Sentinel lymph node scintigraphy in skin melanoma: personal experience

Background. The technique for studying sentinel lymph nodes (SLN) makes it possible to objectively visualize the direction of lymph drainage from the area of the tumor location, to perform targeted biopsy of the lymph node and morphological exa- mination.

Objective. Evaluation of the effectiveness of lymphoscintigraphy in detecting SLN in patients with localized skin melanoma, comparison of the planar lymphoscintigraphy and SPECT/CT, comparison of the effectiveness of radiopharmaceuticals (RP) Technefit^-99mTc and Nanotop^-99mTc, presentation of our own results.

Methods. 182 SLN scintigraphic studies with Technefit^-99mTc or Nanotop^-99mTc were performed in patients with localized skin melanoma. The radiopharmaceutical was administered at four points intradermally along the periphery of the formation or scar. Planar scintigraphy (96 examinations) or SPECT/CT (86 examinations) was performed. After lymphoscintigraphy, an intraoperative search for SLN followed by urgent histological verification was performed.

Results. According to our data, the SLN detection rate was 95.1%, according to planar lymphoscintigraphy – 94.8%, SPECT/CT – 95.3%. With the introduction of «Technefit^-99mTc», the SLN detection rate was 93.8%, with the introduction of «Nanotop^-99mTc» – 97.1%. In most cases, lymph nodes detected by scintigraphy revealed intraoperatively (93.4%). Metastases in the SLN during urgent histological verification were detected in 20 patients.

Discussion. Negative results of lymphoscintigraphy and intraoperative data may be related to the particle size of Technefit^-99mTc. The SLN detection only by the lymphoscintigraphy is probably associated with the close localization of the lymphatic collector to the tumor, which made it difficult to search for SLN intraoperatively.

Conclusion. The use of radiopharmaceuticals «Technefit^-99mTc» and «Nanotop^-99mTc» showed high efficiency in detecting SLN. The difference between planar scintigraphy and SPECT/CT is insignificant, however, the use of SPECT/CT helps to accurately target the SLN, this is especially true when the mass is localized near the lymphatic collector.