Monte Carlo vs. Pencil Beam based optimization of stereotactic lung IMRT

Radiation Oncology

Table 1 Prescribed and resulting isoeffects/EUDs for all patient models plans optimized with fsPB and MC and recalculated with 4DMC; the recalculated MC dose on the static patient models of the fsPB optimized plans are shown in brackets.

		6 MV				15 MV
Quantity type	Prescr.	PB	4D	MC	4D	PB	4D	MC	4D
model 1, one phase static CT
target* poisson EUD	55 Gy	54.25 (57.94)	58.86	53.3	57.35	55.32 (52.77)	55.47	52.09	58.82
target* rms overdosage	2 Gy	1.99 (4.17)	4.48	1.53	3.39	2.02 (0.66)	1.95	1.97	5.83
lung R, mean dose	9 Gy	8.39 (10.58)	10.81	9.1	9.32	8.46 (10.31)	10.47	9	9.26
lung R, mean damage	21%	20.49 (24.48)	24.93	21.68	22.05	20.71 (23.9)	24.21	21.17	21.6
skin, rms overdosage	0.24 Gy	0.23 (0.61)	0.59	0.24	0.24	0.24 (0.52)	0.52	0.24	0.24
model 2, minimum density overwrite one phase static CT
target* poisson EUD	55 Gy	56.47 (57.23)	57.53	54.98	56.2	55.95 (53.68)	54.37	52.47	56.02
target* rms overdosage	2 Gy	2.05 (3.23)	2.83	2.02	1.8	2.02 (0.96)	0.6	2.07	2.6
lung R, mean dose	9 Gy	8.13 (9.63)	9.84	8.91	9.13	8.34 (9.96)	10.06	8.71	8.88
lung R, mean damage	21%	19.9 (22.57)	23.03	21.25	21.66	20.43 (23.14)	23.38	20.59	20.88
skin, rms overdosage	0.24 Gy	0.23 (0.48)	0.48	0.24	0.23	0.24 (0.48)	0.48	0.24	0.23
model 3, average CT
target* poisson EUD	55 Gy	55.03 (57.53)	57.46	52.63	55.88	55.32 (52.57)	55.01	51.85	58.49
target* rms overdosage	2 Gy	1.99 (3.71)	3.09	1.12	1.66	2 (0.52)	1.25	2.01	4.63
lung R, mean dose	9 Gy	8.43 (10.41)	10.64	9.12	9.33	8.49 (10.3)	10.49	9.04	9.3
lung R, mean damage	21%	20.56 (24.14)	24.61	21.74	22.13	20.72 (23.85)	24.23	21.21	21.66
skin, rms overdosage	0.24 Gy	0.24 (0.61)	0.6	0.24	0.23	0.24 (0.53)	0.53	0.24	0.23

target* - the target dose is calculated in the PTV for static planning and the CTV for 4DMC recalculation, respectively.

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