Section 0400-20-09-.21 - THERAPEUTIC ACCELERATOR INSTALLATIONS(1) Operation. (a) No individual except the patient shall be in the treatment room during irradiation.(b) The emergency procedures shall include instructions for:1. Minimizing exposure of individuals in the event of an accident, e.g., alternate means of terminating the accelerator beam.2. Removing the patient from the treatment room.3. Preventing the entrance of individuals into the treatment room.4. Notifying the responsible physician or radiation protection officer.(c) During patient irradiation, both the patient and the control panel shall at all times be kept under observation by the operator.(2) Equipment. (a) A therapeutic-type protective tube housing shall be utilized for x-ray therapy devices.(b) Diaphragms or cones shall be used to collimate the useful beam of radiation to those portions of the body undergoing treatment. Such diaphragms or cone shall transmit not more than 5 percent of the maximum useful beam.(c) A timer shall be provided to terminate the exposure after a preset time regardless of what other exposure limiting devices are present. Where the timing device is utilized as a backup device, the time preset shall not be greater than that necessary to provide the required dose with allowance for equipment variability.(d) Full calibration measurements shall be performed on each therapeutic accelerator: 1. Prior to the first use of the unit for treating humans;2. Prior to treating humans;(i) Whenever spot-check measurements indicate that the output value differs by more than 5 percent from the value obtained at the last full calibration;(ii) Following reinstallation of the unit in a new location;(iii) Following any repair of the unit that includes repair of the components associated with radiation exposure; and3. At intervals not exceeding 1 year.(e) Full calibration measurements required by subparagraph (d) of this paragraph shall include determination of:1. The exposure rate or dose rate to an accuracy within =+ 3 percent for the range of field sizes and for the range of distances (or for the axis distance) used in radiation therapy;2. The congruence between the radiation field and the field indicated by the light beam localizing device;3. The uniformity of the radiation field and its dependence upon the orientation of the useful beam;5. The accuracy of all distance measuring devices used for treating humans.(f) Full calibration measurements shall be made in accordance with the procedure recommended by the Scientific Committee on Radiation Dosimetry of the American Association of Physicists in Medicine (Physics in Medicine and Biology, Vol. 16, No. 3, 1971, pp. 379-396).(g) Full calibration measurements required by subparagraph (d) of this paragraph shall be performed by a qualified expert as defined in Rule 0400-20-04-.04.(h) Spot-check measurements shall be performed on each therapeutic accelerator at intervals not exceeding 1 month.(i) Spot-check measurements required by subparagraph (h) of this paragraph shall include determination of: 2. The congruence between the radiation field and the field indicated by the light beam localizing device;3. The accuracy of all distance measuring devices used for treating humans; and4. The exposure rate, dose rate or a quantity related in a known manner to those rates for one typical set of operating conditions.(j) Spot-check measurements required by subparagraph (h) of this paragraph shall be performed in accordance with procedures established by a qualified expert as defined in Rule 0400-20-04-.04. (A qualified expert need not actually perform the spot-check measurements.) If a qualified expert does not perform the spot-check measurements, the results of the spot-check measurements shall be reviewed by a qualified expert within 15 days.(k) Full calibration measurements required in subparagraph (d) of this paragraph shall be performed using a dosimetry system that has been calibrated by the National Bureau of Standards or by a Regional Calibration Laboratory accredited by the American Association of Physicists in Medicine. The dosimetry system shall have been calibrated within the previous 2 years and after any servicing that may have affected system calibration.(l) Spot-check measurements required by subparagraph (h) of this paragraph shall be performed using a dosimetry system that has been calibrated in accordance with subparagraph (k) of this paragraph. Alternatively, a dosimetry system used solely for spot-check measurements may be calibrated by direct intercomparison with a system that has been calibrated in accordance with subparagraph (k) of this paragraph. This alternative calibration method shall have been performed within the previous 1 year and after each servicing that may have affected system calibration. Dosimetry systems calibrated by this alternative method shall not be used for full calibration measurements.(m) Records of the measurements, tests, corrective actions and instrument calibration made under subparagraphs (d) through (f) and (h) through (l) of this paragraph and the registrants evaluation of the Qualified Expert's training and experience shall be maintained for inspection by the Division.(3) Facility. (a) Provisions shall be made to permit continuous observation of the patients during irradiation. Windows, mirror systems, or closed-circuit television viewing screens used for observing the patient shall be so located that the operator may see the patient from his position at the control panel.(b) An accelerator used only for the treatment of humans shall not be required to have an audible warning device within the treatment room as required by subparagraph (4)(h) of Rule 0400-20-09-.17.(c) An accelerator used only for the treatment of humans shall not be required to have a flashing or rotating warning light in the treatment room but shall have therein a readily observable warning light or lights that operate when and only when radiation is being produced.Tenn. Comp. R. & Regs. 0400-20-09-.21
Original rule filed February 22, 2012; effective May 22, 2012.Authority: T.C.A. §§ 68-202-101 et seq., 68-202-201 et seq. and 4-5-201 et seq.