MRI and Molecular Characterization of Pediatric High-Grade Midline Thalamic Gliomas: The HERBY Phase II Trial.

Background Diffuse midline gliomas (DMG) are characterized by a high incidence of H3 K27 mutations and poorer outcome. The HERBY trial has provided one of the largest cohorts of pediatric DMGs with available radiologic, histologic-genotypic, and survival data. Purpose To define MRI and molecular characteristics of DMG. Materials and Methods This study is a secondary analysis of a prospective trial (HERBY; ClinicalTrials.gov identifier, NCT01390948) undertaken between October 2011 and February 2016. Among 121 HERBY participants, 50 had midline nonpontine-based tumors. Midline high-grade gliomas were reclassified into DMG H3 K27 mutant, H3 wild type with enhancer of zest homologs inhibitory protein overexpression, epidermal growth factor receptormutant, or not otherwise stated. The epicenter of each tumor and other radiologic characteristics were ascertained from MRI and correlated with the new subtype classification, histopathologic characteristics, surgical extent, and outcome parameters. Kaplan-Meier curves and log-rank tests were applied to determine and describe survival differences between groups. Results There were 42 participants (mean age, 12 years ± 4 [SD]; 23 girls) with radiologically evaluable thalamic-based DMG. Eighteen had partial thalamic involvement (12 thalamopulvinar, six anteromedial), 10 involved a whole thalamus, nine had unithalamic tumors with diffuse contiguous extension, and five had bithalamic tumors (two symmetric, three partial). Twenty-eight participants had DMG H3 K27 mutant tumors; there were no differences in outcome compared with other DMGs (n = 4). Participants who underwent major debulking or total or near-total resection had longer overall survival (OS): 18.5 months vs 11.4 months (P = .02). Enrolled participants who developed leptomeningeal metastatic dissemination before starting treatment had worse outcomes (event-free survival, 2.9 months vs 8.0 months [P = .02]; OS, 11.4 months vs 18.5 months [P = .004]). Conclusion Thalamic involvement of diffuse midline gliomas ranged from localized partial thalamic to holo- or bithalamic with diffuse contiguous spread and had poor outcomes, irrespective of H3 K27 subtype alterations. Leptomeningeal dissemination and less than 50% surgical resection were adverse risk factors for survival. Clinical trial registration no. NCT01390948 © RSNA, 2022 Online supplemental material is available for this article. See also the editorial by Widjaja in this issue.

Eating behaviour and oxytocin in patients with childhood-onset craniopharyngioma and different grades of hypothalamic involvement.

BACKGROUND: Patients with childhood-onset craniopharyngioma (CP) often suffer from tumour or treatment-related hypothalamic lesions (HL). These lesions may alter production of oxytocin, which plays a major role in the regulation of eating behaviour and body composition. OBJECTIVE: In CP with different degrees of HL, we investigated associations between HL, eating behaviour/eating attitudes, and oxytocin saliva concentrations (OSC). METHODS: In a cross-sectional case-control study on 34 CP and 73 healthy controls, OSC were measured before, and 60 minutes after breakfast by immunoassay. Eating behaviour, attitudes, and habits were assessed by standardized questionnaires. RESULTS: CP with anterior + posterior HL presented with more adverse eating behaviours/symptoms of eating disorders than CP without HL, CP with anterior HL, and controls. Eating behaviour in CP with anterior HL was similar to controls, except for their tendency towards high dietary restraints. Decreases in postprandial compared with fasting OSC were associated with adverse eating behaviour in CP and controls and with higher BMI in CP. CONCLUSIONS: CP with anterior HL and CP with anterior + posterior HL present with distinct patterns of eating behaviour. Reduced postprandial compared with fasting OSC is associated with weight problems in CP and with adverse eating behaviour and symptoms of eating disorders in both CP and controls.

Low concordance between surgical and radiological assessment of degree of resection and treatment-related hypothalamic damage: results of KRANIOPHARYNGEOM 2007.

BACKGROUND: Assessment of presurgical hypothalamic involvement (psHI) and treatment-related hypothalamic damage (trHD) is relevant for the decision on risk-adapted treatment and rehabilitation strategies in craniopharyngioma. PATIENTS AND METHODS: 129 surgical reports of childhood-onset craniopharyngioma patients recruited 2007-2014 in KRANIOPHARYNGEOM 2007 were analyzed. Data on psHI were available based on surgeon's (63%), reference neuroradiologist's (95%), and local radiologist's (23%) assessment. The surgical degree of resection (DoR) was assessed by neurosurgeon (95%), reference neuroradiologist (73%), and local radiologist (61%). TrHD was assessed by neurosurgeon (33%), by reference neuroradiologist (95%), and by local radiologist (2%). Neurosurgical center size was categorized based on patient load. RESULTS: Surgical assessments on psHI (n = 78), DoR (n = 89) and trHD (n = 42) as documented in surgical reports could be compared with the assessment of respective parameters by reference neuroradiologist. Differences with regard to DoR (p = 0.0001) and trHD (p < 0.0001) were detectable between surgeon's and reference neuroradiologist's assessment, whereas psHI was assessed similarly. Concordance for DoR and trHD was observed in 48 and 62%, respectively. Surgeons estimated a higher rate of complete resections and a lower rate of trHD. Neuroradiological reference assessment of trHD had higher predictive value for hypothalamic sequelae then surgical assessment. Observed differences were not related to neurosurgical center size. CONCLUSIONS: Observed differences between surgical and neuroradiological estimation of risk factors in craniopharyngioma support the necessity of neuroradiological reference review to assure standards of quality. This could be established by central internet-based neuroradiological review in KRANIOPHARYNGEOM 2007. Standardization of surgical reports including specific assessment of tumor/damage location is recommended.

Remote effects of hypothalamic lesions in the prefrontal cortex of craniopharygioma patients.

Albeit histologically low grade (WHO I(o)) brain tumors, craniopharyngiomas and/or their surgical removal frequently affect the hypothalamus, amongst other brain regions at risk. Due to rich hypothalamic connections with prefrontal and limbic regions, hypothalamic injury may adversely affect neural substrates of emotion processing and higher cognitive control, including memory and executive functions. The current study is the first to investigate the consequences of hypothalamic involvement on neural substrates of emotional and cognitive functioning. Ten patients with childhood craniopharyngioma and known hypothalamic involvement and fifteen age- and intelligence matched control subjects (median age: 17.8 and 17.3 yrs.) were studied with functional magnetic resonance imaging and an emotional face recognition task. During encoding, participants were asked to classify neutral and emotional faces. In a subsequent recognition phase, participants had to recognize these old faces within a set of new faces. Behavioral performance was comparable between patients and controls. Neural activity revealed, however, differential recruitment of fronto-limbic brain regions during recognition. Patients exhibited an abnormal pattern of task-induced activation and deactivation in the anterior and posterior rostral medial prefrontal cortex and a higher functional coupling between anterior rostral medial prefrontal cortex and the thalamus. Additionally, we found a higher reactivity in the patients' amygdala to emotional relative to neutral faces when compared to healthy controls. Our data provide first evidence that hypothalamic damage impacts neural correlates of memory retrieval in medial prefrontal cortex, indicating a less efficient use of an area involved in executive control processes. We propose that the deactivation failure in the patients' anterior rostral medial prefrontal cortex is related to an increased coupling with the thalamus and reflects a reduced efficiency to flexibly adapt to task demands.

Thalamic high-grade gliomas in children: a distinct clinical subset?

Pediatric high-grade gliomas (HGGs) of the thalamic region account for up to 13% of pediatric HGGs and usually result in only anecdotal long-term survival. Because very little is known about these tumors, we aimed to further characterize them. In our series of 99 pediatric thalamic HGGs, there were no significant differences in survival between patients with tumors affecting the thalamus alone (including bithalamic lesions) and patients with tumors affecting the thalamus plus adjacent structures. Tumor resection (event-free survival/overall survival) and an early treatment response to radiotherapy/chemotherapy (event-free survival) had independent prognostic significance, as shown by Kaplan-Meier and multivariate Cox regression analyses. When we compared clinical characteristics and outcomes of pediatric thalamic HGG with those of pediatric (nonthalamic) supratentorial (n = 177) as well as pediatric pontine HGG (including diffuse intrinsic pontine gliomas; n = 234), we found that thalamic HGG shared more similarities with pontine than with supratentorial HGG, but overall, it appeared to represent a clinically distinct subgroup of pediatric HGG. The varying extent of tumor resection in the different tumor localizations may play some role in the observed clinical differences, as shown by multivariate Cox regression analyses, but the tumor site itself was also identified as an independent prognostic parameter. Thus, an additional location-specific effect on survival and/or tumor biology, despite different neurosurgical accessibility, has to be considered. Therefore, future investigations should try to further characterize the obviously site-specific heterogeneity of pediatric HGG on a molecular genetic basis.

Post-operative hypothalamic lesions and obesity in childhood craniopharyngioma: results of the multinational prospective trial KRANIOPHARYNGEOM 2000 after 3-year follow-up.

BACKGROUND: Hypothalamic obesity has major impact on prognosis and quality of life (QoL) in childhood craniopharyngioma. PATIENTS AND METHODS: For this study, 120 patients were prospectively recruited during 2001 and 2007 and evaluated after 3 years of follow-up (KRANIOPHARYNGEOM 2000). Body mass index (BMI) and QoL at diagnosis and 36 months after diagnosis were analysed based on the reference assessment of tumour localisation and post-surgical hypothalamic lesions. Treatment was analysed based on the neurosurgical strategy of 50 participating neurosurgical centres, the centre size based on the patient load. RESULTS: BMI SDS at diagnosis was similar in patients with or without hypothalamic involvement. Surgical lesions of anterior and posterior hypothalamic areas were associated with higher increase in BMI SDS during 36 months post-diagnosis compared with patients without or only anterior lesion (+1.8 BMISD, P=0.033, +2.1 BMISD; P=0.011), negative impact on QoL in patients with posterior hypothalamic lesions. Surgical strategies varied among the 50 neurosurgical centres (three large-sized, 24 middle-sized and 23 small-sized centres). Patients treated in small-sized centres presented with a higher rate of hypothalamic involvement compared with those treated in the middle- and large-sized centres. Treatment in large-sized centres was less radical, and the rates of complete resection and hypothalamic surgical lesions were lower in large-sized centres than those of the middle- and small-sized centres. However, a multivariable analysis showed that pre-operative hypothalamic involvement was the only independent risk factor for severe obesity (P=0.002). CONCLUSIONS: Radical neurosurgical strategies leading to posterior hypothalamic lesions are not recommended due to the potential to exacerbate hypothalamic obesity and impaired QoL. Treatment should be confined to experienced multidisciplinary teams.