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Purpose: Malignant intracranial germ cell tumors (GCTs) are rare diseases in Western countries. They arise in midline structures and diagnosis is often delayed. We evaluated imaging characteristics and early tumor signs of suprasellar and bifocal GCT on MRI. Methods: Patients with the diagnosis of a germinoma or non-germinomatous GCT (NGGCT) who received non-contrast sagittal T1WI on MRI pre-therapy were included. Loss of the posterior pituitary bright spot (PPBS), the expansion and size of the tumor, and the expansion and infiltration of surrounding structures were evaluated. Group comparison for histologies and localizations was performed. Results: A total of 102 GCT patients (median age at diagnosis 12.3 years, range 4.4–33.8; 57 males; 67 in suprasellar localization) were enrolled in the study. In the suprasellar cohort, NGGCTs (n = 20) were noticeably larger than germinomas (n = 47; p <.001). Each tumor showed involvement of the posterior lobe or pituitary stalk. A PPBS loss (total n = 98) was observed for each localization and entity in more than 90% and was related to diabetes insipidus. Osseous infiltration was observed exclusively in suprasellar GCT (significantly more frequent in NGGCT; p =.004). Time between the first MRI and therapy start was significantly longer in the suprasellar cohort (p =.005), with an even greater delay in germinoma compared to NGGCT (p =.002). The longest interval to treatment had circumscribed suprasellar germinomas (median 312 days). Conclusion: A loss of the PPBS is a hint of tumor origin revealing small tumors in the neurohypophysis. Using this sign in children with diabetes insipidus avoids a delay in diagnosis. [ABSTRACT FROM AUTHOR]

This study aimed to re-evaluate the prognostic impact of TP53 mutations and to identify specific chromosomal aberrations as possible prognostic markers in WNT-activated medulloblastoma (WNT-MB). In a cohort of 191 patients with WNT-MBs, mutations in CTNNB1, APC, and TP53 were analyzed by DNA sequencing. Chromosomal copy-number aberrations were assessed by molecular inversion probe technology (MIP), SNP6, or 850k methylation array hybridization. Prognostic impact was evaluated in 120 patients with follow-up data from the HIT2000 medulloblastoma trial or HIT registries. CTNNB1 mutations were present in 92.2%, and APC mutations in 6.8% of samples. One CTNNB1 wild-type tumor gained WNT activation due to homozygous FBXW7 deletion. Monosomy 6 was present in 78.6%, and more frequent in children than adults. 16.1% of tumor samples showed TP53 mutations, of those 60% with nuclear positivity for the p53 protein. Loss of heterozygosity at the TP53 locus (chromosome 17p13.1) was found in 40.7% (11/27) of TP53 mutant tumor samples and in 12.6% of TP53 wild-type cases (13/103). Patients with tumors harboring TP53 mutations showed significant worse progression-free survival (PFS; 5-year-PFS 68% versus 93%, p = 0.001), and were enriched for chromosomes 17p (p = 0.001), 10, and 13 losses. Gains of OTX2 (14q22.3) occurred in 38.9% of samples and were associated with poor PFS and OS (5-year-PFS 72% versus 93%, p = 0.017 resp. 5-year-OS 83% versus 97%, p = 0.006). Multivariable Cox regression analysis for PFS/OS identified both genetic alterations as independent prognostic markers. Our data suggest that patients with WNT-MB carrying TP53 mutations or OTX2 gains (58.1%) are at higher risk of relapse. Eligibility of these patients for therapy de-escalation trials needs to be debated. [ABSTRACT FROM AUTHOR]

Rhabdoid tumors (RT) are rare and highly aggressive pediatric neoplasms. Their epigenetically-driven intertumoral heterogeneity is well described; however, the cellular origin of RT remains an enigma. Here, we establish and characterize different genetically engineered mouse models driven under the control of distinct promoters and being active in early progenitor cell types with diverse embryonic onsets. From all models only Sox2-positive progenitor cells give rise to murine RT. Using single-cell analyses, we identify distinct cells of origin for the SHH and MYC subgroups of RT, rooting in early stages of embryogenesis. Intra- and extracranial MYC tumors harbor common genetic programs and potentially originate from fetal primordial germ cells (PGCs). Using PGC specific Smarcb1 knockout mouse models we validate that MYC RT originate from these progenitor cells. We uncover an epigenetic imbalance in MYC tumors compared to PGCs being sustained by epigenetically-driven subpopulations. Importantly, treatments with the DNA demethylating agent decitabine successfully impair tumor growth in vitro and in vivo. In summary, our work sheds light on the origin of RT and supports the clinical relevance of DNA methyltransferase inhibitors against this disease. Rhabdoid tumors (RT) are aggressive paediatric cancers with yet unknown cells of origin. Here, the authors establish genetically engineered mouse models of RT and, using single-cell RNA-seq and epigenomics, identify potential cells of origin for the SHH and MYC subtypes. [ABSTRACT FROM AUTHOR]

Purpose: Survival in recurrent ependymoma (EPN) depends mainly on the extent of resection achieved. When complete resection is not feasible, chemotherapy is often used to extend progression-free and overall survival. However, no consistent effect of chemotherapy on survival has been found in patients with recurrent EPN. Methods: Systemic chemotherapeutic treatment of 138 patients enrolled in the German HIT-REZ-studies was analyzed. Survival depending on the use of chemotherapy, disease-stabilization rates (RR), duration of response (DOR) and time to progression (TTP) were estimated. Results: Median age at first recurrence was 7.6 years (IQR: 4.0–13.6). At first recurrence, median PFS and OS were 15.3 (CI 13.3–20.0) and 36.9 months (CI 29.7–53.4), respectively. The Hazard Ratio for the use of chemotherapy in local recurrences in a time-dependent Cox-regression analysis was 0.99 (CI 0.74–1.33). Evaluable responses for 140 applied chemotherapies were analyzed, of which sirolimus showed the best RR (50%) and longest median TTP [11.51 (CI 3.98; 14.0) months] in nine patients, with the strongest impact found when sirolimus was used as a monotherapy. Seven patients with progression-free survival > 12 months after subtotal/no-resection facilitated by chemotherapy were found. No definitive survival advantage for any drug in a specific molecularly defined EPN type was found. Conclusion: No survival advantage for the general use of chemotherapy in recurrent EPN was found. In cases with incomplete resection, chemotherapy was able to extend survival in individual cases. Sirolimus showed the best RR, DOR and TTP out of all drugs analyzed and may warrant further investigation. [ABSTRACT FROM AUTHOR]

Introduction: Standardisation of imaging acquisition is essential in facilitating multicentre studies related to childhood CNS tumours. It is important to ensure that the imaging protocol can be adopted by centres with varying imaging capabilities without compromising image quality. Materials and method: An imaging protocol has been developed by the Brain Tumour Imaging Working Group of the European Society for Paediatric Oncology (SIOPE) based on consensus among its members, which consists of neuroradiologists, imaging scientists and paediatric neuro-oncologists. This protocol has been developed to facilitate SIOPE led studies and regularly reviewed by the imaging working group. Results: The protocol consists of essential MRI sequences with imaging parameters for 1.5 and 3 Tesla MRI scanners and a set of optional sequences that can be used in appropriate clinical settings. The protocol also provides guidelines for early post-operative imaging and surveillance imaging. The complementary use of multimodal advanced MRI including diffusion tensor imaging (DTI), MR spectroscopy and perfusion imaging is encouraged, and optional guidance is provided in this publication. Conclusion: The SIOPE brain tumour imaging protocol will enable consistent imaging across multiple centres involved in paediatric CNS tumour studies. [ABSTRACT FROM AUTHOR]

Purpose: The diagnosis of diffuse intrinsic pontine glioma (DIPG) is based largely on a combination of clinical and radiological findings due to the difficulty of obtaining a biopsy. An accurate evaluation of magnetic resonance imaging (MRI) scans is consequently essential. Recent analyses on the genomic landscape of DIPG revealed recurrent mutations in the H3F3A and HIST1H3B histone genes. We reviewed cases with available tumor tissue from institutional DIPG series to ascertain the consistency between their histo-molecular findings and clinical-radiological features. Methods: We conducted a radiological and pathological central review of 22 cases enrolled in institutional DIPG trials. We performed immunohistochemical analyses to detect H3F3A/HIST1H3B K27M mutations, histone trimethylation, and EZH2 expression. Mutational analysis was performed for ACVR1, H3F3A, and HIST1H3B genes. Results: Patients' median age at diagnosis was 8 years, and their median overall survival was 11 months. Nineteen/22 cases (86%) showed evidence of K27M mutation on immunohistochemistry and/or mutation analysis. Histone trimethylation expression was low or lacking in these mutated cases. Sequence analysis revealed 13 cases with H3F3A and 1 case with HIST1H3B K27M mutation. There was no significant difference in EZH2 expression between the K27M mutant and wild-type DIPGs. Upon external, blinded MRI re-evaluation one lesion not consistent with DIPG showed no evidence of K27M mutation and retained histone trimethylation expression. Conclusion: In conclusion, our study demonstrates a high frequency of histone K27M mutations in DIPG when MRI features are carefully assessed, thus confirming the consistency of imaging with biological markers in our institutional series of DIPG. [ABSTRACT FROM AUTHOR]

Purpose: Epigenetic profiling has recently identified clinically and molecularly distinct subgroups of ependymoma. The 2016 World Health Organization (WHO) classification recognized supratentorial ependymomas (ST-EPN) with REL-associated protein/p65 (RELA) fusion as a clinicopathological entity. These tumors represent 70% of pediatric ST-EPN characterized by recurrent C11orf95-RELA fusion transcripts, which lead to pathological activation of the nuclear factor 'kappa-light-chain-enhancer' of activated B-cells (NF-κB) signaling pathway. Cyclin-dependent kinase inhibitor 2A (CDKN2A) inactivation has also been reported to correlate with poor prognosis. Here, we systematically describe magnetic resonance imaging (MRI) characteristics of RELA-fused ST-EPN, with respect to CDKN2A deletion status. Methods: Our cohort of patients with ST-EPN (n = 57) was obtained from the database of the German Brain Tumor Reference Center of the German Society for Neuropathology and Neuroanatomy (DGNN), and tumors were diagnosed according to the 2016 WHO classification. Molecular characterization identified 47 RELA-fused tumors. We analyzed the preoperative MRI according to standardized criteria, and comparison was performed between CDKN2A altered (n = 21) and CDKN2A wild type (n = 26) tumors. Results: The RELA-fused ST-EPN showed a spectrum of predominantly hemispheric tumors with cysts and necrosis. Statistical analysis on CDKN2A status revealed significant differences in terms of younger manifestation age (p =0.002) and more intratumoral hemorrhage in T2-weighted imaging (T2WI) (p =0.010) in wild type tumors; however, the location was not a parameter for differentiation. Conclusion: This study first provides comprehensive MRI data for RELA-fused ST-EPN as a distinct entity, with further interest on CDKN2A genomic status. Patient stratification by morphological MRI alone seems difficult at present. The results may support ongoing research in ST-EPN within the framework of the radiogenomics concept. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Purpose: As the efficacy of all pediatric high-grade glioma (HGG) treatments is similar and still disappointing, it is essential to also investigate the toxicity of available treatments.Methods: Prospectively recorded hematologic and nonhematologic toxicities of children treated with radiochemotherapy in the HIT GBM-C/D and HIT-HGG-2007 trials were compared. Children aged 3-18 years with histologically proven HGG (WHO grade III and IV tumors) or unequivocal radiologic diagnosis of diffuse intrinsic pontine glioma (DIPG) were included in these trials. The HIT-HGG-2007 protocol comprised concomitant radiochemotherapy with temozolomide, while cisplatinum/etoposide (PE) and PE plus ifosfamide (PEI) in combination with weekly vincristine injections were applied during radiochemotherapy in the HIT GBM-C/D protocol.Results: Regular blood counts and information about cellular nadirs were available from 304 patients (leukocytes) and 306 patients (thrombocytes), respectively. Grade 3-4 leukopenia was much more frequent in the HIT GBM-C/D cohort (n = 88, 52%) vs. HIT-HGG-2007 (n = 13, 10%; P <0.001). Grade 3-4 thrombopenia was also more likely in the HIT GBM-C/D cohort (n = 21, 12% vs. n = 3,2%; P <0.001). Grade 3-4 leukopenia appeared more often in children aged 3-7 years (n = 38/85, 45%) than in children aged 8-12 years (n = 39/120, 33%) and 13-18 years (24/100, 24%; P =0.034). In addition, sickness was more frequent in the HIT GBM-C/D cohort (grade 1-2: 44%, grade 3-4: 6% vs. grade 1-2: 28%, grade 3-4: 1%; P <0.001).Conclusion: Radiochemotherapy involving cisplatinum-based polychemotherapy is more toxic than radiotherapy in combination with temozolomide. Without evidence of differences in therapeutic efficacy, the treatment with lower toxicity, i. e., radiotherapy with temozolomide should be used. [ABSTRACT FROM AUTHOR]

Context: Quality of life (QoL) after childhood-onset craniopharyngioma (CP) is frequently impaired due to tumor and/or treatment-related factors such as endocrine deficits and hypothalamic involvement/lesions.Patients and methods: In a multinational trial, we prospectively analyzed parental and self-assessment of CP patient QoL at 3 months, 1 and 3 years after CP diagnosis related to growth hormone (GH) substitution. 47 of 194 CP recruited between 2007 and 2015 in KRANIOPHARYNGEOM 2007 were analyzed for QoL 1 and 3 years after CP diagnosis. QoL was assessed by Pediatric Quality of Life (PEDQOL) questionnaire and PEDQOL scores of parental and self-assessed QoL during 3 years follow-up after CP diagnosis were analyzed.Results: Parents estimated QoL of their children worse than patients did themselves. GH substitution had no relevant effect on short-term weight and height development. CP patients GH-treated at 3 years follow-up presented at baseline (1 year after diagnosis, before GH substitution) with reduced self-assessed QoL when compared with GH non-treated CP. QoL stabilized during 1–3 years of follow-up in GH-treated patients, whereas non GH-treated patients experienced decreases in autonomy (p = 0.03), cognition (p = 0.01), and physical function (p = 0.04).Conclusions: Parents assess QoL in CP survivors worse than their children. GH substitution should be considered as a therapeutic option to ameliorate imminent impairments of QoL after CP. [ABSTRACT FROM AUTHOR]

Purpose: High messenger RNA (mRNA) expression of the tropomyosin receptor kinase C gene ( TrkC) has been associated with favorable survival in medulloblastoma patients. Untested is whether it plays a role through modulating the response to therapy or whether it might be a surrogate marker for a favorable molecular subgroup. Methods: The medulloblastoma-derived cell line DAOY was stably transfected to overexpress TrkC (clone DAOY-TrkC) and compared to a control (clone DAOY-EV, empty vector transfected). Cell viability (MTS assay) was tested after irradiation or incubation with chemotherapeutic drugs. Neuroradiologic response to postoperative chemotherapy or craniospinal irradiation (CSI) of medulloblastoma patients aged 3-21 years with postoperative residual disease treated within the consecutive trials HIT'91/HIT2000 was compared to TrkC mRNA expression in their tumor samples. Five well-characterized independent expression-profiling studies covering together 686 medulloblastoma patients were analyzed for TrkC levels according to the molecular subgroups. Results: Cell viability of DAOY-TrkC compared to DAOY-EV was not different after exposure to increasing doses of irradiation, cisplatin, etoposide, or vincristine. While TrkC mRNA expression tended to be higher in non-responders ( n = 5/19) to postoperative CSI ( p = 0.03, ratio 15.5, 95% CI 9-267), this was the case in responders ( n = 23/43) to chemotherapy ( p = 0.04, ratio 6.1, 95% CI 1.1-35), both analyzed with Mann-Whitney U test (not significant after Bonferroni adjustment). The highest TrkC mRNA levels were found in the SHH subgroup across all expression-profiling studies. Conclusions: High TrkC mRNA expression appears to be frequent in the SHH subgroup and seems not to have a major effect on therapy responsiveness in medulloblastoma patients. [ABSTRACT FROM AUTHOR]

Diffuse intrinsic pontine glioma (DIPG) is a rare and deadly childhood malignancy. After 40 years of mostly single-center, often non-randomized trials with variable patient inclusions, there has been no improvement in survival. It is therefore time for international collaboration in DIPG research, to provide new hope for children, parents and medical professionals fighting DIPG. In a first step towards collaboration, in 2011, a network of biologists and clinicians working in the field of DIPG was established within the European Society for Paediatric Oncology (SIOPE) Brain Tumour Group: the SIOPE DIPG Network. By bringing together biomedical professionals and parents as patient representatives, several collaborative DIPG-related projects have been realized. With help from experts in the fields of information technology, and legal advisors, an international, web-based comprehensive database was developed, The SIOPE DIPG Registry and Imaging Repository, to centrally collect data of DIPG patients. As for April 2016, clinical data as well as MR-scans of 694 patients have been entered into the SIOPE DIPG Registry/Imaging Repository. The median progression free survival is 6.0 months (95% Confidence Interval (CI) 5.6-6.4 months) and the median overall survival is 11.0 months (95% CI 10.5-11.5 months). At two and five years post-diagnosis, 10 and 2% of patients are alive, respectively. The establishment of the SIOPE DIPG Network and SIOPE DIPG Registry means a paradigm shift towards collaborative research into DIPG. This is seen as an essential first step towards understanding the disease, improving care and (ultimately) cure for children with DIPG. [ABSTRACT FROM AUTHOR]

The HIT-SIOP-PNET4 randomised trial for standard risk medulloblastoma (MB) (2001-2006) included 338 patients and compared hyperfractionated and conventional radiotherapy. We here report the long-term outcome after a median follow up of 7.8 years, including detailed information on relapse and the treatment of relapse. Data were extracted from the HIT Group Relapsed MB database and by way of a specific case report form. The event-free and overall (OS) survival at 10 years were 76 ± 2 % and 78 ± 2 % respectively with no significant difference between the treatment arms. Seventy-two relapses and three second malignant neoplasms were reported. Thirteen relapses (18 %) were isolated local relapses in the posterior fossa (PF) and 59 (82 %) were craniospinal, metastatic relapses (isolated or multiple) with or without concurrent PF disease. Isolated PF relapse vs all other relapses occurred at mean/median of 38/35 and 28/26 months respectively (p = 0.24). Late relapse, i.e. >5 years from diagnosis, occurred in six patients (8 %). Relapse treatment consisted of combinations of surgery (25 %), focal radiotherapy (RT 22 %), high dose chemotherapy with stem cell rescue (HDSCR 21 %) and conventional chemotherapy (90 %). OS at 5 years after relapse was 6.0 ± 4 %. In multivariate analysis; isolated relapse in PF, and surgery were significantly associated with prolonged survival whereas RT and HDSCR were not. Survival after relapse was not related to biological factors and was very poor despite several patients receiving intensive treatments. Exploration of new drugs is warranted, preferably based on tumour biology from biopsy of the relapsed tumour. [ABSTRACT FROM AUTHOR]

Purpose: Fusiform dilatations of the internal carotid artery (FDCA) represent a vascular complication following surgery for suprasellar tumors in children. Incidence rate and long-term prognosis of FDCA in terms of survival rates, vascular complications, and quality of survival are unknown for patients with childhood-onset craniopharyngioma. Methods: Magnetic resonance imaging (MRI) results of 583 patients with childhood-onset craniopharyngioma, recruited from 2001 to 2015 in the German Childhood Craniopharyngioma Registry, were reviewed for FDCA. Risk factors for FDCA and long-term outcome after FDCA were analyzed. Results: Fourteen of 583 patients (2.4 %) developed FDCA based on reference assessment of MRI. FDCA occurred ipsilateral to the surgical approach and was not related to degree of resection, hypothalamic involvement, or irradiation. The median time interval between first detection of FDCA and initial surgery was 0.79 years (range 0.01-5.56 years). During a median follow-up of 6.47 years (range 1.2-21.9 years) after first detection of FDCA, no bleeding or cerebrovascular events were observed in any patient. Irradiation was not related to FDCA. Survival rates and functional capacity were similar in patients with and without FDCA. Clinically the FDCA was unapparent in all cases and not treated. Conclusion: FDCA is a rare complication related to surgical treatment of childhood-onset craniopharyngioma without major impact on prognosis and clinical course of the disease. Clinical trial number: KRANIOPHARYNGEOM 2000-NCT00258453; KRANIOPHARYNGEOM 2007-NCT01272622. [ABSTRACT FROM AUTHOR]

Introduction: Pilomyxoid astrocytoma (PMA) is a rare WHO grade II tumor occurring most often in young children. PMA is associated with worse outcome as compared to the pathologically related pilocytic astrocytoma (PA). The radiological differentiation of PMAs from PAs is challenging. Furthermore, it is not completely clarified whether PMA is associated with a higher rate of cerebrospinal fluid (CSF) dissemination in the youngest pediatric population as compared to PA. The aim of our study was firstly to compare imaging features of these tumors and, secondly, to evaluate the occurrence of CSF dissemination. Methods: The study population included 15 children with PMA and 32 children with PA. The initial MRI and CT scans from the time of the diagnosis were retrospectively analyzed according to standardized criteria and the findings compared between the two tumor types. Furthermore, we also compared the occurrence of imaging evidences of CSF dissemination. Results: PMAs showed less frequently cystic components ( p = 0.03) and never had large tumor cysts. Gadolinium enhancement of PMAs was more frequently homogeneous ( p = 0.006). PMAs appeared to show more often intratumoral hemorrhages ( p = 0.047). Within the subgroup of children <6 years of age, the PMA histology tended to have a larger effect on the occurrence of CSF dissemination than the age ( p = 0.05 vs. 0.12). Conclusion: Some imaging features like enhancement pattern or presence of cysts or hemorrhage may help differentiating these low-grade gliomas. Our results confirm previous scarce data suggesting a higher rate of CSF dissemination in PMAs, even in the youngest patient population. [ABSTRACT FROM AUTHOR]

Correction to: Child's Nervous System https://doi.org/10.1007/s00381-021-05199-4 The original version of this article unfortunately contained an error. The original article can be found online at https://doi.org/10.1007/s00381-021-05199-4. [Extracted from the article]

Radiotherapy is the only treatment definitely indicated for diffuse pontine gliomas (DIPG). Findings on the role of EGFR signaling in the onset of childhood DIPG prompted the use of nimotuzumab, an anti-EGFR monoclonal antibody. Assuming a potential synergy with both radiotherapy and vinorelbine, a pilot phase 2 protocol was launched that combined nimotuzumab with concomitant radiation and vinorelbine. An amendment in July 2011 introduced re-irradiation at relapse. The primary endpoint for first-line treatment was objective response rate (CR + PR + SD) according to the RECIST. This report concerns the outcome of this strategy as a whole. Vinorelbine 20 mg/m was administered weekly, with nimotuzumab 150 mg/m in the first 12 weeks of treatment; radiotherapy was delivered from weeks 3 to 9, for a total dose of 54 Gy. Vinorelbine 25 mg/m and nimotuzumab were given every other week thereafter until the tumor progressed or for up to 2 years. Re-irradiation consisted of 19.8 Gy, fractionated over 11 days. Baseline and latest MRIs were assessed blindly by an outside neuroradiologist. Twenty five children (mean age 7.4 years) were enrolled as of August 2009 (median follow-up 29 months). A response was observed in 24/25 patients (96 %). The nimotuzumab/vinorelbine combination was very well tolerated, with no acute side-effects. Eleven of 16 locally-relapsing patients were re-irradiated. One-year PFS and OS rates were 30 ± 10 % and 76 ± 9 %, respectively; 2-year OS was 27 ± 9 %; the median PFS and OS were 8.5 and 15 months, respectively. This strategy generated interesting results and warrants further investigation. [ABSTRACT FROM AUTHOR]

Hypertrophic olivary degeneration (HOD) is a rare transsynaptic form of degeneration occurring secondary to the disruption of the dentato-rubro-olivary pathway ('Guillain-Mollaret triangle'). HOD can be caused by ischemic, hemorrhagic, traumatic, or neoplastic lesions, and it can also occur following posterior fossa surgery. MRI characteristics of HOD include T2 signal increase and hypertrophy. To date, blood-brain barrier disruption has not been reported in HOD. Here, we present the first case of HOD with temporary gadolinium enhancement in a 10-year-old child 7 months after resection of a posterior fossa medulloblastoma. The recognition of gadolinium enhancement as a radiological feature of HOD may help to distinguish between this benign secondary condition and tumor recurrence. [ABSTRACT FROM AUTHOR]

Central nervous system primitive neuroectodermal tumors (CNS-PNET) and pineoblastomas (PBL) are rare in adulthood. Knowledge on clinical outcome and the efficacy and toxicities of chemotherapy in addition to radiotherapy is limited. Patients older than 21 years at diagnosis were followed in the observational arm of the prospective pediatric multicenter trial HIT 2000. After surgery, craniospinal irradiation and maintenance or sandwich chemotherapy were recommended. Radiotherapy was normo- (35.2 Gy; tumor region, 55.0 Gy; metastasis, 49.6 Gy) or hyperfractionated (40.0 Gy; tumor bed, 68.0 Gy; metastasis, 50-60 Gy). Maintenance chemotherapy consisted of eight courses (vincristine, lomustine, cisplatin). Sandwich chemotherapy included two cycles of postoperative chemotherapy followed by radiotherapy, and four courses of maintenance chemotherapy. Seventeen patients (CNS-PNET, n = 7; PBL, n = 10), median age 30 years, were included. Eight patients had a postoperative residual tumor and four patients metastatic disease. The median follow-up of ten surviving patients was 41 months. The estimated rates for 3-year progression-free survival (PFS) and overall survival were 68 ± 12 and 66 ± 13 %, respectively. PBL compared to CNS-PNET tended towards a better PFS, although the difference was not clear ( p = 0.101). Both chemotherapeutic (maintenance, n = 6; sandwich, n = 8) protocols did not differ in their PFS and were feasible with acceptable toxicities. Intensified regimens of combined chemo- and radiotherapy are generally feasible in adults with CNS-PNET/PBL. The impact of intensified chemotherapy on survival should be further assessed. [ABSTRACT FROM AUTHOR]

Introduction: With the increasing use of neuroimaging studies, the discovery of incidental neoplastic lesions is becoming more frequent. However, standard procedures are lacking, and little is known about their optimal management. Case Report: We here present the case of a boy with a cerebellar mass incidentally discovered on a CT scan performed after head trauma. In another scan performed after another incident of head trauma 14 months earlier, the lesion could be seen after retrospective examination. In view of the asymptomatic clinical and stable radiological status and the presumed diagnosis of a low-grade glioma, a watch-and-wait strategy was elected. After clinical and radiological progression was observed, the tumour was resected, 2½ years after the initial imaging study. Histological evaluation revealed a WNT pathway-activated classical medulloblastoma. Discussion: To our knowledge, this is the first description of such a long natural history and pre-symptomatic period of a medulloblastoma. The long period of stability followed by a period of accelerated tumour growth is compatible with increasing biological aggressiveness, possibly related to the stepwise accumulation of genetic changes. [ABSTRACT FROM AUTHOR]

Medulloblastoma is a malignant brain tumor of childhood that comprises at least four molecularly distinct subgroups. We have previously described that cerebellar granule neuron precursors may give rise to the subgroup with a molecular fingerprint of Sonic hedgehog (Shh) signaling. Other recent data indicate that precursor cells within the dorsal brain stem may serve as cellular origins for Wnt-associated medulloblastomas. To see whether Shh-associated medulloblastomas are also able to develop in the dorsal brainstem, we analyzed two lines of transgenic mice with constitutive Shh signaling in hGFAP- and Math1-positive brainstem precursor populations, respectively. Our results show that in both of these lines, medulloblastomas arise from granule neuron precursors of the cochlear nuclei, a derivative of the auditory lower rhombic lip. This region is distinct from derivatives of precerebellar lower rhombic lip where medulloblastomas arise in mice with constitutive-active Wnt signaling. With respect to their histology and the expression of appropriate markers, Shh tumors from the murine cochlear nuclei perfectly resemble human Shh-associated medulloblastomas. Moreover, we find that in a series of 63 human desmoplastic medulloblastomas, 21 (33%) have a very close contact to the cochlear nuclei on MR imaging. In conclusion, we demonstrate that precursors of the murine rhombic lip, which either develop into cerebellar or into cochlear granule neurons, may give rise to Shh-associated medulloblastoma, and this has important implications for the cellular origin of human medulloblastomas. [ABSTRACT FROM AUTHOR]

Little is known about pediatric spinal cord high grade gliomas (SCHGG) beyond their dismal prognosis. Here, we analyzed the HIT-GBM database for the influence of surgical resection on survival. Between 1991 and 2010 the HIT-GBM group collected data from European children diagnosed with high grade glioma. Patients with the following inclusion criteria were analyzed in this study: astrocytic histology, WHO grade III or IV, age at diagnosis <18 years, and tumor localized to the spinal cord. 28 patients (mean age 11.28 years, 14 male) with primary SCHGG were identified. The tumor sizes were measured by the span across adjacent vertebrae and varied greatly (range: 1-20, median: 4). Histology was classified as WHO grade III in 15 and grade IV in 13 tumors. Of note, the four largest tumors identified were WHO grade III. Surgery was classified as complete resection ( n = 6), subtotal resection (STR) ( n = 7), partial resection ( n = 12) or biopsy only ( n = 3). 27 patients received chemotherapy, 22 of which also received radiation. With the mean follow-up time of 2.88 (SD ± 2.95) years, 14 patients were still alive resulting in a median overall survival of 2.5 years (SE ± 1.6). The positive prognostic indicators for overall survival were: age younger than 5 years ( P = 0.047), WHO grade III ( P = 0.046), absence of necrosis ( P = 0.025) and gross total resection (GTR) ( P = 0.012). The prognosis of SCHGG might not be as miserable as generally assumed. GTR is of benefit. Larger data sets and meta-analysis are necessary to identify patient sub-groups. [ABSTRACT FROM AUTHOR]

Introduction: The current SIOP (International Society for Paediatric Oncology)-LGG (low grade glioma) study protocol allows chiasmatic tumours identified as LGG on the basis of neuroradiological characteristics to be treated without histological verification. As some tumours do not respond well to treatment, the search for molecular tissue markers will gain importance for future studies. Anecdotal observations of infarctions after surgery for chiasmatic tumours during central reviewing initiated this study. Materials and methods: In 84 patients, histology was obtained during 102 interventions in the years 1992-2009 by 33 biopsies, 67 partial/subtotal and 2 total resections. Median age at the time of operation was 5 years (mean 5 years 11 months). We could identify 17 infarctions following partial resection of chiasmatic LGG. Biopsies were not complicated by infarction. Children developing infarction were considerably younger (median 3 years; mean 4 years 5 months) than the patients without infarction (median 5 years 4 months; mean 6 years 2 months). A total of 51 patients with cerebellar LGG (median 7 years; mean 7 years 4 months) served as a control group, with 65 surgical procedures (2 biopsies, 22 partial/subtotal resections and 41 total resections) performed in the years 2004-2009. Only one total resection (1.5%) in this group was followed by infarction. Conclusion: Partial/subtotal resections of chiasmatic LGG in our study population bear a considerable risk for infarction especially in young children. As there is currently no evidence for a better outcome after tumour resection, we suggest that the sampling of tumour tissue should be performed via biopsies whenever possible. [ABSTRACT FROM AUTHOR]

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Introduction: Pineal parenchymal tumor of intermediate differentiation (PPTID) was recognized in the 2007 World Health Organization (WHO) classification as a new pineal parenchymal neoplasm, intermediate in malignancy (WHO grade II or III) between pineocytoma (grade I) and pineoblastoma (grade IV). The imaging spectrum of this new tumor has not been previously delineated. We describe the imaging spectrum in 11 pathologically proven PPTIDs and identify findings that may suggest the preoperative diagnosis of this newly recognized entity. Methods: Electronic medical records over the last 9 years and teaching files between the years 1985 and 1995 were searched for atypical pineal lesions. Additional cases were added from the teaching files of contributing authors. Results: Imaging studies in nine patients (9/11) showed bulky, aggressive pineal region masses with local brain invasion; two patients (2/11) demonstrated circumscribed pineal masses. Two patients had spinal metastases at presentation. On computed tomography (CT), five patients had classic 'exploded' calcifications characteristic of pineal parenchymal tumors. All tumors were heterogeneously hypointense on T1WIs and heterogeneously hyperintense on T2WIs. Post-contrast scans showed marked heterogeneous (10/11) or uniform (1/11) enhancement. Cystic foci were identified in eight cases. Intratumoral hemorrhage was present in one case. Conclusion: While no singular neuroimaging feature is pathognomonic of PPTID, these tumors are usually larger, demonstrate local invasion, and appear much more heterogeneous than pineocytoma. Because PPTIDs have a higher grade and increased potential for recurrence as compared to pineocytomas, it is important to consider this diagnosis as shorter follow-up, and adjuvant therapy may be indicated in selected cases. [ABSTRACT FROM AUTHOR]

Approximately 30-50% of patients with intracranial primitive neuroectodermal tumors (PNETs) of the central nervous system (CNS) develop spinal metastases. In contrast, primary spinal CNS-PNETs are extremely uncommon. The database and study records of the German/Austrian brain tumor trials HIT 91, HIT SKK 92, and HIT 2000 were retrospectively reviewed to describe clinical features, treatment modalities, and outcome of children with primary CNS-PNETs of the spinal cord who were registered as observational patients. Out of 1,248 patients with medulloblastomas or CNS-PNETs registered in the HIT database four patients (female, n = 3) with primary CNS-PNETs of the spinal cord were identified. Age at diagnosis was 10, 16, 23, and 174 months. Location of primary tumors was medulla oblongata-T3, C2-T1, T10-L2, T7-T10. Two patients had metastatic disease at diagnosis. Complete and incomplete resection was performed in one patient each, whereas two patients underwent a biopsy only. Two patients received chemotherapy only, in accordance with the HIT 91 trial (sandwich chemotherapy arm). They developed disease progression and died six months after diagnosis. One patient was given chemotherapy in accordance with the HIT 2000 trial followed by craniospinal radiotherapy and four courses of maintenance chemotherapy. The patient is in complete remission almost four years after diagnosis. The fourth patient developed disease progression while receiving induction chemotherapy. Hence, chemotherapy was switched to a modified Head Start protocol. After three cycles he underwent double autologous stem cell transplantation and craniospinal irradiation. Forty months after diagnosis the patient is alive and well, but surveillance MRIs still show nodular enhancing lesions in the area of the primary tumor and intracranial meningeal enhancement. Primary CNS-PNETs of the spinal cord probably require multimodal treatment including radiotherapy to achieve sustained tumor control. [ABSTRACT FROM AUTHOR]

Thirty-eight consecutive children treated according to the HIT2000 and HIT91 studies for medulloblastoma who suffered 40 recurrence events were identified from a neuroradiological database. Relapse was associated with younger median age compared with all children treated on HIT2000. Eight patients relapsed with isolated local recurrence. There was no correlation with incomplete surgical removal or violation of the respective treatment protocol. Four patients were younger than 4 years at time of initial presentation and thus were not treated primarily with radiotherapy, suggesting that delayed radiotherapy might be a contributing factor. Meningeal dissemination was present in 32 events; 16 were located in the frontal region, 8 of which were isolated nodular frontal and frontobasal meningeal disease. Circumscribed meningeal recurrences were associated with better overall survival (OS) compared with diffuse, widespread recurrences. Isolated frontobasal meningeal relapses are a well-known phenomenon in medulloblastomas even years after treatment and have been correlated to an underdose of radiation in many literature reports. However, in our patients there was no correlation to possible treatment violations, indicating that inadequate radiation dose to the frontobasal region was unlikely to be a causative factor. Surgical technique varied due to the multicentric nature of our study, so position during surgery was not recognized as a predisposing factor for frontobasal recurrence. [ABSTRACT FROM AUTHOR]

We conducted a phase II study to test methotrexate (5 g/m), as a single agent prior to radiochemotherapy for pediatric high-grade glioma and diffuse intrinsic pontine glioma. Thirty patients (19 male, median age 10.8) were enrolled. Tumors were located as follows: cortex 10, pons 7, other 13. Tumor resection was classified as gross total in 6, subtotal in 6, partial in 4, biopsy in 11 and not performed in 3. WHO grading of the histology was: IV: 11, III: 12 and II: 3. Patients received methotrexate 5 g/m in 24-hour infusions on days 1 and 15. Subsequently 54 Gy radiation was administered with simultaneous chemotherapy including cisplatin, etoposide, vincristine and ifosfamide as previously described. Eight 6-weeks cycles of maintenance chemotherapy consisted of vincristine 1.5 mg/m on days 1, 8 and 15; lomustine 100 mg/m on day 2 and prednisone 40 mg/kg on days 1-17. Event-free survival rates in the whole group of 30 patients were: 43, 20, and 13% after 1, 2 and 5 years, respectively. The response evaluation after methotrexate was available in 19 of the 24 patients who started treatment with measurable disease: CR: 0, PR: 1, SD 18, PD: 0. After radiochemotherapy the response of 24 patients with measurable disease was CR: 1, PR 10, SD 12, PD 1. Both response and event-free survival were superior to the control group of 330 patients treated in various protocols of the same cooperative group. In subgroup analyses the use of dexamethasone during early treatment was linked to poor event free survival. Giving two cycles of high-dose methotrexate prior to radiochemotherapy was feasible, and the approach was taken forward to a randomized phase III trial. [ABSTRACT FROM AUTHOR]

Ependymoblastoma is a rare malignant brain tumor of early childhood. Data on clinical behavior and optimal treatment strategies are scarce. We report on 11 consecutively treated children with centrally confirmed diagnosis of CNS ependymoblastoma, registered between February 1994 and October 2006 to the prospective GPOH-HIT multicenter brain tumor trials, and treated by multimodal regimens. Median age at diagnosis was 3.5 years (range, 1.8-5.6 years), and the median follow-up of survivors was 5.9 years (range, 2.2-12.7 years). Initial stage was M0 in 9, and M0/1 (no cerebrospinal fluid examination done) in 2 patients. Gross-total tumor resection was achieved in 7 patients, incomplete resection in 4 patients. Further primary therapy included chemotherapy in all patients, craniospinal radiotherapy in 5 patients and high-dose chemotherapy in 2 patients. Tumor response to chemotherapy was observed in 1 of 4 evaluable patients. Tumor progression occurred in 7 patients after a median time of 5.0 months (range, 2.5-19.2 months). Five-year progression-free survival was 36.4% (±14.5%), 5-year overall survival 30.3% (±15.9%). Of 4 survivors, 3 had gross-total tumor resection, and all were treated by either craniospinal radiotherapy and/or high-dose chemotherapy with autologous blood stem cell rescue. Prognosis of children with ependymoblastoma is poor, but sustained remissions have been achieved after multimodal treatment. Considerable diagnostic discrepancies between local and central pathologists underscore the importance of central review. Further studies are needed to improve survival of children with this rare malignant central nervous system tumor. [ABSTRACT FROM AUTHOR]

Pediatric neurofibromatosis type 1 (NF-1) patients are prone to developing low-grade glioma (LGG). The HIT-LGG study 1996 aimed to observe the natural history of pediatric LGG and to postpone irradiation in younger children by using carboplatinum and vincristine in case non-surgical treatment was required. A total of 109 of 1,044 (10.4%) protocol patients had a genetic NF-1 trait [57 female patients; median age 5.1 years (range 1-15.4 years)]. Eighty-three patients (76%) suffered from an optic pathway tumor. Neuroimaging only allowed diagnosis in 67 patients. Histology revealed pilocytic astrocytoma WHO grade I in 38 of 42 biopsied patients. Sixty-five (60%) patients received non-surgical treatment, either chemotherapy ( n = 55) or irradiation ( n = 10). The overall survival rate of 96% after a median observation time of 5.25 years contrasts with an event free survival rate (EFS) of 0.24 at 5 years. Progressive LGG were observed even in children older than 11 years. Chiasmatic/postchiasmatic localization was a univariate risk factor for progressive disease. In the chemotherapy group, we observed a 5-year progression-free survival (PFS) rate of 0.73. Similarly, the PFS rate in the irradiation group was 0.78. Multivariate analysis revealed surgical intervention and localization within the optic pathway as factors that increased the risk of tumor progression. In this large prospective multinational study, LGG in NF-1 patients did progress in 75% of patients. Chemotherapy yielded acceptable PFS. The biological factors determining progression remain poorly understood. [ABSTRACT FROM AUTHOR]

The article presents a study related to the evidence of Histone 3 (H3) K27M mutations in diffuse midline gliomas, including high-grade astrocytomas and diffuse intrinsic pontine gliomas (DIPG). It mentions that these mutations are associated with alterations in the epigenetic profile of tumor cells. It states that despite of the presence of H3K27M mutation as detected by immunohistochemistry or sequencing remains a strong argument for the diagnosis of a diffuse midline glioma.

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Atypical teratoid/rhabdoid tumors (ATRT) are rare aggressive neoplasms of the CNS affecting predominantly very young children. We retrospectively reviewed the imaging findings of 9 CT and 32 MR examinations of the brain and spine of 33 children. Of the 33 tumors, 11 were located in the infratentorial compartment, 16 in the supratentorial compartment, 5 in both cranial compartments, and 1 in the lower thoracic spinal cord. The mean age of the children with infratentorial or infra- and supratentorial tumors was significantly lower than the mean age of the children with purely supratentorial tumors. Heterogeneity on imaging, large size and high tumor stages are striking features reflecting the aggressive nature of this histopathological entity. Although not present in the majority of children, a distinct and unusual pattern of a wavy band-like enhancement surrounding a central hypointensity was present in 12 of 32 children (38%) in whom contrast medium was used. To the best of our knowledge this is the largest number of imaging examinations of ATRTs so far reported. A rather unusual pattern of contrast enhancement may be typical of ATRTs. [ABSTRACT FROM AUTHOR]

AbstractObjective??To analyze the outcome of children with pineoblastoma (PB), treated within the prospective multicenter trials HIT-SKK87, HIT-SKK92 and HIT91 of German-speaking countries.Patients??We report on 11 children suffering from PB. Five children younger than 3?years of age received chemotherapy after surgery until eligible for radiotherapy (HIT-SKK87 and HIT-SKK92). Five of six children older than 3?years were treated after surgery with immediate chemotherapy and craniospinal irradiation, and one child received maintenance chemotherapy after postoperative radiotherapy (HIT91).Results??Five of the six older children are still alive in continuous complete remission (CCR) with a median overall survival (OS) and progression free survival (PFS) of 7.9?years. Five of these six HIT91 patients responded to postoperative chemotherapy and radiotherapy. The only patient with tumor progression during initial chemotherapy achieved complete remission with radiotherapy and is alive. In contrast, all five young children died of tumor progression after a median OS of 0.9?years (PFS 0.6?years). They had either metastatic disease (M1) and/or postoperative residual tumor. Response to postoperative chemotherapy was lower than in the older age group, and only one of these children received radiotherapy.Conclusions??Combined chemotherapy and radiotherapy were feasible and effective in the older age group, leading to prolonged remissions in five of six children. Tumor biology may be more aggressive in younger children with PB, who presented more frequently with high-risk features at diagnosis and had poorer response rates to neoadjuvant postoperative chemotherapy. More intensified treatment regimens may be needed for young children with PB. [ABSTRACT FROM AUTHOR]

Summary

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Context:. Brain atrophy is an indicator of diffuse brain pathology that appears even in the early stages of multiple sclerosis (MS). Magnetic resonance imaging (MRI) techniques used in clinical trials suggest a correlation between ventricular enlargement and axonal pathology and clinical disability in MS. Objective:. To evaluate by transcranial sonography (TCS) and MRI ventricular diameters in order to assess prospectively the development of brain atrophy in MS. Setting:. MS outpatient clinic of a university hospital. Patients and Methods:. 38 MS patients (27 females, 11 males) were followed up for 2 years. Ventricular diameters (third ventricle, right and left lateral ventricle) were determined by TCS at baseline, 12 and 24 months and correlated with clinical disability (Expanded Disability Status Scale, EDSS), and the Multiple Sclerosis Functional Composite Score (MSFC). MRI was performed at study entry and after two years. Main outcome measure:. Correlation of ventricular diameters measured by TCS and MRI with assessment of clinical disability in MS patients at baseline and after two years. Results:. TCS and MRI measurements especially of third ventricle diameter matched closely at study entry and after two years (r = 0.9; p < 0.0001). At all time points the width of the third ventricle was significantly correlated with clinical disability (EDSS: r = 0.6, p < 0.01; MSFC: r = –0.6, p < 0.02). In the follow-up over 2 years there was an increase of the width of the third ventricle in comparison with study entry (p < 0.002). Increase of third ventricular width at study entry was associated with higher EDSS levels after 2 years (p = 0.01). Conclusion:. Assessment of ventricular diameters by TCS is a reliable tool with which to monitor brain atrophy in the longitudinal follow-up of MS patients. Because TCS is a simple, inexpensive, non-invasive and generally available bedside-test it may be used in clinical practice as well as in therapeutic trials to assess brain atrophy. [ABSTRACT FROM AUTHOR]

Unlabelled: We report a 7-year-old boy with the typical features of encephalocraniocutaneous lipomatosis (ECCL) including unilateral skin, eye, bone, and asymptomatic central nervous system involvement. The presenting sign were numerous ipsilateral odontomas which have been described in only two previous patients so far. We reviewed all 32 cases reported to date and focus on the dermatological hallmark of the condition, namely a fatty tissue naevus of the scalp for which the term naevus psiloliparus was recently coined. Sporadic occurrence, patchy type of organ involvement and roughly balanced sex ratio in ECCL are compatible with the concept of a lethal autosomal mutation only surviving in a mosaic state.Conclusion: In children presenting with a congenital smooth hairless lesion on the scalp, the diagnosis of naevus psiloliparus should be considered and other signs of encephalocraniocutaneous lipomatosis should be looked for. [ABSTRACT FROM AUTHOR]

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The surgical resection of medulloblastoma (MB), the most frequent malignant brain tumor in children, often remains subtotal. To estimate the response to further treatment the residual tumor is monitored by CT or MRI. The interpretation of both imaging techniques is complicated by disturbances resulting from surgery and radiation. Our study searched for alternative imaging techniques and asked the following questions. 1) Do MB express somatostatin receptors (SSTR), 2) is SSTR scintigraphy a sensitive imaging technique for the follow-up and the detection of vital tumor tissue in children with MB, and 3) do the results of SSTR scintigraphy correlate with the in vitro analysis of MB tissue by SSTR autoradiography. We analyzed the SSTR status in 20 children with MB, aged 1 to 15 years. Sixteen SSTR scintigraphies using Indium-111-DTPA-D-Phel-pentetreotide were performed in 14 children. MB tissue of 14 children was analyzed by SSTR autoradiography using Iodine-125-Tyr3-octreotide. In 8 cases SSTR were measured by both methods in vivo and in vitro. In comparison with conventional imaging, results of SSTR scintigraphy were true positive in 7 of 7 patients, true negative in 9 of 9 patients, including one patient with false positive findings in MRI, false negative in only one patient with small spinal metastases (diameter < 3 mm) and false positive in none of the analyzed patients. In all cases with residual tumor (n = 3) and suspected relapse (n = 4) the diagnosis could be confirmed (n = 4) or excluded (n = 3), consistent with the results of MRI and tumor histology. All MB tissues analyzed by SSTR autoradiography (n = 14) showed an extremely high density of SSTR ranging from 4047 to 15526 dpm/mg MB tissue. MB (n = 8) which were analyzed by SSTR scintigraphy and autoradiography demonstrated consistent results in evaluation by both methods. In cases where the integrity of the blood-brain barrier was tested by Tc-99m-DTPA scintigraphy (n = 10), the SSTR-to-brain scintigraphy index confirmed the tumor specificity of radionuclide uptake. We conclude that 1) MB tissue expresses a particularly high density of SSTR, 2) the high density of SSTR in autoradiography correlates with a sensitive imaging of these tumors by SSTR scintigraphy, 3) SSTR scintigraphy might be a valuable imaging method for detection of vital MB tissue in patients with residual tumor or relapse. [ABSTRACT FROM AUTHOR]

A letter to the editor on medulloblastoma (MB) in malignant pediatric brain tumors is presented.