| (v) no individual, other than the patient, shall be
in the treatment room during exposures from therapeutic radiation
machines operating above 150 kV;
(vi) at energies less than or equal to 150 kV, any
individual, other than the patient, in the treatment room shall be
protected by a barrier sufficient to meet the requirements of §289.231(m)
and (o) of this title;
(vii) use of a technique chart for simulators in accordance
with paragraph (4)(A)(i) of this subsection;
(viii) radiation dose requirements in accordance with
§289.231(m) and (o) of this title;
(ix) personnel monitoring requirements in accordance
with §289.231(n) of this title;
(x) use of protective devices for simulators in accordance
with paragraph (4)(A)(iii) of this subsection;
(xi) credentialing requirements for individuals operating
radiation machines in accordance with subparagraph (C) of this paragraph;
(xii) film processing program for simulators in accordance
with paragraph (4)(A)(viii) of this subsection; and
(xiii) procedures for restriction and alignment of
beam for simulators in accordance with paragraph (4)(B)(iii) of this
subsection.
(H) Registrants with equipment that has been issued
variances by the United States Food and Drug Administration (FDA)
to Title 21, CFR Part 1020 shall maintain copies of those variances
at authorized use locations in accordance with subsection (l) of this
section.
(I) The registrant shall perform radiation surveys
and contamination smears prior to the transfer or disposal of an accelerator
operating at or above 10 MeV. Such survey(s) shall be documented and
maintained by the registrant for inspection by the agency in accordance
with subsection (l) of this section.
(J) Where applicable, the licensed medical physicist
shall perform acceptance testing on the treatment planning system
of therapy-related computer systems in accordance with published protocols
accepted by nationally recognized bodies. In the absence of such a
published protocol, the manufacturer's current protocol shall be followed.
(2) Therapeutic radiation machines capable of operating
at energies below 1 MeV.
(A) Equipment requirements.
(i) When the tube is operated at its leakage technique
factors, the leakage radiation shall not exceed the values specified
at the distance stated for the classification of that radiation machine
system shown in the following Table I. The leakage technique factors
are the maximum-rated peak tube potential and the maximum-rated continuous
tube current for the maximum-rated peak tube potential.
Attached Graphic
(ii) Permanent fixed diaphragms or cones used for limiting
the useful beam shall provide the same or a higher degree of protection
as required for the tube housing assembly.
(iii) Removable and adjustable beam-limiting devices
shall meet the following requirements.
(I) Removable beam-limiting devices shall, for the
portion of the useful beam to be blocked by these devices, transmit
not more than 1.0% of the useful beam at the maximum kVp and maximum
treatment filter. This requirement does not apply to auxiliary blocks
or materials placed in the x-ray field to shape the useful beam to
the individual patient.
(II) Adjustable beam-limiting devices installed before
March 1, 1989, shall, for the portion of the x-ray beam to be blocked
by these devices, transmit not more than 5.0% of the useful beam at
the maximum kVp and maximum treatment filter.
(III) Adjustable beam-limiting devices installed after
March 1, 1989, shall meet the requirements of subclause (I) of this
clause.
(iv) The filter system shall be so designed that:
(I) the filters cannot be accidentally displaced at
any possible tube orientation;
(II) for equipment installed after March 1, 1989, an
interlock system prevents irradiation if the proper filter is not
in place;
(III) the radiation at 5 centimeters (cm) from the
filter insertion slot opening does not exceed 30 roentgens per hour
(R/hr) (300 mGy/hr) under any operating conditions; and
(IV) each filter is marked as to its material of construction
and its thickness. For wedge filters, the wedge angle shall appear
on the wedge or wedge tray.
(v) The tube housing assembly shall be capable of being
immobilized for stationary treatments.
(vi) The tube housing assembly shall be so marked that
it is possible to determine the location of the focal spot to within
5 millimeters (mm), and such marking shall be readily accessible for
use during calibration procedures.
(vii) Contact therapy tube housing assemblies shall
have a removable shield of at least 0.5 mm lead equivalency at 100
kVp that can be positioned over the entire useful beam exit port during
periods when the beam is not in use.
(viii) The timer shall:
(I) have a display provided at the treatment control
panel and a pre-set time selector;
(II) activate with the production of radiation and
retain its reading after irradiation is interrupted. After irradiation
is terminated and before irradiation can be reinitiated, it shall
be necessary to reset the elapsed time indicator to zero;
(III) terminate irradiation when a pre-selected time
has elapsed, if any dose monitoring system present has not previously
terminated irradiation;
(IV) permit selection of exposure times as short as
one second;
(V) not permit an exposure if set at zero;
(VI) not activate until the shutter is opened when
irradiation is controlled by a shutter mechanism unless calibration
includes a timer factor to compensate for mechanical lag; and
(VII) be accurate to within 1.0% of the selected value
or 1 second, whichever is greater.
(ix) The control panel, in addition to the displays
required in clause (viii)(I) of this subparagraph, shall have the
following:
(I) an indication of whether electrical power is available
at the control panel and if activation of the x-ray tube is possible;
(II) an indication of whether x rays are being produced;
(III) means for indicating x-ray tube potential and
current;
(IV) means for terminating an exposure at any time;
(V) a locking device that will prevent unauthorized
use of the therapeutic radiation system (a computerized pass-word
system would also constitute a locking device);
(VI) for therapeutic radiation systems manufactured
after March 1, 1989, a positive display of specific filters in the
beam; and
(VII) emergency buttons/switches that shall be clearly
labeled as to their functions.
(x) There shall be means of determining initially the
SSD to within 1 cm and of reproducing this measurement to within 2
mm thereafter.
(xi) Unless it is possible to bring the radiation output
to the prescribed exposure parameters within 5 seconds, the beam shall
be attenuated by a shutter having a lead equivalency not less than
that of the tube housing assembly. After the unit is at operating
parameters, the shutter shall be controlled electrically by the operator
from the control panel. An indication of shutter position shall appear
at the control panel.
(xii) Each therapeutic radiation system equipped with
a beryllium or other low-filtration window shall be clearly labeled
as such upon the tube housing assembly and at the control panel.
(B) Facility requirements for therapeutic radiation
systems capable of operating above 50 kVp.
(i) Provision shall be made for two-way aural communication
between the patient and the operator at the control panel.
(ii) Windows, mirrors, closed-circuit television, or
an equivalent system shall be provided to permit continuous observation
of the patient during irradiation and shall be so located that the
operator can observe the patient from the control panel.
(I) Should the viewing system described in clause (ii)
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 (ii) of this subparagraph fail or be inoperative,
treatment shall not be performed with the unit until one of the systems
is restored.
(C) Additional facility requirements for therapeutic
radiation systems capable of operation above 150 kVp.
Cont'd... |
