Table 4.

Quality control tests for ${}^{60}\mathrm{C}\mathrm{o}$ teletherapy units (tolerances and action levels are specified in millimeters unless otherwise stated)

Designator	Test	Performance
		Tolerance	Action
Daily
DCO1	Door interlock/last person out	Functional
DCO2	Motion interlock	Functional
DCO3	Couch brakes	Functional
DCO4	Beam status indicators	Functional
DCO5	Patient audiovisual monitors	Functional
DCO6	Room radiation monitors	Functional
DCO7	Emergency off	Functional
DCO8	Beam interrupt/counters	Functional
DCO9	Head swivel lock	Functional
DCO10	Lasers/crosswires	1	2
DCO11	Optical distance indicator	1	2
DCO12	Optical back pointer	2	3
DCO13	Field size indicator	1	2
Monthly
MCO1	Latching of wedges, trays	Functional
MCO2	Wedge interlocks	Functional
MCO3	Gantry angle readouts	0.5°	1°
MCO4	Collimator angle readouts	0.5°	1°
MCO5	Couch position readouts	1	2
MCO6	Couch rotation isocenter	2	3
MCO7	Optical distance indicator	1	2
MCO8	Crosswire centering	1	2
MCO9	Light/Radiation coincidence	2	3
MCO10	Field size indicator	1	2
MCO11	Relative dosimetry	1%	2%
MCO12	Shutter error	Reproducible
MCO13	Beam symmetry (source position)	2%	3%
MCO14	Records	Complete
Annually
ACO1	Reference dosimetry	1%	2%
ACO2	Relative output factor reproducibility	1%	2%
ACO3	Central axis depth dose reproducibility	1%	2%
ACO4	Wedge transmission factor reproducibility	1%	2%
ACO5	Accessory transmission factor reproducibility	1%	2%
ACO6	Output reproducibility vs. gantry angle	1%	2%
ACO7	Beam symmetry reproducibility vs. gantry angle	2%	3%
ACO8	Timer linearity	1%	2%
ACO9	Shutter error	0.03 min.	0.05 min.
ACO10	Collimator rotation isocenter	2	3
ACO11	Gantry rotation isocenter	2	3
ACO12	Couch rotation isocenter	2	3
ACO13	Coincidence of collimator, gantry, couch axes	2	3
ACO14	Coincidence of isocenters	2	3
ACO15	Couch deflection	3	5
ACO16	Independent quality control review	Complete