Table 2. Results of the treatment planning system and measurement errors of PTV and OAR, as well as the pass rate of gamma analysis by film for 10 cases each of the 4-MV and 6-MV IMRT plans.

Test plan before treatment	Plan No.	Monaco MLC parameter
		Temporary adjustment model		Final adjustment model
		Dose difference of IC (%)	Dose difference of OAR (%)	Dose difference of IC(%)	Dose difference of OAR (%)	Gamma pass rate (%)
4 MV	1	1.05	-0.01	1.09	-2.31	95.39
	2	3.02	2.22	1.75	0.44	98.35
	3	1.76	-2.68	0.85	-4.6	97.77
	4	2.35	0.89	0.11	-1.77	97.08
	5	2.73	0.23	2.03	-2.51	96.92
	6	3.63	1.92	2.64	-2.56	96.92
	7	3.30	2.16	2.87	-0.28	95.9
	8	5.21	3.36	1.25	0.42	96.75
	9	-0.32	0.28	-0.59	-0.9	97.71
	10	1.51	-0.17	-0.22	-2.61	97.89
6 MV	1	0.68	-1.19	1.44	1.02	97.23
	2	-0.46	-2.92	0.56	-0.79	99.5
	3	-0.07	-2.41	1.91	0.72	99.67
	4	-0.22	-6.86	0.64	-3.68	97.06
	5	-0.23	-3.22	0.95	-2.43	99.05
	6	-0.62	-1.6	-0.18	0.98	95.29
	7	0.86	-3.49	0.52	0.6	98.03
	8	1.03	-0.76	1.84	1.91	98.95
	9	0.27	-4.72	1.6	-2.69	96.08
	10	0.57	-1.9	1.41	1.54	99.87

The results of the treatment planning system and measurement errors of PTV and OAR, as well as the pass rate of gamma analysis by film, for 10 cases each of the 4-MV and 6-MV IMRT plans. In the 4-MV IMRT plan, the 4 MV-Model C (final adjustment model) showed errors of 3% or less for PTV and 5% or less for OAR in all 10 cases. On the contrary, in the 6-MV IMRT plan, the OAR error value was outside the tolerance limits (less than 5%) in 1 out of 10 cases in the adjusted 6 MV-Model D (temporary adjustment model). However, in the unadjusted 6 MV-Default, the OAR error value was within the tolerance limits in all 10 cases. In the verification of dose distribution using films, gamma analysis of 95% or higher was achieved. Therefore, the 4 MV-Model C (leaf transmission and leaf offset of 0.008 and 0, respectively) was used for 4-MV IMRT treatment, while the 6 MV-Default (0.005 and 0, respectively) was used for 6-MV treatment.