Reducing Radiation Exposure in Patients with Hereditary Renal Cancers

Concern over radiation-induced cancers has increased over the last ten years. A number of spectacular overdoses with medical radiation has alarmed the public and caused a strong reaction in the professional and manufacturing communities. Medical imaging, particularly CT scanning is a major source of ionizing radiation after background radiation in all patients. However, in patients with von Hippel Lindau Disease and other Hereditary Renal Cancers (HRC), scans are performed on a regular basis to monitor the progress of the disease. As a result significant culmulative doses of radiation can occur resulting in doses for which the literature documents an increase risk of cancer. Meanwhile, due to germline mutations in tumor suppressor genes and oncogenes, patients with HRC are at increased theorectical risk for the development of radiation-induced cancers. This is, in part, balanced by increased surveillance in patients with HRC reducing the likelihood of death related to radiation-induced cancers. With improvements in Magnetic Resonance technology, more patients with HRC are scanned in this manner as opposed to CT since no ionizing radiation is involved. However, there have been a number of improvements in CT technology that are dramatically lowering the radiation doses to which HRC patients are exposed. Herein, we review the basis for concern over radiation-induced cancers in the general population and specifically in patients with HRC and describe methods to reduce radiation exposure on CT. These methods include automatic exposure control, modulation of voltage, iterative reconstruction and dual energy CT. Combined, these methods may enable patients with HRC to safely undergo CT as a method for monitoring the status of their renal disease.