Laser fluorescent system for endoscopic tumor diagnostic and irradiation control in photodynamic therapy

The laser fluorescent methods are very promising for photosensitizer distribution control in diagnostics and photodynamic therapy of tumors in intracavital organs. We have developed the laser fluorescent imaging system employing high sensitive CCD-camera. The system is adjusted to the standard endoscope (Olympus), cystoscope and can be also used for surface tumor observations. The high sensitivity of the system makes it possible to evaluate the photosensitizer distribution, its dynamic during PDT treatment and control the irradiation process observing tissues in fluorescent light during endoscopic investigations of stomach and lungs. The ways of improving of fluorescent imaging systems are discussed including the choosing of suitable laser source for fluorescent excitation and special filters for enhancing fluorescent contrast.