Children with one of the deadliest forms of brain cancer may benefit from an additional course of radiation therapy after their disease returns, according to new research from the Icahn School of Medicine at Mount Sinai. The study, published in Practical Radiation Oncology ( 10.1016/j.prro.2026.06.006 ), is the first to examine the experience of giving three courses of radiation treatment to patients with diffuse intrinsic pontine glioma (DIPG) that has recurred.
The study combines Mount Sinai's institutional experience with every previously published case from around the world, creating the largest reported experience to date of three-course re-irradiation for this rare pediatric brain tumor. The findings suggest that carefully selected patients may safely receive additional radiation, helping relieve symptoms and potentially extending survival.
"DIPG is one of the most devastating cancers we treat," said senior author Stanislav Lazarev, MD, Associate Professor of Radiation Oncolog y at the Icahn School of Medicine. "Radiation therapy remains the only treatment consistently shown to help these children. Our study represents the largest reported experience to date and suggests that, in carefully selected patients, a third course of radiation may offer additional symptom relief and valuable time without causing unacceptable side effects."
DIPG is an aggressive tumor that forms in the brainstem, the part of the brain that controls breathing, movement, and other essential functions. The disease primarily affects children between 5 and 10 years old and cannot be removed surgically because of its location. Most children survive only about 12 to 14 months after diagnosis, despite treatment.
Radiation therapy is the standard treatment because it can temporarily slow tumor growth and improve symptoms. As the cancer progresses, some patients receive a second course of radiation. However, physicians have had very little evidence to guide decisions about whether a third course could be beneficial, largely because of concerns that repeated radiation might damage healthy brain tissue.
For the study, Mount Sinai investigators reviewed all published reports of patients who received three courses of radiation for recurrent DIPG and added two patients treated at Mount Sinai. In total, the analysis included 12 patients—the entire published worldwide experience with this approach. Across the group, median survival was 27 months from diagnosis, substantially longer than typically reported for DIPG, and many patients experienced meaningful improvements in neurological symptoms and quality of life following additional radiation treatments.
"Families facing recurrent DIPG have very few treatment options," said first author Lauren Jacobs, MD, a resident physician in Radiation Oncology at the Icahn School of Medicine. "While this approach is not a cure, our findings suggest that additional radiation may help some children feel better and live longer. We hope this work provides physicians with evidence to support informed treatment decisions and serves as the foundation for future clinical trials."
Because the treatment uses standard radiation therapy already available at hospitals around the world, researchers say it could be broadly adopted if larger prospective studies confirm its benefits.
The authors caution that the study was retrospective and included a small number of patients because DIPG is rare. Additional research is needed to identify which patients are most likely to benefit and to establish the safest treatment schedules. The Mount Sinai team plans to develop a prospective clinical study to further evaluate multi-course re-irradiation for recurrent DIPG.
The study was conducted by investigators at the Icahn School of Medicine and did not receive specific external funding.
Full study: https://www.sciencedirect.com/science/article/pii/S1879850026002018?dgcid=author
