The following is an excerpt of a report received from the
Oregon Department of Health via email:
Yesterday, April 27, 2017, while treating a patient with a 2 channel plan the licensee received the fault that the 'dummy' cable could not extend to the end of the applicator on the second channel. The licensee's procedure is to go into the HDR vault, check connections and position of the transfer tubes and then retry. The retry failed as well.
Because this was a 2 channel treatment, the patient had received only half of the treatment. The licensee explained what was going on to the patient and gave them the option of ending the treatment that day or waiting while the licensee did some testing and, if all went well, would finish the treatment. The patient opted to wait.
The licensee changed some of the applicators and transfer tubes, tested without failure, then brought the patient back into the vault to finish the treatment without any issues.
After the patient completed treatment and left, the licensee was able to extend the check source cable out of the afterloader and could see right away that the dummy source/end of cable had a bend in it. The licensee inspected the applicator that was used during the fault and thought there was a slight 'burr' in it. Between the bent cable and burr, there might have been snagging, leading to a fault.
The licensee called service (ELEKTA, Inc.) to come change the check source cable, which was done today, April 28, 2017.
After the check source cable change was completed, the licensee ran all combinations of transfer tubes and applicators without any failures. The licensee believed their theory about the burr and snag may have been wrong as that particular combination ran multiple times without any issues. Therefore, the bent cable caused the fault.
There were no adverse or unintended results for the patient, other than waiting 15 minutes while the licensee did some equipment testing. The patient received the prescribed dose. The system is designed so that if the check source/dummy cable cannot extend all the way to the end of the applicator you cannot proceed with the treatment so no possible way in this event to deliver an unintended dose to the patient.