Koksal 2013.

Study characteristics
Patient sampling	Retrospective patient series
Patient characteristics and setting	81 participants, mean age = 59.8 (SD = 8, range = 38 to 74) years, 77 males/4 females, Turkey Histology of primary tumour Adenocarcinoma: N = 32; squamous cell: N = 43; adenosquamous: N = 4; pleomorphic carcinoma: N = 2; comorbidities: not reported Inclusion criteria Patients with NSCLC who had not received chemotherapy or radiotherapy, with a PET‐CT examination at the time of initial staging who subsequently underwent surgical resection Exclusion criteria None listed Previous/all tests Not reported Clinical setting Tertiary setting The inclusion of only participants who received surgery narrows the range of patients who would receive PET‐CT in practice, namely, patients (clinically) with suspected resectable non‐small cell lung cancer, a proportion of whom would have N2 or N3 disease already on PET‐CT
Index tests	PET‐CT was carried out with an integrated PET/CT scanner (Siemens, Biograph‐6 True Point) within the 30 days before the surgery in all of the participants. Participants were instructed to fast for at least 6 hours before the examination. After confirmation of a normal peripheral blood glucose level (< 180 mg/dL), the participants received an intravenous injection of 145 μCi/kg (maximum 200 μCi) of FDG and rested for 60 minutes before the scan. Images were obtained from the base of skull to mid‐thigh level. Software determined automatically the SUVmax of the primary tumours and each suspicious lymph node stations after delineation of the region of interest on attenuation‐corrected PET‐CT images. All PET‐CT scans were re‐evaluated. SUVmax of the primary tumours and dissected mediastinal and hilar lymph node stations were noted. Positivity of lymph node stations was rated according to 2 criteria: 1) SUVmax > 2.5; 2) FDG uptake higher than the surrounding mediastinal blood pool Covariates Type of PET‐CT scanner: Siemens, Biograph‐6 True Point FDG dose: 145 μCi/kg (maximum 200 μCi) (equivalent to 5.365 MBq/kg up to a max of 740 MBq) Injection‐to‐scan time: 60 min Attenuation correction: yes Cut‐off values for test positivity (malignancy): SUVmax > 2.5, but also data for lymph node stations were considered as positive if there was a FDG uptake higher than the surrounding mediastinal blood pool
Target condition and reference standard(s)	Resection (lobectomy: N = 55, pneumonectomy: N = 25, and wedge resection: N = 1) with complete ipsilateral hilar and mediastinal lymph node dissection
Flow and timing	All participants were accounted for in the data. Index test received within 30 days of reference standard
Comparative
Notes	The author emailed the individual participant data, which we classified according to 2 criteria: 1) SUVmax > 2.5: TP = 8, FN = 4, FP = 22, TN = 47; 2) FDG uptake higher than the surrounding mediastinal blood pool: TP = 8, FN = 4, FP = 31, TN = 38. The former data have been used for analysis Funding: no details reported, but the authors did state they had no financial conflict of interest that could bias the work Adverse events: none reported
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Unclear
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Unclear
		Unclear	High
DOMAIN 2: Index Test All tests
Were the index test results interpreted without knowledge of the results of the reference standard?	Unclear
Was there a pre‐specified cut‐off value?	No
Was a positive result defined?	Yes
		Unclear	Low
DOMAIN 3: Reference Standard
Is the reference standards likely to correctly classify the target condition?	Yes
Were the reference standard results interpreted without knowledge of the results of the index tests?	Unclear
		Low	Low
DOMAIN 4: Flow and Timing
Was there an appropriate interval between index test and reference standard?	Yes
Did all patients receive the same reference standard?	Yes
Were all patients included in the analysis?	Yes
		Low