F. Hosain et al., TARGETED DELIVERY OF ANTINEOPLASTIC AGENT TO BONE - BIODISTRIBUTION STUDIES OF TC-99M-LABELED GEM-BISPHOSPHONATE CONJUGATE OF METHOTREXATE, The Journal of nuclear medicine, 37(1), 1996, pp. 105-107
A methotrexate-bisphosphonate conjugate containing a peptide bond has
been found to possess over five times greater antineoplastic activity
against osteosarcoma in experimental animal models compared with metho
trexate alone. Methods: The conjugate was labeled with Tc-99m in the p
resence of stannous ions to determine biologic distribution, with spec
ial reference to osseous tissue. Biodistribution studies were carried
out in mice after intravenous administration of the labeled conjugate.
Radionuclide imaging of rabbits was also performed. Results: The labe
led conjugate behaved like a bone-seeking agent. Conclusion: The prese
nt study indicates that the concept of treating osteosarcoma or metast
atic tumors of bone with this class of agents has a firm basis.