Current through Register Vol. 48, No. 9, September 27, 2024
6.6.1 Radiological
Physics Support. The services of a radiological physicist shall be utilized in
facilities having therapy systems with energies of one megaelectron volt (1
MeV) and above. The radiological physicist shall be responsible for:
6.6.1.1 Calibration;
6.6.1.2 Supervision and review of patient
dosimetry;
6.6.1.3 Beam data
acquisition and storage for computer dosimetry, and supervision of its
use;
6.6.1.4 Quality assurance,
including spot check review;
6.6.1.5 Consultation with the radiation
therapist in treatment planning, as needed; and
6.6.1.6 Availability and responsiveness to
immediate problems or emergencies.
6.6.2 Surveys.
6.6.2.1 All new facilities, and existing
facilities not previously surveyed, shall have a survey made by, or under the
direction of, the radiological physicist. In addition, such surveys shall be
done after any change in the facility or equipment which might cause a
significant increase in radiation hazard.
6.6.2.2 The registrant shall obtain a written
report of the survey and a copy of the report shall be transmitted by the
registrant to the Department within thirty (30) calendar days of the first
patient treatment following the survey.
6.6.2.3 The survey and report shall indicate
all instances where the installation, in the opinion of the radiological
physicist, is in violation of applicable rules or regulations.
6.6.3 Calibrations.
6.6.3.1 The calibration of systems subject to
RHB 6.5 shall be performed in
accordance with an established calibration protocol acceptable to the
Department before the system is first used for irradiation of a patient and
thereafter at time intervals which do not exceed twelve (12) months and after
any change which might significantly alter the calibration, spatial
distribution, or other characteristics of the therapy beam. The protocol used
shall be a nationally accepted standard, such as one established by the
American Association of Physicists in Medicine.
6.6.3.2 The calibration shall be performed by
or under the direct supervision of the radiological physicist who is physically
present at the facility during the calibration.
6.6.3.3 Calibration radiation measurements
required by
RHB 6.6.3 shall meet the
requirements of
RHB 1.4.4.
6.6.3.4 Calibrations shall be in sufficient
detail that the dose at a reference point in tissue equivalent phantom may be
calculated to within an uncertainty of five percent (5%).
6.6.3.5 The calibration of the therapy unit
shall include, but not be limited to, the following determinations:
6.6.3.5.1 Verification that the equipment is
operating in compliance with the design specifications concerning the light
localizer, all patient positioning lights, and back-pointer alignment with the
isocenter when applicable, variation in the axis of rotation for the table,
gantry, and collimator system, and beam flatness and symmetry at the specified
depth.
6.6.3.5.2 The absorbed dose
rate at various depths in a tissue equivalent phantom for the range of field
sizes used, for each effective energy, that will verify the accuracy of the
dosimetry of all therapy procedures utilized with that therapy beam.
6.6.3.5.3 The uniformity of the radiation
field to include symmetry, flatness, and dependence on gantry angle.
6.6.3.5.4 Verification that existing isodose
charts applicable to the specific machine continue to be valid or are updated
to existing machine conditions.
6.6.3.5.5 Verification of transmission
factors for all accessories such as wedges, shadow trays, and/or universal beam
modifying devices.
6.6.3.6 Records of calibration measurements
under RHB
6.6.3.1 and dosimetry system calibrations under
RHB 6.6.3.3 shall be
maintained for five (5) years after completion of the full
calibration.
6.6.3.7 A copy of the
latest calibrated absorbed dose rate measured pursuant to
RHB 6.6.3.1 shall be
available.
6.6.4 Spot
Checks. Spot checks shall be performed on systems subject to
RHB 6.5 during calibrations and
at intervals established by the radiological physicist, not to exceed monthly,
using a nationally accepted standard such as one established by the American
College of Radiology, American Association of Physicists in Medicine, American
College of Medical Physics, etc.
6.6.4.1 The
spot check procedures shall be in writing and shall have been developed by the
radiological physicist. A copy of the procedures shall be submitted to the
Department upon request.
6.6.4.2 If
a radiological physicist does not perform the spot check measurements, the
results of the spot check measurements shall be reviewed by the radiological
physicist within seven (7) treatment days.
6.6.4.3 The spot check procedures shall
specify the frequency at which tests or measurements are to be performed and
the acceptable tolerance for each parameter measured in the spot check when
compared to the value for that parameter determined in the
calibration.
6.6.4.4 Spot checks
shall be made at a depth consistent with a nationally accepted standard, such
as one established by the American Association of Physicists in
Medicine.
6.6.4.5 Where a system
has built-in devices which provide a measurement of any parameter during
irradiation, such measurement shall not be utilized as a spot check
measurement.
6.6.4.6 A parameter
exceeding a tolerance set by the radiological physicist shall be corrected
before the system is used for patient irradiation.
6.6.4.7 Whenever a spot check indicates a
significant change in the operating characteristics of a system, as specified
in the radiological physicist's spot check procedures, the system shall be
recalibrated, as required in
RHB 6.6.3.
6.6.4.8 Records of spot check measurements
and any necessary corrective actions shall be maintained by the registrant for
a period of three (3) years after completion of the spot check
measurements.
6.6.4.9 Whenever a
spot check requires a radiation measurement, such measurement shall be obtained
using a system satisfying the requirements of
RHB 6.6.3.3 or which has
been intercompared with a system meeting those requirements within the previous
year.
6.6.5 Prohibited
Use. The system shall not be used in the administration of radiation therapy
unless the requirements of
RHB 6.6.1 through
6.6.4 have been met.