Novel Approach to Monitoring Prostate Tumor Oxygenation: Proton MRI of the Reporter Molecule Hexamethyldisiloxane

摘要

Growing evidence iron experimental and clinical studies confirms that solid human tumors have foci of hypoxic cells, which have a profound influence on the therapeutic outcome of cancer chemotherapy and radiotherapy. A strong argument therefore exists for assessing the hypoxic traction of tumors prior to patient treatment, and to tailor this treatment accordingly. It bas been shown that there is linear relationship between R1 of hexamethyldisiloxane (HMDSO) and pO2 and the R1 of HMDSO is insensitive to various inns and minimally sensitive to temperature. The primary sequence for in vivo T1 measurement with water and fat suppression has been established, which can successfully monitor the global tumor oxygenation responding to respiratory intervention by measuring HMDSO spin- lattice relaxation time using spectroscopy. Although the imaging technique still needs to be optimized in tumor, pO2 maps accompanying respiratory intervention bas been obtained in rat muscle. So, Hexamethyldisiloxane shows promise as a reporter molecule to measure tumor oxygenation by 1H MRS and potentially by MRI. This opens new opportunities for MR tumor oximetry, particularly since HMDSO is used widely in biomedical materials and as an ingredient in consumer products; and HMDSO is reported to have minimal toxicity.