Reirradiation practices for children with diffuse intrinsic pontine glioma

Abstract

Background: Diffuse intrinsic pontine gliomas (DIPGs) are a leading cause of brain tumor deaths in children. Current standard of care includes focal radiation therapy (RT). Despite clinical improvement in most patients, the effect is temporary and median survival is less than 1 year. The use and benefit of reirradiation have been reported in progressive DIPG, yet standardized approaches are lacking. We conducted a survey to assess reirradiation practices for DIPG in North America.

Methods: A 14-question REDCap survey was disseminated to 396 North American physicians who care for children with CNS tumors.

Results: The response rate was 35%. Participants included radiation-oncologists (63%; 85/135) and pediatric oncologists/neuro-oncologists (37%; 50/135). Most physicians (62%) treated 1 to 5 DIPG patients per year, with 10% treating more than 10 patients per year. Reirradiation was considered a treatment option by 88% of respondents. Progressive disease and worsening clinical status were the most common reasons to consider reirradiation. The majority (84%) surveyed considered reirradiation a minimum of 6 months following initial RT. Doses varied, with median total dose of 2400 cGy (range, 1200-6000 cGy) and fraction size of 200 cGy (range, 100-900 cGy). Concurrent use of systemic agents with reirradiation was considered in 46%, including targeted agents (37%), biologics (36%), or immunotherapy (25%). One-time reirradiation was the most common practice (71%).

Conclusion: Although the vast majority of physicians consider reirradiation as a treatment for DIPG, total doses and fractionation varied. Further clinical trials are needed to determine the optimal radiation dose and fractionation for reirradiation in children with progressive DIPG.

Keywords: diffuse intrinsic pontine glioma; reirradiation.

Figure 1.

Reirradiation practices. A, Contraindications to reirradiation: Contraindications included size of tumor (18%), poor performance status (70%), edema on imaging (8%), and steroid dependency (11%). Other reasons included short interval to progression, evidence of radiation therapy necrosis, sedation requirements in the child, poor/no clinical response to initial radiotherapy, and intratumoral hemorrhage. B, Time from initial radiation to reirradiation: C, Concurrent therapy used with reirradiation: Concurrent use of systemic agents with reirradiation was considered in 46% of respondents, with targeted agents (37%), biologics (34%), immunotherapy (25%), intravenous chemotherapy (19%), and intrathecal chemotherapy (4%). D, Complications with reirradiation: Complications seen with reirradiation included asymptomatic necrosis (43%), symptomatic necrosis (30%), and bleeding (9%). Other reasons included edema and steroid dependency.

Figure 2.

Reirradiation dosing. A, Total reirradiation dose for diffuse intrinsic pontine glioma (DIPG) patients based on physician responses: Radiation therapy doses varied, with median total dose of 2400 cGy (range, 1200-6000 cGy). B, Dose per fraction of reirradiation in DIPG based on physician responses: Median dose per fraction was 200 cGy (range, 100-900 cGy).