To describe a technique combining the implantation of fiducials and a prostatic spacer (hyaluronic acid (HA)) to decrease the rectal toxicity after an image-guided EBRT with hypofractionation for prostate cancer and to assess the tolerance and the learning curve of the procedure.
Thirty patients with prostate cancer at low or intermediate risk were included in a phase II trial: image-guided EBRT of 62Gy in 20 fractions of 3.1Gy with intensity-modulated radiotherapy (IMRT). A transrectal implantation of 3 fiducials and transperineal injection of 10cc of HA (NASHA gel spacer, Q-Med AB, Uppsala, Sweden) between the rectum and the prostate was performed by one operator. The thickness of HA was measured at 10 points on MRI to establish a quality score of the injection (Maximum score=10) and determine the learning curve of theprocedure.
The quality score increased from patients 1-10, 11-20 to 21-30 with respective median scores: 7[2-10], 5[4-7] and 8[3-10]. The average thicknesses of HA between the base/middle part/apex of the prostate and the rectum were respectively: 15.1mm [6.4-29] 9.8mm [5-21.2] and 9.9mm [3.2-21.5]. The injection of the HA induced a median pain score of 4 [1-8] and no residual pain at mid-long term.
Creating an interface between the rectum and the prostate and the implantation of fiducials were feasible under local anesthesia with a short learning curve and could become a standard procedure before a hypofractionated EBRT for prostate cancer.
Urology. 2016 Oct 07 [Epub ahead of print]
R Boissier, C Udrescu, X Rebillard, J E Terrier, A Faix, O Chapet, D Azria, M Devonec, P Paparel, A Ruffion
Université Lyon 1, Lyon, France; Department of Urology, Hospices Civils de Lyon, Centre Hospitalier Lyon Sud, Pierre Benite, France. Electronic address: ., Department of Radiation Oncology, Hospices Civils de Lyon, Centre Hospitalier Lyon Sud, Pierre Benite, France; EMR3738, Université Lyon 1, Lyon, France., Department of Urology, Clinique Beausoleil, Montpellier, France., Université Lyon 1, Lyon, France; Department of Urology, Hospices Civils de Lyon, Centre Hospitalier Lyon Sud, Pierre Benite, France., Department of Radiation Oncology and Physics, Institut du Cancer de Montpellier, Montpellier, France.