RT Journal Article SR Electronic T1 Predicting Chemotherapy Response to Paclitaxel with 18F-Fluoropaclitaxel and PET JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1995 OP 1999 VO 47 IS 12 A1 Wei-Ann Hsueh A1 Amanda L. Kesner A1 Anne Gangloff A1 Mark D. Pegram A1 Malgorzata Beryt A1 Johannes Czernin A1 Michael E. Phelps A1 Daniel H.S. Silverman YR 2006 UL http://jnm.snmjournals.org/content/47/12/1995.abstract AB Paclitaxel is used as a chemotherapy drug for the treatment of various malignancies, including breast, ovarian, and lung cancers. To evaluate the potential of a noninvasive prognostic tool for specifically predicting the resistance of tumors to paclitaxel therapy, we examined the tumoral uptake of 18F-fluoropaclitaxel (18F-FPAC) in mice bearing human breast cancer xenografts by using small-animal–dedicated PET and compared 18F-FPAC uptake with the tumor response to paclitaxel treatment. Methods: PET data were acquired after tail vein injection of approximately 9 MBq of 18F-FPAC in anesthetized nude mice bearing breast cancer xenografts. Tracer uptake in reconstructed images was quantified by region-of-interest analyses and compared with the tumor response, as measured by changes in tumor volume, after treatment with paclitaxel. Results: Mice with tumors that progressed demonstrated lower tumoral uptake of 18F-FPAC than mice with tumors that did not progress or that regressed (r = 0.55, P < 0.02; n = 19), indicating that low 18F-FPAC uptake was a significant predictor of chemoresistance. Conversely, high 18F-FPAC uptake predicted tumor regression. This relationship was found for mice bearing xenografts from cell lines selected to be either sensitive or intrinsically resistant to paclitaxel in vitro. Conclusion: PET data acquired with 18F-FPAC suggest that this tracer holds promise for the noninvasive quantification of its distribution in vivo in a straightforward manner. In combination with approaches for examining other aspects of resistance, such quantification could prove useful in helping to predict subsequent resistance to paclitaxel chemotherapy of breast cancer.