Louis‐Sylvestre 2006.

Study characteristics
Patient sampling	Prospective study; consecutive sampling
Patient characteristics and setting	38 women with operable vulval cancer; 64 groins; depth of invasion > 1 mm; histology not specified; 12 lateralised and 26 median lesions Excluded if prior excisional biopsy. Included 6 women with clinically suspicious nodes (N1) Median age: 66 years (34 to 90) Setting: a tertiary institution in France; enrolled between June 2002 and December 2005
Index tests	Tc‐99m and blue dye Blue dye was optional and not used in 8 women Histological methods: ultrastaging was not done. IHC staining was performed on SNs if H&E stain was negative
Target condition and reference standard(s)	TC: groin lymph node involvement RS: complete IFL
Flow and timing	1 day pre‐operatively, Tc‐99m was injected in 3 x intradermal peritumoural injections (30 MBq) and immediately followed by LSG. SN site/s were located with hand‐held gamma probe and marked on the skin. Blue dye was injected in the same way intra‐operatively SND and RS were performed during the same operation Withdrawals not described
Comparative
Notes	Considered midline if within 1 cm of the midline This study incorporates the data for 17 women from an earlier publication (Louis‐Sylvestre 2005) Due to the high risk of bias from the inclusion of 6 women with obvious groin involvement, we excluded these women in our data extraction. This resulted in a groin detection rate of 39/52 (compared with the published rate of 47/64) and no false negatives. (The only false negative in this study occurred in a woman with obvious bilateral groin node involvement)
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	High
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?	Unclear
Were other imaging tests performed prior to the index test to rule out groin lymph node metastases?	Unclear
		Unclear