Distraction osteogenesis is inhibited by cancer radiotherapy with Co 60

To investigate the effects of radiotherapy on distraction osteogenesis performed on the same bone in an area that has not received radiation. Radiotherapy (Co60) was carried out in a region where tumors may develop, and then, on the assumption that the tumoral region had been removed, distraction osteogenesis was carried out, and the effects were investigated.

Thirty New Zealand rabbits were randomized into two groups, a study group (15 rabbits) and a control group (15 rabbits). In the study group, Co60 was administered by teletherapy to the distal half of the left tibia. Rabbits in the control group were kept in the same environment for the same period, but were not subjected to radiotherapy. Four weeks after radiotherapy, osteotomy was performed on the proximal part of the left tibia of all subjects, and distraction was carried out until 10mm. After distraction was completed, the outcomes were evaluated radiologically, scintigraphically, and histopathologically, and the results were compared.

New bone formation achieved through distraction osteogenesis in the study group animals was inadequate, while new bone tissue achieved in the control group was superior (P < 0.001).

Radiotherapy has a negative effect on distraction osteogenesis, even if performed on a different part of the bone.