Bony M - Stereotactic Ablative Radiotherapy (SABR) of Bony Metastases in Patients With Oligometastatic Disease

This is a prospective, investigator-initiated, phase II, multicentre-study, investigating the efficacy and toxicity of definitive SABR of osseous oligometastases, when pragmatically introduced into a daily clinical setting.

Patients with a histology or cytology proven non-hematological cancer and at least one lesion in the bones are eligible.

Patients with de novo- and induced oligometastatic disease, as well as patients with oligo-recurrence or oligo-progression disease can be included. A total of 67 patients will be enrolled.

The overall aim is to document long time follow-up in respect to local control rate, OS, PFS, rate of symptomatic skeletal event at the irradiated site(s), time to progression outside the radiation field at 1-, 2- and 5-years and acute/ late toxicities.

The primary endpoint is the rate of local control 1-year post SABR. Patients will have a CT scan and a clinical evaluation every 3 month after SABR according to the standard clinical follow-up program.

During the 1 year follow-up we also perform pain assessment (using the Numeric Pain Rating Scale), report the analgesic consumption and Quality of life (QoL) measured with EQ-5D-5L.

Two dose levels are offered with either 37.5 gy in 3 fractions or 30 gy in 3 fractions, prescribed to the GTV.

Eligibility Criteria:
Inclusion Criteria:

* Histology or cytology proven non-haematological cancer.
* At least one lesion in the bones is required.
* ECOG performance status ≤ 2.
* ≥ 18 years old.
* Life expectancy \> 6 months.
* GTV diameter ≤ 5 cm.
* In case of de novo OMD and OMD recurrence a maximum of 5 targets (including the primary tumour) in a maximum of 3 organ sites are allowed.
* In case of OPD \* and induced OMD\*2 only 3 metastases (including the primary tumour) are allowed.
* The metastatic lesion(s) must be visible on a CT- or MR- scan and suitable for treatment with SABR.
* 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 (CT or PET- CT).
* For spine/paraspinal targets, an MR scan is mandatory, if epidural growth cannot be precluded on the baseline CT scan.
* No curative intended treatment option available.
* An ablative strategy should be deemed clinically relevant and is at the discretion of the treating physician to decide.
* Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

* Patient cannot tolerate physical set up required for SABR.
* Uncontrolled intercurrent illness.
* Pregnancy.
* Bilsky score ≥ 1b. If the patient is treated with surgery, a pre-operative Bilsky score ≥ 1b is an exclusion criterion as well. See appendix A for Bilsky score.
* Presence of myelopathy from the target area.
* Candidate for surgical treatment (determined by the institutions clinical oncologist, neurosurgeon or orthopaedic surgeon).
* For spine/paraspinal lesions where epidural growth cannot be precluded on the baseline CT scan: patients for whom an MR scan is contraindicated.
* Mechanical instability and/or fracture risk \*3.
* For spine disease, involvement of ≥ three contiguous vertebrae.
* Uncontrolled disease in respect to malignant pleural effusion, ascites, lymphangitic carcinomatosis, pleural carcinomatosis or peritoneal carcinomatosis.
* Patients with uncontrolled brain metastases.
* If the patient has received previous radiotherapy, the combined dose at the radiation site must not exceed the dose constraints according to Appendix B. -