Proton beam therapy in the management of skull base chordomas: systematic review of indications, outcomes, and implications for neurosurgeons

BACKGROUND: Chordomas are rare tumours affecting the skull base. There is currently no clear consensus on the post-surgical radiation treatments that should be used after maximal tumour resection. However, high-dose proton beam therapy is an accepted option for post-operative radiotherapy to maximise local control, and in the UK, National Health Service approval for funding abroad is granted for specific patient criteria. OBJECTIVES: To review the indications and efficacy of proton beam therapy in the management of skull base chordomas. The primary outcome measure for review was the efficacy of proton beam therapy in the prevention of local occurrence. METHODS: A systematic review of English and non-English articles using MEDLINE (1946-present) and EMBASE (1974-present) databases was performed. Additional studies were reviewed when referenced in other studies and not available on these databases. Search terms included chordoma or chordomas. The PRISMA guidelines were followed for reporting our findings as a systematic review. RESULTS: A total of 76 articles met the inclusion and exclusion criteria for this review. Limitations included the lack of documentation of the extent of primary surgery, tumour size, and lack of standardised outcome measures. Level IIb/III evidence suggests proton beam therapy given post operatively for skull base chordomas results in better survival with less damage to surrounding tissue. CONCLUSIONS: Proton beam therapy is a grade B/C recommended treatment modality for post-operative radiation therapy to skull base chordomas. In comparison to other treatment modalities long-term local control and survival is probably improved with proton beam therapy. Further, studies are required to directly compare proton beam therapy to other treatment modalities in selected patients

ICAR: endoscopic skull‐base surgery

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The management and outcome for patients with chronic subdural hematoma: A prospective, multicenter, observational cohort study in the United Kingdom

OBJECTIVESymptomatic chronic subdural hematoma (CSDH) will become an increasingly common presentation in neurosurgical practice as the population ages, but quality evidence is still lacking to guide the optimal management for these patients. The British Neurosurgical Trainee Research Collaborative (BNTRC) was established by neurosurgical trainees in 2012 to improve research by combining the efforts of trainees in each of the United Kingdom (UK) and Ireland's neurosurgical units (NSUs). The authors present the first study by the BNTRC that describes current management and outcomes for patients with CSDH throughout the UK and Ireland. This provides a resource both for current clinical practice and future clinical research on CSDH.METHODSData on management and outcomes for patients with CSDH referred to UK and Ireland NSUs were collected prospectively over an 8-month period and audited against criteria predefined from the literature: NSU mortality < 5%, NSU morbidity < 10%, symptomatic recurrence within 60 days requiring repeat surgery < 20%, and unfavorable functional status (modified Rankin Scale score of 4–6) at NSU discharge < 30%.RESULTSData from 1205 patients in 26 NSUs were collected. Bur-hole craniostomy was the most common procedure (89%), and symptomatic recurrence requiring repeat surgery within 60 days was observed in 9% of patients. Criteria on mortality (2%), rate of recurrence (9%), and unfavorable functional outcome (22%) were met, but morbidity was greater than expected (14%). Multivariate analysis demonstrated that failure to insert a drain intraoperatively independently predicted recurrence and unfavorable functional outcome (p = 0.011 and p = 0.048, respectively). Increasing patient age (p < 0.00001), postoperative bed rest (p = 0.019), and use of a single bur hole (p = 0.020) independently predicted unfavorable functional outcomes, but prescription of high-flow oxygen or preoperative use of antiplatelet medications did not.CONCLUSIONSThis is the largest prospective CSDH study and helps establish national standards. It has confirmed in a real-world setting the effectiveness of placing a subdural drain. This study identified a number of modifiable prognostic factors but questions the necessity of some common aspects of CSDH management, such as enforced postoperative bed rest. Future studies should seek to establish how practitioners can optimize perioperative care of patients with CSDH to reduce morbidity as well as minimize CSDH recurrence. The BNTRC is unique worldwide, conducting multicenter trainee-led research and audits. This study demonstrates that collaborative research networks are powerful tools to interrogate clinical research questions.Society of British Neurological Surgeons. PJH supported by NIHR Research Professorship and NIHR Cambridge Biomedical Research Centre.This is the author accepted manuscript. It is permanently embargoed to comply with the publisher’s copyright terms. The final version is available via https://doi.org/10.3171/2016.8.JNS1613

Outcomes following surgery in subgroups of comatose and very elderly patients with chronic subdural hematoma

Increasing age and lower pre-operative Glasgow coma score (GCS) are associated with worse outcome after surgery for chronic subdural haematoma (CSDH). Only few studies have quantified outcomes specific to the very elderly or comatose patients. We aim to examine surgical outcomes in these patient groups. We analysed data from a prospective multicentre cohort study, assessing the risk of recurrence, death, and unfavourable functional outcome of very elderly (≥ 90 years) patients and comatose (pre-operative GCS ≤ 8) patients following surgical treatment of CSDH. Seven hundred eighty-five patients were included in the study. Thirty-two (4.1%) patients had pre-operative GCS ≤ 8 and 70 (8.9%) patients were aged ≥ 90 years. A higher proportion of comatose patients had an unfavourable functional outcome (38.7 vs 21.7%; p = 0.03), although similar proportion of comatose (64.5%) and non-comatose patients (61.8%) functionally improved after surgery (p = 0.96). Compared to patients aged < 90 years, a higher proportion of patients aged ≥ 90 years had unfavourable functional outcome (41.2 vs 20.5%; p < 0.01), although approximately half had functional improvement following surgery. Mortality risk was higher in both comatose (6.3 vs 1.9%; p = 0.05) and very elderly (8.8 vs 1.1%; p < 0.01) groups. There was a trend towards a higher recurrence risk in the comatose group (19.4 vs 9.5%; p = 0.07). Surgery can still provide considerable benefit to very elderly and comatose patients despite their higher risk of morbidity and mortality. Further research would be needed to better identify those most likely to benefit from surgery in these groups

Intraoperative neurophysiological monitoring in paediatric Chiari surgery—help or hindrance?

INTRODUCTION: The role of intraoperative neurophysiological monitoring (IONM) during surgery for Chiari I malformation has not been fully elucidated. Questions remain regarding its utility as an adjunct to foramen magnum decompression surgery, specifically, does IONM improve the safety profile of foramen magnum decompression surgery and can IONM parameters help in intraoperative surgical decision-making. This study aimed to describe a single institution experience of IOM during paediatric Chiari I surgery. METHODS: The methodology comprised a retrospective review of prospectively collected electronic neurosurgical departmental operative database. Inclusion criteria were children under 16 years of age who had undergone foramen magnum decompression for Chiari I malformation with IONM. In addition to basic demographic data, details pertaining to presenting features and post-operative outcomes were obtained. These included primary symptoms of Chiari I malformation and indications for surgery. MRI findings, including the presence of syringomyelia on pre-and post-operative imaging, were reviewed. Details of the surgical technique for each patient were recorded. Only patients with either serial brainstem auditory evoked potential (BAEP) and/or upper limb somatosensory evoked potential (SSEP) recordings were included. Two time points were used for the purposes of analysing IONM data; initial baseline before skin incision and final at the time of skin closure. RESULTS: Thirty-seven children underwent foramen magnum decompression (FMD) with IONM. Mean age was 10.5 years (range 1–16 years) with a male:female ratio 13:24. The commonest clinical features on presentation included headaches (15) and scoliosis (13). Twenty-four patients had evidence of associated syringomyelia (24/37 = 64.9%). A reduction in the SSEP latency was observed in all patients. SSEP amplitude was more variable, with a decrease seen in 18 patients and an increase observed in 12 patients. BAEP recordings decreased in 13 patients and increased in 4 patients. There were no adverse neurological events following surgery; the primary symptom was resolved or improved in all patients at 3-month follow-up. Resolution or improvement in syringomyelia was observed in 19/24 cases. CONCLUSIONS: Our data shows that FMD for Chiari malformation (CM) is associated with changes in SSEPs and BAEPs. However, we did not identify a definite link between clinical outcomes and IONM, nor did syrinx outcome correlate with IONM. There may be a role for IONM in CM surgery but more robust data with better-defined parameters are required to further understand the impact of IONM in CM surgery