Predicting and monitoring response to chemotherapy by 1,3-bis(2-chloroethyl)-1-nitrosourea in subcutaneously implanted 9L glioma using the apparent diffusion coefficient of water and 23Na MRI.
OBJECTIVE
To examine the effects of the alkylating anticancer drug 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) on (23)Na MRI and the water apparent diffusion coefficient (ADC) in subcutaneously- (sc-) implanted 9L glioma in rats.


METHODS
(23)Na MRI and (1)H water ADC measurements were performed on sham-treated control (N = 6) and BCNU-treated (N = 15) Fisher rats one day before BCNU injection and then one, three, and five days after BCNU injection.


RESULTS
The BCNU-treated tumors were divided into BCNU-responsive (R(BCNU)) and BCNU-nonresponsive (NR(BCNU)) groups depending on the tumor volume changes that occurred after therapy. The pretreatment (23)Na MRI signal intensity (SI) and water ADC values were higher in R(BCNU) tumors compared to NR(BCNU) tumors. (23)Na MRI SI and water ADC increased with tumor growth in control and NR(BCNU) groups, but these changes were interrupted by BCNU therapy in R(BCNU) group.


CONCLUSIONS
(23)Na MRI and water ADC measurements may be useful for predicting and monitoring response to chemotherapy in some tumors. However, the changes that occurred in (23)Na MRI SI and water ADC in sc-implanted 9L tumors are in contrast to previously published results for BCNU therapy of orthotopic 9L tumors. This may have important implications for monitoring therapy response in tumors.
Babsky
Andriy M
AM
Indiana Center for Excellence in Biomedical Imaging, Department of Radiology, Indiana University, Indianapolis, Indiana, USA.
Hekmatyar
S K
SK
Zhang
Hong
H
Solomon
James L
JL
Bansal
Navin
N
D000818:Animals; D018906:Antineoplastic Agents, Alkylating / Q000494:pharmacology*; D002330:Carmustine / Q000494:pharmacology*; D045744:Cell Line, Tumor; D005910:Glioma / Q000188:drug therapy*; D008279:Magnetic Resonance Imaging / Q000379:methods; D009607:Nitrosourea Compounds / Q000494:pharmacology; D051381:Rats; D012964:Sodium / Q000378:metabolism; D012979:Sodium Radioisotopes / Q000494:pharmacology*; D013997:Time Factors; D016896:Treatment Outcome; D014867:Water / Q000737:chemistry
D018906:Antineoplastic Agents, Alkylating; D009607:Nitrosourea Compounds; D012979:Sodium Radioisotopes; D014867:Water; D012964:Sodium; D002330:Carmustine