IsoRay Medical is always in a time crunch.
The cesium-131 radioactive isotope that the Richland manufacturer uses to make a cancer treatment decays so quickly that the radioactive seeds typically are made and shipped the same day.
The seeds have to be precisely created and delivered so that they will transmit the correct therapeutic dose of radiation when a surgeon implants them into waiting cancer patients.
Each titanium seed is no longer than a grain of rice and as thin as pencil lead. But inside, cesium-131 is waiting to deliver high, targeted doses of radiation to defeat cancer cells while sparing healthy tissue and organs.
IsoRay Medical was created to take a spin-off technology from Hanford from an idea to actual production. After receiving U.S. Food and Drug Administration approval, the University of Washington first used the seeds to treat a prostate cancer patient in 2004.
Now, the radioactive seeds are used to treat about 1,000 patients around the world each year.
Chemist Lane Bray, one of the publicly traded company’s founders, and other Pacific Northwest National Laboratory scientists had been tackling how to deal with cesium-137, a byproduct of the fission process Hanford used to create nuclear fuel, said Bill Cavanagh, the company’s vice president of research and development.
That isotope of the element has a half-life of 30 years, and its slow decay was a monstrous problem for Hanford cleanup.
Attempts to isolate cesium-137 led Bray to discover his patented chemical process to separate cesium-131 from a mix of other radioactive isotopes. Cesium-131 had been identified as an ideal isotope for brachytherapy more than 50 years ago, in part because of its short half-life of 10 days.
Bray was the first to find a cost-effective way to produce a pure form of the isotope. So far, IsoRay Medical is the only company in the world producing cesium-131 seeds.
“You go from a nuclear weapons complex to curing cancer,” said Clay O’Laughlin, the company’s radioisotopes and facilities manager.
IsoRay Medical started out at PNNL, moved off-site to a single room and then opened its Richland manufacturing facility in 2007.
Each set of radioactive seeds is made to order for a specific patient, Cavanagh said. The dosage is determined based on the doctor’s prescription. Typically, about 40 to 120 seeds are needed per patient.
IsoRay Medical manufactures the entire seed. In the “cold” or non-radioactive lab, workers weld a cap onto one end of each titanium seed, using a camera to magnify it.
A tiny gold bar is inserted inside the seed so the seed can be seen in an ultrasound, O’Laughlin said.
Central to IsoRay Medical is the complicated, patented chemistry Lane developed to separate the desired cesium-131 from a host of nasty, dangerous radioactive materials.
The chemistry has to be done inside a “hot” cell because of how radioactive the material is. It’s kind of like an airlock in space, but instead of keeping breathable air in, the 90,000 pounds of lead keeps the radiation from escaping, O’Laughlin said.
Even the yellowish window that allows the hot cell technician to see what he or she is doing has 14¾ inches of lead and glass.
A hot cell technician directs a robotic arm to perform the chemistry to separate the cesium-131. It takes a high level of skill to manipulate the robotic arm to work with glass instruments, he said.
Once the cesium-131 is separated, it moves to a glove box that protects workers while they insert the isotope into the titanium seeds. The seeds also must be welded shut in the glove box using a laser welding technology the company developed.
The seals of each seed are checked inside a fume hood enclosure. An ultrasonic cleaning method is used to sterilize the outer surface and check the seal.
All of the finished seeds go through a number of checks before they are packaged in the specific configuration ordered by the doctor and then shipped.
Some doctors order only the seeds. Some are loaded into needles, onto soluble thread or in Mick cartridges that act almost like a box magazine for a handgun. Others are inserted within a biodegradable weave that can be placed near the cancer during surgery.
However IsoRay Medical prepares the seeds for the medical procedures, they have to be shielded with lead so no radiation escapes until the seeds are implanted into a patient.
In addition to the seeds, IsoRay Medical also makes a GliaSite brain catheter — a balloon used to treat brain cancers. It can be used to deliver radiation using cesium-131 or another isotope. The company also sells a liquid cesium-131 called Cesitrex.
IsoRay Medical has about 30 employees at its Richland manufacturing facility, which operates at about 20 percent of its capacity.
The seeds are used by research hospitals and large medical centers around the world, including Seattle and Olympia. But they’re not something Tri-City medical centers have tried.
The appeal of cesium-131 is that it delivers a staggeringly high dose of radiation to only a few millimeters of tissue, Cavanagh said.
“The idea is to take the cancer out and then dissipate so you are not harming healthy tissue,” O’Laughlin said.
The patient receives the full dose of radiation within a month, Cavanagh said.
The cost of the radiation seeds is a fraction of what patients and their medical insurance companies pay for external beam radiation therapy, Cavanagh said. For example, with prostate cancer, it may cost about $7,000 for radiation treatment using the company’s seeds and up to $50,000 for external beam radiation therapy. Insurance companies do cover IsoRay Medical’s cancer treatment.
IsoRay Medical recently reconnected with Chuck Moore of Soap Lake, who was the first to be treated for cancer using the company’s radioactive seeds, around the 10-year anniversary of his surgery.
Moore, who will be 85 in July, said the seeds did exactly what they were supposed to — they banished his prostate cancer. He’s been doing so well that his doctor is no longer doing an annual blood test to check for signs of returning cancer.
He was diagnosed early and took several months to research options and talk to others who had gone through various cancer treatments. Moore had his oncologist delay treatment just a bit so that he could use the cesium-131 seeds, he said.
“If I had to do it all over again I would make the same decision,” he said.
IsoRay Medical started out focusing on prostate cancer, but has expanded to include brain, lung, gynecological cancers and more, Cavanagh said. The seeds have been approved to use on any cancer.
The seeds were used to treat a 7-year-old girl in Peru who had an inoperable brain tumor that had partially paralyzed her, Cavanagh said.
Dr. Carlos Alvarez Peña of Lima carefully placed three seeds into the tumor in July. Scans showed the tumor had shrunk within a few weeks. Nine months later, the tumor was dormant and 70 percent smaller, Cavanagh said. The girl was able to walk again days after the seeds were implanted.
“We get to do something that matters,” O’Laughlin said.