The following words and terms, when used in this subchapter,
shall have the following meanings unless the context clearly indicates
otherwise.
"Applicator" means a structure which determines the extent of
the treatment field at a given distance from the virtual source and which may
or may not incorporate the beam limiting device.
"Beam interceptor" means a device located on the central axis
of the primary beam whose purpose is to substantially attenuate the beam so
that the room shielding requirements may be reduced.
"Beam limiting device" means a device which provides a means
to restrict the dimensions of the radiation field and which is an integral part
of the equipment.
"Beam monitoring system" means a system designed to detect
and measure the radiation present in the useful beam.
"Beam scattering filter" means a filter used to scatter a
beam of electrons.
"Central axis of the beam" means a line passing through the
virtual source and the center of the plane figure formed by the edge of the
final beam limiting device.
"Contact therapy system" means an x-ray system used for
therapy not capable of operating above 60 kVp and with a source distance less
than or equal to five centimeters.
"Department" means the New Jersey Department of Environmental
Protection.
"Dose monitoring system" means a system of devices for the
detection, measurement, and display of dose information for the useful
beam.
"Dose monitor unit" means a unit response from the dose
monitoring system from which the absorbed dose can be calculated.
"Field flattening filter" means a filter used to provide dose
uniformity over the area of a useful beam of x-rays at a specified
depth.
"Field size" means the projection on a plane perpendicular to
the beam axis, of the distal end of the collimator as seen from the front
center of the source.
"Full beam detector" means a radiation detector of such size
that the total cross section of the maximum-size useful beam is
intercepted.
"Gantry" means that part of the system supporting and
allowing possible movements of the radiation head.
"Interlock" means a device arranged or connected such that
the occurrence of an event or condition is required before a second event or
condition can occur or continue to occur.
"Interruption of irradiation" means the stopping of
irradiation with the possibility of continuing irradiation without resetting of
operating conditions at the control panel.
"Isocenter" means a fixed point in space located at the
center of the smallest sphere through which the central axis of the beam
pass.
"Leakage radiation" means radiation emanating from the
diagnostic or therapeutic source assembly except for the useful beam.
"Moving beam therapy" means radiation therapy with relative
movement of the useful beam and the patient during irradiation.
"Normal treatment distance" means:
1. For electron irradiation, the nominal source to surface
distance along the central axis of the useful beam, specified by the
manufacturer for the applicator;
2. For x-ray irradiation, the nominal source to isocenter
distance along the central axis of the useful beam; and
3. For non-isocentric equipment, this distance shall be
specified by the manufacturer.
"Phantom" means a volume of material behaving in a manner
similar to tissue with respect to the attenuation and scattering of
radiation.
"Primary dose monitoring system" means a system which will
monitor the quantity of radiation produced during irradiation and which will
terminate irradiation when a pre-selected number of dose monitor units have
been delivered.
"Qualified radiological physicist" means a person who holds
at least a bachelor's degree in one of the physical sciences and who is
certified by the American Board of Radiology either in radiological physics, x-
and gamma ray physics or therapeutic radiological physics, is eligible for such
certification, or has equivalent training and experience.
1. "Equivalent training and experience" means a person has:
i. A bachelor's degree in physical sciences and three years
full time experience working under the direction of a physicist certified by
the American Board of Radiology;
ii. A doctorate or master's degree in physical science and
two years such experience; or
iii. A doctorate or master's degree in radiological or
medical physics and two years of full-time, post-doctoral training with
clinical experience.
"Registrant" means the person required to register with the
Department pursuant to N.J.A.C. 7:28-3.
"Secondary dose monitoring system" means a system which will
terminate irradiation in the event of failure of the primary system.
"Spot check" means an abbreviated calibration procedure which
is performed to assure that a previous calibration continues to be
valid.
"Stationary beam therapy" means radiation therapy without
relative movement of the useful beam and the patient during irradiation.
"Target" means that part of a radiation-producing device used
to intercept a beam of accelerated particles and cause emission of other
radiation.
"Termination of irradiation" means the stopping of
irradiation in a fashion which will not permit continuance of irradiation
without the resetting of operating conditions at the control panel.
"Transmission detector" means a radiation detector through
which the useful beam or part of the useful beam passes.
"Traceable to national standards" means a dosimetry system
calibrated by the National Institute of Standards and Technology (NIST) or
calibrated in a beam which has been standardized by a transfer-grade ionization
chamber having an NIST calibration.
"Treatment field" means the area of the patient's skin which
is to be irradiated.
"Virtual source" means a point from which radiation appears
to originate.
"Wedge filter" means an added filter effecting continuous
progressive attenuation on all or part of the useful beam.
