35.433—Decay of strontium-90 sources for ophthalmic treatments.
(a)
Only an authorized medical physicist shall calculate the activity of each strontium-90 source that is used to determine the treatment times for ophthalmic treatments. The decay must be based on the activity determined under § 35.432.
(b)
A licensee shall retain a record of the activity of each strontium-90 source in accordance with § 35.2433.