Radiotherapy Treatment Planning System (NSS-3D-RTPS-OP) NSS-3D-RTPS-OP software includes virtual fluoroscopy, virtual simulation, dose calculation and plan evaluation function and intends to provide radiation treatment planning for the external beam X-ray treatment of patients with benign and malignant tumors. Virtual fluoroscopy and virtual simulation can be used as a functional package that intend for CT simulation. Overview NSS-3D-RTPS-OP is a clinically treatment plan software system developed by Neusoft Medical based upon best-practice tumor treatment at major medical institutions. As an important component of Neusoft's radiotherapy solution, NSS-3D-RTPS-OP adopts the Collapsed Cone Convolution Superposition (CCCS) algorithm which is the industry's most accurate 3D dose calculation model. Additionally, NSS-3D-RTPS-OP provides powerful 3D visualization tools based on a ray-casting algorithm, allowing the user to visualize actual patient anatomy based on the voxel information provided by the 3D data set. In compliance with the DICOM RT standard, RT plan data can be transfered to other compliant systems.