A diagnostic imaging system for cancer localization using an excimer dye laser

Hematoporphyrin derivative has an affinity for malignant tissue and emits a red fluorescence when exposed to excitatory light. Therefore it is theoretically possible to make a diagnosis of cancer localization by observation of this fluorescence. The authors have been developing a new imaging system for cancer diagnosis using an excimer-dye laser. The excimer pulse has a 308 nm ultraviolet beam emitted by XeCl. Simplification and accuracy of the fluorescence diagnostic procedure was achieved by utilizing the nature of the pulse and a polychrometer. The diagnostic system permits endoscopic examination under ordinary observation light. Investigations have been performed in animal tumor models including FM-mouse (breast cancer) and beagle dog (esophageal cancer). Tumor tissue showed a distinct fluorescence, but no fluorescence could be observed in normal tissue, 72 hours after hematoporphyrin derivative administration.