DHS 157.67(9)
(9)
Full calibration measurements on gamma stereotactic radiosurgery units. DHS 157.67(9)(a)
(a) A licensee authorized to use a gamma stereotactic radiosurgery unit for medical use shall perform full calibration measurements on each unit under any of the following circumstances:
DHS 157.67(9)(a)2.a.
a. Whenever spot-check measurements indicate that the output differs by more than 5% from the output obtained at the last full calibration corrected mathematically for radioactive decay.
DHS 157.67(9)(a)2.b.
b. Following replacement of the sources or following reinstallation of the gamma stereotactic radiosurgery unit in a new location.
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 Note
Note: 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.
DHS 157.67(10)(d)
(d) A licensee authorized to use a teletherapy unit for medical use shall perform safety spot-checks of each teletherapy facility once in each calendar month and after each source installation to assure proper operation of all of the following:
DHS 157.67(10)(d)2.
2. Electrical or mechanical stops installed to limit use of the primary beam of radiation.
DHS 157.67 Note
Note: Examples of the limitations in subd. 2. include restriction of source housing angulation or elevation, carriage or stand travel and operation of the beam on-off mechanism.
DHS 157.67(10)(d)3.
3. Source exposure indicator lights on the teletherapy unit, on the control console and in the facility.
DHS 157.67(10)(d)6.
6. Electrically assisted treatment room doors with the teletherapy unit electrical power turned off.
DHS 157.67(10)(e)
(e) If the results of the checks required in par.
(d) indicate the malfunction of any system, a licensee shall lock the control console in the off position and not use the unit except as may be necessary to repair, replace or check the malfunctioning system.
DHS 157.67(11)
(11)
Periodic spot-checks for remote afterloader units. DHS 157.67(11)(a)(a) A licensee authorized to use remote afterloader units for medical use shall perform a spot-check of each remote afterloader facility and on each unit according to the following criteria:
DHS 157.67(11)(a)1.
1. At the beginning of each day of use of a high dose-rate, medium dose-rate or pulsed dose-rate remote afterloader unit.
DHS 157.67(11)(a)2.
2. Prior to each patient treatment with a low dose-rate remote afterloader unit.
DHS 157.67(11)(b)
(b) A licensee shall have an authorized medical physicist establish written procedures for performing the spot-checks required in par.
(a) of this section. The authorized medical physicist need not actually perform the spot check measurements.
DHS 157.67(11)(c)
(c) To satisfy the requirements of par.
(a), a spot-check shall assure proper operation of all of the following:
DHS 157.67(11)(c)2.
2. Source exposure indicator lights on the remote afterloader unit, on the control console and in the facility.
DHS 157.67(11)(c)3.
3. Viewing and intercom systems in each high dose-rate, medium dose-rate and pulsed dose-rate remote afterloader facility.
DHS 157.67(11)(d)
(d) If the results of the checks required in par.
(c) indicate the malfunction of any system, a licensee shall lock the control console in the off position and not use the unit except as necessary to repair, replace or check the malfunctioning system.
DHS 157.67(11)(f)
(f) A licensee shall have an authorized medical physicist review the results of each spot-check within 15 working days of the spot check. The authorized medical physicist shall notify the licensee as soon as possible in writing of the results of each spot-check.
DHS 157.67(12)
(12)
Periodic spot-checks for gamma stereotactic radiosurgery units. DHS 157.67(12)(a)(a) A licensee authorized to use a gamma stereotactic radiosurgery unit for medical use shall perform spot-checks of each gamma stereotactic radiosurgery facility and on each unit at all of the following times:
DHS 157.67(12)(b)
(b) A licensee shall have an authorized medical physicist do all the following:
DHS 157.67(12)(b)2.
2. Review the results of each spot-check required by par.
(a) 1. within 15 working days of the check. The authorized medical physicist need not actually perform the spot-check measurements.
DHS 157.67(12)(b)3.
3. The authorized medical physicist shall notify the licensee as soon as possible in writing of the results of the spot check.
DHS 157.67(12)(c)1.
1. Assure proper operation of treatment table retraction mechanism, using backup battery power or hydraulic backups with the unit off; helmet microswitches; emergency timing circuits and stereotactic frames and localizing devices.
DHS 157.67(12)(c)2.a.
a. The output for one typical set of operating conditions measured with the dosimetry system described in sub.
(6) (b).
DHS 157.67(12)(c)2.b.
b. The difference between the measurement made in subd.
2. a. and the anticipated output expressed as a percentage of the anticipated output.
DHS 157.67(12)(d)
(d) To satisfy the requirements of par.
(a) 2. and
3., a spot-check shall assure proper operation of all of the following:
DHS 157.67(12)(d)1.
1. Electrical interlocks at each gamma stereotactic radiosurgery room entrance.
DHS 157.67(12)(d)2.
2. Source exposure indicator lights on the gamma stereotactic radiosurgery unit, on the control console and in the facility.
DHS 157.67(12)(e)
(e) A licensee shall arrange for prompt repair of any system identified in par.
(c) or
(d) that is not operating properly.
