John F. Thompson, MD,*1 Lauren E. Haydu, PhD,1 Roger F. Uren, MD1, Robert H. Andtbacka, MD2, Jonathan S. Zager, MD3, Peter D. Beitsch, MD4, Doreen Agnese, MD5, Nicola Mozzillo, MD6, Alessandro Testori, MD7, Tawnya L. Bowles, MD8, Harald J. Hoekstra, MD, PhD9, Mark C. Kelley, MD10, Jeffrey Sussman, MD11, Schlomo Schneebaum, MD12, B. Mark Smithers, MBBS13, Gregory McKinnon, MD14, Eddy Hsueh, MD15, Lisa Jacobs, MD16, Erwin Schultz, MD17, Douglas Reintgen, MD3, John M. Kane, MD18, Erica B. Friedman, MD1, Hejing Wang, MD19, Lisa Van Kreuningen, MS20, Vicki Schiller, MD21, David A. Elashoff, PhD19, Robert Elashoff, MD19, Alistair J. Cochran, MD19, Stacey Stern, MS20, Mark B Faries MD20, and the MSLT-II Trial Group
1Melanoma Institute Australia, The University of Sydney, 2Huntsman Cancer Institute, 3H. Lee Moffitt Cancer Center, 4Dallas Surgical Group, 5Ohio State University, 6Istituto Nazionale dei Tumori Napoli, 7Istituto Europeo de Oncologia, 8IHC Cancer Services – Intermountain Medical Center, 9University Medical Center Groningen, 10Vanderbilt University, 11University of Cincinnati, 12Tel-Aviv Sourasky Medical Center, 13Princess Alexandra Hospital, 14Tom Baker Cancer Centre, 15Saint Louis University, 16Johns Hopkins Medical Institute, 17City Hospital of Nürnberg, Paracelsus Medical University, 18Roswell Park Comprehensive Cancer Center, 19University of California at Los Angeles; 20John Wayne Cancer Institute, 21Providence St John’s Health Center
Corresponding author:
John F Thompson MD
Melanoma Institute Australia
40 Rocklands Road
NORTH SYDNEY NSW 2060
AUSTRALIA
Tel: +612 9911 7366
E: john.thompson@melanoma.org.au
ABSTRACT
Introduction: It has been suggested that preoperative ultrasound (US) assessment of regional lymph nodes in patients who present with primary cutaneous melanoma provides accurate staging and avoids the need for sentinel node (SN) biopsy. However, in most single institution studies the reported sensitivity for preoperative US detection of nodal metastases has been low.
Methods: Preoperative US data and SNB results were analyzed for patients enrolled at 20 centers participating in the screening phase of the second Multicenter Selective Lymphadenectomy Trial. Excised SNs were histopathologically assessed and considered positive if any melanoma was seen.
Results: SNs were identified and removed from 2786 patients who had pre-operative US evaluation. Among those patients, 531 had SN metastases. US was positive (abnormal) in 85 patients (3.1%). Among SN-positive patients, 39 (7.3%) had an abnormal US. When analyzed by lymph node basin, 3222 basins were evaluated, and 38 were true positive (1.2%). By basin, the sensitivity of US was 6.8% (95% CI: 4.7%-8.9%) and the specificity 98.0% (95% CI: 97.5%-98.5%). Median cross sectional area of all SN metastases was 0.13mm2; in US true-positive nodes it was 4.8mm2. US sensitivity increased with increasing Breslow thickness of the primary melanoma (0% for ≤1mm thickness, 12.4% for >4mm thickness). US sensitivity was not significantly greater with higher trial center volume or with pre-US lymphoscintigraphy.
Conclusion: In the MSLT-II screening phase population, SN tumor volume was usually too small to be reliably detected by US. For accurate nodal staging to guide the management of melanoma patients, US is not an effective substitute for SN biopsy.