Skip to main content

Table 4 Dose comparisons of the first and second CBCT images.

From: Use of kilovoltage X-ray volume imaging in patient dose calculation for head-and-neck and partial brain radiation therapy

  Mean dose (Gy) Maximal dose (Gy)
  GTV CTV PTV Left-parotid Right-parotid Brain-stem Spinal-cord Whole-body
kV CT 50.72 51.04 51.02 32.14 30.40 50.92 31.76 55.78
1st kV CBCT 50.23 50.77 50.74 31.88 30.57 51.21 31.17 55.63
Dose difference between 1st kV CBCT and kV CT(%) 0.98% 0.54% 0.54% 0.8% -0.56% 0.57% -1.87% -0.26%
2nd kV CBCT 50.37 50.77 50.76 32.56 28.73 51.36 32.96 55.71
Dose difference between 2nd kV CBCT and kV CT(%) 0.7% 0.53% 0.52% -1.3% 5.81% 0.86% 3.77% -0.11%
  1. Dose comparison of the first and second CBCTs to the reference planning kVCT in a patient (patient 4) with marked anatomical changes. The largest changes in dose difference between CBCT and planning CT are found in the spinal cord (from -1.87% to 3.77%) and in the right parotid (from -0.56% to 5.81%).