Interfractional Variations of Tumor Centroid Position and Tumor Regression during Stereotactic Body Radiotherapy for Lung Tumor

Figure 3

It shows the percentage GTV reduction over time during SBRT treatment. Bars represent the percentage GTV reduction in each fraction. The reference GTV is that obtained from the first verification CT. Vertical lines represent the 95% error bars. Because only 17 verification CT scans were available in the fifth fraction of SBRT, the fourth bar represents only half patients.