Radioimmunotherapy (RIT) has been approved for the treatment of B-cell non-Hodgkin lymphomas in the United States for more than a decade. However, the history of the development of RIT agents for advanced-stage solid malignancies dates back much further, and recent advances have renewed interest in this approach for solid tumors.This paper reviews available evidence for the preclinical and clinical development of RIT agents for solid tumors.Several RIT agents have been studied for the treatment of a variety of solid malignancies, particularly colorectal, breast, prostate, ovarian, pancreatic, hepatocellular, and primary brain tumors. Multiple novel RIT agents are in active clinical investigation, either as single agents or combined with radiosensitizing chemotherapy or with external beam radiotherapy. Improvements in antibody (and antibody fragment) design and the availability of novel radionuclides have improved the therapeutic window for these agents.RIT for solid malignancies shows promise, typically with fewer adverse events than traditional cytotoxic systemic therapy. The greatest efficacy will likely be in the adjuvant setting of minimal residual disease. Newer radionuclides, particularly alpha-emitters, offer increased antitumor potency with less toxicity. Physicians and patients should be encouraged to participate in clinical trials of these promising agents.
