Surveillance magnetic resonance imaging (MRI) is routinely used to detect recurrence in pediatric central nervous system (CNS) tumors. The frequency of neuroimaging surveillance varies without a standardized approach. A single-institutional retrospective cohort study evaluated the frequency of recurrences. This study included 476 patients with the majority diagnosed with low-grade glioma (LGG) (n=138, 29%), high-grade glioma (HGG) (n=77, 16%), ependymoma (n=70, 15%), or medulloblastoma (n=61, 13%). LGG, HGG, and ependymoma patients more commonly had multiply recurrent disease (P=0.08), with ependymoma patients demonstrating ≥2 relapses in 47% of cases. Recurrent disease was identified by imaging more often than clinical symptoms (65% vs. 32%; P=10 years from initial diagnosis. With a higher tendency toward detection of tumor recurrence/progression on MRI surveillance in comparison to clinical progression, surveillance imaging is necessary in routine follow up of pediatric CNS tumor survivors. With some relapses >10 years from initial diagnosis, imaging beyond this time point may be useful in particular tumor types. While the study is limited in outcome analysis, earlier detection of recurrence would lead to earlier initiation of treatment and implementation of salvage treatment regimens which can impact survival and quality of life.

Background: Understanding the effect of selumetinib on FASI may help elucidate the biology, proliferative potential, and role in neurocognitive changes for these NF1-associated lesions. Methods: Patients with NF1-associated LGG and FASI treated with selumetinib on PBTC-029B were age-matched to untreated patients with NF1-associated FASI at Cincinnati Children’s Hospital Medical Center. Paired bidirectional measurements were compared over time using nonparametric tests. Results: Sixteen age-matched pairs were assessed (age range: 2.8–16.9 years, 60% male). Initial FASI burden was not different between groups (median range 138.7 cm² [88.4–182.0] for the treated subjects vs. 121.6 cm² [79.6—181.9] for the untreated subjects; p = 0.98). Over a mean follow-up of 18.9 (±5.9) months, the LGG size consistently decreased with treatment while no consistent change among the treated or untreated FASI size was seen. At the paired time points, the median treated LGG decreased significantly more than the treated FASI (−41.3% (LGG) versus −10.7% (FASI), p = 0.006). However, there was no difference in the median size change in the treated versus untreated FASI (−10.7% (treated FASI) versus −17.9% (untreated FASI), p = 0.08). Among the treated subjects, there was no correlation between the change in LGG and FASI (r = −0.04, p = 0.88). Conclusions: Treatment with selumetinib did not affect the overall FASI size in children with NF1 treated for progressive low-grade glioma.

Background/Objectives: Multiple immune-modulatory strategies have been tested in efforts to mitigate the pro-tumor microenvironment in pediatric high-grade glioma. HSV1716 is an oncolytic virus that previously demonstrated evidence of response in adult and pediatric patients. PBTC-037 was a single-center phase I trial developed and performed by the Pediatric Brain Tumor Consortium (PBTC) to estimate the maximum tolerated dose or recommended phase II dose of HSV1716 administered during surgical resection. Methods: Patients aged 12 to 21 years with recurrent or refractory high-grade glioma for whom surgical resection was clinically indicated were eligible. After maximal tumor resection, patients received one intraoperative dose of HSV1716. Results: Two patients were enrolled; one was later deemed ineligible yet was continued in follow up for safety. Both patients underwent complete tumor resection with the administration of HSV1716. Shortly after the enrollment of the two patients, this study was closed to accrual due to a change in the sponsor’s investment focus. One patient completed the 8-week reporting period without toxicity. The second patient who was later deemed ineligible had no evidence of dose-limiting toxicity. The two patients had progressive disease at 1.9 and 2.9 months after enrollment; both eventually died due to progressive disease at 7.5 months. Conclusion: We describe the administration of HSV1716 to two pediatric patients with recurrent high-grade glioma, without evidence of dose-limiting toxicity. Oncolytic viruses are currently being tested in pediatric patients in larger combinatorial trials. Despite the limited numbers, the data presented here will hopefully provide incremental steps toward improved immunovirotherapy of pediatric brain tumors.