Table 3. The search strategy used for the MEDLINE and EMBASE databases.

#	Search string
1	PET OR “positron emission tomography”
2	MRI OR “magnetic resonance imaging”
3	“distant metastases” OR staging OR “brain metastases”
4	NSLC OR SLC OR “lung cancer”
5	#1 AND #2 AND #3 AND #4