Table 1. Patient selection criteria.

Inclusion criteria	Exclusion criteria
Clinicopathologic considerations	Clinicopathologic considerations
1. Pathologic stage I or II NSCLC	1. Wedge resection
2. Surgical procedures performed with intent to cure	2. Stage IIIA disease or greater
3. Performance of lobectomy or pneumonectomy	3. Treatment with neoadjuvant chemotherapy or chemoradiation therapy
4. Performance of mediastinal lymph node sampling or dissection	4. The presence of synchronous lung masses
5. Follow-up clinic and imaging data for 5 years postoperatively	5. Lost to follow-up without retrievable records or from which recurrence data could not be determined
	6. Adenocarcinoma in situ or more than one tumor in the specimen
	7. Recurrence within 3 months of resection
Imaging considerations	Imaging considerations
1. PET/CT scans performed at the study institution	1. Tumors less than 2 cm
2. Surgical procedures performed within 90 days of imaging study	2. Greater than 90 days between imaging and surgical procedure
3. Imaging performed on one of three dedicated clinical scanners	3. Use of outside or non-dedicated clinical scanner

NSCLC, non-small cell lung cancer; PET/CT, positron emission tomography/computerized tomography.