Assessment of Iterative Closest Point Registration Accuracy for Different Phantom Surfaces Captured by an Optical 3D Sensor in Radiotherapy

Figure 1

Optical sensor in radiotherapy.

(a) One of two camera-projector units of AlignRT (optical sensor) at the ceiling in treatment room. It consists of a stereo camera and a projector producing structured light by laser speckle in a fixed arrangement

(b) Left and right optical sensors at the ceiling above of the treatment table “look” diagonally downwards at the region of irradiation (isocenter). Standing in front of the treatment machine, the -axis of the right-handed coordinate system points to the treatment machine, to the right and to the top. The irradiation gantry hitting the same region is not depicted. , , and describe the rotations around the -, -, and -axes, respectively, as shown. The treatment table can only be translationally shifted in , , and direction