groups. Results: Failure-free survival at 5 years for EBRT and BT are 69% and 71%, respectively (p = 0.91). For T stage, no significant difference in FFS at 5 years is observed between EBRT and BT for either T1 (78% vs. 83%, p = 0.47 ) or T2 (67% vs. 67%, p = 0.89) tumors. Analysis by Gleason score shows sup erior outcomes for Gleason 8-10 lesions treated with EBRT vs. BT (5-year FP S 52% vs. 28%, p = 0.04); outcomes for lower grade lesions (Gleason 4-6) wh en analyzed by Gleason score alone do not significantly differ according to treatment received. Patients with initial PSA values of 10-20 ng/dL have a n improved FFS with EBRT vs. BT at 5 years (70% vs. 53%, p = 0.001); outcom es for patients with initial PSA ranges of 0-4 ng/dL, of > 4-10 ng/dL, and > 20 ng/dL did not differ significantly by treatment received. FFS was also determined for presenting Gleason score/PSA combinations; all Gleason comb inations in the initial PSA range >10-20 ng/dL had superior outcomes with E BRT compared to BT, and this reached statistical significance for Gleason s cores of 2-4 (72% vs. 58%, p = 0.026), Gleason 7 (67% vs. 28%,p = 0.002), a nd Gleason 8-10 (63% vs. 23%, p = 0.05). Conclusion: In our patient population, either EBRT or BT appear equally eff icacious for patients with T1/T2 disease with Gleason scores less than or e qual to 6 or PSA less than or equal to 10 ng/dL. Patients with presenting G leason scores of 8-10 or PSA > 10 ng/dL (but less than or equal to 20 ng/dL ) appear to fare significantly worse with BT alone compared to EBRT alone. Neither EBRT nor BT alone was particularly effective for patients with a pr esenting PSA > 20 ng/dL, as would be anticipated from the significant risks of occult distant metastasis in this group. To our knowledge, this is the first report comparing the outcome of EBRT and BT treatment in patients tre ated concurrently by a single group, and these results, achieved in a commu nity-based practice, compare favorably to data from academic centers regard ing external beam, brachytherapy, or surgical outcomes and should be genera lizable to the community at large. (C) 2000 Elsevier Science Inc.