by
Lauren Dubinsky, Senior Reporter | October 01, 2018
From the October 2018 issue of HealthCare Business News magazine
Still, not everyone agrees that it’s time to abandon lead for radiation shielding. Companies like Calder Industrial Metals, for example, assert that it offers advantages that continue to make it the best option.
“Lead is very quick and easy to install and the room is ready to use straight away,” said Andy Carr, head of external sales at Calder. “You don’t have to wait for the lead to harden or set.”
In the case of a room being relocated, Carr said lead offers unique advantages in that it can be quickly disassembled. It is also recyclable and can be melted and reused.
Radiation therapy rooms
In early 2010, Mount Vernon Cancer Centre in the U.K. began a project to install its first Accuray CyberKnife. For Calder, it was a particularly demanding radiation shielding project.
The architects determined that in order to construct a safe room, while minimizing the impact on the existing hospital structure, lead radiation shielding was the most effective material to use. Calder’s Chevron Rail System was installed and depending on the location within the room, the thickness of the lead varied between 30 millimeters to 300 millimeters.
In total, 102 tons of lead was installed. The overall budget was £3.8 million and the project was completed in eight months.
The H&H Design-Build team added 14" of lead
shielding for the ceiling of a new radiation
therapy to protect occupants above.
Designing a vault for a radiation therapy system was also one of the biggest projects Evearitt has worked on. The design process took Atom Physics about a month, but the entire install project took approximately a year.
He explained that the difference with radiation therapy machines is that once you get above 10 megavolts, you are producing neutrons.
“Not only do you have to protect from the X-rays that are a thousand times higher than a typical X-ray machine, but they create neutrons, which are much harder to stop,” he said. “So you have to have several feet of concrete in place in each of the walls and ceiling.”
MarShield’s biggest project was supplying over 245,000 pounds of high-density concrete shielding blocks to Princess Margret Hospital in Toronto for its cancer treatment therapy room expansion project.
These high-density concrete blocks are dry-stacked and require half the space of concrete vaults. According to the company, the blocks interlock to form a tight, leak-free therapy room of any size or shape.
