Utility of single photon emission computed tomography–computed tomography in selective sentinel lymph node biopsy in patients with melanoma

Abstract Objective To assess the contribution of SPECT–CT lymphoscintigraphy in selective sentinel lymph node biopsy (SLNB) in patients with newly diagnosed malignant melanoma. Material and methods A prospective study was made between July 2009 and October 2010. It included 63 patients diagnosed with melanoma (32 men and 31 women) with mean age of 55 years (range: 25–88) and inclusion criteria for SLNB. The melanomas were located as follows: 28 in trunk, 5 in head and neck, 16 in upper limbs and 17 in lower limbs. Three patients had two melanomas. Preoperative lymphoscintigraphy was performed after pericicatricial/perilesional injection of 74 MBq of 99m Tc-labeled nanocolloid human serum albumin, obtaining early planar images, late whole body study and sectorial images and SPECT–CT in the area of interest. Planar scintigraphy findings were compared with SPECT–CT. Results The sentinel node (SN) was localized by planar imaging in 62/63 (98%) patients. SPECT–CT study located the SN in all the patients with a detection rate of 100%. The number of SNs detected with SPECT–CT was higher than that with the planar study in 27 patients. The SPECT–CT provided additional information (change in location and/or in its accuracy in the localization of location uncertain SN) in 14/63 (22.2%) patients, involving changes in the surgical approach and lymph node staging. Conclusion SPECT–CT detects a higher number of SN than planar lymphoscintigraphy in patients with melanoma. Its contribution is more relevant in the melanomas located on the trunk, head and neck. SPECT–CT modified the SN location by 22% compared to planar scan findings, facilitating a correct surgical approach.