| (iv) Windows, mirrors, closed-circuit television, or
an equivalent system shall be provided to permit continuous observation
of the patient following positioning and during irradiation and shall
be so located that the operator may observe the patient from the console.
(I) Should the viewing system described in clause (iv)
of this subparagraph fail or be inoperative, treatment shall not be
performed with the unit until the system is restored.
(II) In a facility that has a primary viewing system
by electronic means and an alternate viewing system, should both viewing
systems described in clause (iv) of this subparagraph fail or be inoperative,
treatment shall not be performed with the unit until one of the systems
is restored.
(v) Provision shall be made for continuous two-way
aural communication between the patient and the operator at the console
independent of the accelerator. However, where excessive noise levels
or treatment requirements make aural communication impractical, other
methods of communication shall be used. When this is the case, a description
of the alternate method shall be submitted to and approved by the
agency.
(vi) Treatment room entrances shall be provided with
a warning light in a readily observable position near the outside
of all access doors to indicate when the useful beam is "on."
(vii) Interlocks shall be provided such that all entrance
doors shall be closed before treatment can be initiated or continued.
If the radiation beam is interrupted by any door opening, it shall
not be possible to restore the machine to operation without closing
the door and reinitiating irradiation by manual action at the console.
(C) Surveys, calibrations, spot checks, and operational
requirements.
(i) Surveys shall be performed as follows.
(I) All new and existing facilities not previously
surveyed shall have an initial survey made by a licensed medical physicist
with a specialty in therapeutic radiological physics, who shall provide
a written report of the survey to the registrant. The physicist who
performs the survey shall be a person who did not consult in the design
of the therapeutic radiation machine installation and is not employed
by or within any corporation or partnership with the person who consulted
in the design of the installation. In addition, such surveys shall
be done after any change in the facility or equipment that might cause
a significant increase in radiation hazard.
(II) The survey report shall include, but not be limited
to the following:
(-a-) a diagram of the facility that details building
structures and the position of the console, therapeutic radiation
machine, and associated equipment;
(-b-) a description of the therapeutic radiation system,
including the manufacturer, model and serial number, beam type, and
beam energy;
(-c-) a description of the instrumentation used to
determine radiation measurements, including the date and source of
the most recent calibration for each instrument used;
(-d-) conditions under which radiation measurements
were taken; and
(-e-) survey data including:
(-1-) projected annual TEDE in areas adjacent to the
therapy room; and
(-2-) a description of workload, use, and occupancy
factors employed in determining the projected annual TEDE.
(III) The registrant shall maintain a copy of the survey
report and a copy of the survey report shall be provided to the agency
within 30 days of completion of the survey. Records of the survey
report shall be maintained in accordance with subsection (l) of this
section for inspection by the agency.
(IV) The survey report shall include documentation
of all instances where the installation is in violation of applicable
regulations. Any deficiencies detected during the survey shall be
corrected prior to using the machine.
(ii) Calibrations of therapeutic systems shall be performed
as follows.
(I) The calibration of systems subject to this subsection
shall be performed in accordance with an established calibration protocol
before the system is first used for irradiation of a patient and thereafter
at time intervals that do not exceed 12 months and after any change
that might significantly alter the calibration, spatial distribution,
or other characteristics of the therapy beam. The calibration procedures
shall be in writing, or documented in an electronic reporting system,
and shall have been developed by a licensed medical physicist with
a specialty in therapeutic radiological physics. The calibration protocol
entitled, "Protocol for Clinical Reference Dosimetry of High-Energy
Photon and Electron Beams," Task Group 51, Radiation Therapy Committee,
American Association of Physicists in Medicine, Medical Physics 26(9):
1847 - 1870, September 1999, would be accepted as an established protocol.
At a minimum, the calibration protocol shall include items in subclauses
(III) - (V) of this clause below.
(II) The calibration shall be performed by a licensed
medical physicist with a specialty in therapeutic radiological physics
who is physically present at the facility during the calibration.
(III) Calibration radiation measurements required by
subclause (I) of this clause shall be performed using a dosimetry
system:
(-a-) having a calibration factor for cobalt-60 gamma
rays traceable to a national standard;
(-b-) that is traceable to a national standard and
at an interval not to exceed 24 months;
(-c-) that has been calibrated in such a fashion that
an uncertainty can be stated for the radiation quantities monitored
by the system; and
(-d-) that has had constancy checks performed on the
system as specified by the licensed medical physicist with a specialty
in therapeutic radiological physics.
(IV) Calibrations shall be in sufficient detail that
the dose at a reference point in a tissue equivalent phantom can be
calculated to within an uncertainty of 5.0%.
(V) The calibration of the therapy unit shall include,
but not be limited to, the following determinations.
(-a-) Verification that the equipment is operating
in compliance with the design specifications concerning the light
field, patient positioning lasers, and back-pointer lights 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.
(-b-) 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.
(-c-) The uniformity of the radiation field to include
symmetry, flatness, and dependence on gantry angle.
(-d-) Verification that existing isodose charts applicable
to the specific machine continue to be valid or are updated to existing
machine conditions.
(-e-) Verification of transmission factors for all
accessories such as wedges, block trays, and/or universal and custom
made beam modifying devices.
(VI) Calibration of therapeutic systems containing
asymmetric jaws, multileaf collimation, or dynamic/virtual wedges
shall be performed with an established protocol. The procedures shall
be developed by a licensed medical physicist with a specialty in therapeutic
radiological physics and shall be in writing or documented in an electronic
reporting system. Current recommendations by a national professional
association as the American Association of Physicists in Medicine,
Task Group 142 report: "Quality Assurance of Medical Accelerators"
published August 17, 2009, would be considered an established protocol.
(VII) Records of calibration measurements specified
in subclause (I) of this clause and dosimetry system calibrations
specified in subclause (III) of this clause shall be maintained by
the registrant in accordance with subsection (l) of this section for
inspection by the agency.
(VIII) A copy of the latest calibrated absorbed dose
rate measured in accordance with subclause (I) of this clause shall
be available at a designated area within the facility housing that
radiation therapy system.
(iii) Spot checks shall be performed on systems subject
to this paragraph during calibrations and thereafter at weekly intervals
with the period between spot checks not to exceed 5 treatment days.
Such radiation output measurements shall meet the following requirements.
(I) The spot check procedures shall be performed in
accordance with established protocol, shall be in writing, or documented
in an electronic reporting system, and shall have been developed by
a licensed medical physicist with a specialty in therapeutic radiological
physics. Either the spot check protocol entitled, "Comprehensive QA
for Radiation Oncology," Task Group 40, Radiation Therapy Committee,
American Association of Physicists in Medicine, Medical Physics 21(4):
581-618, Cont'd... |
