Sonodynamically Induced Antitumor Effect of a Gallium‐Porphyrin Complex, ATX‐70

The Sonodynamically induced antitumor effect of a gallium‐porphyrin complex, ATX‐70, was evaluated in mice bearing colon 26. In order to find the optimum timing for the ultrasonic exposure after the administration of ATX‐70, the ATX‐70 concentrations in the plasma, skin, and tumor were measured and analyzed. Antitumor effect was estimated by measuring the tumor size. When used alone, ultrasound showed a slight antitumor effect, which became increasingly significant as the dose of ATX‐70 was increased, while use of ATX‐70 alone had no significant effect. At an ATX‐70 dose of 2.5 mg/kg or higher, the average tumor size decreased to smaller than a half by three days after the ultrasonic exposure. This was smaller than a third of the size of the untreated tumors on the same day. From these results, it is concluded that ATX‐70 significantly sensitizes tumors to ultrasound, demonstrating a synergistic antitumor effect.