Tumor Response to Radiopharmaceutical Therapies: The Knowns and the Unknowns.
George Sgouros, Yuni K. Dewaraja, Freddy E. Escorcia, Stephen A. Graves, Thomas A. Hope, Amir Iravani, Neeta Pandit‐Taskar, Babak Saboury, Sara St. James, Pat Zanzonico
Abstract
Radiopharmaceutical therapy (RPT) is defined as the delivery of radioactive atoms to tumor-associated targets. In RPT, imaging is built into the mode of treatment since the radionuclides used in RPT often emit photons or can be imaged using a surrogate. Such imaging may be used to estimate tumor-absorbed dose. We examine and try to elucidate those factors that impact the absorbed dose-versus-response relationship for RPT agents. These include the role of inflammation- or immune-mediated effects, the significance of theranostic imaging, radiobiology, differences in dosimetry methods, pharmacokinetic differences across patients, and the impact of tumor hypoxia on response to RPT.