Aidan Boyle was an evil scientist for Halloween this year. Last year he was a wizard. In between, he was Batman, a princess, an Irishman, a French miss, a cat, a little devil, a pirate, a doctor and a spy, just to name a few.

Halloween not withstanding, Aidan, 10, spent much of the past year in disguise — his way of dealing with a frightening and grueling regimen of chemotherapy that would ultimately destroy a brain tumor that had been diagnosed in August 2007.

The challenge for Aidan and his parents, Tim and Beth Boyle of Peterborough, was to make the process a little less scary and perhaps try to make it fun.

“I didn’t think I was going to see any of the nurses again,” said Aidan, whose chemo treatments started in August of 2008 and ended in July when his doctor said the tumor was gone.

For almost a year Aidan went to Dartmouth Hitchcock Medical Center in Lebanon on Tuesdays for his chemotherapy treatment.

“It was awesome. I got to be with the nurses,” Aidan said when asked about his chemo treatment. “They were so nice to me. I disguised myself almost every day. ... I think the best costume was the princess costume.”

Although Aidan, now a fifth grader at South Meadow School, finds it slightly embarrassing that he donned a pink princess dress and painted his nails for one of his weekly chemotherapy visits at Dartmouth, the humor of the costume at the time was too much for Aidan to pass up and is still his favorite.

Aidan soon became the highlight of the nurse’s day, his mother said. “They said that was the best part of their day, trying to figure out what Aidan was going to be. ... He really developed a very close relationship with the nurses.”

He’s always been a quirky, funny child, she said, and facing this medical crisis just brought that out even more.

“He’s definitely a strong, confident, amazing little boy,” Beth said. “I don’t know how other children handle it.”

“He wore costumes each time he went. It started out as Aidan’s idea and it was a great coping mechanism. It really did away with a lot of his fears. ... He was pretending to be somebody else and that person didn’t have to get chemo. It just eased him into each day.”

Aidan had his bad days as well, Beth said.

“In the beginning he was on a really tough medicine that made him feel really ill,” she said. “He definitely had some hard days. Some days when he was like, ‘I do not want to go to chemo.’ “

Aidan was born with a genetic disorder called neurofibromitosis (type 1), a rare genetic condition that causes brown spots and tumors on the skin, freckling in skin areas not exposed to the sun, tumors on the nerves, and developmental changes in the nervous system, muscles, bone and skin.

Until 2007 Aidan showed no symptoms from the disorder. However in August 2007, after Aidan suffered from a weeklong headache, doctors discovered a brain tumor — a direct, yet unexpected result of his disorder, Beth said.

Aidan underwent two surgical procedures to remove the tumor, but both times it was unsuccessful. The tumor continued to grow. Doctors then prescribed 15 months of chemotherapy in an attempt to stop the growth of the mass and shrink it.

Aidan’s father, Tim, said it was a scary time. After two brain surgeries, he said, he had little hope the chemo would work.

“It was tough,” Beth said. “It was definitely hard. There’s nothing harder than seeing your child go through something like that really. But we all worked together, our families worked together and we both have pretty understanding work places, which helps.”

Shortly before Halloween last year, Beth was busy organizing a benefit to raise money that would help pay for Aidan’s medical bills. Autumn Fun for Aidan was held at Peterborough Elementary School where Aidan was a fourth grader at the time.

“Last year I was scared out of my mind not only for my child’s health but for my own financial well-being. I was concerned about whether I would have a job or not, things like that. So it was extremely stressful. And now I feel blessed.”

Beth, a preschool teacher at Happy Valley School in Peterborough, was able to work part-me around Aidan’s schedule, and then return this year as a fulltime teacher. Tim said, he was also able to take a lot of time off from his job at Millipore in Jaffrey.

During the crisis, friends, family, co-workers, PES staff and perfect strangers supported the family, Beth said. “I’ve created lifelong friends just from people who have supported him. .... If we hadn’t had the support I don’t know how we would have done it.”

In April, the Make a Wish Foundation sent the whole family to Orlando, Fla., so Aidan could go to Disney World. Beth said that 80 percent of the wishes the organization gets are for trips to Disney World. Aidan and his sister Kylie, 8, enjoyed the trip immensely, their parents said. Keeping Kylie happy and not stressed out by her brother’s condition was also a big concern for the parents, they said.

“She adores her brother and looks up to him. It was tough on her, too,” Beth said.

Throughout the ordeal Aidan was always laughing and joking, Tim said, even when he was being prepped for brain surgery. Tim and Beth both remember Aidan waking up after surgery excited about playing on the hospital’s Nintendo game system.

“I think it took his mind off of what just happened,” Tim said.

“It’s amazing how kids can get through stuff like that,” Beth said.

She now relishes that Aidan lives the life of most other fifth graders. He plays the trumpet at school and sings in the chorus.

It was in July they got the good news during a brain scan. “You’re done. It’s gone,” the doctors told Beth, she said. “It was wonderful. The nurses all hugged me and congratulated me, and the doctor was smiling ear to ear. To be done so quickly, to have him react so well to the chemo, it was exciting.”

The 15-month treatment ended after 11 months. When Tim found out his son’s tumor was gone, he said, he felt like a weight had lifted from his shoulders. That wonderful feeling continues, he said.

“I feel like I’m not going to loose him. I’m going to be able to see him grow up, get married, have a life.”

Beth said Aidan’s doctors say it is unlikely the tumor would reoccur.

“It’s not impossible. It is unlikely. It was unlikely to get the first one,” she said.

Aidan recently went back to Dartmouth for his three-month check-up. Everything still looks beautiful, Beth said. He will go every three months for a year. Then he will go every six months, Beth said. She expects his condition will be monitored, to some degree, for the rest of his life.

When asked what he wants to do now that he is healthy, it is very clear that the nurses, doctors and patients at Dartmouth remain in his heart.

“I want to save up a lot of money and buy Beanie Babies ... and send them to Dartmouth for children who are very ill,” he said.

The Beanie Babies are part of his plan to start a charity for sick children, Aidan said.

Aidan has already donated $25 to Dartmouth. He earned the money at his Labor Day lemonade stand.

He also plans to take on one of his costumes again as an adult and become a doctor. Aidan said as a doctor he wants to fight cancer and the flu. “I just want to work with everybody who’s sick.”

Beth said Aidan was already a compassionate child but his health crisis has made him even more so.

“He understands what other kids are going through and he wants to help them.”