single fraction early prostate irradiation (sifepi)

Conditions: Prostate Cancer

Summary: recently, hdr brachytherapy delivering only a 19 gy fraction was proposed as exclusive treatment for low and intermediate risk prostate cancers. with a median 3-year follow-up, the spanish team reported a biochemical control rate of 100% and 87%, respectively, for low risk and intermediate risk tumors. in parallel with these encouraging results regarding biochemical control, the authors described excellent urinary and digestive tolerance, notably the absence of grade \> 2 complications. however, it should be noted, in this study, that special protection was provided to the anterior aspect of the rectum by means of a 10 ml transperineal injection of hyaluronic acid into the prostate-rectal interspace. the idea of using a single high dose (in one fraction) was proposed at the mskcc by the team of fucks et al. which, in 2008, following a median 18-month follow-up, published a a 90% local control rate for spinal metastases after a single dose at 18 to 24 gy. the aim of the present study is to analyze acute urinary and digestive toxicity (\< 180 days) observed following interstitial high dose rate prostate brachytherapy delivering a total dose of 20 gy in one fraction.

expected benefit(s) of the trial * improved quality of life during brachytherapy on account of the absence of radioactive seeds in the prostate: * fewer early urinary complications, * no urine filtration, * no post-operative use of condoms, * no 2-year ban on cremation following treatment, * health cost savings, * acquisition of dosimetric data for inverse optimization. predictable risk(s) for patients predictable risks in the context of this trial involve the frequency of essentially urinary disorders. methodology open, monocentric, phase i-ii study.

Eligibility criteria:
inclusion criteria: * patients suffering from histologically-proven adenocarcinoma-type prostate cancer: * with low risk of biochemical recurrence * with a low intermediate risk of biochemical recurrence (maximum of 1 intermediate risk factor)\* * stage t1c, t2a, t2b * gleason score 6 (3+3) or 7 (3+4) with at most 3 positive biopsies * psa \< 15 ng/ml * age ≥ 18 years * karnofsky index ≥ 70% * life expectancy ≥ 10 years * no contraindication to injection of hyaluronic acid in the prostate-rectal interspace * patient aware of the information leaflet and having signed the informed consent form * patient covered by medical insurance exclusion criteria: * stage ≥ t2c * gleason score 7 (4+3) or ≥ 8 * psa \> 15 ng/ml * presence of the following anatomico-pathological criteria: * involvement of the nerve fibers * peri-tumoral vascular embolisms * capsule involvement * number of positive biopsies ≥ 50% * 100% positive biopsies in a lobe * involvement of the seminal vesicle * prostate volume ≥60 cc * large prostatic transurethral resection and/or dating from less than 6 months * poor urinary function in the absence of alpha-blockers * ipss score \> 15 * post-mictional residue \> 50 cc * flow rate with qmax \< 12 ml/s * remote metastasis * neoadjuvant anti-androgenic treatment * prior treatment with pelvic irradiation and/or chemotherapy * active infection or other underlying severe pathology likely to prevent the patient from receiving treatment * history of cancer other than basocellular cutaneous cancer or other form of cancer in complete remission for more than 5 years * evolving psychiatric disorder * vulnerable persons as defined by article l1121-5 to -8