Stacking Veritas blocks
Special report: The changing world of radiation shielding
September 20, 2013
by Nancy Ryerson
, Staff Writer
Hybrid ORs and imaging equipment mash-ups like PET/MR create new possibilities for screening and treatments. But complex systems create more complex problems to solve — from staff training, to reimbursement questions, to maintenance and even adjustments to the type of shielding used for the rooms housing the equipment.
“The OEMs are marrying modalities, so they’re setting up these interventional or intraoperative suites that will involve several different pieces of equipment,” says Joel Kellogg, product line manager at shielding company ETS-Lindgren. “That’s what’s driving lead requirements in what had traditionally been RF shielded rooms.”
ETS-Lindgren generally specializes in RF and MRI shielding, but has been receiving more requests for radiation shielding as well.
New modalities and increasingly complicated rooms are creating the need for more creative shielding solutions, and better planning to get ready for whatever the next iteration of popular modalities will be. From doors to floors, shielding experts shared what facilities should look for when building a protected and long-term sustainable room.
Prior planning and future-proofing
Experts warn that creating a shielding plan that accounts for new modalities can take longer and be more complex than in the past.
For example, when creating a shielding plan for a facility that was using MRI along with radiation therapy, Rick LeBlanc, president of shielding company Nelco Worldwide, says it was a more than 12 month research and development process working with the manufacturers and hospitals.
LeBlanc recommends involving a physicist early in the design to potentially save money on shielding, and to make sure you don’t have any plans for a room that simply won’t work.
The addition of new equipment creates a challenge especially when the room is already built, but doesn’t have enough shielding or the appropriate kind of shielding to deal with the update.
“The shift from a strictly diagnostic center has really got the industry all confused,” says Tobias Gilk, senior vice president at consulting company RAD-Planning. “We’re trying to figure out how to integrate existing diagnostic tools with new interventional clinical operations, while at the same time, no one wants to take the CT offline to add hand sinks to the room.”
“We’re seeing facilities who put in what were, at the time, contemporary linear accelerators, but now they have the contemporary ones that have a greater demand for shielding,” says Gilk.
“We do a lot of fit and feasibility analysis,” says LeBlanc. “So we’ll come in, evaluate what exists, evaluate how much additional shielding is required. Generally, you can at least get some of it inside the room. Then you have to start getting creative with space that might be available.”
Bulking up shielding for different modalities can be challenging if there’s just not the space for it, Gilk says.
“If you thicken shielding on the inside of the room, it might take up needed space,” says Gilk. “If you thicken it outside, it will encroach on other spaces within the building.” When building a new facility or adding a wing to an existing one, Gilk recommends taking adjacent spaces into account to avoid future problems.
“You can protect people outside the exam room from accidental exposure and reduce shielding by placing non-occupied rooms immediately adjacent to the X-ray source room,” says Gilk. “With layout and design we can reduce the demands on shielding, which also has the benefit of future-proofing.”
Shielding experts can also take the time to determine if a combined shielding option would work better for the project and provide additional savings on shielding. For example, plastic can be used in conjunction with lead, which is very dense but also heavy and more expensive than some other materials.
“We do an awful amount of shielding where we’re using multiple materials to come up with the best overall solutions that meet the shielding needs,” says LeBlanc.
Break on through to the other side
If you’ve passed through a bi-parting sliding door at a hospital, you may not have known that you were moving through the latest in shielded door style. Facilities are choosing the newest door to hit the market both for space reasons and for their aesthetically pleasing look, companies say.
For one, sliding doors take up less space than their swinging counterparts.
“When we’re building out an OR for example we expect the construction cost to be $400, or more, a square foot,” says Gilk. “If we’re putting in a swinging door, then we have to allow twelve to fifteen feet for the door swing, that’s $6,000 worth of space for nothing more than a door swing, which is really hard to justify.” And with radiology construction costs close to those of ORs, Gilk says cost savings is one of the factors driving new shielded sliding doors.
Why haven’t facilities looked to sliding doors before now? Besides familiarity, Gilk says that building codes tended to treat sliding doors with greater restrictions than traditional swinging doors.
Speed is also a factor in sliding doors’ growing popularity. It doesn’t take long to open a door, of course, but in a high pressure operating room every second counts. Some facilities are choosing sliding doors for their speed. Veritas Medical Solutions promotes its sliding doors by noting that they open/close in five to six seconds.
Sliding doors can also work better in more complicated room setups. Joel Kellogg at ETS-Lindgren says he’s gotten requests for sliding shielded doors in inter-operative suites.
“In an operating room, there are a lot of concerns over sterility, you have to integrate the suite together to prevent other doors from being open,” says Kellogg. “So you’re getting these large, complex control systems that are being integrated into these suites.”
LeBlanc of Nelco says another reason facilities are investing in biparting doors is for their more elegant appearance compared with traditional doors.
“The days of the white, sterile look of a hospital are largely over,” says LeBlanc. “Now it’s geared more towards the hospitality industry. You go in some of them and it’s more like a five-star spa.”
Still, sliding doors remain less popular than traditional doors. Veritas says while it has seen an increase in requests for both bi-parting and single-leaf sliding doors, swing-style entry doors remain the company’s top seller.
New tricks and more questions
The CT scanner industry has been focused on dose reduction for several years now, and many facilities have reported successful dose reduction programs. With the emphasis on reduced dose, facilities looking to build a new room may wonder if the same amount of shielding that was used in the past is still necessary today.
Shielding companies disagree on whether dose reduction should have an impact on shielding decisions.
“Generally, if the CT scanner is delivering less dose to the patient then slightly less shielding would be needed,” says Bill Luecke, director of business development at Veritas.
At the same time, the scanners are still capable of producing high dose, as dose reduction is a software update rather than a technical one.
“Even if we’re going to do 99 percent of our scans as low dose, we need to plan the shielding for high dose,” says Gilk. “Lower dose CT clinically is tremendously important, but from a siding and shield design standpoint, it doesn’t have that much impact.”
While using less shielding for CT rooms may not be necessary, Kyle Jones, assistant professor of imaging physics at MD Anderson Cancer Center, and his team have developed a new way of calculating shielding needs for PET facilities that could help save on shielding costs.
“The problem is in a PET facility, you have multiple scan rooms, with patients who are radioactive moving back and forth between them,” says Jones. “That’s a very complicated shielding problem, as compared to one CT room or one radiation room.”
Jones’ paper describes an algorithm facilities can potentially use that incorporates 3D numerical methods to optimize PET shielding, rather than making approximations, which is how shielding needs are traditionally determined.
The algorithm isn’t being used at facilities yet, but Jones predicts that it will come in handy as suites become increasingly complicated.
He says that while lead is relatively cheap, PET facilities require more shielding, so reducing the shielding would be beneficial.
Cutting back on shielding is also critical if a PET room is on an upper floor of a facility, since the additional weight of the room and the building’s ability to support it needs to be considered.
But even as shielding teams solve current challenges, more are certain to appear as technology changes. For example, Jones mentions the proliferation of flat panel CT being used in fluoroscopy labs. He said he hasn’t seen any studies on the impact of that trend yet but expects to see an approach to it to appear in the future.
“Since imaging outside of radiology continues to grow, there’s going to be more and more discussion on the listservs and elsewhere on how to shield those rooms,” Jones says.