Use Of Microwave Thermal Ablation In Management Of Skip Metastases In Extremity Osteosarcomas

Figures & data

Table 1 Patient Data From This Skip Metastases Series

Patient Number	Age (Years)	Gender	Primary Site	Skip Lesion Site	Response To Preop Chemo	Definitive Surgery	Local Recurrence	Follow-up (Months)
1	9	F	Distal femur	Proximal femur	Good	Wide resection	No	62
2	8	M	Distal femur	Proximal femur	Good	Wide resection	No	22 (died)
3	18	F	Distal femur	Proximal femur	Poor	Wide resection	No	14 (died)
4	11	M	Distal femur	Proximal femur	Poor	Amputation	No	12 (died)
5	13	F	Distal femur	Proximal femur	Good	Wide resection	No	44

Figure 1 A nine-year old girl with osteosarcoma in the right distal femur got a very good response for preoperative chemotherapy. Skip metastases in proximal femur and intertrochanteric area were clearly shown in plain radiographs (A) and MR imaging (B) after preoperative chemo. A microwave antenna and a thermocouple (solid arrows) were inserted into the remaining intramedullary canal of the femur and the ablation of skip metastases (hollow arrows) were performed with fluoroscopic guidance (C, D). After the ablation, the bone defect was reconstructed with distal femoral endoprosthesis and hip function was retained (E). No local recurrence of skip metastasis was found in Tc-99m bone scan 36 months after the operation (F).

Figure 2 An 11-year old boy with massive osteosarcoma in the right distal femur got a very poor response for preoperative chemotherapy. Skip metastasis in intertrochanteric area was found in plain radiograph (A) and MR imaging (B) after preoperative chemo. The major neurovascular bundle was surrounded by tumor, leading to a mid-femur above-knee amputation. With fluoroscopic guidance, a microwave antenna and a thermocouple (solid arrows) were inserted into the remaining intramedullary canal of the femur near the skip metastasis (hollow arrows) (C). Skip metastasis was removed with a thorough curettage (D) after the ablation. Myodesis and myoplasty were carried out and hip function was retained. No local recurrence of skip metastasis was found in Tc-99m bone scan 12 months after the operation (E).