Table 1.

Types of commissioning and QA tests

Type	Description
A	Qualitative assessment of registered image, this typical involve using visualization technique such as examining the difference image between the registered image and the reference image.
B	Qualitative assessment of DVF.
C	Qualitative assessment of contours on registered images such as overlaying anatomical structures defined on one image, and these can be overlaid on another image.
D	Quantitative assessment of contours on registered images using metrics such as DICE coefficient and Hausdorff distance.
E	Quantitative assessment of landmark alignment using TRE.
F	Assessment of Jacobian determinant
G	Assessment of other DVF metrics.
H	Consistency and transitivity measurements, these techniques include performing the registration in both directions to ensure that the registration is inverse consistent.
I	Quantitative assessment using digital phantoms, these can also be useful to quantitatively assess the accuracy of image registration.
J	End to end tests using physical phantoms, this ensures that all the different part of the radiotherapy system workflow works accurately.

DVF, deformation vector field; QA, quality assurance; TRE, target registration error.