Evaluating the Therapeutic Dose Distribution of Intensity-Modulated Radiation Therapy for Head and Neck with Cone-Beam Computed Tomography Image: A Methodological Study

Table 3

The effect of simulated setup deviation of patient positioning on the gamma pass rate on the transversal plane at the isocenter position.

Setup deviation		Gamma pass rate
		3%—3 mm	2%—2 mm
No error	0	99.99%	98.00%
Anterior-posterior direction	1 mm	100.00%	95.12%
	2 mm	99.99%	89.23%
	3 mm	95.31%	75.85%
	−1 mm	99.98%	97.06%
	−2 mm	99.99%	94.78%
	−3 mm	97.64%	83.99%
Superior-inferior direction	1 mm	99.75%	96.42%
	2 mm	99.15%	93.92%
	3 mm	97.76%	88.48%
	−1 mm	99.05%	92.94%
	−2 mm	97.22%	86.99%
	−3 mm	95.29%	79.41%
Left-right direction	1 mm	99.99%	97.25%
	2 mm	99.94%	92.00%
	3 mm	96.42%	78.31%
	−1 mm	99.95%	96.19%
	−2 mm	99.99%	94.59%
	−3 mm	98.06%	75.28%