Pre-Owned Varian 21EX/iX Silhouette vs. Pre-Owned Varian 600CD/EX
Varian Clinac Series Low Energy Machine Models: 6/100, 600C, 600C/D, 6EX
Varian Clinac Series High Energy Machine Models: 2100C, 2100C/D, 2300C/D, 21EX, 23EX, 21iX
For many years, cobalt-60 systems were the equipment of choice for radiation therapy in developing regions of the world. Cobalt systems are still a good option today, according to the IAEA, in areas of the world where linear accelerators are not an option due to power requirements, servicing capabilities and humidity concerns.
Over the past two decades, used/refurbished linear accelerators have become a viable option to replace cobalt-60 systems, as costs of pre-owned linear accelerators have decreased. Over the past decade, ROS has delivered and installed dozens of refurbished linear accelerators in countries all over the world, many as replacements for older cobalt machines. Most of the equipment has originated from developed countries including the U.S., Canada, the U.K., Holland, Sweden, Australia and Taiwan.
Low energy radiotherapy machines, such as the Varian Clinac 4/80, Varian Clinac 4/100, Varian Clinac 6/100 and Varian Clinac 600C’s, were for a long period of time the optimal solution to replace cobalt-60 machines. The mechanics and electronics of a machine that produces only one photon energy (either 4MV or 6MV) is simpler and less expensive than the dual energy systems producing two photon energies and five+ electron energies.
When Varian rolled out the Clinac 600CD and Clinac 6EX models, however, various changes were made to the machine that no longer made it as reliable as the older 6/100 and 600C models. To produce higher dose rates, the new machines became less stable. It is not unusual to still see a model Clinac 6/100 operate reliably for decades. It is less common to see a model Clinac 6EX operate for long periods of time without at least one magnetron replaced, or worse, the waveguide replaced. These two parts alone, when replaced, can exceed the value of the entire machine.
Varian decreased the production of the models Clinac 600CD and Clinac 6EX with the introduction of the Silhouette edition for its high energy machines. The Silhouette editions greatly reduce the footprint needed inside a vault to house the machine. While not as small as the low energy machines, it often can be fit into a vault that otherwise would not accommodate a high energy machines.
Over the last three years, the availability of high energy machines in the used equipment market has grown, while the availability of low energy machines has decreased. From 2010 to 2014, many of the centers that were operating low energy machines upgraded them to high energy machines, and as a result, fewer low energy units are available today in the used equipment market. This scarcity has driven prices of low energy machines to increase relative to prices of dual energy machines.
Today, low energy Varian machines of the same year are more expensive than high energy machines, simply due to reduced supply. Radiation therapy clinics seeking to add a used linear accelerator can actually save money by installing a more robust machine, offering two photon energies and five electron energies, even if it means shutting off the higher photon energy. This translates into greater possible treatments for patients.
Replacement parts also play a key role in long term maintenance costs. As low energy machines become scarce, parts become scarce as well, and with scarcity comes a higher cost. High energy machines are plentiful, with lots of parts available, and hence lower costs.
Radiology Oncology Systems, Inc. is a major provider of used and refurbished linear accelerator systems and related products, services and accessories.