DHS 157.67(9)(a)2.c.c. Following any repair of the gamma stereotactic radiosurgery unit that includes removal of the sources or major repair of the components associated with the source assembly. DHS 157.67(9)(a)3.3. At intervals not exceeding one year, with the exception that relative helmet factors need only be determined before the first medical use of a helmet and following any damage to the helmet. DHS 157.67(9)(b)(b) To satisfy the requirement of par. (a), a full calibration measurement shall include determination of all the following: DHS 157.67(9)(b)2.2. Relative helmet factors to verify that the helmet material provides the required shielding to the patient. DHS 157.67(9)(b)3.3. Isocenter coincidence to confirm the centering accuracy of the radiation beam relative to the helmet openings. DHS 157.67(9)(b)6.6. Trunnion centricity to determine the rotational center of the source relative to the helmet openings. DHS 157.67(9)(b)7.7. Treatment table retraction mechanism, using backup battery power or hydraulic backups with the main power to the unit off. DHS 157.67(9)(b)8.8. Helmet microswitches to determine if the switches terminate the radiation beam when tripped by unintended movement of the helmet. DHS 157.67(9)(c)(c) A licensee shall use the dosimetry system described in sub. (6) (a) to measure the output for one set of exposure conditions. The remaining radiation measurements required in par. (b) 1. may be made using a dosimetry system that indicates relative dose rates. DHS 157.67(9)(d)(d) A licensee shall make a full calibration measurement required by par. (a) under published protocols accepted by nationally recognized bodies. DHS 157.67 NoteNote: An example of such a nationally recognized body is the American Association of Physicists in Medicine.
DHS 157.67(9)(e)(e) A licensee shall mathematically correct the outputs determined in par. (b) 1. at intervals not exceeding one month for cobalt-60 and at intervals consistent with one percent physical decay for all other radionuclides. DHS 157.67(9)(f)(f) A full calibration measurement required by par. (a) and physical decay correction required by par. (e) shall be performed by an authorized medical physicist. DHS 157.67(10)(a)(a) A licensee authorized to use teletherapy units for medical use shall perform output spot-checks on each teletherapy unit once in each calendar month that include determination of all of the following: DHS 157.67(10)(a)3.3. The coincidence of the radiation field and the field indicated by the light beam localizing device. DHS 157.67(10)(a)4.4. The accuracy of all distance measuring and localization devices used for medical use. DHS 157.67(10)(a)5.5. The output for one typical set of operating conditions measured with the dosimetry system described in sub. (6) (b). DHS 157.67(10)(a)6.6. The difference between the measurement made in this subd. 5. and the anticipated output expressed as a percentage of the anticipated output, which is the value obtained at last full calibration corrected mathematically for physical decay. DHS 157.67(10)(b)(b) A licensee shall perform measurements required by par. (a) under procedures established by the authorized medical physicist. The authorized medical physicist need not actually perform the spot check measurements. DHS 157.67(10)(c)(c) A licensee shall have the authorized medical physicist review the results of each spot-check within 15 working days. The authorized medical physicist shall notify the licensee in writing of the results of each spot-check within 10 working days.