When the sixth-grade boys at St. Ambrose School in Annandale heard their classmate, Beau Swallow, had been diagnosed with a rare form of cancer, they knew they had to do something to help.

That something soon turned into a head-shaving party earlier this month at a Hair Cuttery in Fairfax. There, Beau shaved his head in preparation for the rigorous chemotherapy treatments he’ll have to undergo for the Ewing’s sarcoma in his chest and lungs. The same night, all the other boys in his grade shaved their heads, too, in support.

The idea for the group shave was suggested by Principal Barbara Dalmut as a way to help Beau feel like he still fit in. The boys went for it almost immediately.

“We heard he was going to lose his hair and he was embarrassed, so we decided to do it, too,” said sixth-grader Aidan Fitzsimon, 11.

Nine boys, including Beau, shaved their heads that night. They were supervised by parents and St. Ambrose faculty, including Dalmut and sixth-grade teacher Patricia Kiernan.

“I was just so proud of them because that’s what we teach here — that we’re all part of the community,” Dalmut said. “Sixth grade is a difficult year to stand out. To make the sacrifice as a group because they love Beau was the ultimate show of their friendship and Christian values.”

Those friendships were on display during the night. After the haircuts, the group went to Sweet Berry, where the boys laughed and joked over gelato.

“It’s kind of fun when you can do this and laugh with your friends,” Fitzsimon said.

Dalmut said she was impressed with the students’ positive attitudes during the night.

“It was nice to see how joyful they were — no regrets, no looking back. They were very comfortable with it,” Dalmut said.

More than being comfortable, some of the students really liked or even preferred their new haircuts.

“We did it so Beau wouldn’t feel different,” said sixth-grader Jack Franchi. “Plus, it just feels really cool. My hair was pretty long and it feels a lot different.”

“This is awesome,” Fitzsimon said. “I’m never gonna have bed head again.”

Along with their new looks, the boys walked away with the feeling that they did something kind for a classmate in need.

“I think they feel really good that they were able to do something good for a friend,” said Debra Caffi, a parent who helped organize the night.

“I’m certain that this is gonna help him,” said Nick Gasteiger, 11. “I was really shocked that Beau had cancer, so I’m happy that I’m able to show some support.”

For Beau, the simple gesture of his friends meant a lot.

“It was great. I felt really good,” he said. “I thought I was gonna be alone and it turned out my classmates would do this for me.”

Even though he was going to shave his head for his treatment, Beau said having his friends do it with him made the whole thing much more fun.

“It’s always more fun having friends around,” he said.

The head-shaving party is just one of the ways the community at St. Ambrose has rallied around Beau and his family since his diagnosis in early January.

Students have supported Beau with e-mails, visits and lots of prayer. The first day back to school, they made him a prayer blanket. In addition, more people have shaved their heads, including a few of Beau’s friends in the fifth grade and on the basketball team and Beau’s social studies teacher, Colin Farrell.

“They’ve called it ‘Team Beau,’’’ Dalmut said. “The whole community is coming together to make food for the family and schedule visits. It’s really pretty amazing.”

Beau’s mother, Tina Swallow, said the support the family has received in the last few weeks has been “unbelievable.” She said Beau was in the hospital with a fever when he first found out about the head-shaving night and that he was thrilled.

“He just couldn’t believe he had such good friends,” she said. “He kept saying, ‘I’m so lucky.’ It’s really neat to see a 12-year-old boy going through such a horrific thing to feel that support.”

According to his mother, Beau finished his first round of chemotherapy earlier this month. His doctors expect that he will have between 10 and 12 sessions over the course of the next year.

“It’s going to be a long haul,” Swallow said. “It’s supposed to be every three weeks if everything goes well.”

The school is planning to have a blood drive in Beau’s honor, in preparation for the blood transfusions he likely will need during his treatment. The drive should take place in February or early March.

In the meantime, the Swallow family has set up a Web site for family and friends, where people can schedule times to visit Beau or days to bring over food. So far, the site has more than 230 members, many of whom are from the St. Ambrose community.

“It’s been unbelievable,” Swallow said. “Talk about a horrible situation, but seeing how much support we’ve received really makes an unbearable situation bearable.”