PNNL develops injectable cancer treatment

An injectable gel developed by Battelle in Richland as a potential new way to treat inoperable cancers has taken a key step toward becoming available for cancer patients.

Advanced Medical Isotope Corp. in Kennewick has signed a one-year option to license the medical isotope product, which was developed at Pacific Northwest National Laboratory. Battelle operates the national lab for the Department of Energy.

The product, called Radiogel, is the result of years of research to develop an isotope product that could be injected into the body, would stay in place and would deliver a high dose of cancer-killing radiation, said Darrell Fisher, PNNL senior scientist.

A clinical team at the University of Washington is waiting to put the Radiogel to use, initially trying it in animals and then using it in patients with difficult-to-treat cancers, Fisher said.

"This is for tumors that can't be surgically removed and tumors that require a higher dose than can be administered with external beam (radiation)," Fisher said. It's proposed for use in liver, brain, head and neck, kidney and pancreatic cancers, plus other cancers that are not good candidates for surgical removal.

The Radiogel includes a polymer and microspheres of the medical isotope yttrium 90 in a water-based solution. The polymer, developed at PNNL, is in liquid form when it's injected to the cancer site in the water-based solution, but quickly turns into a gel at body temperature, which keeps it where the doctor placed it.

The polymer binds the microspheres in place as the yttrium 90 bombards the cancer with radiation with little of the radiation reaching nearby healthy tissue.

"Yttrium 90 is the best isotope for controlled delivery by injection into tumors," Fisher said.

The isotope, which can be produced from strontium left from past plutonium production at the Hanford nuclear reservation, is readily available and low cost, he said. It's high energy, delivering a high dose of beta radiation to kill cancer cells, but contains no gamma radiation that would make the patient radioactive to friends and family.

"We have a strong relationship with Battelle and look forward to advancing the innovative Radiogel over the next year," said James Katzaroff, AMIC chief executive, in a statement.

AMIC also signed an exclusive license in October to deliver yttrium 90 with brachytherapy seeds invented by radiochemists and medical physicists at Battelle in Richland and pharmaceutical chemists at the University of Utah in Salt Lake City.

The brachytherapy seeds resemble metal brachytherapy seeds already used to treat prostate cancer. About the length of a grain of rice, but thinner, they can be injected with a needle. But by using a polymer rather than welded metal for the seeds, they can be produced at less cost, according to AMIC. The technology also allows yttrium 90 to be used as the radiation source in brachytherapy seeds, since the isotope cannot be delivered in metal seeds.

-- Annette Cary: 582-1533; acary@tricityherald.com.

This story was originally published March 3, 2011 at 12:00 AM with the headline "PNNL develops injectable cancer treatment ."