Section 35.433 - Strontium-90 sources for ophthalmic treatments(a) Licensees who use strontium-90 for ophthalmic treatments must ensure that certain activities as specified in paragraph (b) of this section are performed by either:(1) An authorized medical physicist; or(2) An individual who:(i) is identified as an ophthalmic physicist on a specific medical use license issued by the Commission or an Agreement State; permit issued by a Commission or Agreement State broad scope medical use licensee; medical use permit issued by a Commission master material licensee; or permit issued by a Commission master material licensee broad scope medical use permittee; and(ii) holds a master's or doctor's degree in physics, medical physics, other physical sciences, engineering, or applied mathematics from an accredited college or university; and(iii) has successfully completed 1 year of full-time training in medical physics and an additional year of full-time work experience under the supervision of a medical physicist; and(iv) Has documented training in:(A) The creation, modification, and completion of written directives;(B) Procedures for administrations requiring a written directive; and(C) Performing the calibration measurements of brachytherapy sources as detailed in § 35.432 .(b) The individuals who are identified in paragraph (a) of this section must:(1) 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 ; and(2) Assist the licensee in developing, implementing, and maintaining written procedures to provide high confidence that the administration is in accordance with the written directive. These procedures must include the frequencies that the individual meeting the requirements in paragraph (a) of this section will observe treatments, review the treatment methodology, calculate treatment time for the prescribed dose, and review records to verify that the administrations were in accordance with the written directives.(c) Licensees must retain a record of the activity of each strontium-90 source in accordance with § 35.2433 . 83 FR 33109 , July 16, 2018