Colorectal Pulmonary Metastases: Pulmonary Metastasectomy Versus Stereotactic Ablative Radiotherapy

Inclusion Criteria: * Age ≥ 18 years * Eastern Cooperative Oncology Group (ECOG)-Performance status 0 - 2 * Willing to provide informed consent * Patients with 1 to 3 lung metastases from colorectal cancer eligible for both a minimally invasive surgical resection and SABR, as assessed by the multidisciplinary tumor board (MDT) * Radically treated primary colorectal cancer * Patient is able and willing to complete the quality-of-life questionnaires * Previous liver metastases are radically treated with curative intent * Histologically confirmed malignancy with metastatic disease detected on imaging. Biopsy of metastasis is preferred, but not required. Exclusion Criteria: * Previous or present metastases outside liver or lungs * Concurrent malignant cancer, or history of other malignant cancers within the past 5 years (excluding prespecified low-risk cancers) * Hilar or mediastinal lymph node metastases * Poor cardiopulmonary function test * Inability to treat all colorectal metastases * Surgical resection by means of a bilobectomy or pneumonectomy