What You Should Know About CT Simulators
CT Simulation enables precise radiation treatment of tumors. With the right components, any CT scanner can be a CT Simulator. Also referred to as a virtual simulator, a Sim consists of a CT scanner with a flat tabletop, laser patient positioning system, and CT Simulation/3D treatment planning software. This software enables import, manipulation, display, and storage of images from a CT and other imaging modalities.
How a CT Simulator Works
When a patient is scanned with the CT, the Sim software provides an image of the tumor(s) and where it is located. This image is sent to the treatment planning system to create a plan. The plan will allow the linear accelerator to precisely radiate the tumor(s) while the surrounding areas are spared.
Large Bore Required
A CT Simulator system is often a large-bore CT. A large bore has an aperture of approximately 80–90cm. Many CT Simulator systems feature a large bore because patients are often placed in positions that don’t fit easily into a regular-sized bore.
The Most Popular Brands Available Today
Top brands of CT Simulators include:
- GE LightSpeed RT 16 Slice (80cm)
- GE LightSpeed RT 4 Slice (80cm)
- Siemens Open 40 Slice (82cm)
- Siemens Open 20 Slice (82cm)
- Philips Brilliance Big Bore 16 Slice (85cm)
- Philips AcQsim Single Slice (85cm)
- Toshiba Aquilion Large Bore 32 Slice (90cm)
- Toshiba Aquilion Large Bore 16 Slice (90cm)
Couch and Tabletop Requirements
Rather than a cradle-shaped couch that comes with a traditional CT scanner, CT Simulators require a flat carbon fiber tabletop. To conform to CT Simulator requirements, an overlay or insert that fits over the cradle can be added to the CT scanner.
Water Cooled vs. Air Cooled
There are pros and cons to both water-cooled and air-cooled CT Simulators. Geographic location of the facility can affect your choice: water-cooled systems will freeze in the winter in particularly cold geographic areas, for example. Otherwise, there are advantages and disadvantages of each.
Advantages of Water-Cooled
- Less affected by room temperature – Inconsistent humidity and temperature control affect a water-cooled unit far less than an air-cooled unit, leaving cooling up to the facility to have well-maintained air conditioning.
- Quieter fan – When functioning properly, a water-cooled CT scanner is usually quieter. The room is also generally more comfortably warm than a comparable air-cooled room.
- Cleaner gantry – Water-cooled gantries are generally cleaner than air-cooled units because air-cooled system fans tend to pull dust, hair, and other debris into the gantry.
Advantages of Air-Cooled
- May last longer – Air-cooled units do not have water quality issues. With water-cooled, impurities can reduce cooling system performance, so water quality must be monitored when the unit is filled. When reduced performance results in higher temperatures in the gantry, the overall lifespan of components can be reduced.
- Lower maintenance – Air-cooled units have less downtime. Water-cooling systems must be maintained to keep them in good shape. If cooling efficiency deteriorates, the system must work harder. Working harder can increase valve wear and lead to its failure; reduce component life due to higher and varying temperatures; and cause image inconsistency throughout a patient’s treatment schedule. It should be noted that a substantial portion of downtime for water-cooled CTS is related to the cooling system.
CT Simulator Pricing
Comparing systems is not apples to oranges, and cost versus durability and performance should be weighed when deciding which to purchase for a facility. Many factors determine the final price, with the X-ray tube being the most relevant component. To see comparisons of tube models and their relative advantages and disadvantages, please read our What You Should Know About CT Simulator Tubes blog post.
Generally, prices in the used/refurbished category range from approximately $100,000 for a Philips AcQsim large-bore single slice CT to $300,000 for a GE RT 16 CT. Obviously, used systems are much less expensive than new, generally by one-half.
Typical CT room preparation is required with the addition of laser installation. This can be a tricky process if not done by an experienced engineer. Good site preparation requires both knowledge and experience. Many knowledgeable companies (generally contractors or construction companies) fail, not because they don’t know how to read from specifications, but because they simply lack experience. Look for companies who have done CT Simulator and laser installations in the past, and you’ll be one step ahead.
Please consider all of these factors when you are ready to begin your CT Simulator project, as there are many pitfalls to navigate, and if you are not knowledgeable, it will cost you considerable time and money down the road. Over the past 18 years, ROS has successfully installed dozens of CT Simulator systems throughout the world and would be happy to help you succeed with your next project.