Long-term biochemical progression-free survival following brachytherapy for prostate cancer: Further insight into the role of short-term androgen deprivation and intermediate risk group subclassification.

INTRODUCTION: Brachytherapy is a well-established treatment of localized prostate cancer. Few studies have documented long-term results, specifically biochemical progression-free survival (bPFS) in men with brachytherapy alone, with or without short-term androgen deprivation therapy (ADT), or in combination with external beam radiotherapy (EBRT). Our aim was to analyze long-term bPFS of brachytherapy treated patients. MATERIALS AND METHODS: Retrospective analysis of 1457 patients with low and intermediate risk prostate cancer treated with brachytherapy alone (1255) or combined with EBRT (202). Six-months ADT was administrated for all EBRT combined patients and for prostate volume downsizing when >55 cc (328). Failure was by the Phoenix definition. Kaplan-Meier analysis and multivariate Cox regression estimated and compared 10-yr and 15-yr rates of bPFS. RESULTS: Median follow-up was 6.1 yr. Ten and 15-yr bPFS rates of the entire cohort were 93.2% and 89.2%, respectively. On multivariate analysis, PSA density (PSAD), ADT and clinical stage were significantly associated with failure. The most powerful independent factor was PSAD with a HR of 3.5 (95% CI, 1.7-7.4) for PSAD above 0.15. No significant difference was found between low and intermediate risks patients regardless of treatment regimen. However, comparison of two intermediate risk groups, Gleason score (GS) 7, PSA<20 ng/ml versus GS≤6 and PSA = 10-20 ng/ml, revealed 10- and 15-yr bPFS rates of 94.2% and 94.2% compared to 88.2% and 79.9%, (P = 0.022), respectively. ADT improved bPFS rates in low risk patients. The ten and 15-yr bPFS rates were 97.6% and 94.6% compared to 92.3% and 88.2%, (P = 0.020), respectively. CONCLUSIONS: Our retrospective large scale study suggests that brachytherapy provides excellent long-term bPFS rates in low and intermediate risk disease. Combination of brachytherapy with EBRT yields favorable outcomes in GS 7 intermediate risk patients and short-term ADT has a positive effect on outcomes in low risk patients. Further prospective studies are warranted to discriminate the role of adding either EBRT and/or ADT to brachytherapy protocols.

Prospective comparison of PSA kinetics following two different prostate cancer brachytherapy planning methods: preoperative and real-time intraoperative dosimetry planning.

OBJECTIVES: Preoperative planning (PP) and intraoperative planning (IoP) are established (125)I-brachytherapy techniques for the treatment of localized prostate cancer. We prospectively compared the effects of each method on reducing PSA levels. MATERIALS AND METHODS: One hundred eighty patients treated with brachytherapy as monotherapy without neoadjuvant androgen deprivation therapy or external beam radiation using PP (75) or IoP (105) methodologies and with ≥ 5 years of follow-up were included in the study. CT-based dosimetry was calculated 1 month postoperatively. PSA was obtained every 3 months for the first year and semiannually thereafter. Available PSA and dosimetric data from both groups were analyzed and compared. RESULTS: At 5 years after brachytherapy, the probability of having a nadir PSA value < 0.5 ng/ml was 90% in the IoP group compared with 60% in the PP group (P < 0.0001). The rate of PSA decline was 3-fold faster in the IoP group than in the PP group. Dosimetry results highly favored the IoP method: mean V(100) (%) and D(90) (Gy) were 95 and 180 vs. 60 and 81 (P < 0.001), respectively. CONCLUSIONS: Our initial finding of highly superior postimplant CT dosimetry calculations of the IoP method are now substantiated by the biochemical favorable results (PSA kinetics) of this method.

The correlation between palliation of bone pain by intravenous strontium-89 and external beam radiation to linked field in patients with osteoblastic bone metastases.

We studied the correlation between the efficacy of local external beam radiotherapy and the efficacy of strontium-89 in the palliation of osteoblastic metastatic bone pain in 43 patients with cancer. All 43 had been treated with hormonal or chemotherapy according to the primary malignancies and analgetic pharmacotherapy as needed, 36 received local external beam radiotherapy as a palliative before strontium-89 injection, and all 43 were ultimately treated with strontium-89 as salvage therapy. Responses to the first strontium treatment, and to the first radiation treatment if given, were taken from patient files. Pain was evaluated by Karnofsky performance status, analgesic dosage, and duration of response to treatment translated into numeric scores on a pain duration scale and an integrated response scale. The efficacy of limited field external radiation in metastatic bone pain palliation was 80.6% versus 58.1% for strontium-89. Patients treated with both external radiation and strontium had a positive correlation of 0.4 with a probability of P = 0.0158 between the responses to the 2 treatments, indicating that response to external radiotherapy could be viewed as an indicator of strontium-89 efficacy in metastatic osteoblastic bone pain palliation in the same patient. No significant correlation was found between strontium efficacy and gender, location of metastases to weight-bearing bones, duration of hormonal therapy or chemotherapy, or type of primary neoplasm.