Table 2.

Population systematic (Σ) and random (σ) errors of selected contemporary series and correlation with probability of target volume coverage

Series	Σ	σ	Displacements or errors
Hess [10]	Not reported	Not reported	3 mm for 50% coverage
			9 mm for 95% coverage
Bentel [11]	Not reported	Not reported	5–10 mm (87–90% with 5 mm margin)
Gibeau [12]	1 – 2.2	0.7 – 2.3	4.5–5.5 mm for 90%probability of target coverage
De Boer [13]	1.5 – 2.0	1.5 – 2.0	Probability values not specified
Humphrey [14]	0.02 – 0.9	0.4 – 0.7	3 mm for 95% of the errors.
			5 mm for 99% of errors
Zhang [15]	1.5 – 3.2	1.1 – 2.9	5.5 mm for 90% probability of target coverage
Suzuki [16]	0.7 – 1.3	0.7 – 1.6	5 mm margin for PTV and 3 mm for PRV
			Probability values not specified
Present Study	0.96 – 1.2	1.94 – 2.48	93% displacements within 5 mm
			<5 mm CTV-PTV margin in all directions