INTERSTITIAL LYMPHOSCINTIGRAPHY FOR LYMPHATIC MAPPING IN SURGICAL PRACTICE AND RESEARCH

Lymphoscintigraphy is a nuclear medicine technique that gives morpholo gic and functional information about the lymphatic system. The size of radiopharmaceutical used is a critical factor for it to have acceptab le characteristics of uptake by the lymphatics and migration to lymph nodes. A small particle (10-100 nm) with opsonins or a unique surface is required for uptake by lymph-node macrophages. It can be prepared f or application with a simple filtering process producing a predictable size distribution and number of particles for the scan. The radiation dose is safe for the patient and staff. Technetium-99m sulfur colloid is readily available and approved for use. The injection can be perfo rmed by anyone with certification in handling radiopharmaceuticals. Im aging is done with standard gamma cameras available in any nuclear med icine department. The addition of the hand-held gamma probe adds a new dimension to application of the technique of lymphatic mapping and id entification of areas that retain radiopharmaceuticals. Its use is sim ple and reproducible. The application of lymphoscintigraphy and gamma- probe localization techniques in clinical medicine is best exemplified with the now commonly used sentinel node approach to staging and trea ting intermediate-thickness malignant melanoma. A number of other mali gnant diseases such as breast cancer may have their treatments altered with these techniques as well. As a research and diagnostic tool, the creative application of interstitial, lymphoscintigraphy can give imp ortant qualitative information regarding the morphology and physiology of the lymphatic system. The development of these techniques for surg ical research and practice is reviewed.