Sonodynamic approach to tumor treatment

The localization of sonochemical reactions with focused ultrasound is investigated by developing a sonochemically active tissue mimicking phantom. It is demonstrated that the sonochemical effects can be localized within a region of size not larger than typical tumors to be treated. Sonochemically efficient methods of ultrasound irradiation, which may neither require standing wave situations nor extremely high ultrasound intensity in order to induce substantial sonochemical effects, are studied. The ultrasound intensity threshold for the sonochemical reaction is drastically decreased by the second harmonic superimposition. It is also demonstrated by in vitro experiments that a gallium-deuteroporphyrin complex, ATX-70, has three times higher sonochemical activity than hematoporphyrin (Hp) and induces cell damage at twice the rate of Hp in combination with ultrasound