CT and cone-beam CT (CBCT) scans are widely employed within radiotherapy for planning and pre-treatment position verification. The imaging dose associated with these scans, however, can be a cause for concern, and currently there's no quick and easy way to determine this dose. To address this deficit, medical physicist Jun Deng has developed a free-to-download iPhone app called CT Gently.
CT Gently can be used to estimate organ doses, as well as the associated cancer risks, delivered by CT and CBCT scans, based on individual anatomy and scan settings. The novel app also allows users to calculate optimized scanner settings and compare these with reference settings (pre-defined settings from a particular scan protocol or manufacturer, or a scan setting indicated by the user).
Deng, from Yale University School of Medicine and Yale New Haven Hospital (New Haven, CT), explained his motivation: "I am often approached by physicians, physicists or patients asking for an estimate of the dose from a CT or CBCT procedure. Usually I tell them 'give me some time and I'll give you some information', because I have Monte Carlo treatment planning available in-house that allows me to do that dose calculation."
Deng's research group at Yale has performed extensive research into the use of Monte Carlo algorithms for dose calculation, but Monte Carlo simulations are not routinely available in clinics and currently radiotherapy planning systems do not offer CT/CBCT dose calculation capability. "This made me think that maybe I should just combine all of my knowledge in this area and all of the publications, and create a very easy to use tool," he told medicalphysicsweb.