Mayo Clinic said Tuesday that it will build a $188 million facility in Rochester to treat cancer tumors with proton therapy, an alternative to conventional radiation treatment.

Mayo is following the footsteps of other hospitals nationwide that have been adding the proton therapy, which some doctors say may be beneficial for children with cancer because the narrow proton beam leaves less radiation. The treatment is used on adults and children and is used against such cancers as those in the lung, breast and prostate.

Mayo also announced it will build a similar $182 million facility in Scottsdale, Ariz. Together, the facilities will have more than 250 employees.

"We are enthusiastically moving forward with this program because we believe it offers additional, innovative options for cancer patients," said Dr. John Noseworthy, the clinic's president and CEO.

The use of proton beams to treat cancer has been around since the 1940s, but Mayo will use a therapy based on pencil-beam scanning, a narrow proton beam that hadn't been approved by the FDA until recent years.

The 100,000-square-foot Rochester facility will be downtown, northeast of Rochester Methodist Hospital. Parts of the facility are expected to open in late 2014 or early 2015. It will be the first of its kind in the state.

Mayo said there have been studies in Sweden on female breast cancer patients and children with brain cancer that show proton therapy saves money over time.

That's because proton therapy may prevent long-term side effects and other cancers from developing.

Voices of caution

Still, some doctors not involved with Mayo's new facility say they aren't convinced there's a payoff in investing so much money for a treatment that has yet to be proven more effective at killing cancer than traditional radiation therapy.

Vanderbilt University Medical Center had considered opening a proton therapy facility, but paused on that idea during the economic downturn.

"Especially in this age, [with the] cost-consciousness in health care, [we need] to demonstrate the superior value of one technology over another," said Dr. Reid C. Thompson, the center's director of neurosurgical oncology. "I would like to ask of these facilities that they study this technology in that context. We have to prove the value of what we do and is it worth the significant investment in this technology."

Meanwhile, Dr. Vic Liengswangwong, a radiation oncologist at Maplewood Cancer Center, applauded Mayo for building the facility, but cautioned that more research needs to be done to determine whether more widespread use makes sense.

"If everyone in society jumps on the bandwagon, we would lose the golden opportunity to consider medical research to justify the expenses," he said.

Wendy Lee • 612-673-1712