Mandy Cheung, senior radiation therapist, talks to patient Joseph Tracz before doing a laser aligning in the Proton beam therapy facility at Massachusetts General Hospital in Boston. (Yoon S. Byun/Boston Globe via Getty Images)

Two of the region’s largest hospital systems are competing to offer a controversial cancer treatment — joining what critics say is a nationwide medical arms race as hospitals scramble for dominance by investing millions of dollars in technology that has not been proven to be better than cheaper alternatives for some cancers.

MedStar Georgetown University Hospital and Sibley Memorial Hospital, part of Johns Hopkins Medicine, are vying to establish proton beam therapy, a cutting-edge radiation treatment touted by supporters as more precise in targeting tumors and safer for healthy tissue than conventional X-rays.

Sibley’s proposed $130 million facility would open in 2017, taking up one-third the size of a football field. MedStar Georgetown’s slimmer $32 million center could begin operating next year at the Lombardi Comprehensive Cancer Center. Neither project can move forward without a go-ahead from D.C. health planning officials.

The contest is part of the increasingly heated battle for dominance and raises fundamental questions about health care today: how to balance innovation and cost, and how to determine whether one treatment is better than another.

Executives at MedStar Georgetown and Sibley, as well as other experts, generally agree that proton therapy’s greatest potential is in treating children, particularly those with brain and eye tumors. The therapy can be administered at higher doses than conventional radiation and causes fewer long-term side effects.

Proton centers in the U.S.

But they also acknowledge that research has yet to demonstrate that the treatment is better than conventional therapy for other cancers, such as prostate, even though many hospitals want to use proton therapy to treat that disease.

The first hospital proton beam center opened in 1990 at Loma Linda University Medical Center in California. Today, 11 proton facilities are operating in the United States, and at least 17 more are under construction or in development, including one at the University of Maryland in Baltimore that is set to open in two years, according to the National Association for Proton Therapy.

“One of the things that comes across is the fact that proton therapy is not as useful as it is said to be, that it is basically an arms race between different hospitals,” Amha Selassie, director of the independent D.C. State Health Planning and Development Agency, said at a public hearing in January. He will decide on the MedStar Georgetown and Sibley applications, and could approve one or both or deny both.

Some experts say the rush to embrace the technology is misguided.

“So why is the venerable Mayo Clinic building two proton beam facilities? Because it’s competing against Massachusetts General Hospital, M.D. Anderson in Texas, the University of Pennsylvania, Loma Linda in California — all of which have one,” former White House adviser Ezekiel J. Emanuel, an oncologist and vice provost at the University of Pennsylvania, wrote in an op-ed in the New York Times last year.

Hospitals using proton technology get higher Medicare reimbursements than those using conventional radiation — for example, $32,000 per patient compared with less than $19,000 for prostate cancer treatment, according to a recent study in the Journal of the National Cancer Institute.

“The hospitals make a ton of money,” said an executive who declined to be identified because his company has a financial interest in a proton beam technology firm. “It’s beautifully precise, but it’s not for every kind of tumor. It would be like using a Japanese chef knife to cut weeds in the yard.”

In conventional radiation therapy, X-rays deliver radiation as they enter and exit healthy organs. Proton therapy uses a beam of protons, which are positively charged subatomic particles that are much more massive than X-rays. Protons deliver a very low entrance dose and when they arrive at the target — the tumor — they deliver the dose and stop. There’s no exit dose, and healthy tissue is spared.

“There is no doubt it’s shown to be safe and effective for many kinds of cancer,” said Jason A. Efstathiou, assistant professor of radiation oncology at Harvard Medical School and Massachusetts General Hospital, which has had proton therapy since 2001. “The question is, is it better in every indication than other options?”

The treatment’s superiority for treating prostate cancer “hasn’t been proven” because of a lack of rigorous clinical trials, Efstathiou said. Now, Massachusetts General and the University of Pennsylvania are conducting a five-year trial comparing proton treatment and conventional radiation for the disease. “If it’s better, does it justify any additional cost, and if so, by how much?” he said.

Even with the unsettled questions, the technology could be a potent marketing tool for the two hospital systems. Columbia-based MedStar Health, which is the region’s largest health system, operates 10 hospitals in Maryland and the District. Hopkins, based in Baltimore, has in recent years pushed aggressively south to Washington, acquiring Surburban Hospital in Bethesda and then Sibley in Northwest. During two public hearings on their plans, the hospitals traded jabs on everything from which hospital would better serve the poorest of the District’s residents to the type of beam technology used in their projects.

Neither design is now being used to treat patients in this country. Each hospital system is financing its own project.

A preliminary agency report by the D.C. health planning agency found that both hospitals had demonstrated a need for proton services in the District, which has some of the highest cancer rates in the country.An advisory committee to the agency is set to vote at an April 18 meeting; a final decision by Selassie is expected in May.

MedStar Georgetown officials estimate that they would treat about 300 patients a year, including about 50 children, focusing on nine tumor types, including prostate, spine and brain. The average patient would need about 28 treatments, at an average cost of about $1,700 a treatment, or about $48,000.

Health planning officials have questioned whether MedStar Georgetown’s program has the capacity to handle referrals from other hospitals. MedStar Georgetown officials said that they could and that they also could apply for permission to build a second facility, perhaps at MedStar Washington Hospital Center — but that they don’t think that would be necessary.

The University of Maryland’s proton center in Baltimore is expected to start treating patients in two years; a proton center at Hampton University in Virginia’s Tidewater area, about 180 miles to the south, opened in 2010.

Sibley’s facility would treat 765 adults and 152 children a year. Among the adult patients would be those with tumors of the brain and spine, lung, head and neck , and to a lesser extent, prostate. One of the four treatment rooms would be used for research and another for children. The structure would take up about 22,000 square feet on Sibley’s campus.

The charge per treatment is estimated at about $1,500; the total cost for a course of treatment would be about $60,000, hospital officials said. The estimates are based on what other proton centers are using as well as dosages from conventional treatment.

Sibley and Hopkins officials, who say there is enough demand to support two proton centers in the District, estimate that 70 percent of Sibley’s patients would come from within a 100-mile radius, extending into Pennsylvania and West Virginia, as well as from abroad.

Selassie questioned whether Sibley’s geographically large patient pool would result in the “cherry-picking” of affluent international patients at the expense of D.C. residents. He has also questioned how Sibley, long a community hospital, would be able to conduct research. And he has noted that Sibley does not have a license to provide pediatric services.

Sibley officials said they are committed to caring for District patients. The hospital will be collaborating with Hopkins for clinical care and research; Sibley has also applied for a pediatric license and plans to partner with Children’s National Medical Center, Howard University Hospital and United Medical Center in Southeast, officials said.

As a condition for approval, both hospital systems have agreed to set up a full-time cancer screening and treatment clinic in one of the District’s medically under­served areas.

Cyril Allen, medical director at United Medical Center, supports the Sibley plan, noting at a public hearing that neighborhoods with the highest cancer incidence and death rates, in wards 7 and 8, have not received enough support from other D.C. hospitals.

“We have a chance now to climb out,” he said. “We’re at the table now with Sibley, Howard and Johns Hopkins.”