Radziszewski 2010.

Study characteristics
Patient sampling	Prospective study; consecutive sampling; 6 withdrawals explained
Patient characteristics and setting	62 women with clinical stage I/II vulval SCC ≤ 4 cm; depth > 1 mm; histologically confirmed; no obvious nodal involvement; WHO performance status I‐II Median age: 68 years (37 to 94) Setting: tertiary hospital in Poland; January 2002 to December 2006
Index tests	Tc‐99m and blue dye were used (results were compared and reported separately) Histological methods: standard sections with H&E and IHC stains were performed for SN and non‐SN assessment. In addition, all specimens were subjected to a RT‐PCR test for CA9 marker expression
Target condition and reference standard(s)	TC: groin lymph node involvement RS: complete IFL
Flow and timing	24 hours pre‐operatively, Tc‐99m (1.2 mCi) was injected as 3 intradermal perilesional injections and followed 1 hour later by LSG. A 2.5% solution of patent blue was injected in a similar way, 10 minutes before the skin incision Radioactivity was detected intra‐operatively by hand‐held gamma probe. SND and IFL were performed during the same operation
Comparative
Notes	Detection rates were reported separately for blue dye and Tc‐99m 6 women were excluded as they did not fulfil the inclusion criteria (e.g. lymph node metastasis on FNA) SNs and non‐SNs were also assessed for CA9 marker expression by RT‐PCR. This method detected twice as many positive SNs (and 1 additional false negative) as the H&E/IHC method, however the clinical significance of these micrometastases is not known
Methodological quality
Item	Authors' judgement	Risk of bias	Applicability concerns
DOMAIN 1: Patient Selection
Was a consecutive or random sample of patients enrolled?	Yes
Was a case‐control design avoided?	Yes
Did the study avoid inappropriate exclusions?	Yes
		Low	Low
DOMAIN 2: Index Test Test group
Had the test operator performed 10 or more procedures?	No
		High	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
		Unclear	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
Were other imaging tests performed prior to the index test to rule out groin lymph node metastases?	Yes
		Unclear