The impact of sentinel lymph node mapping with hybrid single photon emission computed tomography/computed tomography in patients with melanoma. Comparison to planar radioisotopic lymphoscintigraphy

Melanoma Res. 2023 Jun 1;33(3):239-246. doi: 10.1097/CMR.0000000000000893. Epub 2023 Apr 12.

Abstract

We studied the diagnostic value of 16 slices of single photon emission computed tomography (SPECT)/computed tomography (CT) in the anatomical localization, image interpretation and extra-sentinel lymph nodes (SLNs) detection compared to dynamic and static planar radioisotopic lymphoscintigraphy (PLS) in patients with melanoma. Eighty-two patients with melanoma underwent dynamic PLS, static PLS and SPECT/CT. Data were obtained using a dual head SPECT/CT 16 slices γ-camera. We evaluated the number and localization of SLNs detected with each imaging method. SPECT/CT demonstrated 48 additional SLNs in comparison with PLS in 29 patients. In five truncal and seven head-neck lesions, dynamic and static PLS failed to detect the SLNs found on SPECT/CT (false negative). In one case of truncal and one case of lower limb melanoma, the foci of increased activity interpreted on PLS as possible SLNs were confirmed to be non-nodal sites of uptake on SPECT/CT (false positive). PLS underestimated the number of SLNs detected, whereas SPECT/CT revealed higher agreement compared to the respective number from histological reports. SPECT/CT showed a better prediction of the number of SLNs and higher diagnostic parameters in comparison to planar imaging. SPECT/CT is an important complementary diagnostic modality to PLS, that improves detection, preoperative evaluation, anatomical landmarks of SLNs and surgical management of patients with melanoma.

MeSH terms

  • Humans
  • Lymph Nodes / diagnostic imaging
  • Lymph Nodes / pathology
  • Lymphoscintigraphy / methods
  • Melanoma* / pathology
  • Sentinel Lymph Node Biopsy / methods
  • Sentinel Lymph Node* / diagnostic imaging
  • Sentinel Lymph Node* / pathology
  • Single Photon Emission Computed Tomography Computed Tomography / methods
  • Skin Neoplasms* / pathology
  • Tomography, Emission-Computed, Single-Photon / methods