Selective Therapy of Hepatic Cancers Using Microspheres

Regional chemotherapy is based on the premise that many chemotherapeutic agents display a steep dose response for toxicity and for therapeutic effect. Regional chemotherapy administration represents a means to generate increased drug exposure in the region where the tumor resides, while maintaining a lower drug exposure at the level of dose-limiting normal host tissues elsewhere in the body. Thus, even in circumstances where systemically administered chemotherapy is relatively ineffective, regional chemotherapy may improve the likelihood of response by the generation of much greater drug exposure. With sufficient regional selectivity, dose-limiting toxicity should be manifested by the normal tissues of the region infused and not by tissues elsewhere in the body. In this regard, regional chemotherapy has similarities to radiation therapy, but may be more selective in those situations where tumor and normal tissue in the treated region differ significantly in intrinsic drug sensitivity and blood supply.