Yang 2008.

Study characteristics
Patient sampling	Prospective consecutive? patient series
Patient characteristics and setting	122 participants, median age = 69 (range = 32 to 84) years, 78 males/44 females, China Histology of primary tumour Adenocarcinoma: N = 63; squamous cell: N = 54; bronchoalveolar carcinoma: N = 3; large cell neuroendocrine cancer: N = 2; comorbidities: not reported Inclusion criteria Participants with histologically diagnosed or suspected non‐small cell lung cancer referred for operation during the study period. The participants had stage I, II, and selected IIIA (i.e., the participants with T3 N1 stage and N2 stage with single stationed small N2 nodal metastasis or with only a few small N2 lymph node metastases after mediastinoscopy) Exclusion criteria Allergy to iodine contrast and hyperglycaemia over 9 mmol/L on the day when the FDG PET‐CT scan was performed, participants who received prior chemotherapy or radiotherapy Previous tests Standard preoperative staging procedures, including physical examination, laboratory testing, and ultrasound of the neck and abdomen, chest radiography, pulmonary function, and bronchoscopy Clinical setting Cancer hospital 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	All participants fasted for at least 6 h before examination and had a normal blood glucose levels in peripheral blood. The participants then received an intravenous injection of 370 MBq (10 mCi) of FDG and rested for approximately 60 min before scanning. Scanning was performed with an integrated in‐line PET/CT system (Discovery LS; GE Healthcare). Unenhanced CT was performed first followed by PET emission scan. 2 experienced nuclear medicine physicians were responsible for the interpretation of PET‐CT images. Only 1 final decision was made by these 2 physicians Covariates Type of PET‐CT scanner: integrated PET‐CT scanner (Discovery LS; GE Healthcare) FDG dose: 370 MBq (10 mCi) Injection‐to‐scan time: 60 min Attenuation correction: yes Cut‐off values for test positivity (malignancy): When an area of presumed lymph node showed FDG uptake that was focally prominent compared with surrounding tissues and not related to normal physiologic uptake, it was considered to be positive for malignancy. A site of increased FDG uptakes was defined as negative when it was related to the physiologic biodistribution of FDG
Target condition and reference standard(s)	100 participants underwent lobectomy, 12 participants underwent bilobectomy, 10 participants underwent pneumonectomy. During surgery, experienced thoracic surgeons dissected all visible and palpable lymph nodes in the surgical field that were accessible in the hilum and mediastinum, taking into consideration all results from the preoperative imaging examinations including the results of CT and PET/CT, irrespective of the size of the node. The specimens were stained by a standard haematoxylin‐eosin staining and examined with optical light microscopy
Flow and timing	All participants were accounted for in the results. All participants received the reference standard. There were no uninterpretable results
Comparative
Notes	This study was supported by Research Fund of Shandong Provincial Health Bureau, Shandong Province, China Adverse events: not 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?	Yes
Was there a pre‐specified cut‐off value?	No
Was a positive result defined?	Yes
		Low	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?	No
		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