PortalSim

What is it?

It is a Microsoft Windows-based digital treatment simulation system for radiation therapy facilities. Figure 1 shows the typical look of graphical user interface in dynamic treatment simulation mode. For those who like traditional simulator monitor, it can be switched to full-screen mode (Figure 2) with quite a few digital neuances and superior image quality on a big high-resolution flat panel image monitor.

In many radiation therapy facilities, the conventional simulator still plays an important role in the process of patient positioning and beam port verification. When IMRT and IGRT are pursued, higher patient repositioning accuracy would be desirable to deliver highly 3D conformal high dose region to target volume, and so be the simulation system. With this system in place, the treatment simulation procedure can be conducted comprehensively down to segmental level. If needed the delivery of IMRT or IGRT treatment can be rehearsed and recorded prior to real treatment. On the other hand, it also keeps the conventional way of use but with better image quality by means of digital image enhancement. For example, the digitized orthogonal setup images can be exported via DICOM / DICOM RT connection to RTP systems for HDR/LDR treatment planning, or for quantitative placement verification of brachytherapy applicators such as MammoSite balloon catheter.

Who needs it?

It is developed for a radiation therapy facility that is looking for more efficient and more accurate filmless treatment simulation system for IMRT or IGRT without replacing the conventional analog simulator in high capital investment. It is also a valuable auxiliary tool for researchers who are interested in projects pertaining to deformable image registration, intra-fraction organ motion and tumor tracking and, adaptive radiation therapy.

How it works?

An image frame grabber of high performance is installed in a personal computer to digitize fluoroscopic video from the image intensifier at a rate of 1024x1024 pixels per frame and 30 frames per second. Prior to simulation, the patient’s treatment plan, DRRs, contours, MLC segments and beam block geometry are exported from radiotherapy treatment planning systems to a DICOM / DICOM RT server. This server is coupled with a customized database that is also accessible to and under management of PortalSim. It is also accessible to PortView, a sister client application for remote review of portal images. The intrinsic image distortion of the image intensifier is corrected in real-time manner so that geometrical and anatomical information of the plan can be projected on fluoroscopic image to help set up patient and verify dynamic treatment process. In the case of moving tumor due to respiration, breathing phase can be retrieved from the moving BB imprinted onto fluoroscopic image sequence with the help of a breathing cycle indicator, and thereby PortalSim is endowed with the capability of simulating respiration gated IMRT treatment and four-dimensional image guided radiation therapy. The simulation process can be recorded in AVI format for later review to provide valuable information for improving field design and patient immobilization techniques. The What-You-See-Is-What-You-Get report printing features together with DICOM compatibility eliminates the need of radiographic film.

Download the latest upgrade

PortalSim is constantly evolving. The users are advised to check our website periodically and have your systems upgraded if there is a newer version. The latest version is 2.5 build 580 (February 04, 2008). To download the whole package, please click here.

Highlights of PortalSim

Reference DRR and live distortion-free fluoroscopic image are displayed side-by-side on the same screen with matching crosshairs (Figure 2). Click here to download a demo simulation report.