Dose-effect relationships in neuroendocrine tumour liver metastases treated with [166Ho]-radioembolization.

PURPOSE: Aim of this study was to investigate a dose-response relationship, dose-toxicity relationship, progression free survival (PFS) and overall survival (OS) in neuroendocrine tumour liver metastases (NELM) treated with holmium-166-microspheres radioembolization ([166Ho]-radioembolization). MATERIALS AND METHODS: Single center, retrospective study included patients with NELM that received [166Ho]-radioembolization with post-treatment SPECT/CT and CECT or MRI imaging for 3 months follow-up. Post-treatment SPECT/CT was used to calculate tumour (Dt) and whole liver healthy tissue (Dh) absorbed dose. Clinical and laboratory toxicity was graded by Common Terminology Criteria for Adverse Events (CTCAE), version 5 at baseline and three-months follow-up. Response was determined according to RECIST 1.1. The tumour and healthy doses was correlated to lesion-based objective response and patient-based toxicity. Kaplan Meier analyses were performed for progression free survival (PFS) and overall survival (OS). RESULTS: Twenty-seven treatments in 25 patients were included, with a total of 114 tumours. Median follow-up was 14 months (3 - 82 months). Mean Dt in non-responders was 68 Gy versus 118 Gy in responders, p = 0.01. ROC analysis determined 86 Gy to have the highest sensitivity and specificity, resp. 83% and 81%. Achieving a Dt of ≥ 120 Gy provided the highest likelihood of response (90%) for obtaining response. Sixteen patients had grade 1-2 clinical toxicity and only one patient grade 3. No clear healthy liver dose-toxicity relationship was found. The median PFS was 15 months (95% CI [10.2;19.8]) and median OS was not reached. CONCLUSION: This study confirms the safety and efficacy of [166Ho]-radioembolization in NELM in a real-world setting. A clear dose-response relationship was demonstrated and future studies should aim at a Dt of ≥ 120 Gy, being predictive of response. No dose-toxicity relationship could be established.

Accurate Placement and Revisions for Cervical Pedicle Screws Placed With or Without Navigation: A Systematic Review and Meta-Analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVES: To evaluate the accuracy of placement for cervical pedicle screws with and without the use of spinal navigation. METHODS: A structured search was conducted in electronic databases without any language or date restrictions. Eligible studies reported the proportion of accurately placed cervical pedicle screws measured on intraoperative or postoperative 3D imaging, and reported whether intraoperative navigation was used during screw placement. Randomized Studies (MINORS) criteria were used to evaluate the methodological quality of how accuracy was assessed for cervical pedicle screws. RESULTS: After screening and critical appraisal, 4697 cervical pedicle screws from 18 studies were included in the meta-analysis. The pooled proportion for cervical pedicle screws with a breach up to 2 mm was 94% for navigated screws and did not differ from the pooled proportion for non-navigated screws (96%). The pooled proportion for cervical pedicle screws placed completely in the pedicle was 76% for navigated screws and did not differ from the pooled proportion for non-navigated screws (82%). Intraoperative screw reposition rates and screw revision rates as a result of postoperative imaging also did not differ between navigated and non-navigated screw placement. CONCLUSIONS: This systematic review and meta-analysis found that the use of spinal navigation systems does not significantly improve the accuracy of placement of cervical pedicle screws compared to screws placed without navigation. Future studies evaluating intraoperative navigation for cervical pedicle screw placement should focus on the learning curve, postoperative complications, and the complexity of surgical cases.

Intra-arterial peptide-receptor radionuclide therapy for neuro-endocrine tumour liver metastases: an in-patient randomised controlled trial (LUTIA).

PURPOSE: Peptide receptor radionuclide therapy (PRRT) using [177Lu]Lu-DOTATATE has been shown to effectively prolong progression free survival in grade 1-2 gastroenteropancreatic neuroendocrine tumours (GEP-NET), but is less efficacious in patients with extensive liver metastases. The aim was to investigate whether tumour uptake in liver metastases can be enhanced by intra-arterial administration of [177Lu]Lu-DOTATATE into the hepatic artery, in order to improve tumour response without increasing toxicity. METHODS: Twenty-seven patients with grade 1-2 GEP-NET, and bi-lobar liver metastases were randomized to receive intra-arterial PRRT in the left or right liver lobe for four consecutive cycles. The contralateral liver lobe and extrahepatic disease were treated via a "second-pass" effect and the contralateral lobe was used as the control lobe. Up to three metastases (> 3 cm) per liver lobe were identified as target lesions at baseline on contrast-enhanced CT. The primary endpoint was the tumour-to-non-tumour (T/N) uptake ratio on the 24 h post-treatment [177Lu]Lu-SPECT/CT after the first cycle. This was calculated for each target lesion in both lobes using the mean uptake. T/N ratios in both lobes were compared using paired-samples t-test. FINDINGS: After the first cycle, a non-significant difference in T/N uptake ratio was observed: T/NIA = 17·4 vs. T/Ncontrol = 16·2 (p = 0·299). The mean increase in T/N was 17% (1·17; 95% CI [1·00; 1·37]). Of all patients, 67% (18/27) showed any increase in T/N ratio after the first cycle. CONCLUSION: Intra-arterial [177Lu]Lu-DOTATATE is safe, but does not lead to a clinically significant increase in tumour uptake.

Human brain mapping using co-registered fUS, fMRI and ESM during awake brain surgeries: A proof-of-concept study.

Accurate, depth-resolved functional imaging is key in both understanding and treatment of the human brain. A new sonography-based imaging technique named functional Ultrasound (fUS) uniquely combines high sensitivity with submillimeter-subsecond spatiotemporal resolution available in large fields-of-view. In this proof-of-concept study we show that: (A) fUS reveals the same eloquent regions as found by fMRI while concomitantly visualizing in-vivo microvascular morphology underlying these functional hemodynamics and (B) fUS-based functional maps are confirmed by Electrocortical Stimulation Mapping (ESM), the current gold-standard in awake neurosurgical practice. This unique cross-modality experiment was performed using motor, visual and language-related functional tasks in patients undergoing awake brain tumor resection. The current work serves as an important milestone towards further maturity of fUS as well as a novel avenue to increase our understanding of hemodynamics-based functional brain imaging.

Responsible design and implementation of technologies for the prevention of infectious diseases: towards a values-based assessment framework for the Dutch government.

OBJECTIVES: The Dutch government implemented the apps 'CoronaMelder' and 'CoronaCheck' to prevent the transmission of SARS-CoV-2. They faced many questions on how to responsibly implement such technologies. Here, we aim to develop an assessment framework to support the Dutch national government with the responsible design and implementation of technologies for the prevention of future infectious diseases. STUDY DESIGN: Three-stage web-based Delphi process. METHODS: The assessment framework was developed through two research phases. During the Initial Design phase, a conceptual version of the assessment framework was developed through a scoping review and semistructured interviews with a scientific board. The Consensus phase involved a three-stage web-based Delphi process with an expert community. RESULTS: The final assessment framework consists of five development phases, 10 values, and a total of 152 questions. CONCLUSIONS: Technology assessment frameworks help policymakers to make informed decisions and contribute to the responsible implementation of technologies in society. The framework is now available for the Dutch government and other stakeholders to use in future pandemics. We discuss the possibilities of using the framework transnationally.

Association of pre-radiotherapy tumour burden and overall survival in newly diagnosed glioblastoma adjusted for MGMT promoter methylation status.

PURPOSE: We retrospectively evaluated the association between postoperative pre-radiotherapy tumour burden and overall survival (OS) adjusted for the prognostic value of O6-methylguanine DNA methyltransferase (MGMT) promoter methylation in patients with newly diagnosed glioblastoma treated with radio-/chemotherapy with temozolomide. MATERIALS AND METHODS: Patients were included from the CENTRIC (EORTC 26071-22072) and CORE trials if postoperative magnetic resonance imaging scans were available within a timeframe of up to 4weeks before radiotherapy, including both pre- and post-contrast T1w images and at least one T2w sequence (T2w or T2w-FLAIR). Postoperative (residual) pre-radiotherapy contrast-enhanced tumour (CET) volumes and non-enhanced T2w abnormalities (NT2A) tissue volumes were obtained by three-dimensional segmentation. Cox proportional hazard models and Kaplan Meier estimates were used to assess the association of pre-radiotherapy CET/NT2A volume with OS adjusted for known prognostic factors (age, performance status, MGMT status). RESULTS: 408 tumour (of which 270 MGMT methylated) segmentations were included. Median OS in patients with MGMT methylated tumours was 117 weeks versus 61weeks in MGMT unmethylated tumours (p < 0.001). When stratified for MGMT methylation status, higher CET volume (HR 1.020; 95% confidence interval CI [1.013-1.027]; p < 0.001) and older age (HR 1.664; 95% CI [1.214-2.281]; p = 0.002) were significantly associated with shorter OS while NT2A volume and performance status were not. CONCLUSION: Pre-radiotherapy CET volume was strongly associated with OS in patients receiving radio-/chemotherapy for newly diagnosed glioblastoma stratified by MGMT promoter methylation status.

The meaning of screening: detection of brain metastasis in the adjuvant setting for stage III melanoma.

BACKGROUND: The incidence of melanoma is increasing and 37% of patients with metastatic melanoma eventually have brain metastasis (BM). Currently, there is no consensus on screening for BM in patients with resected stage III melanoma. However, given the high incidence of BM, routine screening magnetic resonance imaging (MRI) of the brain is considered in patients with completely resected stage III melanoma before the start of adjuvant treatment. The aim of this study was to assess the yield of screening for BM in these patients. MATERIALS AND METHODS: A single-center cohort study was carried out in the Erasmus MC, Rotterdam, The Netherlands, a large tertiary referral center for patients with melanoma. Eligible patients with complete resection of stage III melanoma and a screening MRI of the brain, made within 12 weeks after resection and before adjuvant treatment (programmed cell death protein 1 inhibitors, dabrafenib-trametinib), available between 1 August 2018 and 1 January 2021, were included. RESULTS: A total of 202 patients were included. Eighteen (8.9%) of 202 patients had extracranial metastasis at screening. Two (1.1%) of the remaining 184 patients had BM at screening, resulting in a switch from adjuvant treatment to ipilimumab-nivolumab. At a median follow-up of 21.2 months, BM was detected in another 4 (2.4%) of 166 patients who started with adjuvant treatment. CONCLUSIONS: The yield of screening MRI of the brain is low after complete resection of stage III melanoma, before the start of adjuvant treatment. Therefore, routine screening MRI is not recommended in this setting.

Herpes zoster after COVID vaccination.

COVID-19 presents in various ways, but mainly as a pulmonary disease (Marzano, 2020). Skin manifestations have been reported, including reactivation of the varicella-zoster virus (Marzano, 2020). Our case report describes two adults developing herpes zoster after vaccination with tozinameran (the Pfizer-BioNTech COVID-19 mRNA vaccine). A possible cause for this reaction is a transient lymphocytopenia that occurs after the vaccination - similar to that in COVID-19 disease (Mulligan, 2020; Wang, 2020; Qin, 2020; Brabilla, 2020; Wang, 2020; Wei, 2017). In the context of vaccinating older and/or immunocompromised adults, our observations can be the starting point for further evaluation of a possible relationship between COVID-19, COVID vaccines, and herpes zoster.

Current Status and Future Direction of Hepatic Radioembolisation.

Radioembolisation is a locoregional treatment modality for hepatic malignancies. It consists of several stages that are vital to its success, which include a pre-treatment angiographic simulation followed by nuclear medicine imaging, treatment activity choice, treatment procedure and post-treatment imaging. All these stages have seen much advancement over the past decade. Here we aim to provide an overview of the practice of radioembolisation, discuss the limitations of currently applied methods and explore promising developments.

Clinical practice of language fMRI in epilepsy centers: a European survey and conclusions by the ESNR Epilepsy Working Group.

PURPOSE: To assess current clinical practices throughout Europe with respect to acquisition, implementation, evaluation, and interpretation of language functional MRI (fMRI) in epilepsy patients. METHODS: An online survey was emailed to all European Society of Neuroradiology members (n = 1662), known associates (n = 6400), and 64 members of European Epilepsy network. The questionnaire featured 40 individual items on demographic data, clinical practice and indications, fMRI paradigms, radiological workflow, data post-processing protocol, and reporting. RESULTS: A total of 49 non-duplicate entries from European centers were received from 20 countries. Of these, 73.5% were board-certified neuroradiologists and 69.4% had an in-house epilepsy surgery program. Seventy-one percent of centers performed fewer than five scans per month for epilepsy. The most frequently used paradigms were phonemic verbal fluency (47.7%) and auditory comprehension (55.6%), but variants of 13 paradigms were described. Most centers assessed the fMRI task performance (75.5%), ensured cognitive-task adjustment (77.6%), trained the patient before scanning (85.7%), and assessed handedness (77.6%), but only 28.6% had special paradigms for patients with cognitive impairments. fMRI was post-processed mainly by neuroradiologists (42.1%), using open-source software (55.0%). Reporting was done primarily by neuroradiologists (74.2%). Interpretation was done mainly by visual inspection (65.3%). Most specialists (81.6%) were able to determine the hemisphere dominance for language in more than 75% of exams, attributing failure to the patient not performing the task correctly. CONCLUSION: This survey shows that language fMRI is firmly embedded in the preoperative management of epilepsy patients. The wide variety of paradigms and the use of non-CE-marked software underline the need for establishing reference standards.

A proteomic study of resistance to Brown Ring disease in the Manila clam, Ruditapes philippinarum.

Marine mollusk aquaculture has more than doubled over the past twenty years, accounting for over 15% of total aquaculture production in 2016. Infectious disease is one of the main limiting factors to the development of mollusk aquaculture, and the difficulties inherent to combating pathogens through antibiotic therapies or disinfection have led to extensive research on host defense mechanisms and host-pathogen relationships. It has become increasingly clear that characterizing the functional profiles of response to a disease is an essential step in understanding resistance mechanisms and moving towards more effective disease control. The Manila clam, Ruditapes philippinarum, is a main cultured bivalve species of economic importance which is affected by Brown Ring disease (BRD), an infection induced by the bacterium Vibrio tapetis. In this study, juvenile Manila clams were subjected to a 28-day controlled challenge with Vibrio tapetis, and visual and molecular diagnoses were carried out to distinguish two extreme phenotypes within the experimental clams: uninfected ("RES", resistant) and infected ("DIS", diseased) post-challenge. Total protein extractions were carried out for resistant and diseased clams, and proteins were identified using LC-MS/MS. Protein sequences were matched against a reference transcriptome of the Manila clam, and protein intensities based on label-free quantification were compared to reveal 49 significantly accumulated proteins in resistant and diseased clams. Proteins with known roles in pathogen recognition, lysosome trafficking, and various aspects of the energy metabolism were more abundant in diseased clams, whereas those with roles in redox homeostasis and protein recycling were more abundant in resistant clams. Overall, the comparison of the proteomic profiles of resistant and diseased clams after a month-long controlled challenge to induce the onset of Brown Ring disease suggests that redox homeostasis and maintenance of protein structure by chaperone proteins may play important and interrelated roles in resistance to infection by Vibrio tapetis in the Manila clam.

68Ga-PSMA-PET/CT and Diffusion MRI Targeting for Cone-Beam CT-Guided Bone Biopsies of Castration-Resistant Prostate Cancer Patients.

INTRODUCTION: Precision medicine expands the treatment options for metastatic castration-resistant prostate cancer (mCRPC) by targeting druggable genetic aberrations. Aberrations can be identified following molecular analysis of metastatic tissue. Bone metastases, commonly present in mCRPC, hinder precision medicine due to a high proportion of biopsies with insufficient tumor cells for next-generation DNA sequencing. We aimed to investigate the feasibility of incorporating advanced target planning and needle guidance in bone biopsies and whether this procedure increases biopsy tumor yield and success rate of molecular analysis as compared to the current standards, utilizing only CT guidance. MATERIALS AND METHODS: In a pilot study, ten mCRPC patients received 68Ga-prostate-specific membrane antigen (PSMA)-PET/CT and diffusion-weighted MRI as biopsy planning images. These datasets were fused for targeting metastatic lesions with high tumor densities. Biopsies were performed under cone-beam CT (CBCT) guidance. Feasibility of target planning and needle guidance was assessed, and success of molecular analysis and tumor yield were reported. RESULTS: Fusion target planning and CBCT needle guidance were feasible. Nine out of ten biopsies contained prostate cancer cells, with a median of 39% and 40% tumor cells by two different sequencing techniques. Molecular analysis was successful in eight of ten patients (80%). This exceeds previous reports on CT-guided biopsies that ranged from 33 to 44%. In two patients, important druggable aberrations were found. DISCUSSION: A biopsy procedure using advanced target planning and needle guidance is feasible and can increase the success rate of molecular analysis in bone metastases, thereby having the potential of improving treatment outcome for patients with mCRPC. LEVEL OF EVIDENCE: Level 4, case series.

The effects of glyphosate and AMPA on the mediterranean mussel Mytilus galloprovincialis and its microbiota.

Glyphosate, the most widely used herbicide worldwide, targets the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) enzyme in the shikimate pathway found in plants and some microorganisms. While the potential for glyphosate to induce a broad range of biological effects in exposed organisms has been demonstrated, the global molecular mechanisms of toxicity and potential effects in bacterial symbionts remain unclear, in particular for ecologically important marine species such as bivalve molluscs. Here, the effects of glyphosate (GLY), its degradation product aminomethylphosphonic acid (AMPA), and a mixture of both (MIX) on the mussel M. galloprovincialis were assessed in a controlled experiment. For the first time, next generation sequencing (RNA-seq and 16S rRNA amplicon sequencing) was used to evaluate such effects at the molecular level in both the host and its respective microbiota. The results suggest that the variable capacity of bacterial species to proliferate in the presence of these compounds and the impairment of host physiological homeostasis due to AMPA and GLY toxicity may cause significant perturbations to the digestive gland microbiota, as well as elicit the spread of potential opportunistic pathogens such as Vibrio spp.. The consequent host-immune system activation identified at the molecular and cellular level could be aimed at controlling changes occurring in the composition of symbiotic microbial communities. Overall, our data raise further concerns about the potential adverse effects of glyphosate and AMPA in marine species, suggesting that both the effects of direct toxicity and the ensuing changes occurring in the host-microbial community must be taken into consideration to determine the overall ecotoxicological hazard of these compounds.

Exploring new landmarks: analysis of Twitter usage during the 41st ESNR Annual Meeting.

We analyzed the use of Twitter during the 41st Annual Meeting of the European Society of Neuroradiology (ESNR) held in Rotterdam from 19 to 23 September 2018. The aim was to check the status of the European neuroradiology Twitter community and to discover which topics were discussed most often. The data were compared with a similar analysis performed during the Annual Meeting of the American Society of Neuroradiology (ASNR) in 2014. Even though the analysis demonstrated a low use of Twitter during the ESNR meeting, the platform still generated an important volume of impressions and engagement. This use was noted by the global community because topics of the meeting, such as the value of radiological reporting and advanced imaging, were discussed worldwide. These data, also compared to the American meeting, suggests a need for more prolific use and engagement with ESNR social media accounts in order to draw our members into discussions during meetings and to reinforce the place of European neuroradiology in the debate on key imaging topics as well as promoting society events.

Exploring quantitative group-wise differentiation of Alzheimer's disease and behavioural variant frontotemporal dementia using tract-specific microstructural white matter and functional connectivity measures at multiple time points.

OBJECTIVES: This study explored group-wise quantitative measures of tract-specific white matter (WM) microstructure and functional default mode network (DMN) connectivity to establish an initial indication of their clinical applicability for early-stage and follow-up differential diagnosis of Alzheimer's disease (AD) and behavioural variant frontotemporal dementia (bvFTD). METHODS: Eleven AD and 12 bvFTD early-stage patients and 18 controls underwent diffusion tensor imaging and resting state functional magnetic resonance imaging at 3 T. All AD and 6 bvFTD patients underwent the same protocol at 1-year follow-up. Functional connectivity measures of DMN and WM tract-specific diffusivity measures were determined for all groups. Exploratory analyses were performed to compare all measures between the three groups at baseline and between patients at follow-up. Additionally, the difference between baseline and follow-up diffusivity measures in AD and bvFTD patients was compared. RESULTS: Functional connectivity of the DMN was not different between groups at baseline and at follow-up. Diffusion abnormalities were observed widely in bvFTD and regionally in the hippocampal cingulum in AD. The extent of the differences between bvFTD and AD was diminished at follow-up, yet abnormalities were still more pronounced in bvFTD. The rate of change was similar in bvFTD and AD. CONCLUSIONS: This study provides a tentative indication that quantitative tract-specific microstructural WM abnormalities, but not quantitative functional connectivity of the DMN, may aid early-stage and follow-up differential diagnosis of bvFTD and AD. Specifically, pronounced microstructural changes in anterior WM tracts may characterise bvFTD, whereas microstructural abnormalities of the hippocampal cingulum may characterise AD. KEY POINTS: • The clinical applicability of quantitative brain imaging measures for early-stage and follow-up differential diagnosis of dementia subtypes was explored using a group-wise approach. • Quantitative tract-specific microstructural white matter abnormalities, but not quantitative functional connectivity of the default mode network, may aid early-stage and follow-up differential diagnosis of behavioural variant frontotemporal dementia and Alzheimer's disease. • Pronounced microstructural white matter (WM) changes in anterior WM tracts characterise behavioural variant frontotemporal dementia, whereas microstructural WM abnormalities of the hippocampal cingulum in the absence of other WM changes characterise Alzheimer's disease.

Dementia imaging in clinical practice: a European-wide survey of 193 centres and conclusions by the ESNR working group.

PURPOSE: Through a European-wide survey, we assessed the current clinical practice of imaging in the primary evaluation of dementia, with respect to standardised imaging, evaluation and reporting. METHODS: An online questionnaire was emailed to all European Society of Neuroradiology (ESNR) members (n = 1662) and non-members who had expressed their interest in ESNR activities in the past (n = 6400). The questionnaire featured 42 individual items, divided into multiple choice, single best choice and free text answers. Information was gathered on the context of the practices, available and preferred imaging modalities, applied imaging protocols and standards for interpretation, reporting and communication. RESULTS: A total of 193 unique (non-duplicate) entries from the European academic and non-academic institutions were received from a total of 28 countries. Of these, 75% were neuroradiologists, 12% general radiologists and 11% (neuro) radiologists in training. Of responding centres, 38% performed more than five scans/week for suspected dementia. MRI was primarily used in 72% of centres. Over 90% of centres acquired a combination of T2w, FLAIR, T1w, DWI and T2*w sequences. Visual rating scales were used in 75% of centres, most often the Fazekas and medial temporal atrophy scale; 32% of respondents lacked full confidence in their use. Only 23% of centres performed volumetric analysis. A minority of centres (28%) used structured reports. CONCLUSIONS: Current practice in dementia imaging is fairly homogeneous across Europe, in terms of image acquisition and image interpretation. Hurdles identified include training on the use of visual rating scales, implementation of volumetric assessment and structured reporting.

Inter-rater agreement in glioma segmentations on longitudinal MRI.

BACKGROUND: Tumor segmentation of glioma on MRI is a technique to monitor, quantify and report disease progression. Manual MRI segmentation is the gold standard but very labor intensive. At present the quality of this gold standard is not known for different stages of the disease, and prior work has mainly focused on treatment-naive glioblastoma. In this paper we studied the inter-rater agreement of manual MRI segmentation of glioblastoma and WHO grade II-III glioma for novices and experts at three stages of disease. We also studied the impact of inter-observer variation on extent of resection and growth rate. METHODS: In 20 patients with WHO grade IV glioblastoma and 20 patients with WHO grade II-III glioma (defined as non-glioblastoma) both the enhancing and non-enhancing tumor elements were segmented on MRI, using specialized software, by four novices and four experts before surgery, after surgery and at time of tumor progression. We used the generalized conformity index (GCI) and the intra-class correlation coefficient (ICC) of tumor volume as main outcome measures for inter-rater agreement. RESULTS: For glioblastoma, segmentations by experts and novices were comparable. The inter-rater agreement of enhancing tumor elements was excellent before surgery (GCI 0.79, ICC 0.99) poor after surgery (GCI 0.32, ICC 0.92), and good at progression (GCI 0.65, ICC 0.91). For non-glioblastoma, the inter-rater agreement was generally higher between experts than between novices. The inter-rater agreement was excellent between experts before surgery (GCI 0.77, ICC 0.92), was reasonable after surgery (GCI 0.48, ICC 0.84), and good at progression (GCI 0.60, ICC 0.80). The inter-rater agreement was good between novices before surgery (GCI 0.66, ICC 0.73), was poor after surgery (GCI 0.33, ICC 0.55), and poor at progression (GCI 0.36, ICC 0.73). Further analysis showed that the lower inter-rater agreement of segmentation on postoperative MRI could only partly be explained by the smaller volumes and fragmentation of residual tumor. The median interquartile range of extent of resection between raters was 8.3% and of growth rate was 0.22 mm/year. CONCLUSION: Manual tumor segmentations on MRI have reasonable agreement for use in spatial and volumetric analysis. Agreement in spatial overlap is of concern with segmentation after surgery for glioblastoma and with segmentation of non-glioblastoma by non-experts.