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. 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."
Stanislav Lazarev, MD, Senior Author, Associate Professor of Radiation Oncology, Icahn School of Medicine
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.
Source:
Journal reference:
Jacobs, L. M., et al. (2026). Multi-Course Reirradiation in Diffuse Intrinsic Pontine Glioma. Practical Radiation Oncology. DOI: 10.1016/j.prro.2026.06.006. https://www.sciencedirect.com/science/article/pii/S1879850026002018?dgcid=author
Facts Only
* The study examined giving three courses of radiation therapy to patients with recurrent diffuse intrinsic pontine glioma (DIPG).
* The study was conducted by investigators at the Icahn School of Medicine at Mount Sinai.
* The research is published in Practical Radiation Oncology (DOI: 10.1016/j.prro.2026.06.006).
* The analysis combined all previously published worldwide cases with two additional patients treated at Mount Sinai, totaling 12 patients.
* Median survival across the group was 27 months from diagnosis.
* Many patients experienced meaningful improvements in neurological symptoms and quality of life after additional radiation treatments.
* Radiation therapy is the standard treatment for DIPG.
* DIPG affects children between 5 and 10 years old and cannot be surgically removed due to its location.
* Physicians have had little evidence guiding decisions about a third course of radiation due to concerns over repeated radiation damage.
Executive Summary
Research from the Icahn School of Medicine at Mount Sinai examined the experience of giving a third course of radiation therapy to patients with recurrent diffuse intrinsic pontine glioma (DIPG). The study combined existing worldwide published cases with two additional patients treated at Mount Sinai, creating the largest reported experience to date for this treatment in DIPG. The findings suggest that carefully selected patients may safely receive this additional radiation, potentially leading to symptom relief and extended survival.
Radiation therapy remains the only consistently shown treatment for DIPG, which is an aggressive brainstem tumor primarily affecting children aged 5 to 10. Standard treatment involves initial radiation, and some patients receive a second course as the cancer progresses. However, there was limited evidence regarding the benefit of a third course due to concerns about potential damage to healthy brain tissue from repeated radiation. The study analyzed 12 patients in total, showing a median survival of 27 months from diagnosis, which is longer than typically reported for DIPG, and indicating meaningful improvements in neurological symptoms and quality of life for many participants following additional treatment.
The investigators suggest that while this approach is not a cure, the findings offer evidence to support informed treatment decisions by providing a basis for potential future clinical trials. Researchers caution that the study was retrospective and small, emphasizing the need for further prospective research to identify optimal patient selection criteria and safe radiation schedules.
Full Take
The investigation into multi-course re-irradiation for recurrent DIPG shifts the clinical dialogue from established treatment limitations to empirical evidence regarding patient benefit, which carries significant weight in pediatric oncology where survival is already precarious. The core tension lies between leveraging institutional experience to offer potential relief and the inherent scientific caution required when dealing with repeated exposure to a sensitive organ like the brainstem. The finding that median survival was extended to 27 months for this group, coupled with symptom improvement, suggests a potential benefit worth investigating further, moving the focus from therapeutic futility to prognostic utility.
The pattern observed is one of cautious, data-driven expansion of treatment protocols in the face of unmet needs, tempered by strong methodological constraints regarding sample size and retrospective design. The implication for human agency centers on balancing hope—suggested by improved quality of life and survival—against rigorous safety standards that demand prospective validation. The reluctance to adopt this approach broadly stems from the understanding that extending radiation carries risks, making the transition from "possible benefit" to "standard care" a slow, heavily scrutinized process requiring prospective study.
Bridge questions include: What specific biomarkers or prognostic factors identified in this cohort might predict which patients safely tolerate a third course? How can clinical guidelines be developed quickly to incorporate this experience while maintaining safety thresholds? What long-term effects must be prioritized when establishing multi-course protocols for such a vulnerable population?