Lung metastasectomy is the only therapeutic option to provide a long-survival in patients with colorectal lung metastases. Recent studies have shown that radiofrequency (RF) ablation is a safe and useful therapeutic option for the treatment of unresectable lung metastases. In this phase-II trial, clinical utility of lung RF ablation will be evaluated in patients with resectable colorectal lung metastases.

This will be a phase-II clinical trial.

Lung metastasectomy is the only therapeutic option to provide a long-survival in patients with colorectal lung metastases. Recent studies have shown that radiofrequency (RF) ablation is a safe and useful therapeutic option for the treatment of unresectable lung metastases. In this clinical trial, clinical utility of lung RF ablation will be evaluated.

Patients with resectable lung metastases will receive lung RF ablation.

All subjects will be followed for overall survival, safety, change in respiratory function, cancer-specific survival, and local tumor progression.

Inclusion Criteria:

• Primary lesions (colorectal cancer) are resected.
• Lung metastases appear.
• No extrapulmonary metastases or after locoregional treatments.
• Lung metastasis is considered to be controllable either by metastasectomy or radiofrequency (RF) ablation.
• Five or less lung metastases measuring 3cm or smaller.
• PET study within 8 weeks before metastasectomy or RF ablation.
• White blood count of 3000/mm3 or more.
• Platelet count of 100,000/mm3 or more.
• Hemoglobin level of 8.0 g/dl.
• Serum creatinine level of 2.0 mg/dl or less.
• PaO2 of 70 mm Hg or more（Room air）or SpO2 of 93%.
• Serum bilirubin level of 2.0 mg/dl or less.
• Performance status of 0 or 1.
• Expected survival of 1 year or more.
• Age of 20 years or more.
• Informed consent from the patient.

Exclusion Criteria:

• Risk to injure lung vessels 5 mm or larger.
• Lung metastases adjacent to the heart, trachea, esophagus, and aorta.
• Association of uncontrollable malignancies.
• Lung hilar lymph node metastasis.
• One lung.
• Pulmonary hypertension.
• Coagulopathy.
• Impossible to stop using anticoagulants.
• Active infection or C-reactive protein of 3 or higher.
• Association of active inflammation.
• Fever (higher than 38 degrees celsius).
• Previous external-beam radiotherapy for the treated lung.
• Pregnant.
• Judgment to be an inappropriate candidate by a attending physician.