In vivo fluorescence detection of human bladder carcinoma without sensitizing agents

The diagnosis of transitional cell bladder carcinoma and especially carcinoma in situ of the bladder in spinal cord disordered persons is often made difficult by catheters, infections or stone-induced chronic inflammation. Fluorescence tagging of tumors by sensitizing agents such as hematoporphyrin derivatives enhances visualization but presents a number of drawbacks for the patients, even at low doses. We have developed a cystoscopic fiber optic instrument, based on a mercury arc lamp, for in vivo detection of human bladder carcinoma without sensitizing agents. The tissue autofluorescence upon UV excitation (365 nm) is detected and a demarcation contrast ratio for carcinoma in situ and transitional cell carcinoma of 2.6 and 3.2 respectively is obtained. This demarcation ratio is 60 percent higher than the contrast ratio obtained after photosensitizer injection. The integration of a reliable diagnostic method with a known efficient therapeutic technique (Nd YAG laser irridiation) opens the way for cost-effective preventive care of high-risk patients.