10 CFR § 35.63 - Determination of dosages of unsealed byproduct material for medical use.
(a) A licensee shall determine and record the activity of each dosage before medical use.
(b) For a unit dosage, this determination must be made by -
(1) Direct measurement of radioactivity; or
(2) A decay correction, based on the activity or activity concentration determined by -
(ii) 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
(c) For other than unit dosages, this determination must be made by -
(1) Direct measurement of radioactivity;
(2) Combination of measurement of radioactivity and mathematical calculations; or
(3) Combination of volumetric measurements and mathematical calculations, based on the measurement made by:
(d) 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.
(e) A licensee shall retain a record of the dosage determination required by this section in accordance with § 35.2063.