64E-5.6412. Full Calibration Measurements on Gamma Stereotactic Radiosurgery Units

(1) A licensee authorized to use a gamma stereotactic radiosurgery unit for medical use shall perform full calibration measurements on each gamma stereotactic radiosurgery:

(a) Before the first medical use of the unit;

(b)1. Before medical use whenever spot-check measurements indicate that the output differs by more than 5 percent from the output obtained at the last full calibration corrected mathematically for radioactive decay;

2. Before medical use following replacement of the source or following reinstallation of the gamma stereotactic radiosurgery unit in a new location;

3. 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; and

(c) At intervals not exceeding 1 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 a helmet.

(2) Full calibration measurements of the gamma stereotactic radiosurgery unit shall include the determination of:

(a) The output within 3 percent;

(b) Relative helmet factors;

(c) Isocenter coincidence;

(d) Timer constancy and linearity over the range of use;

(e) On-off errors;

(f) Trunnion centricity;

(g) Treatment table retraction mechanism, using backup battery power or hydraulic backups with the unit off;

(h) Helmet microswitches;

(i) Emergency timing circuits; and

(j) Stereotactic frames and localizing devices (trunnions).

(3) A licensee shall use the dosimetry system described in Rule 64E-5.640, F.A.C., to measure the output for one set of exposure conditions.  The remaining radiation measurements required in paragraph 64E-5.6412(2)(a), F.A.C., may be made using a dosimetry system that indicates relative dose rates.

(4) A licensee shall make full calibration measurements required by subsection 64E-5.6412(1), F.A.C., in accordance with published protocols accepted by nationally recognized bodies.

(5) A licensee shall correct mathematically the outputs determined in paragraph 64E-5.6412(2)(a), F.A.C., at intervals not exceeding 1 month for cobalt-60 and at intervals consistent with 1 percent physical decay for all other radionuclides.

(6) Full calibration measurements required by subsection 64E-5.6412(1), F.A.C., and physical decay corrections required by subsection 64E-5.6412(5), F.A.C., shall be performed by the authorized medical physicist.

(7) A licensee shall maintain a record of each gamma stereotactic radiosurgery unit calibration for three years. The record shall include:

(a) The date of the calibration;

(b) The manufacturer’s name, model number, and serial number for both the gamma stereotactic radiosurgery unit and the source;

(c) The model numbers and serial numbers of the instruments used to calibrate the gamma stereotactic radiosurgery unit;

(d) The results and an assessment of the full calibrations; and

(e) The signature of the authorized medical physicist.

Rulemaking Authority 404.051, 404.061, 404.071, 404.081, 404.141 FS. Law Implemented 404.022, 404.051(1), (4), (5), (6), (8), (9), (10), (11), 404.061(2), (3), 404.071(1), 404.081, 404.141 FS. History–New 2-11-10, 12-26-13.