Overview
Phase 1-2 study, comparing ultra-hypofractionnated (UH) to a moderately hypofractionnated (MH) radiation therapy, with image guided HDR prostate brachytherapy. Using iso-equivalent doses, a non-inferiority analysis will be done in order to prove UH non-inferior to MH, toxicity wise. Acceptability, tolerability, acute and late toxicity will be reported. MRI visible dominant intra-prostatic lesion will be outlines and variability between radiation oncologists and radiologists will be reported. As secondary objective, biochemical and clinical failure free survival will be reported at 5 & 10 years.
Description
Phase 1 : consists in a feasibility study (First 28 patients).
Phase 2 : monocentric prospective comparative cohort study.
Recruitment :
- "Centre intégré de cancérologie du CHU de Québec-Université Laval."
- Recruitment period: December 2015 to June 2023
Brachytherapy :
- Implantation under general or spinal anesthesia
- Foley catheter insertion in bladder.
- TRUS prostate localisation.
- Prostate volume measurement.
- Gold fiducial markers (3) insertion.
- Prostate brachytherapy catheters (14 à 21) insertion.
- Cystoscopy for bladder and urethra integrity control.
- Re-insertion of foley catheter after cystoscopy.
Planning imaging: TRUS or CT scan (has needed).
Structures delineation by radiation oncologist (brachytherapist).
- Prostate
- Seminale vesicles
- Rectum
- Colon sigmoïde
- Bladder
- Urethra
- Penile bulb
Dosimetric optimisation
- Oncentra Prostate v. 4.2.2 d'Elekta brachytherapy (Veenendaal, The Netherlands)
- Oncentra Brachy version 4.6 (if under CT scan).
Treatment (brachytherapy dose delivery).
- 15 Gy in one fraction
- Direct interstitial dose monitoring (20 patients or more). Fiber-optic dosimeter inserted in prostate brachytherpy catheter for live dose delivery mesurements.
Foley ablation under full bladder, same day or day after therapy.
- Radiotherapy
-
- Via IMRT, VMAT or SBRT technics.
- Dose : 25 Gy in 5 fractions administered over a 7 days period. 2 to 3 fractions separated by 2 days, weekend break.
- PTV includes prostate and the first centimeter of seminal vesicle.
Simulation
- one week post brachytherapy
- standard has described in the department procedure manual.
- maximal CT scan slice thickness : 2-3mm.
- uretro-graphy done to identify urogenital sphincter.
Multiparametric MRI
- If no counter-indication and available,
- a T2 tridimensional sequence for prostate delineation
- slice thickness : 1 mm.
- a diffusion weighted sequence will be done.
- a DTI with tractography can be done optionally.
- contrast media (gadolinium) is optional.
Physique
- Linac energy (between 6 MV to 18 MV).
- ARC therapy technique will be used
- planification softwares: Éclipse, Pinnacle or Raystation.
- Portal (kV-kV) imagery will be used for marker match.
- CBCT will be done at each fraction delivered.
Clinical and dosimetric data will be collected prior treatment.
Primary objectives :
- Toxicity analysis will be quantitatively evaluated using CTCAE (v5) at 1, 2 and 5 years post-therapy, and has needed at FU visits. Kaplan-Meier statistical analysis will be used to report toxicity evolution through time.
- median IPSS scores will be reported at 3, 6, 12 months and yearly (1, 2, 3, 4 et 5) post-therapy. IPSS median time to baseline return will be calculated.
- IPSS urinary scores, sexual function (SHIM) and GI toxicity (CTCAE-v5) and quality of life questionnaires ( EPIC-26) will be given at 3, 6 months and yearly thereafter (1, 2, 3, 4 et 5) post-treatment.
Secondary objectives : Biochemical disease-free survival has per Phoenix definition (by American Society of Radiation Oncology - ASTRO) recommendation will be reported using Kaplan-Meier analysis.
Eligibility
Inclusion Criteria:
- Biopsy proven Prostate adenocarcinoma
- Stage T1c, T2 (Annex 2)
- Stage Nx or N0
- Stage Mx or M0
- PSA < 20ng/ml
- Gleason Score 6 or 7
- Having the ability to sing a written consent
Exclusion Criteria:
- Age < 18ans
- Clinical Stage T3 or T4
- Stage N1
- Stage M1
- PSA > 20
- Gleason Score 8 to 10
- IPSS Score > 20 alpha-blocking medication.
- Prior pelvic radiotherapy.
- History of active collagenosis (Lupus, Sclerodermia, Dermatomyosis)
- Past history of Inflammatory Bowell Disease
- Bilateral hip prosthesis