[Fast neutron radiotherapy in the treatment of limb-salvage surgery in patients with osteosarcoma].

Preoperative radiotherapy and systemic chemotherapy are effective for reducing the size of a tumor and rendering it resectable. The results achieved with systemic chemotherapy are ultimately reflected in improved survival. Moreover, limb-saving procedure in the treatment of osteosarcoma has become possible with rationality in carefully selected patients. Since 1975, 38 patients with osteosarcoma within an age range of 5 to 56 years, (average 17.9 years) have been treated by fast neutron radiotherapy, systemic chemotherapy and limb-salvage surgery. Twenty-two of these 38 patients underwent en bloc resection of the femur, eight resection of the proximal tibia and five resection of the proximal humerus. Only one of the 38 patients had evidence of local tumor recurrence and overall, 31 patients are currently alive without distant metastasis after 9 to 120 months follow-up. Preoperative fast neutron radiotherapy was employed and it was suggested that fast neutrons had a higher relative biological effectiveness and a greater therapeutic gain factor in comparison with X-rays. Fast neutron radiotherapy thus seems capable of playing a significant role in the treatment of osteosarcoma and is specifically useful for preservation of the affected limb.