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BACKGROUND Pediatric low-grade gliomas (LGG) not amenable to resection, while often indolent, represent a significant source of cancer-related morbidity and an unmet therapeutic need. Standardly, these patients are treated with sequential lines of chemotherapy, while delaying as long as possible radiation. Magnetic resonance-guided laser interstitial therapy (LITT) is a minimally invasive procedure that utilizes real-time MR thermography to ablate brain lesions. METHODS A 15-year-old girl was diagnosed with a suprasellar, hypothalamic LGG, BRAF V600E mutation positive. The tumor was unresectable, and due to progressive vision loss and headaches, the patient underwent treatment. Despite sequential trials of thioguanine/procarbazine/lomustine/vincristine, carboplatin/vincristine, dabrafenib, and combination dabrafenib/trametinib, the patient continued to experience debilitating headaches, malnutrition, school absenteeism, and overall poor quality-of-life. Using real-time, sequential MRI-thermometry and the Neuroblate cooled directional laser catheter, the bulk of the enhancing tumor was heated to a killing temperature. RESULTS At 1-year post LITT, the patient’s symptoms were dramatically improved, including greatly improved headaches, malnutrition, school absenteeism, and overall quality of life. LITT was generally well tolerated, though the patient had slight progressive left homonymous hemianopia, thought secondary to LITT impact on the optic tracts. The tumor progressively shrank over the year post-LITT to a peak of 42% volume reduction. CONCLUSION We report a case of a pediatric patient with an unresectable low grade glioma who underwent LITT with excellent clinical and radiographic effects. LITT should be considered for children with unresectable and morbid LGGs that fail to respond to more conventional therapies.

Constitutional mismatch repair deficiency (CMMRD) is an autosomal recessive condition in which affected patients carry biallelic germline mutations in the MMR genes. This highly penetrant syndrome results in nearly universal development of malignant neoplasms at a young age, most commonly pediatric brain tumors. Importantly, in addition to brain tumors, patients frequently develop multiple metachronous or even synchronous tumors making it impossible to treat these cancers with current chemotherapeutic approaches due to the complexity of different chemoradiation regimens required, resulting in excess toxicity and lack of efficacy. We first, assessed the metachronous (defined here as serial tumors diagnosed >1 year apart or after completion of definitive treatment for the initial tumor) or synchronous cancers (defined here as tumors diagnosed within a year of each other or during the definitive treatment for the initial tumor) in all patients within the consortium. Strikingly, 47% developed synchronous and/or metachronous cancers leading to patient demise. Molecular analysis revealed that all synchronous tumors (n=26) harbored a hypermutational burden accompanied by high genomic microsatellite instability and the relevant signatures. We therefore treated two patients with glioblastomas who had synchronous solid tumors with checkpoint inhibitors. In both patients, objective tumor response was associated with clinical benefit and prolonged survival. Biomarker analysis revealed increased tumor mutational burden, microsatellite instability and immune cell infiltration. These cases highlight the role of universal, mechanism based and tumor-agnostic approach to treat patients with brain tumors with additional synchronous cancers in the setting of cancer predisposition.

The Children’s Brain Tumor Network (formerly known as Children’s Brain Tumor Consortium- CBTTC) is a global organization pioneering a model of open-science medical research to improve treatment and discover cures. Started in 2011, our objective was to utilize a regulatory, agreement, and governance architecture to remove existing research barriers that slowed down the pace of research and collaboration. Our network now includes 17 institutions working together to empower research. As of December 2019, over 3,600 subjects have been enrolled resulting in collection of over 45,000 specimens. Clinical data collection is longitudinal and includes medical history, diagnosis, treatment, pathology slides and reports, radiology imaging and reports, and outcome data. The tissue is collected flash-frozen, in freezing media, and fresh for the generation of pre-clinical models including cell lines. Blood is collected from the subject, with blood or saliva collected from the parents for germline comparison. Additionally, the Children’s Brain Tumor Network- Pediatric Brain Tumor Atlas has generated 952 WGS and RNAseq, 221 proteomics, with annotated clinical data. All of this data, both generated raw and processed data, has been made available broadly to the scientific community via cloud-based platforms, including the Gabriella Miller Kids First Data Resource Portal, Cavatica, and PedCbioportal. As of January 2020, we have 45 approved biospecimen requests and 80 genomic/molecular data requests. In summary, the Children’s Brain Tumor Network’s goal is to accelerate the pace of discovery by providing resources and expanding the network of scientists working towards a cure.

BACKGROUND: Pediatric glioblastoma (GBM; WHO grade IV astrocytoma) continues to carry a poor prognosis. While the use of concurrent and adjuvant temozolomide (TMZ) has been adopted as a standard treatment in adults, there is no standard systemic therapy for pediatric GBM. Recent studies in adults suggest benefit to the addition of tumor treating fields (TTF) to standard TMZ-based chemoradiotherapy, while a recent study in children showed improvement with the addition of lomustine (CCNU) to standard TMZ-based chemoradiotherapy. No studies to this point have been published using the combination of TMZ, TTF, and CCNU in either adult or pediatric GBM. METHODS: A single patient was treated with aggressive local surgery achieving gross total resection. This was followed by 60 Gy in 30 fractions with concurrent temozolomide (75 mg/m2) given daily during radiotherapy. Post-radiation adjuvant therapy consisted of dose escalated temozolomide (160 mg/m2) given on days 1-5 of a 42-day cycle, CCNU (90 mg/m2) on day 1, and continuous tumor treating fields (started with cycle 1 of adjuvant chemotherapy). RESULTS: Chemoradiotherapy was tolerated well without grade III or IV toxicity. Thus far, the patient has received 2 cycles of adjuvant temozolomide/CCNU without grade III or IV toxicity. At 3 months post-radiotherapy, there is no evidence of tumor recurrence. CONCLUSION: We report the first case of a pediatric patient with GBM receiving a maintenance combination of TTF, TMZ, and CCNU after tumor resection and standard TMZ-based chemoradiotherapy. Prospective trials are necessary to validate the tolerability, safety, and efficacy of this aggressive combination therapy.