Ablative Radiotherapy to Restrain Every Metastasis Safely Treatable (ARREST-2): A Randomized Phase II/III Trial

Critères d'inclusion

• Age 18 or older • willing and able to provide informed consent • ECOG performance status 0-2 • Life expectancy \> or equal to 6 months • Histologically confirmed malignancy with evidence of metastatic disease on imaging • All sites of disease can be safely treated on a preliminary radiation plan • \> or equal to 11 metastases (the primary tumor does not have to be controlled and can be included as a target if it can feasibly and safely be treated with SABR. If the primary tumor is treated, a minimum of 12 targets are required0 at least 11 metastases are required in addition to the primary tumor.) • Investigations required within 12 weeks of enrollment: • Brain: MRI is required for all patients with known untreated or previously treated brain metastases. MRI is strongly recommended for all tumor sites with a propensity to develop brian metastases. • Body: 18-FDG PET/CT imaging is recommended, except for tumors where FDG uptake is not expected (e.g. prostate, renal cell carcinoma). PSMA-PET or choline-PET is recommended for prostate cancer. In situations where a PET scan is unavailable, or for tumors that do not take up radiotracer, a CT neck/chest/abdomen/pelvis and bone scan are required. • Liver: For patients with liver metastases, a diagnostic or simulation MRI is required to confirm the total number of metastases. • No plans for systemic therapy (i.e. chemotherapy, targeted agent, immunotherapy) for 3 months from the time of enrolment. Reasons may include: a break from systemic therapy is desired by the patient and medical oncologist, the patient declines next line of systemic therapy, or no further systemic therapy options are available. Exceptions include hormone therapy for breast cancer or prostate cancer, which may be continued. • SABR or palliative radiotherapy should commence no later than 2 weeks after randomization. • For patients with brain metastases that are going to be treated regardless of the study arm, there must be additional extracranial disease present that will be treated with SABR on Arm 2 and not treated with SABR on Arm 1.