Optimizing radioimmunoconjugate delivery in the treatment of solid tumor.

Radioimmunotherapy (RIT) is a therapeutic modality which delivers alpha, beta or Auger emitters directly to targeted cancer cells. It has the advantage of regressing tumors while reducing non-targeted toxicities with the help of the targeting antibody. RIT applications relate to hematologic malignancies and now extend to solid tumors. Therapeutic efficacy of solid tumor RIT was limited by the inadequate penetration of radioimmunoconjugate (RIC). This paper reviews the properties of tumor vasculature abnormalities, the mechanisms of RIC penetration into solid tumors and strategies to enhance RIC delivery to facilitate RIT in reaching its full potential as a systemic cancer therapy.