Stereotactic Body Radiotherapy for Localized Prostate Cancer: A Systematic Review and Meta-Analysis of Over 6,000 Patients Treated On Prospective Studies
A partir d'une revue systématique de la littérature publiée entre 1990 et 2018 (38 études), cette méta-analyse évalue l'efficacité, du point de vue de la survie sans récidive biochimique, et la toxicité d'une radiothérapie corporelle stéréotaxique chez les patients atteints d'un cancer de la prostate (6 116 cas ; durée médiane de suivi : 39 mois)
Résumé en anglais
Purpose : Utilization of stereotactic body radiotherapy (SBRT) for treatment of localized prostate cancer is increasing. Guidelines and payers variably support the use of prostate SBRT. We therefore sought to systematically analyze biochemical recurrence-free survival (bRFS), physician-reported toxicity, and patient-reported outcomes following prostate SBRT.
Methods and Materials : A systematic search leveraging Medline via PubMed and EMBASE for original articles published between January 1990 and January 2018 was performed. This was supplemented by abstracts with sufficient extractable data from January 2013 to March 2018. All prospective series assessing curative intent prostate SBRT for localized prostate cancer reporting bRFS, physician-reported toxicity, and/or patient-reported quality of life (QOL), with a minimum of 1-year follow-up were included. The study was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Meta-analyses were performed with random-effect modeling. Extent of heterogeneity between studies was determined by the I2 and Cochran Q tests. Meta-regression was performed using Knapp Hartung methods.
Results : Thirty-eight unique prospective series were identified comprising 6,116 patients. Median follow-up was 39 months across all patients (range, 12-115 months). Ninety-two percent, 78%, and 38% of studies included low, intermediate, and high-risk patients. Overall, 5- and 7-year bRFS rates were 95.3% (95%CI 91.3%-97.5%) and 93.7% (95%CI 91.4%-95.5%). Estimated late grade ≥3 genitourinary and gastrointestinal toxicity rates were 2.0% (95%CI 1.4%-2.8%) and 1.1% (95%CI 0.6%-2.0%), respectively. By 2-years post-SBRT, EPIC urinary and bowel domain scores returned to baseline. Increasing dose of SBRT was associated with improved biochemical control (p=0.018), but worse late grade ≥3 GU toxicity (p=0.014).
Conclusions : Prostate SBRT has substantial prospective evidence supporting its use, with favorable tumor control, patient-reported QOL, and toxicity demonstrated. SBRT has sufficient evidence to be supported as a standard treatment option for localized prostate cancer, while ongoing trials assess its potential superiority.
