LIGHT IRRADIATION METHOD, LIGHT IRRADIATION DEVICE, LIGHT IRRADIATION SYSTEM, DEVICE SYSTEM FOR PHOTODYNAMIC DIAGNOSIS OR PHOTODYNAMIC THERAPY, SYSTEM FOR SPECIFYING TUMOR SITE AND SYSTEM FOR TREATING TUMOR
The present invention provides a light irradiation method using a pulse laser, which can be applied to technology of PDD and/or PDT, and a system for treating a tumor, which has an enhanced tumoricidal effect. A light irradiation method of irradiating a cell into which a photosensitive compound capable of generating singlet oxygen has been incorporated with a pulse laser having a wavelength within a Soret band is provided. The pulse width of the pulse laser can be set to 100 psec or less, and the wavelength can be set to 405±10 nm. As the photosensitive compound capable of generating singlet oxygen, an agent for photodynamic therapy (PDT) or an agent for photodynamic diagnosis (PDD) can be used.