Ultraweak biophoton emission imaging of transplanted bladder cancer.

Biophoton emission or spontaneous ultraweak light emission has been observed from almost all living organisms, with intensities ranging from 10(-19) to 10(-16) W/cm2. The measurement of biophoton emission offers the attractive possibility of noninvasive monitoring of the underlying physiological function of a living system. In the present study, ultraweak biophoton emission from mice with transplanted bladder cancer was detected by a two-dimensional photon-counting system. Photon counts were observed to be 1.51-4.73 times higher from the regions of untreated tumor than from normal regions. Our study suggests that this novel technique may be applicable to the diagnosis of superficial tumors.