To observe the quality of life (QOL) and to report on toxicity and outcome parameters after the (repeated) use of local ablative therapy (LAT) i.e. stereotactic radiotherapy (SRT) for patients with multiple (4-10) brain metastases

Phase IV prospective non-randomized observational trial (registry trial) for patients with a DS-GPA > 1.5 or an estimated life expectancy of >3 months and an established diagnosis on dedicated brain MRI of 4-10 BM of any solid primary tumor.

We plan to deliver a local ablative therapy (LAT) i.e. SRT in 1 to 5 fractions on visible BM and post-surgical cavities if applicable.

Our primary aim is to provide quality of life (QOL) data and our secondary aim is to report on several toxicity and outcome parameters for this patient cohort.

Inclusion Criteria:

1. Male or female, ≥ 18 years of age
2. Minimal 4 and up to a maximum of 10 synchronous BM diagnosed on a high resolution contrast-enhanced MRI scan (T1 gadolinium) not dated more than 4 weeks prior to inclusion.
3. Maximal lesion diameter of single gross tumor volume (GTV) of 3 cm
4. Maximal cumulative GTV (+CTV for cavity) of 30cm3
5. Karnofsky performance status ≥ 70
6. DS-GPA or expected overall survival (if no DS-GPA applicable) of ≥ 1.5 or >3 months respectively.
7. Any solid primary tumour. Lymphoma, germ cell tumor, small cell lung carcinoma and multiple myeloma are excluded.
8. Ability to provide written informed consent and to participate in the procedure of the questionnaires.

Exclusion Criteria:

1. BM not amenable to SRT
2. Previous SRT or surgery on the same lesion
3. Co-morbidities considered clinically precluding the safe use of an MRI examination or SRT
4. Any psychological, sociological or geographical issue potentially hampering compliance with the study
5. Pregnancy
6. Concurrent use of systemic therapy
7. More than 10 BM on planning-MRI
8. Maximum cumulative GTV (+CTV for cavity) of more than 30cm3 on planning-MRI
9. A brainstem metastasis with a PTV of more than 20 cm3
10. Leptomeningeal disease

Adult patients with an established diagnosis on dedicated brain magnetic resonance (MRI) of 4-10 brain metastases (BM) of any solid tumor with an estimated life expectancy of >3 months or a disease specific grade prognostic index (DS-GPA) of ≥ 1.5.