The Mayo Clinic has received its largest-ever donation from a living person.

The clinic, which typically receives its most substantial gifts from estates, said Friday that philanthropist and longtime patient Richard O. Jacobson has donated $100 million to help establish two cancer centers-one in Rochester, where it is headquartered, and another at its Phoenix campus.

Specifically, the gift will go toward the establishment of a proton beam therapy program. Proton beam therapy represents a more advanced method of treating some cancers than traditional radiotherapy. The process uses a beam to target a tumor, thereby sparing surrounding tissue and nearby organs and enabling higher therapeutic doses to be used.

The new program will use the most advanced technology, which will result in fewer short- and long-term side effects among patients, according to Mayo.

“My dream has always been to establish a major new facility for Mayo Clinic,” Jacobson said in a statement. “I began going to Mayo for my care when I was a child and continue to get my care there. Mayo Clinic makes a profound impact on people.”

Mayo estimates that it will cost $400 million to build the two cancer centers-a quarter of which will be covered by Jacobson's gift. The remaining portion of the funding is being sought from other benefactors. The two cancer centers are expected to be fully operational by early 2016.

The facility that will house the new cancer center in Rochester will be named after Jacobson-a Belmond, Iowa, native who founded Des Moines-based Jacobson Companies, one of the largest privately owned warehouse companies in the United States.

The Mayo Clinic estimates that 1,240 patients will be treated with proton beam therapy each year in the not-yet-built Richard O. Jacobson Building on its Rochester campus-which will total 110,000 square feet. That same number of patients is expected to be treated annually at the Phoenix cancer center.

The largest gift in the Mayo Clinic's history totaled $141.5 million. It came from the estate of former San Antonio, Texas, resident and Mayo patient Barbara Woodward Lips in 1995.