Illustrations of the target shapes, tumor cell density distributions, and dose distributions for four simplified situations in the study: (1) GTV only, (2) with out considering the lymph node and setup errors, (3) , and (4) uncertainties.
Three representative DVHs used for the study. Relative dose and volume are used in the DVH. The prescription dose refers to the point at 90%. , , and are 102.5%, 95.2%, and 94.1% for DVH1; 102.2%, 93%, and 90.5% for DVH2; and 102.5%, 94.5%, and 85.5% for DVH3, respectively.
TCP dose response curves for three different DVHs and three GTV volumes of 1, 10, and , respectively.
TCP dose response curves for various dose distributions represented by values with three different tumor cell density decay slopes represented by values. (a) For various values with , A dose distribution of appears to match the cell density decay slope for proper CTV coverage. (b) For various values with , appears to be the match. (c) For various values with , appears to be the match.
Calculated (a) and (b) from the TCP curves in Fig. 4 varying with various .
TCP dose response curves for various probabilities of lymph node metastasis represented by and various dose to the represented by : (a) , (b) , and (c) .
TCP dose response curves for various systematic or random setup errors with a fixed 3 mm GTV-to-PTV margin. (a) Systematic error. (b) Random error.
TCP dose response curves for the combination of systematic error (represented by ) and random errors (represented by ) and in comparison to that with no random and systematic errors ( and ). (a) For , (b) for , and (c) for .
Normalized change in the TCP versus the expected PTV margins for two different recipes for combining various random and systematic errors. Recipe 1 is a simple addition of the factors from random and systematic errors. Recipe 2 is the square root of the sum of square of the two factors. The figure shows that recipe 2 consists of the corresponding plots that only have either random or systematic error.
Illustration of dose distributions across the target in the AP, lateral, and S-I directions for 2D, 3D, and stereotactic planning techniques. The shadow area is the target area. Dose outside the shadow area is the incidental dose. For 2D technique (left column), incidental dose is large and only in the AP direction. For 3D technique (middle column), incidental dose has gradual falloff in the AP and lateral directions, with almost no incidental dose in the I-S direction. For stereotactic technique (right column), incidental dose has almost isotropic falloff in all directions.
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