Objectives: Description of early results using a new modality in musculoskeletal oncology.

Introduction: Radiofrequency as a malignant tumor ablative modality has been employed during the last decade in liver tumors. Extra-hepatic application in malignancies is new and its indications are not precisely defined. It has been used for more than ten years for osteoid osteoma ablation. Radiofrequency allows destruction of a precise sphere around the application tip. Ablation efficiency is monitored by the change in tissue conductance following tissue necrosis.

Methods: 10 patients scheduled to undergo limb sparing surgery were included. During the pre-operative angiography and embolization, tumors were treated by radio-frequency ablation. The precise location of the needle electrode was defined by real-time ultrasonography. The relation of the needle tip to large blood vessels was monitored by comparison of ultrasonography to angiography. Thus, precise ablation of the tumor tissue was possible without risk to the neurovascular bundle.

Results: Tumor necrosis was uniform in the center of the ablative sphere and declined to 60 percent in the periphery. No complications were encountered.

Discussion: This method appears to allow further shrinkage of the tumors prior to limb sparing surgery. This technique is rapid and does not require delay of surgery, as does isolated limb perfusion or neo-adjuvant chemotherapy. The procedure can be performed in sedated patients, thus obviating the need for general anesthesia prior to limb sparing surgery. It can be employed in areas were isolated limb perfusion is not anatomically feasible such as the pelvis. Further studies are required in order to better define the role of this technique as compared to intra-arterial chemotherapy or isolated limb perfusion.