DISCHARGE LAMP FOR PHOTODYNAMIC THERAPY

PROBLEM TO BE SOLVED : To provide a discharge lamp which mainly emits light suitable for photodynamic therapy (PDT) and photodynamic diagnosis (PDD) in a photosensitive agent used for the therapy and diagnosis. SOLUTION : The discharge lamp emits light of which the wavelength is suitable for an absorption wavelength of the photosensitive agent with a relatively high extinction coefficient in a wavelength range of 600-800 nm. In the discharge lamp, Na of 0.1μmol/cm3 or more as a light-emitting element is included in order to emit light with a wavelength of 600-640 nm, and at least one kind of gas of rare gases Ne, Ar, Kr and Xe is included.