Abstract
Purpose of study: To investigate the safety, efficacy, and feasibility of using high intensity focused ultrasound (HIFU) for the treatment of malignant bone tumors.
Methods: Forty-four patients with biopsy-proven malignant bone tumors were treated with HIFU (osteosarcoma: 32; chondrosarcoma: 3; periosteal osteosarcoma: 2; Ewing sarcoma: 1; other malignant bone tumor: 3, and unclassified tumor: 2). These tumors were situated as follows: distal femur – 20; proximal tibia – 7; mid-shaft of femur – 6; ilium – 2; shaft of fibula – 2; other – 4. HIFU was given as a noninvasive limb-salvage treatment in combination with neoadjuvant chemotherapy (methotrexate, adriamycin, cisplatin and ifosfamide) in thirty-four patients (Enneking’s Stage_b). Ten patients with stage IIIb (9 patients with lung metastasis) were treated with HIFU alone with palliative intent. The largest dimension of the tumors ranged from 5 to 46 cm. Postoperative biopsy, follow-up imaging (DSA, CT or MRI, and ECT), and functional evaluation were performed, and median survival time was calculated using the Kaplan-Meier method.
Results: Histopathological examination demonstrated clear evidence of tumor destruction and regrowth of normal bone in the treated region. When compared with baseline, follow-up imaging indicated complete coagulative necrosis of the treated tumors. Enneking’s functional scores were > 20, 15–20, and < 15 in 20, 14 and 5 cases respectively. Median follow-up was 23 months (range 10 to 40 months). Total survival rate was 85% (38/44). One patient with stage_b disease, and 5 patients with stage IIIb disease died as a result of distant metastases after HIFU treatment. 5 patients underwent amputation after local recurrence. Few complications were observed during follow-up. These were limited to 3 pathological fractures, 2 cases of peripheral nerve damage, restricted joint movement in 1 case, and epiphyseal separation in 1 case.
Conclusions: HIFU is safe, effective, and feasible in the treatment of patients with malignant bone tumors.
The abstracts were prepared by Mr Roger Tillman. Correspondence should be addressed to BOOS at the Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London WC2A 3PN
