Inclusion Criteria:

General

• Any age
• Previously diagnosed malignancy (including aggressive fibromatosis) originally acquired during childhood (<21 years-of-age)
• Patients who have undergone previous RFA may be enrolled again (different disease site) or receive subsequent ablation (same disease site) as long as the eligibility criteria are met at the time of re-enrollment, or a second ablation on study.
• The subject is medically appropriate for the study as determined by a consensus of professionals at multidisciplinary tumor conference prior to enrollment. This discussion will be documented in the chart of the potential subject to be recruited for this study.
• Histopathological material is available prior to the RF ablation except in patients with obvious tumor recurrence.
• No Pacemakers or Automatic Implantable Cardioverter/Defibrillators (AICDs)
• No tissue burns anticipated from implanted metal
• Normal renal function (Creatinine < 2mg/dL)
• Absolute neutrophil count (ANC) > 1000/cu.mm.
• No uncorrectable coagulopathy (INR>1.5, PTT and PT > 1.5 x the upper limit of normal)
• No uncorrectable thrombocytopenia (platelet count < 50,000/mm3)
• Life expectancy over 30 days
• RF ablation targets in the liver, lung or musculoskeletal system that meet the following criteria:

Hepatic lesions

• Intrahepatic metastases not amenable to other therapy
• Primary hepatic tumor if RF ablation of a portion of the tumor can lead to primary tumor resection rather than hepatic transplantation
• Single primary or multiple tumors in the liver
• At least one over 0.5 cm in diameter
• Edge of lesion not contiguous with main hepatic or common biliary duct.

Musculoskeletal lesions

• Local or regional recurrence of primary bone or soft tissue tumor not amenable to resection or radiotherapy
• Osseous, soft tissue or lymph node metastases not amenable to resection or radiotherapy.
• Head, neck, spine, extremity, chest wall, flank, abdominal wall, or pelvic bone or girdle lesions are treatable under this protocol
• RFA target < 50% of axial area in weight bearing bone unless reinforced with internal fixation (bone cement infusion) or in non-ambulatory patient.

Lung lesions

• No supplemental oxygenation is required.
• Metastatic solid tumor that has recurred or progressed after primary thoracotomy or thoracoscopic removal that is not amenable to radiotherapy, surgery or chemotherapy
• In the investigator's opinion, no supplemental oxygen will likely be required at rest for more than 30 days after RF ablation.
• Tumor burden < 20% of lung volume