Focal Salvage High Dose-Rate Brachytherapy for Locally Recurrent Prostate Cancer after Primary Radiotherapy Failure: Results from a Prospective Clinical Trial
Mené sur 15 patients atteints d'un cancer de la prostate ayant récidivé localement après une radiothérapie externe (durée médiane de suivi : 36 mois), cet essai évalue, du point de vue de l'absence d'échec biochimique, de la toxicité génito-urinaire et de la qualité de vie des patients, l'intérêt d'une curiethérapie de sauvetage à haut débit de dose
Purpose : While there is increasing data that supports whole-gland salvage therapy for recurrent prostate cancer, toxicity remains a significant concern. We hypothesized that focal therapy, treating only a portion of the prostate containing recurrent disease, might be equally effective and associated with less toxicity. The objectives of this prospective study were to explore the toxicities, quality of life (QOL) and efficacy of focal salvage high-dose rate (HDR) brachytherapy in patients with multiparametric MRI-visible, biopsy-confirmed local recurrence after previous definitive external beam radiotherapy (XRT). Methods and Materials : Fifteen patients with locally recurrent prostate cancer following previous external beam radiotherapy were enrolled in this prospective study. Patients were treated with ultrasound-based HDR brachytherapy with a prescription dose of 27 Gy divided in two implants separated by 1 week to the clinical target volume (CTV) defined as the quadrant of the prostate where the MRI visible recurrent lesion was located. Toxicity, quality of life, and biochemical outcomes were analyzed. Post-salvage MRI was performed to assess radiotherapy response. Results : Median follow up was 36 months. The median size of the recurrence on MRI was 9 mm (range 7-20 mm), and CTV at the time of HDR was 6.1 mL (range 2.2-16.1 mL). Only one grade 3 genitourinary toxicity event was observed. There was no urinary retention observed. 3-year PSA failure-free rate was 61%. There was no significant change in EPIC urinary or bowel domains over time. Fourteen patients had a post-HDR MRI, of which 12 had a treatment response. Conclusions : Our results suggest that focal salvage HDR brachytherapy is well tolerated and promising. External validation is needed.