Radiation-Induced Second Cancer Risk Estimates From Radionuclide Therapy

Abstract

The use of radionuclide therapy in the clinical setting is expected to increase significantly over the next decade. There is an important need to understand the radiation-induced second cancer risk associated with these procedures. In this study the radiation-induced cancer risk in five radionuclide therapy patients was investigated. These patients underwent serial SPECT imaging scans following injection as part of a clinical trial testing the efficacy of a 131 Iodine-labeled radiopharmaceutical. Using these datasets the committed absorbed doses to multiple sensitive structures were calculated using RAPID, which is a novel Monte Carlo-based 3D dosimetry platform developed for personalized dosimetry. The excess relative risk (ERR) for radiation-induced cancer in these structures was then derived from these dose estimates following the recommendations set forth in the BEIR VII report. The radiation-induced leukemia ERR was highest among all sites considered reaching a maximum value of approximately 4.5. The radiation-induced cancer risk in the kidneys, liver and spleen ranged between 0.3 and 1.3. The lifetime attributable risks (LARs) were also calculated, which ranged from 30 to 1700 cancers per 100,000 persons and were highest for leukemia and the liver for both males and females followed by radiation-induced spleen and kidney cancer. The risks associated with radionuclide therapy are similar to the risk associated with external beam radiation therapy.

Prediction of Absorbed Dose to Normal Organs with Endocrine Tumors for I-131 by use of 99mTC Single Photon Emission Computed Tomography/Computed Tomography and Geant4 Application for Tomographic Emission Simulation

“…Compared with other treatment methods, the advantages of this method are the ability to directly transfer the radiation dose to the tumors and reduce the irradiation of normal tissues. [ 1 2 3 ] Owing to the ever-increasing application of radionuclides in medical diagnosis and treatment processes, a specific treatment protocol should be designed by assessing the absorbed dose to the tumors and normal tissues to maximize the dose administered to the tumors and minimize the dose absorbed by the normal tissues. [ 4 ] In the therapeutic processes, widely used radionuclides such as I-131 can be used for the treatment of thyroid disease, Ra-223 for relieving and treatment of bone tumors, Lu-177 for the treatment of neuroendocrine tumors, and Y-90 for radioembolization.…”