Doctors said 2-year-old Cash Hyde would likely die after they found a stage 4 brain tumor surrounding his optic nerve just a year ago this week.
And he nearly did. After being subjected to seven different chemotherapy drugs, the little boy from Missoula, Montana suffered septic shock, a stroke and pulmonary hemorrhaging.
Cash was so sick he went 40 days without eating. His organs were threatening to shut down. His father, Mike Hyde, intervened, slipping cannabis oil into his son's feeding tube.
In Montana, medical marijuana is legal. Hyde had used it himself to treat his attention deficit disorder. When Cash was diagnosed in May 2010, Mike got him a marijuana card and purchased the drug from his own supplier.
Cash, now 3, made a miraculous recovery at Primary Children's Hospital in Salt Lake City, but his father's bold action -- taken behind doctors' backs -- has raised serious questions about a parent's role in medical treatment.
Hyde said he believes it was the marijuana oil that helped Cash eat again and that the drug -- illegal in most states, including Utah, can cure cancer.
"Not only was it helpful," Hyde, 27, told ABCNews.com. "It was a godsend."
Dr. Linda Granowetter, a professor of pediatrics at New York University and chief of the Division of Pediatric Hematology and Oncology, told ABCNews.com that Hyde's intervention was "fascinating" but "somewhat bothersome."
Granowetter said she agrees that cannabis -- the chemical form, THC can be found in the prescription drug Marinol -- is effective in treating adult nausea that accompanies chemotherapy. But there have been no clinical trials in children.
"Its virtue is we know exactly what you are getting and how much," she said. "I think that the fact that he didn't have the rapport and ability to be honest with the doctor is very troubling. Care is impeded when there is not complete trust."
Hyde, who quit his job as a car salesman when Cash was diagnosed with cancer, said he was afraid Cash's doctor might take the marijuana away.
"When you are told your kid has cancer, whoa," said Hyde, 27. "Then they tell me they have to do aggressive chemo and he's probably not going to make it. It's a lot to take on."
He had read claims by researchers online about cannabis's properties: "It's one of the best nausea and pain medications on the market," he said.
Because there are no pediatric oncology facilities in rural Montana, where Cash's tumor was discovered in a CT scan at the local emergency room, he was rushed to Salt Lake City, the nearest treatment center.
He was given the highest possible doses of chemotherapy for two months. He lost his appetite and threw up eight to 10 times a day.
"When he started the chemo, he was so sick," said Hyde. "For the first six weeks, he was blind. But his tumor was shrinking… It's the nastiest thing to see someone you love go through this."
Doctors had inserted a gastric feeding tube to administer cancer-fighting drugs and to help with his nutrition, but when August came the family experienced another medical "rollercoaster ride," according to Hyde.
"The G-tube burned out the inside of his stomach," said Hyde. "He didn't even have the will to eat."
By September, Cash had stopped eating for 40 days. "He was suffering terribly, and the doctors said it was the best they could do for him," said Hyde, who asked doctors to stop the chemotherapy drugs.
Instead, Hyde boiled up marijuana he had purchased in Montana with olive oil and measured 3 mm. doses that he poured into his son's G-tube twice a day.
Because it was illegal to use medical marijuana in Utah, Hyde never told his doctors.
Cash Hyde Makes 'Miracle' Recovery'
"In two weeks he was weaned of all the nausea drugs, and he was eating again and sitting up in and laughing," according to Hyde, who said doctors called his son's recovery "a miracle."
NYU's Granowetter said cannabis "certainly can increase appetite and improve mood...but the idea that it can cure cancer is ludicrous."
She said the drug is most effective in teens who have previously used marijuana. "In young adults or children who have not had it before, it can make them paranoid."
"It's awfully hard to gauge if a child would have a bad reaction," according to Granowetter, who said she would welcome clinical trials on children.
"We know from research that 30 to 60 percent of parents with children are giving them alternative meds like vitamins, shark tooth and herbs from Chinatown," she said. "That's why we spend a lot of time asking parents what else they are giving kids and trying to be non-judgmental and work with them and guide them."
She said most pediatric oncologists are "open-minded" about alternative treatments.
Mike Hyde said he did eventually tell the Utah doctors, who were surprised by how Cash bounced back with no permanent organ damage. They say the boy has a 50 to 80 percent chance that the cancer will come back, according to Hyde, who has since started a foundation to help children with cancer.
"We were told I was one of the best dads," said Hyde, who lived with his wife and their other 6-year-old son in a camper in a parking lot for the nine months of treatment. "Every encounter in Salt Lake City, we were positive and never quit fighting. I was told he was going to die, but I knew he hadn't stopped the fight."
For more information on Cash and how to help other children with cancer, go to the Cash Hyde Cancer Foundation.