It was Aug. 28, 2015, and Aaron was looking forward to his senior year in high school. One evening, he experienced a headache that he assumed was caused by sinus problems. As a new employee at Rodizio Grill in Allentown, he didn’t want to miss his evening shift, but soon after he arrived at work he fainted.

He was rushed to a local hospital, where a CT scan revealed a growth in his brain. He was transported to The Children's Hospital of Philadelphia, where an MRI showed two germinomas, a kind of brain tumor. A biopsy determined they were cancerous.

Aaron went through four rounds of chemotherapy and then 25 sessions of proton therapy at the Roberts Proton Therapy Center. This innovative form of radiation treatment delivers more precise radiation doses to cancerous tumors, avoiding healthy tissue.

Aaron, now 17, used to spend his free time “playing basketball, volleyball — really anything with a ball,” he says. “After I started chemo, I couldn’t do some of the things I used to do.” He could still hang out with friends and practice the piano and drums, and he’s now slowly getting back to being able to play sports again.

Most importantly, he accomplished something he wasn’t sure would be possible after his cancer diagnosis: He completed his senior year at William Allen High School. He was thrilled to walk across the graduation stage and receive his diploma in June. “That was due to the help of his social workers,” says his grandfather, Thomas, who was also impressed with how positive every CHOP staff member remained. “We’ve never heard a discouraging word at all.”

When the Parkway Run & Walk happens on Sunday, Sept. 25, Aaron will be a freshman at Lehigh Carbon Community College majoring in psychology, with the goal of transferring to the University of Oregon. The Parkway Run benefits pediatric cancer research and care at The Children’s Hospital of Philadelphia, and this year Aaron is a Patient Ambassador. Aaron and his team will be doing their part to make sure other pediatric cancer patients reach important milestones, like high school graduation.