Background A previous study based on Norwegian Cancer Registry data suggested regional differences in overall survival (OS) after treatment for medulloblastoma (MB) and supratentorial primitive neuroectodermal tumor (CNS-PNET) in Norway. The purpose of the present study was to confirm in an extended cohort whether there were regional differences in outcome or not, and if so try to identify possible explanations. Material and methods Data from patients aged 0-20 years diagnosed with and treated for MB/CNS-PNET at all four university hospitals in Norway from 1974 to 2013 were collected and compared. Results Of 266 identified patients, 251 fulfilled inclusion criteria. MB was diagnosed in 200 and CNS-PNET in 51 patients. Five-year OS and event-free survival (EFS) were 59% and 52%, respectively. There was a significant difference in five-year OS and EFS between MB and CNS-PNET patients; 62% versus 47% (P = 0.007) and 57% versus 35% (P 0.001). In multivariable analysis, two factors were found to significantly contribute to improved five-year OS and EFS, whereas one factor contributed to improved five-year OS only. Gross total resection (GTR) versus non-GTR (hazard ratio [HR] 0.53, P = 0.003; HR 0.46, P 0.001) and cerebrospinal irradiation (CSI) versus non-CSI (HR 0.24, P 0.001; HR 0.28, P < 0.001) for both, and treatment outside Oslo University Hospital for OS only (HR 0.64, P = 0.048). Conclusion Survival was comparable with data from other population-based studies, and the importance of GTR and CSI was confirmed. The cause for regional survival differences could not be identified.

Central nervous system tumours constitute 25% of all childhood cancers; more than half are located in the posterior fossa and surgery is usually part of therapy. One of the most disabling late effects of posterior fossa tumour surgery is the cerebellar mutism syndrome (CMS) which has been reported in up to 39% of the patients but the exact incidence is uncertain since milder cases may be unrecognized. Recovery is usually incomplete. Reported risk factors are tumour type, midline location and brainstem involvement, but the exact aetiology, surgical and other risk factors, the clinical course and strategies for prevention and treatment are yet to be determined.

CMS-06. THE NOPHO-EUROPEAN STUDY ON CEREBELLAR MUTISM SYNDROME (CMS) Morten Wibroe1, Shivaram Avula2, Johan Cappelen3, Charlotte Castor4, Niels Clausen5, Irene Devenney6, Greg Fellows21, Pernilla Grillner7, Ramneek Gupta8, Bengt Gustavsson7, Mats Heyman7, Stefan Holm7, Atte Karppinen9, Rosita Kiudeliene10, Camilla Klausen1, Päivi Lähteenmäki11, Tuula Lönnqvist9, Stephen Lowis21, Conor Mallucci2, René Mathiasen1, Mattias Mattson12, Pelle Nilsson13, Kristiina Nordfors14, Per Nyman6, Karsten Nysom1, Karin Persson15, Jouni Pesola20, Barry Pizer2, Olof Rask4, MagnusSabel16,KjeldSchmiegelow1,AstridSehested1, IngridTonning-Olsson4, Ingrid Kristin Torsvik17, Kirsten van Baarsen18, David Walker19, Mia Westerholm-Ormio9, Barbara Zetterqvist7, and Marianne Juhler1; University Hospital Rigshospitalet, Copenhagen, Denmark; Alder Hey Children’s Hospital, Liverpool, UK; St Olavs University Hospital, Trondheim, Norway; Skåne University Hospital, Lund, Sweden; University Hospital Aarhus, Skejby, Denmark; Linköping University Hospital, Linköping, Sweden; Karolinska University Hospital, Stockholm, Sweden; Technical University of Denmark, Copenhagen, Denmark; Helsinki University Hospital, Helsinki, Finland; HospitalofLithuanian Universityof Health Sciences Kauno Klinikos, Kaunas, Lithuania; Turku University Hospital, Turku, Finland; University Hospital of Umeå, Umeå, Sweden; Uppsala University Hospital, Uppsala, Sweden; Tampere University Hospital, Tampere, Finland; BarnReHab Skåne, Lund, Sweden; Sahlgrenska University Hospital, Göteborg, Sweden; Haukeland University Hospital, Bergen, Norway; Radboud University Medical Centre, Nijmegen, The Netherlands; Children Brain Tumour Research Centre, Nottingham, UK; Kuopio University Hospital, Kuopio, Finland; Bristol Royal Children’s Hospital, Bristol, UK BACKGROUND: The cerebellar mutism syndrome (CMS) is one of the most disabling late effects afterneurosurgery foraposterior fossa tumour inchildhood. The reported incidences vary substantially in previous studies. AIMS: Pathophysiology is unknown, but damage to cerebello-thalamo-cerebral circuits is likely.Thestudyfocusesontheriskfactors fordevelopmentandseverityofCMS including surgery (approaches, techniques and tissue and vascular damage, reoperation) and host genome variants. METHODS: Multicentre study developed as a NOPHO collaborative study coordinated from Righospitalet, Copenhagen with online data registration and database management at Karolinska, Stockholm and quarterly online participant meetings. Registration includes clinical data and speech samples collected preoperatively and at four defined postoperative points for the subsequent 12 months. Therapy, including neurosurgery, is by local standards. A blood sample for genetic analysis is collected from all patients. Imaging is collected and reviewed centrally. RESULTS: The study aims to recruit 550 children. It opened in five Nordic and Baltic countries during 2014/2015; in the Netherlands in February 2016 and will open in the UK during2016.Two Germancentreswill join in2017.The target accrualof550 patients will be reached by the end of 2018. As of February 2016, 67 patients have been included from 12 centres. Mutism has occurred in 7 cases. CONCLUSION: The study will be the largest prospective international study on CMS to date, and the first one to 1) systematically register surgery, use of steroids, standardized speech samples and 2) to investigate the influence of host genome. Neuro-Oncology 18:iii16–iii17, 2016. doi:10.1093/neuonc/now066.5 #The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com. at D T U L irary on Jauary 3, 2017 http://neuro-oy.oxfordjournals.org/ D ow nladed from

Carotid arterial bleeding is a feared and possible life-threatening complication of transsphenoidal surgery. We present a case of a meningioma that during resection had a serious complication with laceration of the internal carotid artery (ICA). These patients rarely undergo endovascular treatment, with indications mainly due to the development of pseudoaneurysms or penetrating trauma. However, endovascular treatment with covered stents of carotid arterial bleedings is a feasible alternative due to technical advances and smaller sized stentgrafts that expand treatment options.

Dear editor, First, we would like to thank the editorial board for the interest in our study and the thorough and extensive commentary [18] to our publication, “The impact of provider surgical volumes on survival in children with primary tumours of the central nervous system—a population-based study” [48]. The editorial includes comments on central publications and addresses some of the problems with the available evidence concerning the volume-outcome relationship. We appreciate the opportunity to comment further on the argumentation for and against centralization of paediatric neurosurgery. If a surgeon does not practice surgery, he or she will not master the procedures. This is self-evident. This is why training and licensing is required to become specialists and subspecialists. Although, accepting a volume-outcome relationship, there are still many unanswered questions as to what to gain from centralisation of different neurosurgical procedures. Here, we would like to expand the literary review in the editorial and comment on the specific points in respect to our study. The magnitude and importance of the volume-outcome relationship is difficult to assess from a review of the available literature. Major limitations rise from the fact that the data source are mainly American administrative claims databases or discharge summaries of variable quality that do not contain much clinical data. Usually, such record data only allow for crude adjustments for age, sex, ethnicity, hospital size and socioeconomic status [often just assessed as mean income in the postal code of the patient’s residential address (!)]. The severity and incidence of the treated disease is not corrected for, and there are often considerable limitations in data concerning differences in referral and case mix [28, 29]. It should further be remembered that high volume institutions in the USA more often treat younger patients, whites, patients with private insurance and residents of wealthier areas. Hospitals with the highest volumes typically also have more elective cases. In publications based on American administrative databases, the main outcome is usually surgical mortality, measured as in-house-mortality. Although 30-day mortality has a better face validity, the correlation to in-house mortality rates are generally at least moderate (kappa > 0.40), but with variance across conditions [14]. Surgical mortality has in the USA been endorsed as an Inpatient Quality Indicator (IQI) by the Agency for Healthcare Research and Quality in eight surgical procedures for adults, including craniotomies (the other seven are specific surgical procedures, while craniotomy is the opening of a body part). The line of logic is that since (1) surgical mortality in craniotomies is defined as a quality indicator, and (2) surgical mortality in many publications is lower in high-volume providers of care, then (3) surgical volume is a quality indicator (quod erat demonstrandum). However, studies by the Veterans Affair (VA) National Surgical Quality Improvement Program (NSQIP), which prospectively collects clinical data on all major surgical operations in the VA, do not reach the same conclusions as studies based on administrative claims data: “Unlike retrospective studies that are based on administrative databases, NSQIP studies have failed to demonstrate a direct relationship between volume and risk-adjusted outcomes of surgery across various specialties. These studies have emphasized that the quality of systems of care was more important than volume in determining the overall quality of surgical care at an institution. High-volume hospitals could still deliver poor care in as much as low-volume hospitals could deliver good care. NSQIP studies have also underscored the major limitations of claims data and administrative databases in the provision of adequate risk-adjustment models that are crucial for volume-outcome studies” [35].

BACKGROUND:Provider volume is often a central topic in debates about centralization of procedures. In Norway, there is considerable variation in provider volumes of the neurosurgical centers treating children. We sought to explore long-term survival after surgery for central nervous system tumors in children in relation to regional provider volumes.METHOD:Based on data from the Norwegian Cancer Registry we analyzed survival in all reported central nervous system tumors in children under the age of 16 treated over two decades, between March 1988 and April 2008; a total of 816 patients with histologically confirmed disease.RESULTS:There was no overall difference in survival between regions. In the subgroup of PNET/medulloblastomas, both living in the high-provider volume health region and receiving treatment in the high-volume region was significantly associated with inferior survival.CONCLUSIONS:In this population-based study of children operated over a period of two decades, we found no evidence of improved long-term survival in the high-provider volume region. Surprisingly, a subgroup analysis indicated that survival in PNET/medulloblastomas was significantly better if living outside the most populated health region with the highest provider volumes. One should, however, be careful of interpreting this directly as a symptom of quality of care, as there may be unseen confounders. Our study demonstrates that provider case volume may serve as an axiom in debates about centralization of cancer surgery while perhaps much more reliable and valid but less quantifiable factors are important for the final results.

BACKGROUND:This paper surveys hormonally inactive pituitary tumours on the basis of the current international literature; it also reflects the experience of the authors.INTERPRETATION:Pituitary tumours are frequently diagnosed and usually show a low potential for growth. Although benign they may invade adjacent structures such as the cavernous and sphenoid sinuses. The diagnosis is usually made on the basis of pituitary failure or visual problems, or incidentally. Tumour debulking or removal, usually by transsphenoidal surgery, is indicated if there is a compression of the optic chiasm or if the tumour shows signs of growth on consecutive MRI scans. Surgery is an effective treatment of these tumours, with little risk of complications. Repeated surgery, either transsphenoidally or by craniotomy, is indicated if chiasmal decompression is not achieved initially. Fractionated single beam irradiation or stereotactic radiosurgery is indicated in cases where there is a residual of growing tumours that may not be removed surgically.

BACKGROUND:Prolactinoma represents the most commonly occurring hormone-secreting pituitary adenoma. The majority of prolactinomas are small, only rarely do we find larger prolactinomas, so-called macroadenomas. They are almost exclusively benign. The symptoms are mainly caused by elevated prolactin levels and result in changes to the reproductive and sexual function. In cases of macroprolactinomas, symptoms caused by local mass effects can be seen. A variety of other conditions may also cause hyperprolactinaemia; the goal of the examination is to identify the cause.MATERIAL AND METHODS:We have reviewed recent literature and compared findings with current management of hyperprolactinaemia and prolactinoma in Norwegian university hospitals.RESULTS AND INTERPRETATION:The primary treatment is medical, intended to normalize prolactin levels, restore gonadal function, and reduce tumour size. With the new selective dopamine agonists, the treatment is often simple and efficient, but not all patients are in need of treatment.

A 27-YEAR-OLD MALE patient underwent surgery for a cerebellar ganglioglioma in which a pleomorphic xanthoastrocytoma constituted the gliomatous element. Neither radiation nor chemotherapy was administered. The patient was well for 12 years and then he suffered a recurrence and underwent a gross total resection. Histological examination revealed a ganglioglioma with thrombosed blood vessels, areas of tumor necrosis, and scattered mitoses. These anaplastic changes, which were restricted to the glial component of the tumor, may herald a more aggressive clinical course. However, 11 months after the second operation, there have been no signs of tumor recurrence.