The added value of SPECT-CT for the identification of sentinel lymph nodes in early stage oral cancer

Inne J Den Toom,Elisabeth Bloemena,K Hakki Karagozoglu,Otto S Hoekstra,Stijn Van Weert,Annelies Van Schie,Remco De Bree

doi:10.1007/s00259-017-3613-8

Abstract

PurposeTo assess the role of single-photon emission computed tomography with computed tomography (SPECT-CT) for the identification of sentinel lymph nodes (SLNs) in patients with early stage (T1–T2) oral cancer and a clinically negative neck (cN0).MethodsIn addition to planar lymphoscintigraphy, SPECT-CT was performed in 66 consecutive patients with early stage oral cancer and a clinically negative neck. The addition of SPECT-CT to planar images was retrospectively analyzed for the number of additional SLNs, more precise localization of SLNs, and importance of anatomical information by a team consisting of a nuclear physician, surgeon, and investigator.ResultsIdentification rate for both imaging modalities combined was 98% (65/66). SPECT-CT identified 15 additional SLNs in 14 patients (22%). In 2/15 (13%) of these additional SLNs, the only metastasis was found, resulting in an upstaging rate of 3% (2/65). In 20% of the patients with at least one positive SLN, the only positive SLN was detected due to the addition of SPECT-CT. SPECT-CT was considered to add important anatomical information in two patients (3%). In 5/65 (8%) of the patients initially scored SLNs on planar lymphoscintigrams were scored as non-SLNs when SPECT-CT was added. There were four false-negative SLN biopsy procedures in this cohort.ConclusionsThe addition of SPECT-CT to planar lymphoscintigraphy is recommended for the identification of more (positive) SLNs and better topographical orientation for surgery in sentinel lymph node biopsy for early stage oral cancer.

Highlights

Sentinel lymph node biopsy (SLNB) in early stage oral cancer is increasingly accepted as standard of care for staging of occult lymph node metastasis
The addition of SPECT-CT to planar lymphoscintigraphy is recommended for the identification of more sentinel lymph nodes (SLNs) and better topographical orientation for surgery in sentinel lymph node biopsy for early stage oral cancer
In the rest of the patients, a better topographical orientation for the surgeon had been provided by SPECT-CT compared with planar imaging, but the reading team had the impression that SLNB could be successfully performed with planar lymphoscintigraphy only

Summary

Introduction

Sentinel lymph node biopsy (SLNB) in early stage oral cancer is increasingly accepted as standard of care for staging of occult lymph node metastasis. Trials in which only neck dissection is performed after positive SLNB have demonstrated that SLNB is a sensitive method for the detection of occult cervical lymph node metastases. Eur J Nucl Med Mol Imaging (2017) 44:998–1004 with floor-of-mouth tumors, probably due to the Bshinethrough phenomenon^; the large injection spot of the primary tumor overshines the eventual sentinel lymph nodes (SLNs) in level I. Studies of SPECTCT in SLNB, which included different locations of primary tumors, found especially advantages for tumors with close proximity to the SLN and complex lymphatic regions which is the case in the head-and-neck region [6]

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