title: Biomaterial characteristics and application of silicone rubber and PVA hydrogels mimicked in organ groups for prostate brachytherapy.
abstract: It is definite that transparent material with similar structural characteristics and mechanical properties to human tissue is favorable for experimental study of prostate brachytherapy. In this paper, a kind of transparent polyvinyl alcohol (PVA) hydrogel and silicone rubber are developed as suitable substitutions for human soft tissue. Segmentation and 3D reconstruction of medical image are performed to manufacture the mould of organ groups through rapid prototyping technology. Micro-structure observation, force test and CCD deformation test have been conducted to investigate the structure and mechanical properties of PVA hydrogel used in organ group mockup. Scanning electron microscope (SEM) image comparison results show that PVA hydrogel consisting of 3 g PVA, 17 g de-ionized water, 80 g dimethyl-sulfoxide (DMSO), 4 g NaCl, 1.5 g NaOH, 3 g epichlorohydrin (ECH) and 7 freeze/thaw cycles reveals similar micro-structure to human prostate tissue. Through the insertion force comparison between organ group mockup and clinical prostate brachytherapy, PVA hydrogel and silicone rubber are found to have the same mechanical properties as prostate tissue and muscle. CCD deformation test results show that insertion force suffers a sharp decrease and a relaxation of tissue deformation appears when needle punctures the capsule of prostate model. The results exhibit that organ group mockup consisting of PVA hydrogel, silicone rubber, membrane and agarose satisfies the needs of prostate brachytherapy simulation in general and can be used to mimic the soft tissues in pelvic structure.
authors.affiliation: Centre for Advanced Mechanisms and Robotics, School of Mechanical Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Pan
authors.initials: P
authors.lastname: Li
authors.affiliation: Centre for Advanced Mechanisms and Robotics, School of Mechanical Engineering, Tianjin University, Tianjin 300072, China. Electronic address: shanjmri@tju.edu.cn.
authors.forename: Shan
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Division of Medical Physics, Department of Radiation Oncology, Thomas Jefferson University, Kimmel Cancer Center, 111 South 11th Street, Philadelphia, PA 19107, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Department of Imaging, Tianjin Union Medicine Center, Tianjin 300121, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.affiliation: Centre for Advanced Mechanisms and Robotics, School of Mechanical Engineering, Tianjin University, Tianjin 300072, China.
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Yang
mesh_terms: D040761:Biomimetic Materials; D001918:Brachytherapy / Q000295:instrumentation*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008422:Materials Testing; D055595:Mechanical Phenomena; D009339:Needles; D010388:Pelvis; D011142:Polyvinyl Alcohol; D011467:Prostate / Q000166:cytology; D012826:Silicone Elastomers
chemical_list: D012826:Silicone Elastomers; C062364:polyvinyl alcohol hydrogel; D011142:Polyvinyl Alcohol
keywords: Mechanical properties; Micro-structure; Organ group mockup; Polyvinyl alcohol hydrogel; Prostate brachytherapy; Silicone rubber