A licensee shall determine and record the activity of each dosage before medical use.

For a unit dosage, this determination must be made by—

Direct measurement of radioactivity; or

A decay correction, based on the activity or activity concentration determined by—

A manufacturer or preparer licensed under § 32.72 of this chapter or equivalent Agreement State requirements; or

An NRC or Agreement State licensee for use in research in accordance with a Radioactive Drug Research Committee-approved protocol or an Investigational New Drug (IND) protocol accepted by FDA; or

A PET radioactive drug producer licensed under § 30.32(j) of this chapter or equivalent Agreement State requirements.

For other than unit dosages, this determination must be made by—

Direct measurement of radioactivity;

Combination of measurement of radioactivity and mathematical calculations; or

Combination of volumetric measurements and mathematical calculations, based on the measurement made by:

A manufacturer or preparer licensed under § 32.72 of this chapter or equivalent Agreement State requirements; or

A PET radioactive drug producer licensed under § 30.32(j) of this chapter or equivalent Agreement State requirements.

Unless otherwise directed by the authorized user, a licensee may not use a dosage if the dosage does not fall within the prescribed dosage range or if the dosage differs from the prescribed dosage by more than 20 percent.

A licensee shall retain a record of the dosage determination required by this section in accordance with § 35.2063.