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# Request for Interpretation of 10 CFR 35.33 (c) Regarding Diagnostic Misadministration Reporting Threshold Levels

## HPPOS-270 PDR-9306100037

See the memorandum from S. A. Treby to J. E. Glenn dated May 31, 1991.

This OGC memo responds to an Region I request for guidance on which threshold level in 10 CFR 35.33 (c) applies for notifying the NRC and the referring physician of a diagnostic misadministration in instances in which "a patient, not scheduled for a nuclear medicine study at all, inadvertently receives a diagnostic dosage of a radiopharmaceutical." It is OGC opinion that any diagnostic misadministration to a patient not intended to receive any radiopharmaceutical is a dosage "five-fold different" from the intended dosage; thus making applicable the reporting requirements of 10 CFR 35.33 (c).

According to the request for guidance from Region I, the facts in this incident are as follows: A recent NRC inspection revealed that a diagnostic misadministration of a radiopharmaceutical occurred at Ephrata Community Hospital ("Ephrata") on November 17, 1987. The misadministration occurred because the nursing staff submitted an incorrect request for a "biliary study" instead of a "biliary sono study". The Nuclear Medicine staff performed a "hepatobiliary" study using 4 millicuries of Hepatolite Visofenin when the patient should not have received any radiopharmaceutical at all. The dose to the target organ and the whole body of the patient from this misadministration as estimated by the licensee's consultant were supposedly less the 2 rem and 500 millirem, respectively. The licensee's consultant considered that the above criteria in 10 CFR 35.33 (c) applies in the instance when a patient who is not scheduled to receive any radiopharmaceuticals receives them.

At the outset, we note that as stated in the request for guidance from Region I, this incident was a diagnostic misadministration. The term misadministration is defined (in relevant part) in 10 CFR 35.2 as an administration of: (2) a radiopharmaceutical to the wrong patient; or (4) a diagnostic dosage of a radiopharmaceutical differing from the prescribed dosage by morethan 50 percent.

The administration of a radiopharmaceutical to a patient who is not supposed to receive any certainly falls within the definition in (2) above. In addition, such an incident is also within the scope of definition (4) above, on the basis that when no dosage of a radiopharmaceutical is prescribed, any dosage is a dosage differing from the prescribed dosage by more than 50 percent.

10 CFR 35.33 (c) requires notification of the NRC and the referring physician of a diagnostic misadministration within 15 days:
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"if the misadministration involved the use of byproduct material not intended for medical use, administration of a dosage five-fold different from the intended dosage, or administration of byproduct material such that the patient is likely to receive an organ dose greater that 2 rem or a whole body dose greater than 500 millirem."

Region I has asked which of the latter two thresholds applies in this case (i.e., the threshold of a dosage five-fold different from the intended dosage or the threshold of an organ dose of greater than 2 rem or a whole body dose greater than 500 millirem). The licensee applied the organ or whole body dose criterion and therefore did not report the misadministration to the NRC. OGC believes that if either the "five-fold different" dose level threshold or the organ dose / whole body dose threshold in 35.33 (c) is exceeded, then a licensee is required to notify the NRC and the referring physician. It is true, as the memorandum requesting guidance states, that application of the "five-fold different" dose threshold in 35.33 (c) would mean that any diagnostic administration to a patient not intended to receive a dosage would have to be reported to the NRC because the intended dosage would be zero. OGC does not agree with the conclusion in the memorandum that such a result could be considered as inconsistent with the current requirement in 35.33 (c), which makes it clear that not all diagnostic misadministration have to be reported to NRC.

OGC believes that the "five-fold different" threshold does apply, on the basis that when no dosage is intended, any dosage is "five-fold different from the intended dosage." In other words, notification is required for any diagnostic misadministration involving a dosage to a patient not intended to receive any radiopharmaceutical, because any dosage is five-fold different from the intended dosage. There is no legal basis, either in the plain language of 35.33 (c) or in the statement of consideration, for concluding that the five-fold different dose threshold should not be applied to an incident such as occurred at Ephrata.

Based on OGC's interpretation of 35.33 (c), both dose thresholds in 35.33 (c) apply to any diagnostic misadministration and if either threshold is exceeded, notification is required. Therefore, Ephrata was required to notify both the NRC and the referring physician of the November 12, 1987 diagnostic misadministration on the basis that the dosage administered was five fold different from the intended dosage.

**Regulatory references:** 10 CFR 35.2, 10 CFR 35.33

**Subject codes:** 2.2, 12.11

**Applicability:**Byproduct Material

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