CPT® Code 38792

An injection procedure is conducted to identify the sentinel node, which is a critical component in lymph node mapping. The sentinel node is the first lymph node that receives lymphatic drainage from a tumor site, making it essential for determining the spread of cancer. This procedure utilizes a combination of a weak radioactive tracer, specifically technetium-labeled sulfur colloid (technetium-99), and a blue dye known as isosulfan blue. The radioactive tracer is injected directly into the tumor site or the tumor bed, allowing it to travel through the lymphatic system to the sentinel node. The identification of the sentinel node is facilitated by a hand-held probe that detects the radioactive signal emitted by the tracer. The process of tracking the radioactive dye can take anywhere from 45 minutes to 8 hours. Following the detection of the sentinel node, the blue dye is injected, which stains the lymph tissue a bright blue, enhancing visibility during subsequent surgical procedures. Once both dyes have reached the sentinel node, a lymph node biopsy can be performed, which is reported separately. This procedure is crucial for staging cancer and planning appropriate treatment strategies.