Lee-Collier Runner-Up 3

Lee-Collier Runner-Up 3

Daniel Dosoretz

CEO, Radiation Therapy Services

When Daniel Dosoretz arrived in Fort Myers in 1980, cancer patients who needed radiation therapy didn't have many choices in town. That was about to change.

Dosoretz, a radiation oncologist who was attracted to the area by its favorable demographics leaning towards an elderly population, saw opportunities to build first-class radiation-treatment centers close to home.

After establishing the first treatment center in Fort Myers, Dosoretz and partners Michael Katin and Howard Sheridan established a second center across the Caloosahatchee River in Cape Coral, so cancer patients wouldn't have to drive to Fort Myers for treatment.

Today, Fort Myers-based Radiation Therapy Services is the largest operator of radiation-treatment centers in the country. The company operates 70 treatment centers in 14 states stretching from Florida to California.

"Our idea was to provide the same kind of service that you would get in Boston," says Dosoretz, 52, who previously was an attending physician at Massachusetts General Hospital and assistant professor of radiology at Harvard Medical School.

His advice to entrepreneurial doctors is to take some risks with the business. "They don't want to buy a building, even if they do the math," he says. "If they provide a good service, they need to invest in themselves."

In the beginning, Dosoretz and his partners put their own money into the venture. "We were on the line for every building, every machine," he says. "It was millions of dollars we owed." Radiation Therapy Services, which does business as 21st Century Oncology, went public in 2004 and its stock trades on the Nasdaq exchange (symbol RTSX; recent price $26).

Dosoretz's mentor is his 83-year-old father, who was the son of a blacksmith in Buenos Aires, Argentina, and rose from humble roots to become a well-known physician in that city. Dosoretz came to the U.S. and Massachusetts General to complete his residency after graduation from the University of Buenos Aires Medical School. He became a U.S. citizen in 1985.

- Jean Gruss

Revenues 2003: $139 million 2004: $171 million 2005: $227 million

(23% increase) (32% increase)

Average annual growth: 27.5%

EMPLOYEES 2004: 720 2005: 980 2006: 1,031