On February 02, 2017, the NRC issued a Notice of Violation to Spectrum Health Hospitals for a Severity Level III violation involving the failure to implement written procedures which provided high confidence that an administration of yttrium-90 microspheres was in accordance with the written directive, as required by 10 CFR 35.41(a)(2). Specifically, on April 27, 2016, the licensee did not follow its procedure to verify the catheter position prior to administration of the yttrium-90 microspheres. As a result, a medical event occurred as the patient received a dose in an unintended treatment segment.