The role of SPECT/CT in detection and localization of sentinel lymph node in breast cancer

Abstract

Objectives: The purpose of this study was to compare SPECT/CT and planar lymphoscintigraphy in detecting hot nodes. Methods: In this retrospective study, planar and SPECT/CT lymphoscintigraphy were performed in 119 consecutive women with invasive breast cancer. Both images were assessed for the number of lymph nodes and their anatomical site. Hot nodes were categorized based on the classification used by surgeons as level I, II, III nodes. In addition, pathology reports were retrieved which provided additional information concerning the characteristics of the lesions missed or detected by either or both imaging modalities. Results: SPECT/CT detected hot nodes in 81 (68%) patients, while planar lymphoscintigraphy detected hot nodes in 70 (58.8%) patients. SPECT/CT and planar imaging had 38 (32%) patients in common where they did not detect any hot nodes. According to histopathology, 15 (12.6%) out of 36 patients with negative lymphoscintigraphic sentinel node identification on both modalities had nodal metastasis. The higher lymph node detection rate by SPECT/CT was significant (p = 0.019). Conclusion: When compared to planar lymphoscintigraphy, SPECT/CT refines preoperative lymph node detection and thus (N) staging. As such, we recommend that SPECT/CT ought to be performed in a particular set of patients, for it improves localization of the draining nodes, detects nodes missed on planar, and excludes false positives in cases of lymphatic/blood vessel radiotracer accumulation. © 2018 Lebanese Order of Physicians. All rights reserved.