The following information was provided by the
Kentucky Department for Public Health & Safety, Radiation Health Branch (KY
RHB) via email:
KY RHB was notified on August 20, 2024, by a representative from Leonard Lawson Cancer Center [of the following:]
The date of discovery is August 20, 2024 at 13:30 EDT.
There were two medical events for the same patient receiving Ra-223 dichloride. In each of the two cases, the patient was under dosed.
The authorized user physician and the patient have been notified of the medical events.
[The first dose is being tracked under a different NRC Event number. See EN 57275]
The second dose was administered on August 7, 2024, with a prescribed dose of 89.2 micro Ci and an administered dose of 45.53 micro Ci with a difference of 53.9 percent.
The written directive procedure is to measure the dose in the dose calibrator and then administer the dose. The medical physicians deviated from the written directive procedure and adjusted the dose based of the following calculation:
Volume to administered equals (Body weight in kg x 1.35 micro Ci/kg)/(decay factor x 27 micro Ci/ml).
The concentration provided in the formula is different than the concentration for each dose. The concentration for the second dose was 18.12 micro Ci/ml. Also, this formula was taken from an old Bayer document from 2013. The current Bayer document provides the following formula.
Volume to administered equals (Body weight in kg x 1.49 micro Ci/kg)/(decay factor x 30 micro Ci/ml).
The problem is the document does not instruct one to use an actual concentration for the patient specific dose.
The two reasons for the medical events are:
1) The medical physicist did not follow the written directive procedure. He added the volume calculation step.
2) The Bayer documentation does not instruct you to use the actual concentration for the patient specific dose.
The incident remains under evaluation and investigation for corrective actions.
A Medical Event may indicate potential problems in a medical facility's use of radioactive materials. It does not necessarily result in harm to the patient.