Quantitative T1rho magnetic resonance imaging of RIF-1 tumors in vivo: detection of early response to cyclophosphamide therapy.

Abstract

This study compares two potential magnetic resonance imaging (MRI) indices for noninvasive early detection of tumor response to chemotherapy: the spin-lattice relaxation in the rotating frame (T1rho) and the transverse relaxation time (T2). Measurements of these relaxation parameters were performed on a s.c. murine radiation-induced fibrosarcoma (RIF-1) model before and after cyclophosphamide treatment. The number of pixels exhibiting T1rho values longer than controls in viable regions of the tumor increased significantly as early as 18 h after drug administration and remained elevated up to 36 h after treatment (P < 0.005). Although a trend of increasing T2s relative to controls was noted in viable regions of the tumor 36 h after treatment, the changes were not statistically significant. Histological examination indicated a decrease in mitotic index that paralleled the changes in T1rho. We conclude that T1rho measurements may be useful for noninvasive monitoring of early response of tumors to chemotherapy.

• Authors: U Duvvuri, H Poptani, M Feldman, L Nadal-Desbarats, M S Gee, W M Lee, R Reddy, J S Leigh, J D Glickson
• Journal: Cancer research (Cancer Res) Vol. 61 Issue 21 Pg. 7747-53 (Nov 01 2001) ISSN: 0008-5472 [Print] United States
• PMID: 11691788 (Publication Type: Comparative Study, Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Antineoplastic Agents, Alkylating
• Cyclophosphamide

Topics

• Animals
• Antineoplastic Agents, Alkylating (pharmacology)
• Cell Division (drug effects)
• Cell Survival (drug effects)
• Cyclophosphamide (pharmacology)
• Dose-Response Relationship, Drug
• Female
• Fibrosarcoma (drug therapy, etiology, pathology)
• Magnetic Resonance Imaging (methods)
• Mice
• Mice, Inbred C3H
• Neoplasms, Radiation-Induced (drug therapy, pathology)