A few years ago, a group of cancer doctors wanted to open a radiation treatment center in Woodbury. And a rival group wanted to stop them.

Since then, the turf battle has turned into one of the most expensive lobbying campaigns at the Legislature, with one side even outspending Minnesota Vikings lobbyists in 2011.

The two medical groups — Minnesota Oncology and Minneapolis Radiation Oncology (MRO) — have spent millions of dollars on dueling lobbyists since 2007, when the Legislature imposed a moratorium on new radiation treatment facilities in 14 counties, including the Twin Cities and Duluth metro areas.

This year, the Legislature is considering extending the moratorium, said to be the only one in the country, through 2020.

“The amount of money that’s being spent is breathtaking,” admits Dr. Thomas Flynn, president of Minnesota Oncology, which has 58 physicians. “My personal view is that it’s not something that we should be spending time and money on. [But] we’ve had to have a voice there, because we feel it’s an important issue.”

Minnesota Oncology, which had hoped to build the Woodbury center, has spent about $1 million to try to overturn the moratorium, so far without luck. MRO, which owns or operates a dozen such facilities at Minnesota hospitals, has spent more than $3 million to keep the moratorium in place.

Each side accuses the other of putting its own financial interests ahead of patients.

The debate touches on a sensitive issue in medicine: Who should control, and profit from, the kind of big-ticket medical technology that requires a huge upfront investment?

In this case, the fight is over an expensive machine called a linear accelerator, which uses radiation to treat cancer and other tumors. Installation and setup costs alone can run into the millions, including the protective housing, which requires thick concrete walls and lead lining.

In general, about half of all cancer patients get some radiation therapy, often in short, daily doses over weeks at a time. And experts say that it’s a lucrative business, with charges in the range of $40,000 to $50,000 per patient.

MRO and its supporters say there are plenty of radiation facilities already, including 19 in the Twin Cities area, and that adding more will only raise health care costs.

“Nobody thinks they should be on every street corner,” said Todd Freeman, MRO’s attorney and spokesman, adding that virtually every metro hospital already has one.

Minnesota Oncology, though, says it wouldn’t build more if they weren’t needed, and that some patients are forced to drive longer than necessary.

“It’s something that patients and the marketplace ought to decide,” said Flynn. His group owns one center, in Maplewood, and co-owns a second in downtown St. Paul.

Georgette Peterson, of Newport, has driven to the St. Paul center for radiation treatment every weekday for the past four weeks and admits it’s a bit of a hassle. At 56, she’s being treated for a noncancerous brain tumor. She walks into a vault-like chamber, and lies on a gurney with a plastic mask covering her head and shoulders, trying not to move as a rotating device circles around her.

Peterson’s treatment takes only about 3 to 5 minutes; the drive requires a half-hour each way, longer in snow. “I hate driving anyway,” she said, and the treatment makes her tired and nauseated. She wishes, she said, that she had an option closer to home, and to that extent, she’s bothered by the moratorium. “Money should not talk,” she said.

But MRO and other critics say that if the moratorium were lifted, a group like Minnesota Oncology could put others out of business by referring all its own patients to its own radiation facilities.

“They want to [build] those cancer centers so they don’t have to refer out,” said Freeman. He said that’s what happened when Minnesota Oncology opened its first radiation center, across the street from St. John’s Hospital in Maplewood.

That’s also one reason the Legislature stepped into the dispute and imposed the moratorium, said Rep. Kim Norton, DFL-Rochester, one of the main sponsors.

The concern, she said, was that private radiation facilities were “opening up and kind of skimming off patients” from hospitals, which rely on that income to subsidize their operations. “It has to do with fairness in the medical field,” she said.

But Flynn and his colleagues say they’re trying to offer patients a more convenient and “integrated model” of care that lets them get chemotherapy and radiation at the same location.

The moratorium, they say, just gives an unfair advantage to MRO, which operates many of the hospital-based radiation facilities.

“Their intent was to simply shut us out of the marketplace totally — in fact, to shut everybody out of the marketplace instead of themselves,” said Dr. Irving Lerner, a retired oncologist who is now a registered lobbyist for Minnesota Oncology.

Lerner acknowledges that the radiation treatment business is profitable. “Clearly, there’s a lot of money in it, and that’s clearly why the whole thing started,” he said.

But, he added, “my personal conviction is that the patients get lost in this whole battle. And I think the focus needs to be on the patients.”

Bill Hargis, former mayor of Woodbury, agrees. After he got radiation for prostate cancer, he testified against the moratorium on behalf of Minnesota Oncology.

“It kind of ticks you off that, you know, the real battle is a turf battle,” said Hargis, 63.

And the money spent on lobbying?

“It doesn’t make sense,” he said. “I don’t know what one of these machines cost, but they each could have bought one by now.”