Stereotactic Ablative Radiotherapy (SABR) for the Treatment of Patients With Metastatic Cancer, ID-COMET Trial

Inclusion Criteria: * Age 1 year or older. * Willing to provide informed consent. * ECOG ≤ 3. * Life expectancy \> 6 months. * Trials 1-3: Histologically confirmed lung, prostate or colorectal malignancy with metastatic disease detected on imaging. Biopsy of metastasis is preferred, but not required. * Trial 4: Any malignancy with metastasis. Participants with liquid tumors are eligible provided they have biopsy confirmed refractory disease and are eligible for salvage radiotherapy. * Newly diagnosed metastatic (1-10 sites)patients for Trials 1-3. Previously diagnosed metastatic patients (1-10 sites or oligoprogression in 5 or fewer sites with no limit on total number for Trial 4. * Restaging completed within 12 (+/- 4) weeks prior to randomization. * For patients receiving thoracic radiotherapy, the enrolling physician must confirm there are no computed tomography (CT) changes suggestive of fibrotic interstitial lung disease (ILD) (i.e., reticular changes, traction bronchiectasis, or honeycombing) reported on any prior CT scans. If any are present, the patient must be assessed by a respirologist to rule out ILD prior to enrollment. * Participants of child-bearing potential must agree to use adequate contraceptive methods (e.g., hormonal or barrier method of birth control; abstinence) prior to study entry. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately…