Evaluation of [131I]iodoerythronitroimidazole as a predictor for the radiosensitizing effect.
The aim of this study was to evaluate whether radiolabeled iodoerythronitroimidazole (IETNIM) could predict the radiosensitization effect on tumors. Tumor-bearing mice were irradiated at a dose of 25, 31 and 37 Gy after the injection of IETNIM. They were also exposed to 37 Gy radiation at 35, 70, 140 and 240 min after the i.p. injection of IETNIM. After the irradiation, tumor growth assays were conducted and the effect of IETNIM as a radiosensitizer was estimated as enhancement factor (EF). Tumor uptake was measured at 35, 70, 140 and 240 min after i.p. injection of [131I]IETNIM, which were the same intervals used in the radiosensitization study. EF of IETNIM in mice treated with 25, 30 and 37 Gy irradiation was 0.72, 0.98 and 1.28, respectively. EF of IETNIM in mice irradiated at 35, 70, 140 and 240 min after the injection was 1.50, 1.69, 1.46 and 1.08, which corresponded to the tumor uptake and blood clearance of [131I]IETNIM. [131I]IETNIM may be a suitable radiopharmaceutical to predict the radiosensitization effect of misonidazole analogs on tumors.
Inoue
T
T
Department of Nuclear Medicine, University of Texas MD Anderson Cancer Center, Houston 77030, USA.
Yang
D J
DJ
Wallace
S
S
Cherif
A
A
Tansey
W
W
Kim
E E
EE
Hunter
N
N
Milross
C G
CG
Milas
L
L
Podoloff
D A
DA
D000818:Animals; D017690:Cell Transplantation; D005260:Female; D007457:Iodine Radioisotopes; D008297:Male; D008325:Mammary Neoplasms, Experimental / Q000378:metabolism / Q000532:radiotherapy; D051379:Mice; D008809:Mice, Inbred C3H; D008920:Misonidazole / Q000493:pharmacokinetics / Q000494:pharmacology*; D009368:Neoplasm Transplantation; D009593:Nitroimidazoles / Q000138:chemical synthesis / Q000493:pharmacokinetics; D011237:Predictive Value of Tests; D011838:Radiation-Sensitizing Agents / Q000493:pharmacokinetics / Q000494:pharmacology*; D019275:Radiopharmaceuticals / Q000138:chemical synthesis / Q000493:pharmacokinetics; D014407:Tumor Cells, Cultured
D007457:Iodine Radioisotopes; D009593:Nitroimidazoles; D011838:Radiation-Sensitizing Agents; D019275:Radiopharmaceuticals; C104966:iodoerythronitroimidazole; D008920:Misonidazole