title: A (99m)Tc-labeled misonidazole analogue: step toward a (99m)Tc-alternative to [18F]fluromisonidazole for detecting tumor hypoxia.
abstract: The PET radiopharmaceutical [(18)F]Fluromisonidazole ([(18)F]FMISO) is presently the agent of choice for the clinical imaging of tumor hypoxia. Considering the logistic advantages of (99m)Tc and wider availability of SPECT machines, a (99m)Tc-radiopharmaceutical for this purpose constitutes an attractive choice. In the work presented here, a misonidazole analogue was radiolabeled with (99m)Tc(CO)3 core and the complex was evaluated in Swiss mice bearing fibrosarcoma tumor. The results obtained are compared with the biodistribution of [(18)F]FMISO carried out in the same tumor-bearing animal model. Misonidazole-(99m)Tc(CO)3 complex showed significant uptake and retention in tumor. Notably, the rate of clearance of misonidazole complex from the tumor was slower than that of [(18)F]FMISO. The maximum tumor/muscle ratio obtained with misonidazole-(99m)Tc(CO)3 complex was significantly higher than that of [(18)F]FMISO. The study constitutes a positive step toward the development of a (99m)Tc-analogue of [(18)F]FMISO.
authors.affiliation: 1 Radiopharmaceuticals Division, Bhabha Atomic Research Centre , Mumbai, India .
authors.forename: Madhava B
authors.initials: MB
authors.lastname: Mallia
authors.forename: Anupam
authors.initials: A
authors.lastname: Mathur
authors.forename: Haladhar D
authors.initials: HD
authors.lastname: Sarma
authors.forename: Sharmila
authors.initials: S
authors.lastname: Banerjee
mesh_terms: D000818:Animals; D005354:Fibrosarcoma / Q000000981:diagnostic imaging*; D000860:Hypoxia / Q000175:diagnosis* / Q000000981:diagnostic imaging*; D051379:Mice; D008920:Misonidazole / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D015609:Organotechnetium Compounds / Q000008:administration & dosage*; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals / Q000008:administration & dosage*; D014018:Tissue Distribution; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
chemical_list: D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C031843:fluoromisonidazole; D008920:Misonidazole
keywords: [18F]Fluoromisonidazole; [99mTc(CO)3(H2O)3]+ precursor; fibrosarcoma; hypoxia; iminodiacetic acid