ABSTRACT

Sentinel lymph node is the first lymph node that drains the tumor and it represents the histopathology of whole lymphatic basin. Sentinel lymph node concept serves as a significant determinant to avoid futile lymph node dissections with high morbidity and also to lead to appropriate therapeutic option and to provide prognostic information especially in solid tumors like breast cancer and malignant melanoma in which lymph node metastasis has a prognostic significance. Single-photon emission computed tomography/computed tomography (SPECT/CT), as one of the most recently introduced hybrid imaging systems, provides additional value to conventional nuclear medicine imaging in sentinel lymph node detection. SPECT/CT is useful for easy assessment of true anatomic localisation and the number of sentinel lymph nodes, for detection of sentinel lymph nodes adjacent to injection site that are difficult to be detected on planar imaging, and for confirmation of false positive foci. SPECT/CT has also an important role for radioguided occult lesion localisation (ROLL) method, in which mostly non-palpable occult tumoral lesions can be easily and precisely localised and resected with gamma probe guidance. Sentinel lymph node detection and lymphatic mapping are expected to be increasingly used in head-and-neck, gynecologic, and male genital cancers as followed by technological improvements in hybrid imaging.