Radionuclide scintigraphy in monitoring reparative processes in irradiated bone replants

The remodeling of irradiated bone re-implant placed into simultaneously irradiated bed was studied by scintigraphy method using 99Tc-labeled drug (TcLD) (perfoteh). The data obtained were compared with data of radiologic control. The study included 11 patients with osteogenic sarcoma who were operated on after chemo-radiotherapy course. The peculiarities of operation were as follows. Resected bone with tumor was irradiated by single 60 G dose, after that the bone was re-implanted. It was revealed that 1 month postoperatively TcLD retention in contact zone of bone fragments was 2—2.5 times higher as compared with the symmetric zone of healthy bone. Remodeling peak was observed 1.5—2 months after operation. Over that interval TcLD retention decreased gradually and by 18 months the contact zone was not detected on scintigrams. According to the data of radiologic control the peak of remodeling took place at 6—8 months after operation. The study showed that irradiated re-implant preserved mechanical stiffness and worked as a biologic prosthesis while substituting the newly formed bone. Scintigraphy is an additional method the earlier assessment of reparative processes in extracorporal irradiated reimplant as compared to the assessment of radiologic control.