RESUMO
OBJECTIVE: Low-dose-rate brachytherapy (LDR-BT) in localized prostate cancer is available since 15 years in Italy. We realized the first national multicentre and multidisciplinary data collection to evaluate LDR-BT practice, given as monotherapy, and outcome in terms of biochemical failure. METHODS: Between May 1998 and December 2011, 2237 patients with early-stage prostate cancer from 11 Italian community and academic hospitals were treated with iodine-125 ((125)I) or palladium-103 LDR-BT as monotherapy and followed up for at least 2 years. (125)I seeds were implanted in 97.7% of the patients: the mean dose received by 90% of target volume was 145 Gy; the mean target volume receiving 100% of prescribed dose (V100) was 91.1%. Biochemical failure-free survival (BFFS), disease-specific survival (DSS) and overall survival (OS) were estimated using Kaplan-Meier method. Log-rank test and multivariable Cox regression were used to evaluate the relationship of covariates with outcomes. RESULTS: Median follow-up time was 65 months. 5- and 7-year DSS, OS and BFFS were 99 and 98%, 94 and 89%, and 92 and 88%, respectively. At multivariate analysis, the National Comprehensive Cancer Network score (p < 0.0001) and V100 (p = 0.09) were correlated with BFFS, with V100 effect significantly different between patients at low risk and those at intermediate/high risk (p = 0.04). Short follow-up and lack of toxicity data represent the main limitations for a global evaluation of LDR-BT. CONCLUSION: This first multicentre Italian report confirms LDR-BT as an excellent curative modality for low-/intermediate-risk prostate cancer. ADVANCES IN KNOWLEDGE: Multidisciplinary teams may help to select adequately patients to be treated with brachytherapy, with a direct impact on the implant quality and, possibly, on outcome.
Assuntos
Braquiterapia/métodos , Neoplasias da Próstata/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Braquiterapia/mortalidade , Relação Dose-Resposta à Radiação , Humanos , Itália/epidemiologia , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Padrões de Prática Médica , Antígeno Prostático Específico , Neoplasias da Próstata/mortalidade , Dosagem Radioterapêutica , Resultado do Tratamento , Ultrassonografia de Intervenção/métodosRESUMO
AIMS AND BACKGROUND: Clinical studies published in the last decade have shown the possible improvement in prognosis of patients with prostatic carcinoma undergoing radiation therapy with dose escalation or in combination with hormone therapy. However, in studies on hormone therapy, moderate doses of radiation therapy have been used, whereas in studies with high-dose radiotherapy, hormone therapy usually was not administered. Therefore, it is not clear whether the concomitant use of high doses and prolonged hormone therapy could determine an additional beneficial effect. The aim of the present study was therefore to evaluate the relative prognostic role of different dose levels (< 70 versus > or = 70 Gy) of external beam radiotherapy and of different hormone therapies (neoadjuvant only versus neoadjuvant + adjuvant). METHODS: A total of 426 patients (median age, 71 yrs; range, 51-87 yrs) underwent external beam radiotherapy (70 Gy median dose to prostate volume +/- 45 Gy to pelvic lymph nodes) and neoadjuvant hormone therapy (bicalutamide for 30 days; goserelin, 3.6 mg every 28 days starting two months before radiotherapy and for its entire duration). Dose to the prostate was < 70 Gy in 44.8% of patients and > or = 70 Gy in 55.2%. A total of 244 patients received adjuvant hormonal therapy. The distribution according to the clinical stage was 48.1% T2 and 51.9% T3. The distribution according to the Gleason score was 14.3% grades 2-4, 66.7% grades 5-7 and 19.0% grades 8-10. The distribution according to pretreatment prostate-specific antigen levels (in ng/mL) was 7.0% for 0-4, 29.3% for 4-10, 30.3% for 10-20, and 33.3% for > 20. RESULTS: With a median follow-up of 35 months (range, 1-151), 81 patients (19.0%) showed biochemical recurrence, 17 patients (4.0%) showed local disease progression, and 12 patients (2.8%) showed distant metastases. Overall, 23 patients (5.4%) showed disease progression. Four patients (0.9%) died. At the time of this writing, no patient has died from prostatic carcinoma. At univariate analysis, the radiation dose delivered to the tumor and the administration of adjuvant hormone therapy were shown to be significantly correlated with biochemical disease-free survival. At multivariate analysis, the single parameter significantly correlated with biochemical disease-free survival was the radiation dose delivered to the tumor. In the subset of patients not treated with adjuvant hormone therapy, there was a significant correlation between radiation dose and biochemical disease-free survival at univariate and multivariate analysis. A similar correlation between adjuvant hormone therapy and biochemical disease-free survival was observed in the subset of stage cT3 patients at univariate and multivariate analysis. In patients undergoing combined treatment without adjuvant hormone therapy, a significant correlation was observed between clinical stage and biochemical disease-free survival, at univariate and at multivariate analysis. CONCLUSIONS: The results of the study confirmed the positive impact of radiotherapy doses > 70 Gy and of adjuvant hormone therapy in patients with locally advanced prostatic carcinoma. Owing to the lack of evidence of a correlation between radiation dose and biochemical outcome in patients undergoing prolonged hormone therapy, the role of further dose escalation in patients undergoing combined hormone and radiation therapy is still unclear.