Abstract: An ultrasonic apparatus for thereapeutical use, especially for remedying a malignant tumor, through activation of a drug at a desired local portion inside of a living body by sequentially irradiating a plurality kinds of convergent ultrasonic waves having different focal positions of different acoustic pressure distribution shapes but having a mutually overlapping focal zone and by switching them within a short period. The drug is activated as a promotor for an ultrasonic therapeutical effect through continuous generation and rupture of cavitation caused by the irradiated and switched ultrasonic waves.

Abstract: Physiological function-enhancing agents to be used for the treatment of tumors comprise a compound capable of stimulating the generation of at least one type of active oxygen, such as superoxide radicals and singlet oxygen, upon ultrasonic irradiation (e.g., porphyrins, chlorins, methylene-blue, fluorescein, acridine derivatives, rhodamines and tetracyclines).Irradiating ultrasonic waves onto tumor tissues, with this agent orally or parenterally administered in advance, causes the active ingredient present at the irradiated site to generate active oxygen (e.g., superoxide radicals and singlet oxygen), which serves to destruct the tumor cells.These agents are very low in toxicity and exhibit antitumor activity only upon ultrasonic irradiation. Hence, there is no risk of causing any systemic idsorder. In addition, these act exclusively upon tumor tissues when combined with ultrasonic irradiation, with no adverse effect upon normal tissues.