Florida Administrative Code › 64 - DEPARTMENT OF HEALTH › 64E - Division of Environmental Health › Chapter 64E-5 - CONTROL OF RADIATION HAZARDS › Section 64E-5.508 - X-Ray and Electron Therapy Systems with Energies of 1 MeV and Above

Current through Reg. 50, No. 138; July 16, 2024
(1) Definitions. In addition to the
				definitions in Rule  64E-5.501, F.A.C., the following
				definitions shall apply to this section:
(a)
				"Applicator" means a structure which determines the extent of the treatment
				field at a given distance from the virtual source.
(b) "Beam scattering filter" means a filter
				used in order to scatter a beam of electrons.
(c) "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 first beam limiting device.
(d) "Dose monitoring system" means a system
				of devices for the detection, measurement and display of quantities of
				radiation.
(e) "Dose monitor unit"
				means a unit response from the dose monitoring system from which the absorbed
				dose can be calculated.
(f)
				"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.
(g) "Field size" means the dimensions along
				the major axes of an area in a plane perpendicular to the specified direction
				of the beam of incident radiation at the normal treatment distance and defined
				by the intersection of the major axes and the 50% percent isodose line.
				Material shall be placed in the beam such that dose maximum is produced at the
				normal treatment distance when field size is being determined.
(h) "Gantry" means that part of the system
				supporting and allowing possible movements of the radiation head.
(i) "Interruption of irradiation" means the
				stopping of irradiation with the possibility of continuing irradiation without
				resetting of operating conditions at the control panel.
(j) "Isocenter" means a fixed point in space
				located at the center of the smallest sphere through which the central axis of
				the beam passes in all conditions.
(k) "Moving beam therapy" means radiation
				therapy with relative displacement of the useful beam and the patient during
				irradiation. It includes arc therapy, skip therapy and rotational
				therapy.
(l) "Normal treatment
				distance" means:
1. For electron irradiation,
				the virtual source to surface distance along the central axis of the useful
				beam as specified by the manufacturer for the applicator.
2. For x-ray irradiation, the virtual source
				to isocenter distance along the central axis of the useful beam. For
				nonisocentric equipment, this distance shall be that specified by the
				manufacturer.
(m)
				"Radiation head" means the structure from which the useful beam
				emerges.
(n) "Shadow tray" means a
				device attached to the radiation head to support auxiliary beam limiting
				material.
(o) "Stationary beam
				therapy" means radiation therapy without relative displacement of the useful
				beam or the patient during irradiation.
(p) "Target" means that part of a radiation
				head which by design intercepts a beam of accelerated particles with subsequent
				emission of other radiation.
(q)
				"Virtual source" means a point from which radiation appears to
				originate.