Rob 2007.

Study characteristics
Patient sampling	Prospective study; consecutive sampling (unpublished information). 9 women with 'bulky nodes' were excluded (unpublished information)
Patient characteristics and setting	59 women with vulval SCC stage IB/II; 86 groins Excluded lesions > 4 cm and women with clinically suspicious nodes Age range: 26 to 95 years Setting: a university hospital in the Czech Republic; recruited from December 2001 to December 2005
Index tests	Blue dye only (16 women) and combined technique (blue dye and Tc‐99m; 43 women) Frozen section and ultrastaging with H&E and IHC were performed for SNs. Standard methods were used for non‐SNs
Target condition and reference standard(s)	TC: groin lymph node involvement RS: complete IFL
Flow and timing	Tracer agents were injected intradermally around tumour at 3 sites. Tc‐99m was injected 3 to 4 hours pre‐operatively in a volume of 0.2 to 0.4 ml. Blue dye (1 to 2 ml) was injected 2 to 3 minutes pre‐operatively. SN location was marked on skin. Tc‐99m was detected intra‐operatively by a gamma probe. First SN was identified and nodes exhibiting at least 10% of activity at the area of application were also removed. Blue stained lymphatics were identified visually SND and IFL were performed during the same operation
Comparative
Notes	Investigators reported the blue dye and combined technique accuracy results separately. Additional methodological information and groin data (for the combined technique) were supplied to us by the investigators via email (4 July 2013). 16% of identified SNs were deep femoral groin nodes Frozen section was 98% accurate in this study and influenced the extent of the IFL The optimum timing of pre‐operative LSG was 45 minutes after the Tc‐99m injection
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?	Unclear
		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
		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