By Erin Digitale, Stanford Medicine
This article originally appeared in the Stanford Medicine News Center. Click here to access the original article.
Editor’s note: On June 11, Stephen De La Torre completed his treatment.
On June 4, a 7-year-old boy who had a rare, malignant brain tumor removed became the first person treated at Stanford Medicine’s new, ultracompact proton therapy facility.
The milestone arrived near the end of patient Stephen De La Torre’s planned radiotherapy treatments; his doctors expect to send him home next week to resume life as a normal, active kid. But Stephen’s treatment is just the start of making a highly effective cancer therapy much more accessible to patients in Northern California and, eventually, around the world.
“Our new ability to offer protons is really exciting, especially for pediatric patients, because in many cases it lowers their risk of long-term treatment side effects,” said Susan Hiniker, MD, Stephen’s pediatric radiation oncologist at Stanford Medicine Children’s Health.
The Sridhar B. Seshadri Proton Therapy Suite, the first of its kind in the world, is unique because its small, less costly equipment fits in a compact space.
Until now, the nearest options for most Northern California patients who needed proton therapy were hundreds of miles away. Hospitals have struggled to build traditional proton therapy facilities because the equipment is expensive and so large it requires an area the size of a football field.

The innovative new design is the product of a collaboration between Stanford Medicine and two medical technology companies. When it is replicated, the new design will lower the barriers to proton therapy treatment not just locally but globally.
That will be good for patients of all ages. On June 4, the Stanford Medicine team also treated the first adult patient with proton therapy which can be used for a wide variety of tumors, including those in the head and neck, spine, lungs, liver, and prostate.
“The key is being able to eliminate cancer without causing unacceptable collateral damage,” said Bill Loo, MD, PhD, professor of radiation oncology, who has led efforts to bring proton therapy to Stanford Medicine.
“With protons, we can deposit the dose of radiation in a more controlled way.”
Protons will be especially helpful for children like Stephen. Kids’ growing bodies are extra-sensitive to even low doses of radiation, said Hiniker, who is also an associate professor of radiation oncology at Stanford Medicine. “Being able to send radiation to just the right spot, and avoid healthy tissues nearby, is extremely beneficial.”
Vanquishing a brain tumor
After several months of unexplained symptoms, Stephen was diagnosed earlier this year with an ultrarare brain tumor, known as a papillary tumor of the pineal region.
The tumor, about the size of an AA battery, was blocking drainage of cerebrospinal fluid from his brain, causing swelling that led to headaches, vision problems, nausea and lethargy. On March 9, Stephen had surgery at Lucile Packard Children’s Hospital Stanford to excise the tumor.
“Our surgeons told us that his tumor was located really close to the brain stem, so they removed what they could safely,” said Stephen’s mom, Tricia De La Torre. “He needed radiation to eliminate the rest.”
When Hiniker first met with Stephen’s parents, Tricia and her husband, Stephen De La Torre Sr., she told them that while Stephen’s case was unique and complex, there could be some benefits to proton therapy for their son. Although cancerous, the tumor is slow growing, and the goal of radiation treatment would be to eliminate what was left of it, Hiniker explained. But minimizing the dose to the surrounding developing brain and brain stem — which controls key body functions such as breathing and heartbeat — would be beneficial.
Protons are the charged particles in the center of an atom. Because of their charge, they can be steered and stopped more precisely than the photons in X-rays, allowing radiation oncologists to conform the dose of protons precisely to the shape of a tumor.




