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(188)Re-HEDP is an established radiopharmaceutical used for pain palliation in patients with osseous metastasis. Considering commercial availability of (188)W/(188)Re generator, the accessibility to a lyophilized kit would make preparation of this radiopharmaceutical feasible at the hospital radiopharmacy having access to a generator. A protocol for the preparation of a single-vial lyophilized hydroxyethane 1,1-diphosphonic acid (HEDP) kit was developed and its consistency was checked by preparing six batches. Each sterile lyophilized kit prepared as per the protocol contained 9 mg of HEDP, 3 mg of gentisic acid, and 4 mg of SnCl2.2H2O. Randomly selected kits from all six batches were subjected to thorough quality control tests that were passed by all batches. (188)Re-HEDP could be prepared by addition of 1 mL of freshly eluted Na(188)ReO4 (up to 3700 MBq) containing 1 μmol of carrier ReO4(-) (perrhenate) and heating at 100°C for 15 minutes. (188)Re-HEDP with >95% radiochemical purity could be consistently prepared using the lyophilized kits. Sterile (188)Re-HEDP prepared using the lyophilized kit was evaluated in patients with osseous metastasis. Post-therapy images of the patient were compared with (99m)Tc-MDP bone scan and found to be satisfactory. The bone-to-background as well as tumor-to-normal bone uptake ratio was found to be significant. All patients who received therapy reported significant pain relief within a week to 10 days post-administration of (188)Re-HEDP. [ABSTRACT FROM AUTHOR]

The PET radiopharmaceutical [18F]Fluromisonidazole ([18F]FMISO) is presently the agent of choice for the clinical imaging of tumor hypoxia. Considering the logistic advantages of 99mTc and wider availability of SPECT machines, a 99mTc-radiopharmaceutical for this purpose constitutes an attractive choice. In the work presented here, a misonidazole analogue was radiolabeled with 99mTc(CO)3 core and the complex was evaluated in Swiss mice bearing fibrosarcoma tumor. The results obtained are compared with the biodistribution of [18F]FMISO carried out in the same tumor-bearing animal model. Misonidazole-99mTc(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 [18F]FMISO. The maximum tumor/muscle ratio obtained with misonidazole-99mTc(CO)3 complex was significantly higher than that of [18F]FMISO. The study constitutes a positive step toward the development of a 99mTc-analogue of [18F]FMISO. [ABSTRACT FROM AUTHOR]