Journal of Bioequivalence & Bioavailability

Abstract

Transperineal Implementation of Biocompatible Balloon in Patients Treated With Radiotherapy for Prostate Carcinoma: Feasibility and Quality Assurance Study in Terms of Anatomical Stabilization Using Image Registration Techniques

Vassilis K, Matsopoulos G, Georgakopoulos J, Kalogeropoulos T, Platoni K, Asimakopoulos C, Beli I, Pantelakos P, Zygogianni A, Kouvaris J and Kelekis N

The purpose of this study was to evaluate the feasibility of the transperineal implementation of biocompatible balloon (Prospace®) as well as the quality assurance of the procedure in terms of anatomical stabilization of the implant and reproductivity of treatment parameters during radiation therapy. Between December 2011 and February 2012, ten patients diagnosed with localized low risk prostate cancer, GS <7, PSA <10, cT1-2, were treated with external three dimensional conformal radiation therapy (3DCRT). Before the initiation of treatment, the Prospace® balloon was implanted by a minimally invasive procedure, though the perineum in the intermediate space between the rectum and the prostate. All patients underwent 3DCRT with 76-78 Gy in 38-39 daily fractions (2.0 Gy/ fraction). We evaluated the implant stabilization by examining by Computed Tomography its position right after implantation and three weeks after initiation of treatment, by using non-rigid registration technique. We also evaluated the acute toxicity according to EORTC/RTOG radiation toxicity criteria and also according to Subjective-RectoSigmoid (S-RS) scale based on the endoscopic terminology of the World Organization for Digestive Endoscopy, as well as pain related to Prospace implementation according to Visual Analogue Score (VAS). By using registration techniques, the Prospace device was found stable in sequential CTs with x,y,z-axis displacements up to 2.1 mm, 3 mm and 2.2 mm, respectively. The mean VAS score related to Prospace was 1.4(± 0.5) and the mean score of rectal toxicity according to S-RS score was 1.9(± 0.6). The implementation of PROSPACE is feasible. Implant’s position is relative stable. The procedure is minimally invasive with no recorded side effects. The incidence of patient-reported acute Gastrointestinal (GI) and Genitourinary (GU) toxicity as well as findings from flexible rectosigmoidoscopy, following high dose of 3DCRT after the prospace implantation, were low. The study is on-going and further results with analyzed data from more patients will be reported.