Targeted high-resolution ultrasound is not an effective substitute for sentinel lymph node biopsy in patients with primary cutaneous melanoma.
OBJECTIVE
To reassess traditional ultrasound descriptors of sentinel lymph node (SLN) metastases, to determine the minimum cross-sectional area (CSA) of an SLN metastasis detectable by ultrasound (US), and to establish whether targeted, high-resolution US of SLNs identified by lymphoscintigraphy before initial melanoma surgery can be used as a substitute for excisional SLN biopsy.


METHODS
US was performed on SLNs identified in 871 lymph node fields in 716 patients. SLN biopsy was performed within 24 hours of lymphoscintigraphy and US examination. The CSA of each SLN metastatic deposit was determined sonographically and histologically.


RESULTS
The sensitivity of targeted US in the detection of positive SLNs was 24.3% (95% CI, 19.5% to 28.7%), and the specificity was 96.8% (95% CI, 95.9% to 97.7%). The sensitivity was highest for neck SLNs (45.8%) and improved with greater Breslow thickness. The median histologic CSA of the SLN metastatic deposits was 0.39 mm(2) (12.75 mm(2) for US true-positive results and 0.22 mm(2) for US false-negative results). True-positive, US-detected SLNs had significantly greater CSAs (t test P < .001) than undetected SLN metastases and were more likely to be spherical in cross-section. More than two sonographic descriptors of SLN metastases or rounding of the node alone were factors highly suggestive of a melanoma deposit.


CONCLUSIONS
US is not an appropriate substitute for SLN biopsy, but it is of value in preoperative SLN assessment and postoperative monitoring.
Melanoma Institute Australia and Sydney Melanoma Unit, Royal Prince Alfred and Mater Hospitals, Sydney, New South Wales, Australia
Amira
A
Sanki
Roger F
RF
Uren
Marc
M
Moncrieff
Kayla L
KL
Tran
Richard A
RA
Scolyer
Hui-Yi
HY
Lin
John F
JF
Thompson
D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D015331:Cohort Studies; D016001:Confidence Intervals; D003287:Contrast Media; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging* / Q000473:pathology* / Q000556:secondary; D008875:Middle Aged; D009367:Neoplasm Staging; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy; D012878:Skin Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology*; D018608:Ultrasonography, Doppler; D055815:Young Adult
D003287:Contrast Media