Magnetic Resonance Studies of Photosensitizers and Their Effect in Tumors

摘要

In this project we used specifically fluorine labeled photosensitizers which will be of utility in the treatment of breast cancer via photodynamic therapy(PDT). The accumulation of the photosensitizer in the tumor and the muscle were evaluated using noninvasive 19F spectroscopic modality in mice bearing RIF tumor. By determining the relative disposition of the sensitizer we can determine the best time to irradiate the tumor causing minimal damage to nearby healthy cells around the tumor. The absorption, distribution and elimination of the labeled sensitizer were determined using 19F spectroscopy of tumor models after administering a single dose of the sensitizer. The tumor regression was achieved by irradiating the tumor with an appropriate wavelength laser light. The process of tumor regression and the accompanying changes in the high energy phosphates and diffusion process were monitored by 31 P and 1 H MR studies. The 31 P MR studies performed before and after the use of 19F labeled PS(DOD2,DOD6) showed changes in the spectra and tumor regression was observed after PDT studies under fractionated laser doses. The corresponding nonlabeled compounds showed less significant 31 P spectral changes and lower tumor response following PDT.