lymphoscintigrafi

Lyphoscintigrafi, or lymphoscintigraphy, is a nuclear medicine imaging method used to assess the lymphatic system. It involves the administration of a radiopharmaceutical tracer that allows visualization of lymph flow from a region of interest to the corresponding regional lymph nodes, including sentinel nodes in cancer care.

The procedure typically uses technetium-99m labeled colloids, such as Tc-99m nanocolloid, injected intradermally around the area of concern. After injection, a gamma camera sequentially images the lymphatic channels to follow tracer movement, identifying the drainage pathways and the first draining (sentinel) lymph nodes. Dynamic imaging captures early lymph flow, followed by static images at later time points; many centers also combine single-photon emission computed tomography with computed tomography (SPECT/CT) for improved anatomic localization.

Indications include sentinel lymph node mapping in cancers such as breast cancer and melanoma, to guide biopsy and staging. It is also used in the assessment of lymphedema to delineate lymphatic drainage patterns and identify obstructions or insufficiencies, and to evaluate suspected lymphatic obstruction or thoracic duct patency in complex cases.

Interpretation relies on the pattern and timing of tracer uptake. Normal results show rapid lymphatic flow with uptake in one or more regional sentinel nodes. Delayed drainage, diffuse or absent uptake, or alternative drainage pathways can indicate obstruction, metastatic involvement, or technical factors.

Safety and limitations: the procedure involves low-dose radiation exposure and has a favorable safety profile. Limitations include variable lymphatic anatomy, limited spatial resolution, potential difficulty in obese or edematous patients, and the need for specialized equipment and expertise.