105 - Brachytherapy Versus External Beam Dose-Escalated Boost for Intermediate-Risk Prostate Cancer: Definitive Results of the GETUG P05 Trial
Presenter(s)
A. Lapierre1, J. Berthiller2, F. Mallet3, G. Crehange4, N. Vial5, D. Peiffert6, M. Silva7, F. Rocher8, L. Votron9, A. Bossi10, C. Verry11, L. Thomas12, C. Hennequin13, C. Murariu14, R. De Crevoisier15, and O. Chapet1; 1Centre Hospitalier Lyon Sud, Pierre Benite, France, 2Hospices Civils de Lyon, Lyon, France, 3Polyclinique Courlancy, Reims, France, 4Institut Curie, Paris, France, 5Lucien Neuwirth Cancer Institute, SAint Priest en Jarez, France, 6Institut de Cancérologie de Lorraine, Vandoeuvre-Les-Nancy, France, 7Centre François Baclesse, Caen, France, 8ICB, CHALON SUR SAONE, France, 9Clinique Claude Bernard, Albi, France, 10Institute Gustave Roussy, Villejuif, France, 11Centre Hospitalier Universitaire Grenoble-Alpes, Maquis du Grésivaudan, 38700 La Tronche, France, 12Department of Radiation Oncology. Institut Bergonie, Bordeaux, France, 13CHU Saint-Louis, Paris, France, 14Institut Jean Godinot, Reims, France, 15CRLCC Eugène Marquis, Rennes, France
Purpose/Objective(s):
We evaluated external beam radiotherapy combined with a brachytherapy boost versus exclusive external beam radiotherapy (EBRT) for intermediate-risk prostate cancer.Materials/Methods:
GETUG P05 is an open-label randomized phase III trial. Patients with intermediate-risk histologically proven prostate cancer (defined as a PSA level between 10 ng/ml and 20ng/ml, and/or a Gleason score of 7 (3+4 of 4+3) and/or a T2b stage) were randomized between 2 treatment arms. Both arms received external beam radiation therapy (EBRT) delivering 46 Gy to the prostate and the first centimeter of the seminal vesicles. The treatment was then followed by a boost delivered to the prostate only, according to randomization: Arm A included a brachytherapy boost, utilizing either Iodine-125 permanent implants (110 Gy) or High-Dose-Rate (HDR) brachytherapy (Iridium-192, 14 Gy), with the choice between the two brachytherapy techniques left to the discretion of each participating center. Arm B consisted of an EBRT dose escalation boost, delivering a total dose of 80 Gy to the prostate only. Primary endpoint was PSA progression-free survival (PSA-PFS) at 5 years according to Phoenix criteria. Secondary endpoints included OS, PC-specific survival (PCSS), metastasis-free survival (MFS), adverse events (AE) and quality of life (QoL).Results:
We randomized 298 patients in 27 centers from 16/12/2013 to 20/03/2017, out of which 296 were evaluable, 155 in the EBRT arm and 141 in the brachytherapy arm (79 LDR, 55 HDR, 7 unknown). Median age was 69 (65-74); 87.5% patients had Gleason 7 (60.5% 3+4 and 27% 4+3) and 12.5% Gleason 6; initial mean PSA was 8.90 (sd=3.97). Both arms did not differ in terms of patient characteristics. Thirty-five PSA-PFS events occurred during a median PFS follow-up of 61.7 (55.5-62.8) months. Five years PSA-PFS was 87.8% in the brachytherapy arm and 88.8% in the EBRT arm (p=0.86). OS did not differ in both groups either (respectively 96.0% vs 92.7% (p=0.30)). Brachytherapy modality (I125 of HDR) had no influence on PSA-PFS. Quality of life and sexual function were not different in both arms. There was no benefit of brachytherapy boost in either the 3+4 or 4+3 subgroup. Regarding adverse events, the most frequent toxicities were pollakiuria and dysuria. There were statistically more acute and late urinary toxicities in the brachytherapy arm (respectively 55% vs 26% p<0.0001) and 82% vs 64% p=0.0007). However, most toxicities were grade 1 and 2 and there was no difference regarding grade 3 toxicities. There was no difference in gastrointestinal toxicities regardless of the grade and no grade 4 toxicity was observed in our study.Conclusion:
Brachytherapy boost after EBRT failed to demonstrate a benefit in PSA-PFS at 5 years. Severe toxicities and quality of life did not differ for EBRT alone or EBRT with brachytherapy boost. Clinical trials information: NCT02271659