Cancer types
Title of study
Clinical study for the Investigation of the ProSpace
Version Number
Approval Date 
1.4.1, 26 February 2020
Short Title
ProSpace
Study site
Principle Investigator
Investigator Maastro
Dr. B. Vanneste
Sponsor
BioProtect Ltd
Trial registry
Objectives 

The objective of this clinical study is to demonstrate that the ProSpace Balloon, when properly inserted between the prostate and the rectum is safe and effective in reducing the volume of the rectum receiving greater or equal to 70 Gy (VRectum70) by means of IMRT in prostate cancer patients undergoing radiotherapy.

Primary Endpoint 

The primary effectiveness endpoint will be evaluated in subjects with prostate cancer who are undergoing radiotherapy by means of IMRT and who receive the ProSpace, with individual patient success defined as a reduction of at least 25% of the volume of the rectum receiving greater or equal to 70 Gy (VRectum70) when compared to pre-implantation values. The study will be considered a success if the rate is significantly greater than 75%; the hypothesis will be evaluated using a one-sided exact binomial test. The primary safety endpoint is the rate of occurrence of Grade 1 or greater rectal adverse events and implantation procedure related adverse events with a duration of at least 2 days through 6 months. This rate will be compared between the ProSpace group and the control group, and the study will be considered a success if statistical significance is achieved on a one-sided non-inferiority test.

Secondary Endpoints 

• The rate of Grade 2 or greater rectal or implantation procedure related adverse events with a duration of at least 5 days and implantation procedure related adverse events in the Balloon Group subjects compared to Control Group subjects in the 6-month follow-up period post marking and/or balloon implantation.
• Degree of all GU acute toxicity as determined by the Expanded Prostate CancerIndex Composite (EPIC).
• Additional dosimetry parameters (DRectum100, DRectum90, DRectum80, DRectum70) will be evaluated in the balloon arm only, where subjects will serve as their own control (dosimetry reduction after balloon implantation) as the dosimetry parameters are compared to their baseline values per subject.
• Core lab evaluation of distance of rectal wall from the prostate at baseline and last XRT visit. This data will be measured and quantified.