PMMA/SWCNTs Composites for Prostate Brachytherapy MRI Contrast Agent Markers
K.S. Martirosyan, R.J. Stafford, A.M. Elliott, S.J. Frank
University of Houston, US
Keywords: prostate brachytherapy, PMMA, carbon nanotube, MRI marker
Abstract:Prostate brachytherapy (PB) is an alternative to traditional external beam radiation or surgery for men who have prostate cancer. PB used implanted radioactive titanium seeds and has increased in popularity over recent years due to its effectiveness and relative convenience. While Magnetic Resonance Imaging (MRI) is the superior imaging modality, for PB it is currently not used because the radioactive titanium seeds generates MRI artifacts and appears as black holes (negative contrast) and cannot be accurately localized within the prostate and periprostatic tissue. To overcome this disadvantage, we developed a novel medical device referred to as Encapsulated Contrast Agent Markers (ECAMs), contained Co-based or Gd-based T1 contrast agents that allows visualization of the precise location of radioactive titanium seeds by MRI. We report here on fabrication of poly(methy1 methacrylate) (PMMA) with single-walled carbon nanotubes (SWCNTs) composites that can be potentially used as capsulation materials for MRI PB markers and study of their MRI response. In vitro testing of fabricated markers using clinical MRI sequencing protocols as well as a 3D T1-W fast spoiled gradient echo protocol have displayed well T1 positive signal. The study revealed that fabricated PMMA/SWCNTs composites are suitable for using as capsule materials for PB MRI markers.