Dose Information

IRB Dose Calculator

Dose information for prospective, human-use research involving the use of radiation from machines or materials can be found by using the IRB Radiation Dose Calculator (link for University of Utah providers and staff only).

We are happy to announce that the long awaited web-based dose calculator has entered into the final testing phase. If you would like to use the calculator in its current form, please note that not all the procedures are currently available. We may continue to make formatting and layout changes before everything is finalized. We would like your input on the calculator and any recommendations you may have to make it better. Please send any questions or comments to the Medical Physicist.

When using the calculator, be sure to only include those procedures that are not considered Standard of Care. The calculator will determine the dose for each procedure and the total dose for all procedures combined. Keep in mind that the procedures in the calculator are based on machines and protocols specific to the University of Utah Hospital and Clinics. Also, the doses reported by the calculator are not intended to be used for patient-specific dose determination; the doses are based on reference patients and standard imaging protocol parameters. If you have any questions or if there is a procedure that you need that is not listed in the dose calculator, contact the Medical Physicist.

Dose Information

The Medical Physicist performs dose calculations based on specific patient information for a diagnostic procedure or procedures. Generally, there are four scenarios in which dose calculations are performed:

1. Dose to patients
2. Dose to the fetus
3. Dose to the public
4. Dose to the worker

Calculations will be performed using best estimates based on current science and practices within the hospitals and clinics; or, when available, actual data from specific exam will be used. Dose calculations will be based on Standard Man references for average organ and body sizes, unless actual patient data would significantly alter calculation results. All results will include a calculation of effective dose equivalent based on ICRP 60 methodologies; ICRP 26 methodology will be used if specifically requested or for dose calculations that will be used to demonstrate compliance with State of Utah dose limits.

Dose to Patients

Dose to the patients is calculated for patients undergoing diagnostic procedures involving exposure to ionizing radiation from radioactive materials or radiation generating machines. Most often, these calculations are performed in support of applications to the Institutional Review Board for individuals undergoing procedures outside normal standard of care practice as part of a research proposal. Calculations may also be performed at the request of a physician on behalf of a patient who has received diagnostic imaging. Calculations results will be provided to the requesting physician in the case of actual patient exposure or the principle investigator (or designee) in the case of research proposals.

Dose to the Fetus

Exposure of pregnant patients and workers is discussed in section 6 of the safety manual (available to Health Sciences Employees and Staff on the WIKI page). Fetal dose calculations are performed upon request of the patient's physician. Results will be provided to the patient's physician and not directly to the patient. Based upon the results of the fetal dose calculation or the circumstances prompting the request for calculation, a detailed report may be prepared by the Medical Physicist to assist the patient's physician in understanding the basis for the results and likely effects.

Dose to the Public

Compliance with public dose limits is mainly demonstrated through calculations performed for shielding recommendations and as radiation use in areas change. These calculations are performed as needed and results are maintained in the office of the Medical Physicist. Because of the many different areas of radiation use, each area supervisor should notify the Medical Physicist of any changes in radiation use (to include workload) or location so that a formal determination of effect of public dose can be completed.

Additionally, the Medical Physicist will be involved with shielding design as part of new construction or remodeling of any area in which ionizing radiation will be used.

Dose to the Worker

Typically, worker exposure is best determined through the use of dosimetry. However, in situations where dosimetry is unavailable (because of lost/damage dosimeter or unmonitored employees), calculations will be performed to asses occupational exposure. Additionally, calculations may be performed to assist in facility planning and work-flow issues.