Al18F-NOTA-Octreotide PET/CT and 18F-FDG PET/CT for Detecting Cerebellar Hemangioblastoma in a Patient With Von Hippel-Lindau Disease.

ABSTRACT: Von Hippel-Lindau disease is a hereditary syndrome associated with various benign and malignant tumors, including hemangioblastomas. A 42-year-old man with a history of Von Hippel-Lindau disease underwent surgery for pancreatic neuroendocrine tumor and renal clear cell carcinoma and was recommended to undergo Al18F-NOTA-octreotide and 18F-FDG PETCT examination to assess potential metastases. 18F-FDG PET/CT showed low uptake in the right cerebellum, which demonstrated increased Al18F-NOTA-octreotide activity. Cerebellar mass resection surgery was performed. Pathological result was consistent with hemangioblastoma. This case report indicates the significant role of Al18F-NOTA-octreotide in the diagnosis of hemangioblastoma.

The effectiveness of diffusion kurtosis imaging metrics for distinguishing between brainstem glioma and cerebellar medulloblastoma.

Background: In some clinical situations, distinguishing between cerebellar medulloblastoma and brainstem glioma is important. We assessed whether diffusion kurtosis imaging (DKI) metrics could be used to distinguish cerebellar medulloblastomas from brainstem gliomas in children. Patients and methods: This prospective study was approved by the institutional review board. Seventy patients were separated into two groups according to eventual diagnosis: brainstem glioma (n = 30) and cerebellar medulloblastoma (n = 40). Both groups underwent brain magnetic resonance imaging (MRI), including DKI. The Kurtosis value for the tumor region and the ratio between Kurtosis values between the tumor and the normal parenchyma (rKurtosis) were compared between groups using the Mann-Whitney U test. Receiver operating characteristic curve analysis and the Youden's Index were applied to identify a cutoff value for distinguishing between the two tumor types, and the area under the curve (AUC), sensitivity, and specificity for the selected cutoff value were calculated. Results: Compared with brainstem gliomas, cerebellar medulloblastomas had significantly higher Kurtosis and rKurtosis values (p < 0.05). Medulloblastoma could be differentiated from brainstem gliomas using a Kurtosis value of 0.91 or an rKurtosis value of 0.90, both of which achieved 100% sensitivity, 96.7% specificity, and AUC values of 0.990. Conclusions: DKI measurements can contribute to distinguishing between cerebellar medulloblastoma and brainstem glioma in children.

A case report of cerebellar hemangioblastoma simulated brain metastasis shown by magnetic resonance imaging.

RATIONALE: Hemangioblastomas occur both sporadically and as an important component of von Hippel-Lindau (VHL) disease. The typical MRI features of hemangioblastoma are cysts with enhanced cystic wall nodules in the cerebellum or lesions with uniform enhancement on the surface or inside the spinal cord. If there is edema around hemangioblastoma, it is easy to be misdiagnosed as brain metastasis on MRI. PATIENT CONCERNS: A 41-year-old male patient was found to have a lump in the pancreas during a health examination 3 months ago. Subsequently, the patient underwent surgical treatment. The postoperative pathology suggests that the pancreatic lesion is a neuroendocrine tumor. The patient subsequently came to our hospital for consultation on further treatment plans. Abnormal signals were found in the right cerebellum during pituitary magnetic resonance imaging (MRI) before the development of a treatment plan for neuroendocrine tumors. Subsequently, the patient underwent cerebellar mass resection surgery. The pathological result after the surgery was hemangioblastoma. DIAGNOSIS: The patient underwent surgery to remove the tumor and was diagnosed with hemangioblastoma by pathological examination. Subsequently, the patient's genetic testing results confirmed the diagnosis of VHL syndrome. INTERVENTIONS: The patient underwent cerebellar mass resection surgery. OUTCOMES: The patient recovered after surgical resection. LESSONS: In this report, we emphasize the atypical MRI manifestations of hemangioblastoma. For patients with VHL syndrome-related hemangioblastoma, genetic testing is necessary for the patient and their family members.

Application of the Rotterdam postoperative cerebellar mutism syndrome prediction model in patients undergoing surgery for medulloblastoma in a single institution.

OBJECTIVE: Postoperative cerebellar mutism syndrome (CMS) develops in up to 40% of children with medulloblastoma. The Rotterdam model (RM) has been reported to predict a 66% risk of CMS in patients with a score of ≥ 100. The aim of this study was to retrospectively apply the RM to an independent cohort of patients with newly diagnosed medulloblastoma and study the applicability of the RM in predicting postoperative CMS. METHODS: Participants had to have their first tumor resection at the authors' institution and be enrolled in the SJMB12 protocol (NCT01878617). All participants underwent structured serial neurological evaluations before and then periodically after completing radiation therapy. Imaging was reviewed by the study neurologist who was blinded to CMS status when reviewing the scans and retrospectively applied RM score to each participant. RESULTS: Forty participants were included (14 females and 26 males). Four (10%) patients had CMS. The median age at tumor resection was 11.7 years (range 3.5-17.8 years). Tumor location was midline in 30 (75%), right lateral in 6 (15%), and left lateral in 4 (10%). The median Evans index was 0.3 (range 0.2-0.4), and 34 (85%) patients had an Evans index ≥ 0.3. Five participants required a ventricular shunt. The median tumor volume was 51.97 cm3 (range 20.13-180.58 cm3). Gross-total resection was achieved in 35 (87.5%) patients, near-total resection in 4 (10%), and subtotal in 1. The median RM score was 90 (range 25-145). Eighteen participants had an RM score of ≥ 100, and of these 16.7% (n = 3) had CMS. Of the 22 patients with an RM score < 100, 1 child developed CMS (4.5%, CI 0.1%-22.8%); 3 of the 18 patients with an RM score ≥ 100 developed CMS (16.7%, CI 3.6%-41.4%). The observed rate of CMS in the cohort of children with an RM score ≥ 100 was significantly lower than the observed rate in the original RM cohort (66.7%, CI 51%-80.0%, p < 0.001). A greater risk of CMS in patients with an RM score ≥ 100 could not be confirmed (p = 0.31). CONCLUSIONS: At the authors' institution, the incidence of CMS in patients who had an RM ≥ 100 was significantly lower than the RM cohort. These findings raise questions regarding generalizability of RM; however, fewer cases of CMS and a relatively small cohort limit this conclusion.

Rupture of a flow aneurysm secondary to spontaneous extracranial to intracranial revascularisation in the posterior fossa following radiation-induced vasculopathy for cerebellar tumour.

Paediatric patients receiving cranial irradiation therapy for brain tumours are at increased risk of cerebrovascular complications. Radiation-induced moyamoya syndrome (MMS) is a well-recognised complication of this. We present a case of an 8-year-old boy with a history of medulloblastoma, who underwent surgical excision followed by post-operative adjuvant oncological treatment. Six years later, he developed cerebellar/intraventricular haemorrhage. He underwent an emergency external ventricular drain (EVD) insertion followed by posterior fossa suboccipital craniotomy. On dural opening, an abnormal vessel was visualised on the surface of the right cerebellar hemisphere, which was not disturbed. No obvious abnormalities were identified intra-operatively. Cerebral catheter angiography confirmed the presence of a right-sided occipital artery (OA) to posterior inferior cerebellar artery (PICA) extracranial to intracranial (EC-IC) bypass with a zone of the distal PICA territory supplied by this EC-IC bypass. A presumed flow aneurysm originated from the bypass in the distal PICA, identified as cause for the haemorrhage. We highlight a rare cause for intracranial haemorrhage in this cohort of patients. Children who have undergone radiotherapy may have exquisitely sensitive cerebral vasculature and need careful vigilance and evaluation for vasculopathic complications following spontaneous haemorrhage.

The Application of Sodium Fluorescein in Resection of Medulloblastoma Under YELLOW 560 Filter: Feasibility and Preliminary Results of a Monocentric Cohort and Systematic Review.

BACKGROUND: Maximizing surgical resection of medulloblastoma (MB) affects overall survival; nevertheless, surgical resection remains a because of the infiltrative behavior of this tumor. Several dyes have been tested for improving tumor visualization; however, few reports with different protocols of fluorophores use are available and the results are inconsistent. Hence, we report our experience with sodium fluorescein in MB surgery, aiming to assess the role of this technique on the extent of resection. Furthermore, we performed a literature review of this topic. METHODS: Fluorescence characteristics, extent of resection, and clinical outcome were analyzed in 9 consecutively operated patients with MB. A comprehensive literature search and review for English-language articles concerning fluorescein application in MB was conducted. RESULTS: In our cohort, no side effect related to fluorescein occurred; all tumors presented with an intense or moderate yellow-green enhancement, and fluorescein was judged fundamental in distinguishing tumors from viable tissue in 7 of 9 cases. Gross total resection or near-total resection (i.e., a residual tumor volume <1.5 cm3) was achieved in 8 patients. The review explored the different techniques and surgical interpretations as well as surgical radicality; we did not find a homogenous protocol for fluorescein injection in the published articles. Fluorescence appeared moderate or intense in almost all cases, with a high percentage of usefulness and consensual achievement of a high rate of gross total resection. CONCLUSIONS: Based on these results, we can infer that fluorescein-guided surgical resection is a safe and valuable method for patients with MB.

MR dynamic-susceptibility-contrast perfusion metrics in the presurgical discrimination of adult solitary intra-axial cerebellar tumors.

OBJECTIVES: Adult solitary intra-axial cerebellar tumors are uncommon. Their presurgical differentiation based on neuroimaging is crucial, since management differs substantially. Comprehensive full assessment of MR dynamic-susceptibility-contrast perfusion-weighted imaging (DSC-PWI) may reveal key differences between entities. This study aims to provide new insights on perfusion patterns of these tumors and to explore the potential of DSC-PWI in their presurgical discrimination. METHODS: Adult patients with a solitary cerebellar tumor on presurgical MR and confirmed histological diagnosis of metastasis, medulloblastoma, hemangioblastoma, or pilocytic astrocytoma were retrospectively retrieved (2008-2023). Volumetric segmentation of tumors and normal-appearing white matter (for normalization) was semi-automatically performed on CE-T1WI and coregistered with DSC-PWI. Mean normalized values per patient tumor-mask of relative cerebral blood volume (rCBV), percentage of signal recovery (PSR), peak height (PH), and normalized time-intensity curves (nTIC) were extracted. Statistical comparisons were done. Then, the dataset was split into training (75%) and test (25%) cohorts and a classifier was created considering nTIC, rCBV, PSR, and PH in the model. RESULTS: Sixty-eight patients (31 metastases, 13 medulloblastomas, 13 hemangioblastomas, and 11 pilocytic astrocytomas) were included. Relevant differences between tumor types' nTICs were demonstrated. Hemangioblastoma showed the highest rCBV and PH, pilocytic astrocytoma the highest PSR. All parameters showed significant differences on the Kruskal-Wallis tests (p < 0.001). The classifier yielded an accuracy of 98% (47/48) in the training and 85% (17/20) in the test sets. CONCLUSIONS: Intra-axial cerebellar tumors in adults have singular and significantly different DSC-PWI signatures. The combination of perfusion metrics through data-analysis rendered excellent accuracies in discriminating these entities. CLINICAL RELEVANCE STATEMENT: In this study, the authors constructed a classifier for the non-invasive imaging presurgical diagnosis of adult intra-axial cerebellar tumors. The resultant tool can be a support for decision-making in the clinical practice and enables optimal personalized patient management. KEY POINTS: • Adult intra-axial cerebellar tumors exhibit specific, singular, and statistically significant different MR dynamic-susceptibility-contrast perfusion-weighted imaging (DSC-PWI) signatures. • Data-analysis, applied to MR DSC-PWI, could provide added value in the presurgical diagnosis of solitary cerebellar metastasis, medulloblastoma, hemangioblastoma, and pilocytic astrocytoma. • A classifier based on DSC-PWI metrics yields excellent accuracy rates and could be used as a support tool for radiologic diagnosis with clinician-friendly displays.

Pearls & Oy-sters: Cognitive and Affective Dysfunction Caused by a Small Cerebellar Hemangioblastoma.

The primary function of the cerebellum is the coordination and regulation of movement; therefore, cerebellar tumors usually present with ataxia, dysarthria, and vertigo. Large tumors also cause elevated intracranial pressure that may lead to a disturbance of consciousness. Furthermore, it has become increasingly evident that the cerebellum plays a substantial role in cognitive and affective processing. A 44-year-old female patient presented with a 1-month history of depression and flat affect. She had no cerebellar symptoms including no coordination dysfunction or dysarthria. Cognitive function tests revealed impairments in attention, execution, and processing speed. Hamilton Depression Scale and Hospital Anxiety Depression Scale indicated moderate-to-severe depression. Magnetic resonance (MR) imaging revealed a 7-mm enhancing lesion in the culmen of the cerebellar vermis with surrounding edema. Technetium-99m ethyl cysteinate dimer single-photon emission tomography (SPECT) showed hypoperfusion in the left frontal lobe. Although she was initially treated with corticosteroids for presumed sero-negative autoimmune encephalitis, her symptoms persisted. She then underwent cerebellar lesion resection. The histologic diagnosis was hemangioblastoma. The patient's symptoms dramatically improved within 1 week of resection, including improved batteries for cognitive function and depression. Complete regression of cerebellar edema and left frontal lobe hypoperfusion was observed on MR and SPECT images, respectively. This case reiterates the crucial influence of the cerebellum on cognitive and affective function. Moreover, cognitive dysfunction may be masked in cases with focal cerebellar symptoms or elevated intracranial pressure and, consequently, not adequately evaluated.

Bruns Nystagmus in Cerebellopontine Angle Hemangioblastoma.

Bruns nystagmus is a form of jerk nystagmus that has a localizing value in cerebellopontine angle (CPA) tumors. Hemangioblastomas involving the CPA is rare. A case of a 57-year-old male presented with Bruns nystagmus which led to the discovery of a large CPA hemangioblastoma is described. The nystagmus was compatible with the laterality of the tumor. High quality video of Bruns nystagmus was recorded.

Neuroanaesthetic challenges in a pregnant patient with a huge cerebellopontine angle meningioma.

Intracranial malignancy among pregnant women is extremely rare. Neuroanaesthesia for such high-risk patients demands extreme precautions. Our patient presented with a huge right cerebellopontine angle meningioma during the first trimester of her pregnancy. We share our valuable perianaesthetic challenges in managing her tumour-debulking surgery and a brief review of intracranial neoplasm during pregnancy.

Concurrent medulloblastoma and cardiac fibroma: a rare presentation of Gorlin-Goltz syndrome.

BACKGROUND: Gorlin-Goltz syndrome is a rare autosomal dominant disorder resulting from PTCH1 gene mutation and presents with variable clinical manifestations. The co-occurrence of medulloblastoma and cardiac fibroma in Gorlin-Goltz syndrome is extremely rare. The present article discusses a patient diagnosed with Gorlin-Goltz syndrome and concurrent medulloblastoma and cardiac fibroma. CASE PRESENTATION: A 19-month-old boy transferred to our hospital after a radiological finding of posterior fossa lesion and hydrocephalus. A pericardial mass was noted after persistent arrhythmias. Both tumors were excised for definitive management. The histopathological sections were diagnostic of desmoplastic nodular medulloblastoma, WHO grade 4 and cardiac fibroma. Molecular and genetic investigations confirmed a pathogenic variant of PTCH1 gene, suggestive of autosomal dominant Gorlin-Goltz syndrome. CONCLUSION: Co-occurrence of medulloblastoma and cardiac fibroma is extremely rare and poses a management dilemma. Genetic counseling and antenatal screening are of utmost importance to early detect and manage patients with Gorlin-Goltz syndrome.

Cerebellar mutism syndrome of non-tumour surgical aetiology-a case report and literature review.

Cerebellar mutism syndrome (CMS) is a well-known complication of posterior fossa (PF) tumour surgery. CMS has previously been reported in cases of non-tumour surgical aetiology in a limited number of publications. We report a case of a 10-year-old girl who suffered a cerebellar haemorrhage and subsequent CMS following surgical treatment of a ruptured arteriovenous malformation (AVM) in the cerebellar vermis. The AVM was removed acutely through a transvermian access, and hydrocephalus was treated with temporary external drainage. In the postoperative period, she suffered diffuse vasospasms of the anterior cerebral circulation and had a permanent shunt placed for hydrocephalus. Her mutism resolved after 45 days but severe ataxia persisted. To our knowledge, this is the first reported case of CMS related to a vermian haemorrhagic stroke with postoperative diffuse vasospasms. Based on this case, we present a literature review on CMS of non-tumour surgical origin in children.

Exceptionally rare IDH1-mutant adult medulloblastoma with concurrent GNAS mutation revealed by in vivo magnetic resonance spectroscopy and deep sequencing.

Medulloblastoma (MB) is the most common malignant brain tumor occurring in childhood and rarely found in adults. Based on transcriptome profile, MB are currently classified into four major molecular groups reflecting a considerable biological heterogeneity: WNT-activated, SHH-activated, group 3 and group 4. Recently, DNA methylation profiling allowed the identification of additional subgroups within the four major molecular groups associated with different clinic-pathological and molecular features. Isocitrate dehydrogenase-1 and 2 (IDH1 and IDH2) mutations have been described in several tumors, including gliomas, while in MB are rarely reported and not routinely investigated. By means of magnetic resonance spectroscopy (MRS), we unequivocally assessed the presence the oncometabolite D-2-hydroxyglutarate (2HG), a marker of IDH1 and IDH2 mutations, in a case of adult MB. Immunophenotypical work-up and methylation profiling assigned the diagnosis of MB, subclass SHH-A, and molecular testing revealed the presence of the non-canonical somatic IDH1(p.R132C) mutation and an additional GNAS mutation, also rarely described in MB. To the best of our knowledge, this is the first reported case of MB simultaneously harboring both mutations. Of note, tumor exhibited a heterogeneous phenotype with a tumor component displaying glial differentiation, with robust GFAP expression, and a component with conventional MB features and selective presence of GNAS mutation, suggesting co-existence of two different major tumor subclones. These findings drew attention to the need for a deeper genetic characterization of MB, in order to get insights into their biology and improve stratification and clinical management of the patients. Moreover, our results underlined the importance of performing MRS for the identification of IDH mutations in non-glial tumors. The use of throughput molecular profiling analysis and advanced medical imaging will certainly increase the frequency with which tumor entities with rare molecular alterations will be identified. Whether these findings have any specific therapeutic implications or prognostic relevance requires further investigations.

MRI features of pediatric atypical teratoid rhabdoid tumors and medulloblastomas of the posterior fossa.

BACKGROUND: Atypical teratoid rhabdoid tumor (AT/RT) occurs at a younger age and is associated with a worse prognosis than medulloblastoma; however, these two tumor entities are mostly indistinguishable on neuroimaging. The aim of our study was to differentiate AT/RT and medulloblastoma based on their clinical and MRI features to enhance treatment planning and outcome prediction. METHODS: From 2005-2021, we retrospectively enrolled 16 patients with histopathologically diagnosed AT/RT and 57 patients with medulloblastoma at our institute. We evaluated their clinical data and MRI findings, including lesion signals, intratumoral morphologies, and peritumoral/distal involvement. RESULTS: The age of children with AT/RT was younger than that of children with medulloblastoma (2.8 ± 4.9 [0-17] vs. 6.5 ± 4.0 [0-18], p < 0.001), and the overall survival rate was lower (21.4% vs. 66.0%, p = 0.005). Regarding lesion signals on MRI, AT/RT had a lower ADCmin (cutoff value ≤544.7 × 10-6  mm2 /s, p < 0.001), a lower ADC ratio (cutoff value ≤0.705, p < 0.001), and a higher DWI ratio (cutoff value ≥1.595, p < 0.001) than medulloblastoma. Regarding intratumoral morphology, the "tumor central vein sign" was mostly exclusive to medulloblastoma (24/57, 42.1%; AT/RT 1/16, 6.3%; p = 0.007). Regarding peritumoral invasion on T2WI, AT/RT was more prone to invasion of the brainstem (p < 0.001) and middle cerebellar peduncle (p < 0.001) than medulloblastoma. CONCLUSIONS: MRI findings of a lower ADC value, more peritumoral invasion, and absence of the "tumor central vein sign" may be helpful to differentiate AT/RT from medulloblastoma. These distinct MRI findings together with the younger age of AT/RT patients may explain the worse outcomes in AT/RT patients.

Resection cavity auto-contouring for patients with pediatric medulloblastoma using only CT information.

PURPOSE: Target delineation for radiation therapy is a time-consuming and complex task. Autocontouring gross tumor volumes (GTVs) has been shown to increase efficiency. However, there is limited literature on post-operative target delineation, particularly for CT-based studies. To this end, we trained a CT-based autocontouring model to contour the post-operative GTV of pediatric patients with medulloblastoma. METHODS: One hundred four retrospective pediatric CT scans were used to train a GTV auto-contouring model. Eighty patients were then preselected for contour visibility, continuity, and location to train an additional model. Each GTV was manually annotated with a visibility score based on the number of slices with a visible GTV (1 = < 25%, 2 = 25-50%, 3 = > 50-75%, and 4 = > 75-100%). Contrast and the contrast-to-noise ratio (CNR) were calculated for the GTV contour with respect to a cropped background image. Both models were tested on the original and pre-selected testing sets. The resulting surface and overlap metrics were calculated comparing the clinical and autocontoured GTVs and the corresponding clinical target volumes (CTVs). RESULTS: Eighty patients were pre-selected to have a continuous GTV within the posterior fossa. Of these, 7, 41, 21, and 11 were visibly scored as 4, 3, 2, and 1, respectively. The contrast and CNR removed an additional 11 and 20 patients from the dataset, respectively. The Dice similarity coefficients (DSC) were 0.61 ± 0.29 and 0.67 ± 0.22 on the models without pre-selected training data and 0.55 ± 13.01 and 0.83 ± 0.17 on the models with pre-selected data, respectively. The DSC on the CTV expansions were 0.90 ± 0.13. CONCLUSION: We successfully automatically contoured continuous GTVs within the posterior fossa on scans that had contrast > ± 10 HU. CT-Based auto-contouring algorithms have potential to positively impact centers with limited MRI access.