Single Fraction Early Prostate Irradiation (SiFEPI)

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