Local Excision Versus Total Mesorectal Excision in Patients with Good Response After Neoadjuvant Radiochemotherapy for T2-T3 Low Rectal Cancer: Preliminary Results of the GRECCAR 2 Randomized Phase 3 Trial

Abstract

an eyeball phantom that uses a programmable x-y motion stage with a connected joystick to drive the simulated eyeball’s rotational movement. Results: Both tumor (size and location inside the eyeball) and eyeball (size) were fabricated in the size similar to human’s. Eyeball’s movement can be programmed in various speeds and patterns. Experimental data from phantom validation under the CT simulator and from the 2D/ 3D transformation based on the video camera tracking were obtained. For eight testing positions (center of the simulated tumor) in the validation experiment, we compared the ground true coordinate from the CT space and predicted coordinate from our derived transformation. The maximum root-sum-squared error (RSSE) of three coordinates (X, Y, Z) is less than 0.70 mm and the mean-squared error is 0.44 mm among eight test positions. Conclusions: This video camera tracking technique and the 2D/3D transformation are feasible for robotic radiosurgery on ocular tumor. Error analysis indicates that the accuracy is clinically acceptable. Author Disclosure: W. Zhao: None. H. Chen: None. X. Wu: None. G.F. Hatoum: None.