Diagnostic fluorescence imaging agent

Class

Diagnostic fluorescence imaging agent (non-therapeutic; intraoperative tumor-margin/sentinel-lymph-node visualization dye, not a treatment with a molecular drug target)

Notes

original target text: Diagnostic fluorescence imaging agent (non-therapeutic; intraoperative tumor-margin/sentinel-lymph-node visualization dye, not a treatment with a molecular drug target)

This entry describes a diagnostic fluorescence imaging agent rather than a therapeutic drug. Such agents are fluorescent dyes administered before or during surgery to help clinicians visually distinguish tumor tissue from normal tissue, or to trace lymphatic drainage to identify the sentinel lymph node — the first node a tumor would drain to and thus the most informative one to sample for staging. The biological rationale rests on differences between malignant and healthy tissue, or on the physical route lymph fluid takes from a tumor site, which cause the dye to accumulate preferentially in the tissue of surgical interest. Once there, the dye is illuminated with light of a specific wavelength (often in the near-infrared range, which penetrates tissue better and produces less background signal), and it re-emits light at a longer wavelength that a specialized camera system detects and displays, often overlaid on the normal surgical view. This mechanism broadly matters in oncologic surgery, where the goal is to remove all malignant tissue while preserving healthy structures and avoiding unnecessary removal of uninvolved lymph nodes. It is used across tumor types where surgical resection is standard, including breast cancer, melanoma, and various gastrointestinal and gynecologic cancers.