105 CMR 120.437
Therapeutic Radiation Machines - Photon Therapy Systems (500 kV and Above) and Electron
Therapy Systems (500 keV and Above)
(A) Possession of Survey Instrument(s). Each facility location authorized to use a therapeutic
radiation machine in accordance with 105 CMR 120.437 shall possess appropriately calibrated
portable monitoring equipment. As a minimum, such equipment shall include a portable
radiation measurement survey instrument capable of measuring dose rates over the range ten Sv
(one mrem) per hour to ten mSv (1000 mrem) per hour. The survey instrument(s) shall be
operable and calibrated in accordance with 105 CMR 120.438.
(B) Leakage Radiation Outside the Maximum Useful Beam in Photon and Electron Modes.
(1) The absorbed dose due to leakage radiation (excluding neutrons) at any point outside
the maximum sized useful beam, but within a circular plane of radius two meters which is
perpendicular to and centered on the central axis of the useful beam at the nominal treatment
distance (i.e. patient plane), shall not exceed a maximum of 0.2% and an average of 0.1% of
the absorbed dose on the central axis of the beam at the nominal treatment distance.
Measurements shall be averaged over an area not exceeding 100 square centimeters at a
minimum of 16 points uniformly distributed in the plane;
(2) Except for the area defined in 105 CMR 120.437(B)(1), the absorbed dose due to
leakage radiation (excluding neutrons) at one meter from the electron path between the
electron source and the target or electron window shall not exceed 0.5% of the absorbed dose
on the central axis of the beam at the nominal treatment distance. Measurements shall be
averaged over an area not exceeding 100 square centimeters;
(3) For equipment manufactured after July 9, 1999, the neutron absorbed dose outside the
useful beam shall be in compliance with International Electrotechnical Commission (IEC)
Document 601-2-1 (most current revision); and
(4) For each therapeutic radiation machine, the registrant shall determine, or obtain from
the manufacturer, the leakage radiation existing at the positions specified in 105 CMR
120.437(B)(1) through (B)(3) for the specified operating conditions. Records on leakage
radiation measurements shall be maintained at the installation for inspection by the Agency.
(C) Leakage Radiation Through Beam Limiting Devices.
(1) Photon Radiation. The secondary collimators shall attenuate the useful beam such that
at the nominal treatment distance, the maximum absorbed dose anywhere in the area shielded
by the beam limiting device(s) shall not exceed 2% (averaged over a one cm squared area)
of the maximum absorbed dose on the central axis of the useful beam measured in a 100 cm2
radiation field, or maximum available field size if less than 100 cm ;
(2) Electron Radiation. All adjustable or interchangeable electron applicators shall
attenuate the radiation, including but not limited to photon radiation generated by electrons
incident on the beam limiting device and electron applicator and other parts of the radiation
head, such that the absorbed dose in a plane perpendicular to the central axis of the useful
beam at the nominal treatment distance shall not exceed:
(a) A maximum of 2% and average of 0.5% of the absorbed dose on the central axis of
the useful beam at the nominal treatment distance. This limit shall apply beyond a line
seven centimeters outside the periphery of the useful beam; and
(b) A maximum of 10% of the absorbed dose on the central axis of the useful beam at
the nominal treatment distance. This limit shall apply beyond a line two centimeters
outside the periphery of the useful beam.
(3) Measurement of Leakage Radiation.
(a) Photon Radiation. Measurements of leakage radiation through the beam limiting
devices shall be made with the beam limiting devices closed and any residual aperture
blocked by at least two tenth value layers of suitable absorbing material. In the case of
overlapping beam limiting devices, the leakage radiation through each set shall be
measured independently at the depth of maximum dose. Measurements shall be made
using a radiation detector of area not exceeding ten square centimeters;
(b) Electron Radiation. Measurements of leakage radiation through the electron
applicators shall be made with the electron beam directed into the air and using a
radiation detector of area up to but not exceeding one square centimeter suitably
protected against radiation which has been scattered from material beyond the radiation
detector. Measurements shall be made using one centimeter of water equivalent build
up material.
(D) Filters/Wedges.
(1) Each wedge filter which is removable from the system shall be clearly marked with an
identification number. For removable wedge filters, the nominal wedge angle shall appear
on the wedge or wedge tray (if permanently mounted to the tray). If the wedge or wedge tray
is significantly damaged, the wedge transmission factor shall be redetermined;
(2) If the absorbed dose rate information required by 105 CMR 120.437(I) relates
exclusively to operation with a field flattening filter or beam scattering foil in place, such foil
or filter shall be removable only by the use of tools;
(3) For equipment manufactured after the effective date of these regulations which utilize
a system of wedge filters, interchangeable field flattening filters, or interchangeable beam
scattering foils:
(a) Irradiation shall not be possible until a selection of a filter or a positive selection to
use "no filter" has been made at the treatment control panel, either manually or
automatically;
(b) An interlock system shall be provided to prevent irradiation if the filter selected is
not in the correct position;
(c) A display shall be provided at the treatment control panel showing the wedge
filter(s), interchangeable field flattening filter(s), and/or interchangeable beam scattering
foil(s) in use; and
(d) An interlock shall be provided to prevent irradiation if any filter and/or beam
scattering foil selection operation carried out in the treatment room does not agree with
the filter and/or beam scattering foil selection operation carried out at the treatment
control panel.
(E) X-ray/Neutron Contamination of the Useful Beam. For equipment manufactured after the
effective date of these regulations, the registrant shall determine during acceptance testing, or
obtain from the manufacturer, data sufficient to ensure that x-ray stray radiation in the useful
electron beam, absorbed dose at the surface during x-ray irradiation and stray neutron radiation
in the useful x-ray beam are in compliance with International Electrotechnical Commission (IEC)
Document 601-2-1 (most current revision).
(F) Beam Monitors. All therapeutic radiation machines subject to 105 CMR 120.437 shall be
provided with redundant beam monitoring systems. The sensors for these systems shall be fixed
in the useful beam during treatment to indicate the dose monitor unit rate.
(1) Equipment manufactured after the effective date of these regulations shall be provided
with at least two independently powered integrating dose meters. Alternatively, common
elements may be used if the production of radiation is terminated upon failure of any
common element.
(2) Equipment manufactured on or before the effective date of these regulations shall be
provided with at least one radiation detector. This detector shall be incorporated into a useful
beam monitoring system;
(3) The detector and the system into which that detector is incorporated shall meet the
following requirements:
(a) Each detector shall be removable only with tools and, if movable, shall be
interlocked to prevent incorrect positioning;
(b) Each detector shall form part of a beam monitoring system from whose readings in
dose monitor units the absorbed dose at a reference point can be calculated;
(c) Each beam monitoring system shall be capable of independently monitoring,
interrupting, and terminating irradiation; and
(d) For equipment manufactured after the effective date of these regulations, the design
of the beam monitoring systems shall ensure that the:
1. Malfunctioning of one system shall not affect the correct functioning of the other
system(s); and
2. Failure of either system shall terminate irradiation or prevent the initiation of
radiation.
(e) Each beam monitoring system shall have a legible display at the treatment control
panel. For equipment manufactured after the effective date of these regulations, each
display shall:
1. Maintain a reading until intentionally reset;
2. Have only one scale and no electrical or mechanical scale multiplying factors;
3. Utilize a design such that increasing dose is displayed by increasing numbers; and
4. In the event of power failure, the beam monitoring information required in 105
CMR 120.437(F)(3)(e)3. displayed at the control panel at the time of failure shall be
retrievable in at least one system for a 20 minute period of time.
(G) Beam Symmetry.
(1) Bent-beam linear accelerators subject to 105 CMR 120.437 shall be provided with
auxiliary device(s) to monitor beam symmetry;
(2) The device(s) referenced in 105 CMR 120.437(G)(1) shall be able to detect field
asymmetry greater than 10%; and
(3) The device(s) referenced in 105 CMR 120.437(G)(1) shall be configured to terminate
irradiation if the specifications in 105 CMR 120.437(G)(2) can not be maintained.
(H) Selection and Display of Dose Monitor Units.
(1) Irradiation shall not be possible until a new selection of a number of dose monitor units
has been made at the treatment control panel;
(2) The pre-selected number of dose monitor units shall be displayed at the treatment
control panel until reset manually for the next irradiation;
(3) After termination of irradiation, it shall be necessary to reset the dosimeter display
before subsequent treatment can be initiated; and
(4) For equipment manufactured after the effective date of these regulations, after
termination of irradiation, it shall be necessary for the operator to reset the pre-selected dose
monitor units before irradiation can be initiated.
(I) Air Kerma Rate/Absorbed Dose Rate. For equipment manufactured after October 6, 2006,
a system shall be provided from whose readings the air kerma rate or absorbed dose rate at a
reference point can be calculated. [The radiation detectors specified in 105 CMR 120.437(F)
may form part of this system.] In addition:
(1) The dose monitor unit rate shall be displayed at the treatment control panel;
(2) If the equipment can deliver under any conditions an air kerma rate or absorbed dose
rate at the nominal treatment distance more than twice the maximum value specified by the
manufacturer, a device shall be provided which terminates irradiation when the air kerma rate
or absorbed dose rate exceeds a value twice the specified maximum. The dose rate at which
the irradiation will be terminated shall be a record maintained by the registrant;
(3) If the equipment can deliver under any fault condition(s) an air kerma rate or absorbed
dose rate at the nominal treatment distance more than ten times the maximum value specified
by the manufacturer, a device shall be provided to prevent the air kerma rate or absorbed
dose rate anywhere in the radiation field from exceeding twice the specified maximum value
and to terminate irradiation if the excess absorbed dose at the nominal treatment distance
exceeds four Gy (400 rad); and
(4) For each therapeutic radiation machine, the registrant shall determine, or obtain from
the manufacturer, the maximum value(s) specified in 105 CMR 120.437(I)(2) and (I)(3) for
the specified operating conditions. Records of these maximum value(s) shall be maintained
at the installation for inspection by the Agency.
(J) Termination of Irradiation by the Beam Monitoring System or Systems During Stationary
Beam Radiation Therapy.
(1) Each primary system shall terminate irradiation when the pre-selected number of dose
monitor units has been detected by the system;
(2) If the original design of the equipment included a secondary dose monitoring system,
that system shall be capable of terminating irradiation when not more than 15% or 40 dose
monitor units above the pre-selected number of dose monitor units set at the control panel
has been detected by the secondary dose monitoring system; and
(3) For equipment manufactured after July 9, 1999, an indicator on the control panel shall
show which monitoring system has terminated irradiation.
(K) Termination of Irradiation. It shall be possible to terminate irradiation and equipment
movement or go from an interruption condition to termination condition at any time from the
operator's position at the treatment control panel.
(L) Interruption of Irradiation. If a therapeutic radiation machine has an interrupt mode, it shall
be possible to interrupt irradiation and equipment movements at any time from the treatment
control panel. Following an interruption it shall be possible to restart irradiation by operator
action without any reselection of operating conditions. If any change is made of a pre-selected
value during an interruption, irradiation and equipment movements shall be automatically
terminated.
(M) Timer. A suitable irradiation control device shall be provided to terminate the irradiation
after a pre-set time interval.
(1) A timer shall be provided which has a display at the treatment control panel. The timer
shall have a pre-set time selector and an elapsed time indicator;
(2) The timer shall be a cumulative timer which activates with an indication of
"BEAM-ON" and retains its reading after irradiation is interrupted or terminated. After
irradiation is terminated and before irradiation can be reinitiated, it shall be necessary to reset
the elapsed time indicator;
(3) The timer shall terminate irradiation when a pre-selected time has elapsed, if the dose
monitoring systems have not previously terminated irradiation.
(N) Selection of Radiation Type. Equipment capable of both x-ray therapy and electron therapy
shall meet the following additional requirements:
(1) Irradiation shall not be possible until a selection of radiation type (x-rays or electrons)
has been made at the treatment control panel;
(2) The radiation type selected shall be displayed at the treatment control panel before and
during irradiation;
(3) An interlock system shall be provided to ensure that the equipment can principally emit
only the radiation modality which has been selected;
(4) An interlock system shall be provided to prevent irradiation with x-rays, except to obtain
an image, when electron applicators are fitted;
(5) An interlock system shall be provided to prevent irradiation with electrons when
accessories specific for x-ray therapy are fitted; and
(6) An interlock system shall be provided to prevent irradiation if any selected operations
carried out in the treatment room do not agree with the selected operations carried out at the
treatment control panel.
(O) Selection of Energy. Equipment capable of generating radiation beams of different energies
shall meet the following requirements:
(1) Irradiation shall not be possible until a selection of energy has been made at the
treatment control panel;
(2) The nominal energy value selected shall be displayed at the treatment control panel until
reset manually for the next irradiation. After termination of irradiation, it shall be necessary
to reset the nominal energy value selected before subsequent treatment can be initiated;
(3) Irradiation shall not be possible until the appropriate flattening filter or scattering foil
for the selected energy is in its proper location; and
(4) For equipment manufactured after July 9, 1999, the selection of energy shall be in
compliance with International Electrotechnical Commission (IEC) Document 601-2-1 (most
current revision).
(P) Selection of Stationary Beam Radiation Therapy or Moving Beam Radiation Therapy.
Therapeutic radiation machines capable of both stationary beam radiation therapy and moving
beam radiation therapy shall meet the following requirements:
(1) Irradiation shall not be possible until a selection of stationary beam radiation therapy or
moving beam radiation therapy has been made at the treatment control panel;
(2) The mode of operation shall be displayed at the treatment control panel;
(3) An interlock system shall be provided to ensure that the equipment can operate only in
the mode which has been selected;
(4) An interlock system shall be provided to prevent irradiation if any selected parameter
in the treatment room does not agree with the selected parameter at the treatment control
panel;
(5) Moving beam radiation therapy shall be controlled to obtain the selected relationships
between incremental dose monitor units and incremental movement. For equipment
manufactured after July 9, 1999:
(a) An interlock system shall be provided to terminate irradiation if the number of dose
monitor units delivered in any 10° of rotation or one cm of linear motion differs by more
than 20% from the selected value;
(b) Where angle terminates the irradiation in moving beam radiation therapy, the dose
monitor units delivered shall differ by less than 5% from the dose monitor unit value
selected;
(c) An interlock shall be provided to prevent motion of more than 5° or one cm beyond
the selected limits during moving beam radiation therapy;
(d) An interlock shall be provided to require that a selection of direction be made at the
treatment control panel in all units which are capable of both clockwise and
counter-clockwise moving beam radiation therapy.
(e) Moving beam radiation therapy shall be controlled with both primary position
sensors and secondary position sensors to obtain the selected relationships between
incremental dose monitor units and incremental movement.
(6) Where the beam monitor system terminates the irradiation in moving beam radiation
therapy, the termination of irradiation shall be as required by 105 CMR 120.437(J); and
(7) For equipment manufactured after July 9, 1999, an interlock system shall be provided
to terminate irradiation if movement:
(a) Occurs during stationary beam radiation therapy; or
(b) Does not start or stops during moving beam radiation therapy unless such stoppage
is a pre-planned function.
(Q) Facility Design Requirements for Therapeutic Radiation Machines Operating above 500
kV. In addition to shielding adequate to meet requirements of 105 CMR 120.439, the following
design requirements are made:
(1) Protective Barriers. All protective barriers shall be fixed, except for access doors to the
treatment room or movable beam interceptors;
(2) Control Panel. In addition to other requirements specified in 105 CMR 120.430, the
control panel shall also:
(a) Be located outside the treatment room;
(b) Provide an indication of whether electrical power is available at the control panel
and if activation of the radiation is possible;
(c) Provide an indication of whether radiation is being produced; and
(d) Include an access control (locking) device which will prevent unauthorized use of
the therapeutic radiation machine;
(3) Viewing Systems. Windows, mirrors, closed-circuit television or an equivalent viewing
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 treatment control panel. The therapeutic radiation machine shall not be used
for patient irradiation unless at least one viewing system is operational;
(4) Aural Communications. Provision shall be made for continuous two-way aural
communication between the patient and the operator at the control panel. The therapeutic
radiation machine shall not be used for irradiation of patients unless continuous two-way
aural communication is possible;
(5) Room Entrances. Treatment room entrances shall be provided with warning lights in
a readily observable position near the outside of all access doors, which will indicate when
the useful beam is "ON" and when it is "OFF";
(6) Entrance Interlocks. Interlocks shall be provided such that all access controls are
activated before treatment can be initiated or continued. If the radiation beam is interrupted
by any access control, it shall not be possible to restore the machine to operation without
resetting the access control and reinitiating irradiation by manual action at the control panel;
(7) Beam Interceptor Interlocks. If the shielding material in any protective barrier requires
the presence of a beam interceptor to ensure compliance with 105 CMR 120.221(A) and (B),
interlocks shall be provided to prevent the production of radiation, unless the beam
interceptor is in place, whenever the useful beam is directed at the designated barrier(s);
(8) Sliding Shielding Doors. Registrants with treatment rooms which utilize sliding
shielding doors or other doors so massive that they may become jammed in the case of
catastrophe will have in place an emergency plan to address such failure. In addition:
(a) Each door to a treatment room installed after July 9, 1999 will be equipped with an
independent means of opening operable by a single able individual;
(b) Each sliding door installed after July 91, 1999 will be equipped with an electronic
sensor which will immediately stop and disable the door closer (or reverse its motion)
in the event of an imminent collision between the door and a person or object in its path.
(9) Emergency Cutoff Switches. At least three emergency power cutoff switch shall be
located in the radiation therapy room and shall terminate all equipment electrical power
including radiation and mechanical motion. This switch is in addition to the termination
switch required by 105 CMR 120.437(K). All emergency power cutoff switches shall include
a manual reset so that the therapeutic radiation machine cannot be restarted from the unit's
control console without resetting the emergency cutoff switch;
(10) Safety Interlocks. All safety interlocks shall be designed so that any defect or
component failure in the safety interlock system prevents or terminates operation of the
therapeutic radiation machine; and
(11) Surveys for Residual Radiation. Surveys for residual activity shall be conducted on
all therapeutic radiation machines capable of generating photon and electron energies above
10 MV prior to machining, removing, or working on therapeutic radiation machine
components which may have become activated due to photo-neutron production.
(R) Qualified Medical Physicist Support.
(1) The services of a Qualified Medical Physicist shall be required in facilities having
therapeutic radiation machines with energies of 500 kV and above. The Qualified Medical
Physicist shall be responsible for:
(a) Full calibration(s) required by 105 CMR 120.437(T) and protection surveys required
by 105 CMR 120.434(A);
(b) Supervision and review of dosimetry;
(c) Beam data acquisition and transfer for computerized dosimetry, and supervision of
its use;
(d) Quality assurance, including quality assurance check review required by 105 CMR
120.437(U)(5);
(e) Consultation with the authorized user in treatment planning, as needed; and
(f) Perform calculations/assessments regarding medical events.
(2) Radiation therapy facilities shall have a minimum of one half-time qualified medical
physicist available on a regular, on going, basis. In addition, radiation therapy facilities will
have a minimum of one full time equivalent qualified medical physicist for every 500 total
patients per year.
(3) If the Qualified Medical Physicist is not a full-time employee of the registrant, the
operating procedures required by 105 CMR 120.437(S) shall also specifically address how
the Qualified Medical Physicist is to be contacted for problems or emergencies, as well as
the specific actions, if any, to be taken until the Qualified Medical Physicist can be contacted.
(S) Operating Procedures.
(1) No individual, other than the patient, shall be in the treatment room during treatment or
during any irradiation for testing or calibration purposes;
(2) Therapeutic radiation machines shall not be made available for medical use unless the
requirements of 105 CMR 120.434(A), 120.437(T) and (U) have been met;
(3) Therapeutic radiation machines, when not in operation, shall be secured to prevent
unauthorized use;
(4) When adjustable beam limiting devices are used, the position and shape of the radiation
field shall be indicated by a light field.
(5) If a patient must be held in position during treatment, mechanical supporting or
restraining devices shall be used; and
(6) A copy of the current operating and emergency procedures shall be maintained at the
therapeutic radiation machine control console.
(T) Acceptance Testing, Commissioning and Full Calibration Measurements.
(1) Acceptance testing, commissioning and full calibration of a therapeutic radiation
machine subject to 105 CMR 120.437 shall be performed by, or under the direct supervision
of, a Qualified Medical Physicist.
(2) Acceptance testing and commissioning shall be performed in accordance with "AAPM
Code of Practice for Radiotherapy Accelerators: Report of AAPM Radiation Therapy Task
Group 45" or most current AAPM recommendation or most current AAPM published
recommendations and shall be conducted before the first medical use following installation
or reinstallation of the therapeutic radiation machine.
(3) Full calibration shall include measurement of all parameters required by Table II of
"Comprehensive QA for Radiation Oncology: Report of AAPM Radiation Therapy
Committee Task Group 40" or the most current AAPM published recommendations and shall
be performed in accordance with "AAPM Code of Practice for Radiotherapy Accelerators:
Report of AAPM Radiation Therapy Task Group 45" or most current AAPM
recommendation or the most current AAPM published recommendations. Although it shall
not be necessary to complete all elements of a full calibration at the same time, all parameters
(for all energies) shall be completed at intervals not exceeding 12 calendar months, unless
a more frequent interval is required in Table II.
(4) The Qualified Medical Physicist shall perform all elements of a full calibration
necessary to determine that all parameters are within acceptable limits:
(a) Whenever quality assurance check measurements indicate that the radiation output
differs by more than 5% from the value obtained at the last full calibration and the
difference cannot be reconciled. Therapeutic radiation machines with multi-energy
and/or multi-mode capabilities shall only require measurements for those modes and/or
energies that are not within their acceptable range; and
(b) Following any component replacement, major repair, or modification of components
that could significantly affect the characteristics of the radiation beam. If the repair,
replacement or modification does not affect all modes and/or energies, measurements
shall be performed on the effected mode/energy that is in most frequent clinical use at
the facility. The remaining energies/modes may be validated with quality assurance
check procedures against the criteria in 105 CMR 120.437(T)(4)(a).
(5) The registrant shall maintain a record of each calibration in an auditable form for the
duration of the registration. The record shall include the date of the calibration, the
manufacturer's name, model number, and serial number for the therapeutic radiation
machine, the model numbers and serial numbers of the instruments used to calibrate the
therapeutic radiation machine, and the signature of the Qualified Medical Physicist
responsible for performing the calibration.
(U) Periodic Quality Assurance Checks.
(1) Periodic quality assurance checks shall be performed on all therapeutic radiation
machines subject to 105 CMR 120.437 at intervals not to exceed those specified in
"Comprehensive QA for Radiation Oncology: Report of AAPM Radiation Therapy
Committee Task Group 40" or the most current AAPM published recommendations;
(2) To satisfy the requirement of 105 CMR 120.437(U)(1), quality assurance checks shall
include determination of central axis radiation output and a representative sampling of
periodic quality assurance checks contained in "Comprehensive QA for Radiation Oncology:
Report of AAPM Radiation Therapy Committee Task Group 40" or the most current AAPM
published recommendations. Representative sampling shall include all referenced periodic
quality assurance checks in an interval not to exceed 12 consecutive calendar months;
(3) The registrant shall use a dosimetry system which has been inter-compared within the
previous 12 months with the dosimetry system described in 105 CMR 120.434(C)(1) to make
the periodic quality assurance checks required in 105 CMR 120.437(U)(2);
(4) The registrant shall perform periodic quality assurance checks required by 105 CMR
120.437(U)(1) in accordance with procedures established by the Qualified Medical Physicist;
(5) The registrant shall review the results of each periodic radiation output check according
to the following procedures:
(a) The authorized user and Qualified Medical Physicist shall be immediately notified
if any parameter is not within its acceptable tolerance. The therapeutic radiation machine
shall not be made available for subsequent medical use until the Qualified Medical
Physicist has determined that all parameters are within their acceptable tolerances;
(b) If all quality assurance check parameters appear to be within their acceptable range,
the quality assurance check shall be reviewed and signed by either the authorized user or
Qualified Medical Physicist within three treatment days; and
(c) The Qualified Medical Physicist shall review and sign the results of each radiation
output quality assurance check at intervals not to exceed 30 days.
(6) Therapeutic radiation machines subject to 105 CMR 120.437 shall have safety quality
assurance checks listed in the most currently published recommendations of reports of the
AAPM Radiation Therapy Committee Task Group 40 at intervals not to exceed the
frequencies recommended therein;
(7) To satisfy the requirement of 105 CMR 120.437(U)(6), safety quality assurance checks
shall ensure proper operation of:
(a) Electrical interlocks at each external beam radiation therapy room entrance;
(b) Proper operation of the "BEAM-ON", interrupt and termination switches;
(c) Beam condition indicator lights on the access doors, control console, and in the
radiation therapy room;
(d) Viewing systems;
(e) Electrically operated treatment room door(s) from inside and outside the treatment
room;
(f) At least one emergency power cutoff switch. If more than one emergency power
cutoff switch is installed and not all switches are tested at once, each switch shall be
tested on a rotating basis. Safety quality assurance checks of the emergency power cutoff
switches may be conducted at the end of the treatment day in order to minimize possible
stability problems with the therapeutic radiation machine.
(8) The registrant shall promptly repair any system identified in 105 CMR 120.437(U)(7)
that is not operating properly; and
(9) The registrant shall maintain a record of each quality assurance check required by
105 CMR 120.437(U)(1) and (7) for three years. The record shall include the date of the
quality assurance check, the manufacturer's name, model number, and serial number for the
therapeutic radiation machine, the manufacturer's name, model number and serial number
of the instrument(s) used to measure the radiation output of the therapeutic radiation
machine, and the signature of the individual who performed the periodic quality assurance
check.
(V) Quality Assurance Checks for IMRT shall:
(1) Include commissioning and testing of the treatment planning and delivery systems,
routine quality assurance of the delivery system, and patient-specific validation of treatment
plans [Note: IMRT is a rapidly evolving modality and the QA program shall also evolve to
handle new issues that arise.]; and
(2) Be performed in accordance with "Dosimetry Tools and Techniques for IMRT - The
report of AAPM Task Group 120" (2010), or current AAPM Recommendation"; and
(3) Be performed in accordance with the manufacturer's contractual specifications.