10 CFR §35.2432

1. (a)A licensee shall maintain a record of the calibrations of brachytherapy sources required by § 35.432 for 3 years after the last use of the source.
2. (b)The record must include—
   1. (1)The date of the calibration;
   2. (2)The manufacturer's name, model number, and serial number for the source and the instruments used to calibrate the source;
   3. (3)The source output or activity;
   4. (4)The source positioning accuracy within the applicators; and
   5. (5)The name of the individual, the source manufacturer, or the calibration laboratory that performed the calibration.