Hydrogel Rheology Bench Test White Paper

This white paper presents a detailed analysis of the rheological behaviors of SpaceOAR Vue Hydrogel and Barrigel under varying pressure conditions. The objective of the study is to compare how these hydrogels respond to stress, particularly in the context of their application as perirectal spacers during prostate cancer radiation therapy. The paper outlines the methodology used for rheological testing, including the preparation of hydrogel samples and the application of forces ranging from 0.1 to 5.0 N. The results indicate that SpaceOAR Vue Hydrogel maintained its volume with a minimal change of -7.0% at maximum stress, while Barrigel exhibited a significant change of -42.2% under the same conditions. The findings are contextualized with literature on average anorectal pressures, providing insight into the performance of these materials in clinical scenarios. Limitations of the bench tests are also discussed, emphasizing that laboratory results may not directly predict clinical outcomes.