SOFT- Stereotactic Ablative Radiotherapy of Infra-diaphragmatic Soft Tissue Metastases

Inclusion Criteria:

* Histology or cytology proven non-haematological cancer.
* At least one metastasis should be localized in the infra-diaphragmatic soft tissue.
* Eastern Cooperative Oncology Group (ECOG) scale of performance status ≤ 2.
* ≥ 18 years old.
* Life expectancy \> 6 months.
* Target diameter (GTV) ≤ 5 cm.
* Metastatic lesions must be visible, imaging defined targets and suitable for treatment with SABR.
* In case of de novo OMD and oligometastatic recurrence a maximum of 5 targets (including the primary tumour) in a maximum of 3 organ sites are allowed.
* In case of oligoprogressive disease (OPD) \* and induced OMD \*\* only 3 metastases (including the primary tumour) are allowed.
* All metastatic sites are treated or planned for ablative therapy (including surgery). For OPD, only the sites in progression is required to fulfil this criterion.
* A baseline scan within 28 days of inclusion (PET-CT or CT and MR scanning).
* No curative intended treatment option available.
* An ablative strategy should be deemed clinically relevant and it is at the discretion of the treating physician to decide.
* Ability to understand and the willingness to sign a written informed consent document.
* If the target is in the liver, a Child-Pugh Score A is required.

Exclusion Criteria:

* Patient cannot tolerate physical set up required for SABR.
* Active bowel obstruction.
* Uncontrolled intercurrent illness.
* Medical contraindication to undergoing MR-imaging.
* Pregnancy.
* Patients with uncontrolled brain metastases.
* Uncontrolled disease in respect to malignant pleural effusion, ascites, lymphangitic carcinomatosis, pleural carcinomatosis or peritoneal carcinomatosis.
* If the patient has received previous radiotherapy, the combined dose at the radiation site must not exceed the dose constraints.