Radioimmunotherapy-An Overview

Cancer is one of the leading causes of morbidity and death worldwide. Carcinogenesis is a process where normal cells turn malignant through a series of evolutionary events. There are numerous agents whose exposure can lead to the initiation of carcinogenesis in humans or animals, for example, cancer causing chemicals, pollutants, heavy metals, alfatoxins, viruses, bacteria, parasites, etc. Hodgkin’s disease (HD) as well as non-Hodgkin lymphoma, Burkitt’s lymphoma, and nasopharyngeal carcinoma are some of the cancers developed due to the infection caused by various oncogenic DNA or RNA viruses. Chemotherapy, radiation therapy, immunotherapy, surgical excision, etc. are some of the existing treatment modalities to counter tumors. Radioimmunotherapy (RIT) is an exciting new approach to treating cancer. It involves the conjugation of a therapeutic radionuclide with a monoclonal antibody (mAb), where the ablative properties of therapeutic radionuclides are used to kill cancer cells. The damage to the cancer cells is either through the α, β, or auger electrons emitted by these radionuclides. The choice of radionuclide is based on the type of tumor. This technique is well-established and accepted for hematological malignancies, and so far, products like ¹³¹I-tositumomab (Bexxar) and ⁹⁰Y-ibritumomab tiuxetan (Zevalin) are commercially available for non-Hodgkin lymphomas (NHLs). However, the application of RIT to solid tumors is still challenging, and different approaches are being adopted as well as investigated to increase its therapeutic index in solid tumors.