Table 2

Diagnostic performance of LymphPET and ultrasound in axillary staging

Axillary imaging assessment	n	Macrometastases	Micrometastases	Non-metastases	Sensitivity	Specificity	NPV
Ultrasound‡		40	16
US-neg	124	17	12	95	57.5	71.8	86.3
US-det	46	14	4	28
US-met	19	9	0	10
LymphPET†
Negative	131	16	11	104	60	77.2	87.8
Positive	58	24	5	29
Combination*
Negative	100	9	9	82	77.5	61.1	91
Positive	89	31	7	51

‡US-neg, no lymph nodes detected by ultrasound; US-det, lymph nodes detected by ultrasound; US-met, suspected metastatic lymph nodes detected by ultrasound.

†maxLUV of LymphPET was set at 0.27 (negative < 0.27, positive ≥0.27).

*Negative, no lymph nodes detected by ultrasound and maxLUV in LymphPET < 0.27; positive, lymph nodes detected by ultrasound and/or maxLUV in LymphPET ≥0.27.

Sensitivity, specificity, and NVP were calculated according to lymph node macrometastases.