Extracorporeal irradiation in malignant bone tumors: Single institution experience and review of literature

In the last couple of decades, the management of malignant bone tumor (MBT) has seen a sea change. With the advent in surgical technics, radiation therapy, and chemotherapy, it has moved from disabling amputation to limb salvage surgery. Extracorporeal irradiation (ECI) and re-implantation of resected bone is a useful method of limb salvage of MBTs. In our study, we analyzed and presented the results of 8 cases of MBTs treated with this modality. Between 2014 and 2017, 8 patients with primary MBT were enrolled for ECI technique who are meeting the eligibility criteria. Before taking the patient for ECI treatment, a multispecialty tumor board discussion was done for each patient. All of them received neo-adjuvant and adjuvant chemotherapy except the patients with histology of giant cell tumor. Following neoadjuvant chemotherapy bone excision surgery was performed, and the resected bone was taken for ECI with the dose of 50 Gray in a single fraction. After ECI, bone segment was re-implanted at osteotomy site in the same setting. After completion of adjuvant chemotherapy, the patients were then followed up for any sequelae, local and systemic control, ambulation, and functional outcome. Out of 8 patients, there were 5 males and 3 females with mean age of 22 (range 13-36). The involved bone was the tibia in 6 patients, ischium in 1 patient, and femur in 1 patient. Histopathologically, the malignancies included 3 osteosarcoma, 3 Giant cell tumor, 1 Ewing's sarcoma and 1 chondrosarcoma. At median follow-up of 12 months (range 6-26 months), local control rate was 87.5% and systemic control rate was 75%. Perioperative ECI and re-implantation is a useful, convenient, and inexpensive technique. The overall treatment time is reduced. The patient's own bone fits perfectly to the resection site with reduced risk of graft site infection. The risk of local recurrence due to tumor re-implantation is negligible with tumoricidal radiation doses of ECI, and it is usually associated with manageable sequelae. Recurrence rates are acceptable and salvageable with surgery.