A licensee authorized to use gamma stereotactic radiosurgery units for medical use must perform spot checks of each gamma stereotactic radiosurgery facility and on each unit:
A licensee must:
perform the spot checks required under subpart 1 according to written procedures established by the authorized medical physicist. The authorized medical physicist need not actually perform the spot check measurements; and
have the authorized medical physicist review the results of each spot check within 15 days. The authorized medical physicist must notify the licensee as soon as possible in writing of the results of each spot check.
To satisfy subpart 1, item A, monthly spot checks must, at a minimum:
ensure proper operation of:
the treatment table retraction mechanism, using backup battery power or hydraulic backups with the unit off;
determine:
the output for one typical set of operating conditions measured with the dosimetry system described under part 4731.4468, subpart 2;
the difference between the measurement made in subitem (1) and the anticipated output, expressed as a percentage of the anticipated output, that is, the value obtained at last full calibration corrected mathematically for physical decay;
To satisfy subpart 1, items B and C, spot checks must ensure proper operation of:
source exposure indicator lights on the gamma stereotactic radiosurgery unit, on the control console, and in the facility;
A licensee must arrange for repair of any system identified under subpart 3 that is not operating properly as soon as possible.
If the results of the checks required under subpart 4 indicate the malfunction of any system, a licensee must 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.
29 SR 755
March 12, 2009
Official Publication of the State of Minnesota
Revisor of Statutes