Mayo Clinic plans to build a $233 million facility for cancer patients at its Florida hospital that includes "proton beam" radiation, an advanced treatment that Mayo currently provides at medical centers in Rochester and Phoenix after making big infrastructure investments earlier this decade.

The 140,000-square-foot facility being planned for Jacksonville is scheduled for completion in 2023.

Monday's announcement came about three years after Mayo said it would spend $100 million for a new medical building that significantly expanded space for cancer patients in Florida, a state where Mayo and some of nation's most prominent health care groups all compete for patients.

"This facility will give us the ability to offer our patients the full spectrum of cancer treatment options," Dr. Kent Thielen, the chief executive of Mayo Clinic in Florida, said in a statement.

There's already a proton beam treatment center in Jacksonville operated by a different health care provider. A Mayo spokeswoman said by e-mail that Mayo will be unique in Florida for running a "Comprehensive Cancer Center" as designated by the National Cancer Institute that includes proton beam therapy.

Mayo Clinic is Minnesota's largest private employer with a network of hospitals and clinics that spans five states. At a price of more than $300 million overall, the clinic opened new centers for proton beam therapy in Rochester in 2015 and Phoenix in 2016.

The technology is designed to provide precise treatment of certain cancers while delivering low doses of radiation to healthy tissue.

Advocates for proton beam radiation have decried decisions by health insurers to deny coverage in some cases for the costly treatment. Some patients have filed lawsuits as a result.

The judge assigned to one such case recused himself earlier this year in a written order where he called it "immoral and barbaric" for an insurance company to deny a patient the treatment if it is available.

But researchers published a study last year saying some advertisements for proton beam centers have promoted the treatment as an option in some cases that aren't endorsed by professional guidelines.

The researchers wrote of an "urgent need for comparative effectiveness [proton beam therapy] research in order to develop updated and high-quality evidence-based recommendations that can be used to inform its judicious use and to generate appropriate informational materials for patients."

Mayo officials have said they set prices for proton beam treatments at rates comparable to standard radiation, so there's not a financial incentive for doctors to use the high-tech care.

Last year, Mayo Clinic and Eagan-based Blue Cross and Blue Shield of Minnesota announced a new contract that expanded access to the therapy.

"Proton radiation represents a major technological advancement in the treatment of cancer, allowing for radiation therapy used to be carefully and exactly directed in a manner superior to traditional radiotherapy," Mayo said in a statement. The clinic is involved in active research studies involving use of proton beam therapy.

Christopher Snowbeck • 612-673-4744 Twitter: @chrissnowbeck