Medical apparatus for photodynamic therapy and method for controlling therapeutic light

A medical apparatus for photodynamic therapy comprising:

• a light source for irradiating concentration measurement light and therapeutic light to a tumor site, the concentration measurement light being used for obtaining concentration of a photosensitizer permeated into the tumor site, the therapeutic light being used for treating the tumor site, wherein a light amount of each of the concentration measurement light and the therapeutic light is adjustable;
• an ultrasonic wave detection device for detecting ultrasonic waves to output an ultrasonic signal, the ultrasonic waves being generated by the photosensitizer absorbing the concentration measurement light;
• a concentration distribution calculator for obtaining concentration distribution of the photosensitizer at a specific depth in the tumor site based on the ultrasonic signal;
• and
• a therapeutic light controller for controlling an irradiation condition of the therapeutic light to be irradiated to the tumor site based on the concentration distribution.