Calling the scheme "horrific," a judge sentenced a Detroit-area cancer doctor to 45 years in prison Friday for collecting millions from insurance companies while poisoning more than 500 patients through needless treatments that wrecked their health.

U.S. District Judge Paul Borman this week heard stories of brittle bones and fried organs as patients chillingly described the effects of excessive chemotherapy at the hands of Dr. Farid Fata.

Fata "shut down whatever compassion he had as a doctor and switched it to making money," Borman said. Moments earlier, the judge called it a "huge, horrific series of criminal acts."

Fata, 50, offered no excuses before getting his punishment. Stone-faced all week in court, he repeatedly broke down in loud sobs as he begged for mercy Friday.

"I misused my talents, yes, and permitted this sin to enter me because of power and greed," Fata said. "My quest for power is self-destructive."

He said his patients knocked on his door for "compassionate care" but "I failed, yes, I failed."

Fata pleaded guilty last year to fraud, money laundering and conspiracy. He didn't strike a deal with prosecutors, so Borman needed much of the week to hear details about treatments. Patients and relatives hired a bus to get to court to watch.

"He preyed on our trust, our exhaustion, our fears," said Ellen Piligiam, whose late father, a doctor, was administered powerful drugs he didn't need for a tumor in his shoulder.

Federal prosecutor Catherine Dick had asked for a 175-year prison sentence, while Fata sought 25 years.

"It is not mob justice. It is appropriate for this crime," Dick told the judge, referring to the extraordinary request.

Outside court, many former patients, dressed in yellow in solidarity, were disappointed with the punishment.

"Prosecutors did a fantastic job — and he got 45 years. It's a lifetime sentence for the rest of us," said Monica Flagg, 53, who was treated for cancer before doctors examining a broken leg found she had no cancer. "What about all the grave markers out there that all the victims' families have to look at?"

Liz Lupo held a picture of her mother, Marianne Lupo, who died in 2007 at age 62. She believes Fata's treatments hastened her death.

"It's not justice at all," Lupo said.

The government identified 553 victims, along with insurance companies. Medicare and insurers paid at least $17 million.

Fata will get credit for about two years served in custody since his arrest in 2013. His stay in the federal prison system also could be shortened with good behavior.

His clinic, Michigan Hematology Oncology, had seven offices in the Detroit area and a related business that performed tests to look for cancer. Testifying for the government, two experts from Harvard medical school said they were troubled after looking at a small portion of patient files.