Table 1 Baseline demographic and clinical characteristics

Sex (male/female)

19/13

Age^a (years), median (range)

65 (14–87)

Primary cancer

 Non-small cell lung cancer

  EGFR wild-type

14

  EGFR mutant

5

 Small cell lung cancer

3

 Breast cancer

  HER2-positive

4

  HER2-negative

1

 Gastrointestinal cancer

2

 Oesophageal cancer

1

 Sinonasal adenoid cystic carcinoma

1

 Rhabdomyosarcoma

1

KPS^a, median (range)

90 (50–100)

Neurological deficits^a

24 (75%)

RTOG-RPA Class^a (I/II/III)

8/18/6

Multiple BM^a

16 (50%)

Prior radiotherapy (per lesion)

  Proton therapy

1

  SRS

21

  WBRT + SRS

3

  SRS × 2

9

  SRS × 3

2

  SRS × 4

1

Time from primary radiotherapy to MET-PET (months), median (range)

18.8 (4–120)