Delayed Systemic Therapy Following Destructive Local Treatment of Pulmonary Oligometastases After No Evidence of Disease (NED) in Colorectal Cancer.

"Oligometastatic Radiotherapy Group: Patients will receive radiotherapy to lung lesions, with the lung metastases outlined as the Gross Tumor Volume (GTV). The prescribed dose will be based on a BED (Biologically Effective Dose) of 72-100 Gy, using either conventional split, macrodissected, or SBRT (Stereotactic Body Radiation Therapy) at the investigator's discretion. No systemic therapy will be administered.~Oligometastatic Radiofrequency Ablation Group: For lesions suitable for radiofrequency ablation, this will be performed in consultation with the Department of Interventional Medicine, considering patient and family preferences. Systemic therapy will not be given.~Oligometastatic Surgery Group: For lesions suitable for surgical resection, patients will undergo surgery after consultation with the Department of Surgery. No systemic therapy will be performed."