Scintigraphic evaluation of tumor regression during preoperative chemotherapy of osteosarcoma

The effect of preoperative chemotherapy (PCT) on the uptake of 99mTc-labeled diphosphonates into tumor bone was quantitatively assessed from serial scan studies of 30 osteosarcomas and correlated with the histomorphological changes determined from the surgical specimens. The parametric images of the tumor blood pool and labeled methylene diphosphonate (99mTc-MDP) plasma clearance by the tumor bone enabled a sensitive distinction to be made preoperatively between a good (> 90% tumor cell destruction) and a poor (< 90% tumor cell destruction) tumor response. 99mTc-MDP parametric imaging is a highly sensitive and specific modality for an objective and accurate assessment of tumor regression during PCT of osteosarcoma. (orig./GDG)