Preoperative Ultrasound is Not Useful for Identifying Nodal Metastasis in Melanoma Patients Undergoing Sentinel Node Biopsy: Preoperative Ultrasound in Clinically Node-Negative Melanoma

Abstract

Background Sentinel lymph node biopsy (SLNB) is widely used in melanoma. Identifying nodal involvement preoperatively using high-resolution ultrasound may offer less invasive staging. This study assessed feasibility and staging results of clinically-targeted ultrasound (before lymphoscintigraphy) compared to SLNB. Methods From 2005–2009, 325 patients with melanoma underwent ultrasound before SLNB. We reviewed demographics and histopathologic characteristics, then compared ultrasound and SLNB results. Sensitivity, specificity, positive and negative predictive value (PPV, NPV) were determined. Results 325 patients, 58% male; 42% female, median age 58 years (range 18–86) were included. A total of 471 basins were examined with ultrasound. Only 6 patients (1.8%) avoided SLNB by undergoing ultrasound-guided fine needle aspiration of involved nodes, then therapeutic lymphadenectomy. 65 patients (20.4%) had 69 SLNB positive nodal basins; 17 nodal basins from 15 patients with positive ultrasounds were considered true-positive. 45 SLNB positive basins had negative ultrasounds (false-negative). 7 node-positive basins did not undergo ultrasound because of unpredicted drainage. 253 patients with negative SLNBs had negative ultrasounds in 240 nodal basins (true-negative) but false-positive ultrasounds occurred in 40 basins. Overall, sensitivity of ultrasound was 33.8%, specificity 85.7%, PPV 36.5% and NPV 84.2%. Sensitivity and specificity improved somewhat with increasing Breslow depth. Sensitivity was highest for the neck, but specificity was highest for the groin. Conclusions Routine preoperative ultrasound in clinically node-negative melanoma is impractical due to low sensitivity. Selected patients with thick or ulcerated lesions may benefit. Because of variable lymphatic drainage patterns, preoperative ultrasound without lymphoscintigraphic localization will provide incomplete evaluation in many cases.

Ultrasound-guided fine needle aspiration cytology as an addendum to sentinel lymph node biopsy can perfect the staging strategy in melanoma patients

“…When compared to the literature, the sensitivity in our hands (51%) is significantly higher than previously reported rates, which differ from 4% to 39% [24][25][26][27][28][29]. In these relatively small series, Starritt et that high-resolution ultrasound (HRUS) yielded a sensitivity of 12% (2/17) [28].…”

“…In these relatively small series, Starritt et that high-resolution ultrasound (HRUS) yielded a sensitivity of 12% (2/17) [28]. Chai et al demonstrated a sensitivity of 34%, but only 10 patients (3.4%) could undergo US-FNAC prior to the surgical SN in their study [29]. The preliminary results of one larger series, pre-SN US-FNAC in the MSLT-2 study, reported sensitivity of merely 4.2% (8/193) [24].…”

Acute Toxoplasmosis Mimicking Melanoma Metastases: Review of Conditions Causing False-Positive Results on ¹⁸F-FDG PET/CT

“…Occult lymph node metastasis is present in 15-20% of patients with melanoma of the head and neck and clinically negative nodes. According to Chai et al [24], preoperative ultrasound (US) is not useful for identifying nodal metastasis in clinically node-negative melanoma patients undergoing sentinel node (SN) biopsy. In 471 patients, the overall sensitivity of US was 33.8%, specificity 85.7%, positive predictive value 36.5%, and negative predictive value 84.2%, respectively.…”

“…The sensitivity and specificity appeared to improve somewhat with increasing Breslow depth. Sensitivity was highest for the neck, but specificity was highest for the groin [24]. However, the combination of preoperative US and US-guided FNA cytology can identify 65% of SN metastases and thus reduce the need for surgical SN procedures [25].…”

Short-Term and Long-Term Management of Melanoma

“…The authors concluded that routine preoperative US in clinically node-negative melanoma is impractical because of its low sensitivity, but selected patients with thick or ulcerated lesions may benefit. However, because of variable lymphatic drainage patterns, preoperative US without lymphoscintigraphic localization will provide incomplete evaluation in many cases (28). These data can be extrapolated for patients in the follow-up setting given the low sensitivity of US in clinically node-negative patients.…”