VTR: Virtual Treatment Room

Virtual Treatment Room, hereafeter VTR (formerly known as ARIS), is a software developed by Pi Medical which simulates the treatment set-up and delivery of a radiotherapy treatment process. A software offering a virtual environment for visualization and validation of radiotherapy set-ups, patient set-up and treatment delivery including anti-collision registration and information tools.

VTR can visualize and photrealisticaly simulate most available linear accelerators, utilizing any setup and and available accessory, and thus can be used as a demonstrator of plans and techniques by dosimetrists and technicians or as a training and educational tool for dosimetrists and technicians professionals and students.

VTR represents the Room Eye View (REV) of the treatment geometry and additionally can check at the same time for potential collision between the model of a patient and the treatment unit, or a collision between the parts of the treatment unit (i.e. Gantry head with treatment table etc.) with accuracy of 1 mm.

The models used in VTR can change according to the user needs. At present, supports linear acceleratos from Siemens, Philips, Elekta and Varian along with their accessories.

Room Eye View

The user can change some variables according to his treatment plan and visualise the result on screen

The variables that can be changed are Gantry angle, table angle (isocentrically and eccentrically), table lateral movement, table longitudinal movement and up/down movement. Field type can be selected (Symmetric, Asymmetric, MLC) and field dimensions can be changed.

The patient can be positioned dynamically on the table with different orientations (supine, prone, head towards/away from the gantry, decubitus and in relation to the isocenter of the treatment set-up). The field dimensions can be changed according to the plan.

Photon and electron modes are available and additional accessories can be used, such as block trays, electron tubes, stereotactic bed, portal imaging, bodyfix devices, beam stopper and multi leaf collimators.

Beam Eye View

A Beam Eye View (Perpendicular to the beam view) of the set up is also available. The simulation can be done statically by changing the parameters using the mouse or the keypad, and dynamically where the whole treatment between two predefined angles can be visualized.

The user can also change the viewing angle of the scene or zoom in/out for a better observation of the scene.

Collision Detection

In addition to the above simulation of the treatment set-up, the software can also detect any collision between some critical objects. For example collision between patient and gantry head, or between the table and the portal imaging. Furthermore, VTR checks for the intersection of the treatment field with any metallic parts of the bed that may attenuate the useful beam.

The advantage of VTR is, that it uses graphical (and not geometrical) methods for collision detection which increases its accuracy, a crucial  for conformal techniques used in radiotherapy today.

The system is operating under Windows 2000/XP operating system. It includes a database for the patient, the treatment plans and their parameters, which is able to automatically import parameters from any TPS using the DICOM RT protocol. The movements, scales and co-ordinates of the simulation are following the IEC 1217 standard.





 Demo videos:

Control tools for the treatment table 14.4 MB
General visualization tools 8.8 MB

Real Simulation of multi-fields and rotation technique

6.6 MB

Control tools for linear accelerator gantry and collimator

8.1 MB

Visualization tools for patient, anatomy and irradiation fields

35.6 MB




1. M. Tsiakalos, E. Schrebmann, K. Theodorou, C. Kappas, "Graphical treatment simulation and automated collision detection for conformal and stereotactic radiotherapy treatment planning", Med. Phys. 28 (7), 2001, p. 1359-1363.

2. M. Tsiakalos, S. Vathis, D. Baltas "Treatment simulation & colition detection: ARIS software", in Progress in CT-3D Simulation, ed. R.F. Mould,  Medintec Germany (2003).