When Survivorship Starts at Treatment: Proton Therapy for Pediatric Cancer

By Young Kwok, MD and Katarina Steacy, CRNP

Over the last several decades, there’s been a revolution in pediatric cancers. Better surgical techniques, more effective chemotherapy agents and regimens, and improved radiation delivery have boosted long-term survival from less than 10% forty years ago to more than 85% for many of these diseases now.

But a longer life can’t be the only measure of success – between 60% and 90% of survivors are left with chronic conditions later in life from the intensive treatments necessary to cure their disease. Depending on which organ or system was affected, these young patients might be left with learning disabilities, infertility, limb disparities, secondary malignancies, or more.

To avoid these consequences, many pediatric patients could benefit from intensity-modulated proton therapy (IMPT) – the most advanced form of proton therapy and what we offer at Maryland Proton Treatment Center. Compared to conventional photon therapy, IMPT’s targeted delivery and lower dose spares more healthy tissue, making long-term side effects from radiation therapy less likely.

Dr. Young Kwok, MD
Professor of Radiation Oncology, University of Maryland School of Medicine

The younger a patient must receive radiation therapy, the higher their likelihood of having a secondary malignancy later in life. But because IMPT often requires half the dose of conventional radiation or less, the chance of developing a second malignancy is significantly reduced. Having IMPT on board as a therapeutic option is also particularly important for tumors residing in specific tissues, including:

• Brain: This organ not only serves as a master control for learning, memory, and motor function, but also signals hormone production in other organs, including those that launch puberty. Sensitively treating the brain with IMPT can lower the risk of cognitive deficits as well as delayed or arrested puberty. ¹, ²,³
• Pelvis: IMPT’s targeted nature can protect reproductive organs in or around the pelvis, such as the ovaries, uterus, and testes, preserving their role in hormone production and fertility later in life. ⁴,⁵,⁶
• Bones: Bone lengthening during development relies on healthy growth plates, which are easily damaged by conventional radiation. IMPT can target bony tumors while sparing growth plates, preserving their function. ⁷,⁸

Delivering IMPT to children requires special considerations, and we discuss these for each case in our multidisciplinary pediatric tumor board. Every other Thursday, a group including pediatric radiation oncologists, medical oncologists, surgical oncologists, anesthesiologists, nurses, social workers, child-life specialists, and others meet to craft a specific care plan for every patient.

Our partnership with the Ulman Foundation helps us connect adolescent and young adult cancer patients with resources targeted to this population, and our connection with the Ronald McDonald House Charities Maryland helps families from outside the area stay together during treatment. We also work with insurance companies to facilitate coverage for IMPT. Our goal is to help any pediatric patient who might benefit from this revolutionary therapy to receive it.

References 

1. Superior Intellectual Outcomes After Proton Radiotherapy Compared With Photon Radiotherapy for Pediatric Medulloblastoma. J Clin Oncol. 2020 Feb 10;38(5):454-461. doi: 10.1200/JCO.19.01706. Epub 2019 Nov 27.

2. Long-term toxic effects of proton radiotherapy for paediatric medulloblastoma: a phase 2 single-arm study. Lancet Oncol. 2016 Mar;17(3):287-298. doi: 10.1016/S1470-2045(15)00167-9. Epub 2016 Jan 30.

3. Endocrine outcomes with proton and photon radiotherapy for standard risk medulloblastoma. Neuro Oncol. 2016 Jun;18(6):881-7. doi: 10.1093/neuonc/nov302. Epub 2015 Dec 19.

4. Treatment Outcomes After Proton Therapy for Ewing Sarcoma of the Pelvis. Int J Radiat Oncol Biol Phys. 2020 Aug 1;107(5):974-981.

5. Dose escalation in pediatric pelvic Ewing’s Sarcoma: Insights from a national treatment planning exercise. Phys Med. 2025 Sep:137:105063. doi: 10.1016/j.ejmp.2025.105063. Epub 2025 Aug 8.

6. Proton Radiotherapy for Pediatric Bladder/Prostate Rhabdomyosarcoma: Clinical Outcomes and Dosimetry Compared to Intensity-Modulated Radiation Therapy. International Journal of Radiation Oncology*Biology*Physics, Volume 81, Issue 5, 2011, Pages 1367-1373, ISSN 0360-3016,

7. Proton-Based Radiotherapy for Unresectable or Incompletely Resected Osteosarcoma. Cancer. 2011 Mar 29;117(19):4522–4530. doi: 10.1002/cncr.26037

8. Local Control After Proton Therapy for Pediatric Chordoma. International Journal of Radiation Oncology, Biology, Physics, 2020; 109, 1406-1413