Intraoperative MRI without an intraoperative MRI suite: a workflow for glial tumor surgery.

BACKGROUND: Intraoperative MRI (iMRI) has emerged as a useful tool in glioma surgery to safely improve the extent of resection. However, iMRI requires a dedicated operating room (OR) with an integrated MRI scanner solely for this purpose. Due to physical or economical restraints, this may not be feasible in all centers. The aim of this study was to investigate the feasibility of using a non-dedicated MRI scanner at the radiology department for iMRI and to describe the workflow with special focus on time expenditure and surgical implications. METHODS: In total, 24 patients undergoing glioma surgery were included. When the resection was deemed completed, the wound was temporarily closed, and the patient, under general anesthesia, was transferred to the radiology department for iMRI, which was performed using a dedicated protocol on 1.5 or 3 T scanners. After performing iMRI the patient was returned to the OR for additional tumor resection or final wound closure. All procedural times, timestamps, and adverse events were recorded. RESULT: The median time from the decision to initiate iMRI until reopening of the wound after scanning was 68 (52-104) minutes. Residual tumors were found on iMRI in 13 patients (54%). There were no adverse events during the surgeries, transfers, transportations, or iMRI-examinations. There were no wound-related complications or infections in the postoperative period or at follow-up. There were no readmissions within 30 or 90 days due to any complication. CONCLUSION: Performing intraoperative MRI using an MRI located outside the OR department was feasible and safe with no adverse events. It did not require more time than previously reported data for dedicated iMRI scanners. This could be a viable alternative in centers without access to a dedicated iMRI suite.

Two years of neurosurgical intraoperative MRI in Sweden - evaluation of use and costs.

BACKGROUND: The current shortage of radiology staff in healthcare provides a challenge for departments all over the world. This leads to more evaluation of how the radiology resources are used and a demand to use them in the most efficient way. Intraoperative MRI is one of many recent advancements in radiological practice. If radiology staff is performing intraoperative MRI at the operation ward, they may be impeded from performing other examinations at the radiology department, creating costs in terms of exams not being performed. Since this is a kind of cost whose importance is likely to increase, we have studied the practice of intraoperative MRI in Sweden. METHODS: The study includes data from the first four hospitals in Sweden that installed MRI scanners adjacent to the operating theaters. In addition, we included data from Karolinska University Hospital in Solna where intraoperative MRI is carried out at the radiology department. RESULTS: Scanners that were moved into the operation theater and doing no or few other scans were used 11-12% of the days. Stationary scanners adjacent to the operation room were used 35-41% of the days. For scanners situated at the radiology department doing intraoperative scans interspersed among all other scans, the proportion was 92%. CONCLUSION: Our study suggests that performing exams at the radiology department rather than at several locations throughout the hospital may be an efficient approach to tackle the simultaneous trends of increasing demands for imaging and increasing staff shortages at radiology departments.

Peripheral vertigo and subsequent risk of depression and anxiety disorders: a prospective cohort study using the UK Biobank.

BACKGROUND: Peripheral vertigo is often comorbid with psychiatric disorders. However, no longitudinal study has quantified the association between peripheral vertigo and risk of psychiatric disorders. Furthermore, it remains unknown how the white matter integrity of frontal-limbic network relates to the putative peripheral vertigo-psychiatric disorder link. METHODS: We conducted a cohort study including 452,053 participants of the UK Biobank with a follow-up from 2006 through 2021. We assessed the risks of depression and anxiety disorders in relation to a hospitalization episode involving peripheral vertigo using Cox proportional hazards models. We also examined the associations of peripheral vertigo, depression, and anxiety with MRI fractional anisotropy (FA) in a subsample with brain MRI data (N = 36,087), using multivariable linear regression. RESULTS: Individuals with an inpatient diagnosis of peripheral vertigo had elevated risks of incident depression (hazard ratio (HR) 2.18; 95% confidence interval (CI) 1.79-2.67) and anxiety (HR 2.11; 95% CI 1.71-2.61), compared to others, particularly within 2 years after hospitalization (HR for depression 2.91; 95% CI 2.04-4.15; HR for anxiety 4.92; 95% CI 3.62-6.69). Depression was associated with lower FA in most studied white matter regions, whereas anxiety and peripheral vertigo did not show statistically significant associations with FA. CONCLUSIONS: Individuals with an inpatient diagnosis of peripheral vertigo have increased subsequent risks of depression and anxiety disorders, especially within 2 years after hospitalization. Our findings further indicate a link between depression and lower microstructural connectivity as well as integrity beyond the frontal-limbic network.

Depression, anxiety and brain volume after hearing loss and tinnitus: cohort study in the UK Biobank.

BACKGROUND: Hearing loss and tinnitus have been proposed as potential indicators of impaired mental health and brain morphological changes. AIMS: To assess the associations of hearing loss and tinnitus with the risk of depression and anxiety and with brain volume. METHOD: We conducted a community-based cohort study including 129 610 participants aged 40-69 years at recruitment to the UK Biobank with a follow-up period during 2006-2021 to estimate the risk of depression and anxiety after detection of hearing loss and reported tinnitus. We also assessed the associations of hearing loss and tinnitus with brain volume in a subsample with available brain magnetic resonance imaging data (N = 5222). RESULTS: We observed an increased risk of depression among individuals with hearing loss (hazard ratio [HR] 1.14, 95% CI 1.03-1.26), tinnitus (HR 1.30, 95% CI 1.21-1.41) or both (HR 1.32, 95% CI 1.15-1.52), compared with individuals with neither hearing loss nor tinnitus. Similar results were noted for anxiety (HR 1.18, 95% CI 1.07-1.30 for hearing loss; HR 1.32, 95% CI 1.22-1.43 for tinnitus; and HR 1.48, 95% CI 1.30-1.68 for both). Hearing loss was associated with decreased overall brain volume as well as decreased volume of different brain regions. The latter associations disappeared after adjustment for whole intracranial volume. Tinnitus was associated with greater left accumbens and right occipital pole volume after adjustment for the whole intracranial volume. CONCLUSIONS: Individuals with tinnitus are at increased risk of depression and anxiety. Hearing loss, on the other hand, is associated with both mood disorders and altered brain morphology.

Risk of hematological malignancies from CT radiation exposure in children, adolescents and young adults.

Over one million European children undergo computed tomography (CT) scans annually. Although moderate- to high-dose ionizing radiation exposure is an established risk factor for hematological malignancies, risks at CT examination dose levels remain uncertain. Here we followed up a multinational cohort (EPI-CT) of 948,174 individuals who underwent CT examinations before age 22 years in nine European countries. Radiation doses to the active bone marrow were estimated on the basis of body part scanned, patient characteristics, time period and inferred CT technical parameters. We found an association between cumulative dose and risk of all hematological malignancies, with an excess relative risk of 1.96 (95% confidence interval 1.10 to 3.12) per 100 mGy (790 cases). Similar estimates were obtained for lymphoid and myeloid malignancies. Results suggest that for every 10,000 children examined today (mean dose 8 mGy), 1-2 persons are expected to develop a hematological malignancy attributable to radiation exposure in the subsequent 12 years. Our results strengthen the body of evidence of increased cancer risk at low radiation doses and highlight the need for continued justification of pediatric CT examinations and optimization of doses.

Label-efficient deep semantic segmentation of intracranial hemorrhages in CT-scans.

Intracranial hemorrhage (ICH) is a common finding in traumatic brain injury (TBI) and computed tomography (CT) is considered the gold standard for diagnosis. Automated detection of ICH provides clinical value in diagnostics and in the ability to feed robust quantification measures into future prediction models. Several studies have explored ICH detection and segmentation but the research process is somewhat hindered due to a lack of open large and labeled datasets, making validation and comparison almost impossible. The complexity of the task is further challenged by the heterogeneity of ICH patterns, requiring a large number of labeled data to train robust and reliable models. Consequently, due to the labeling cost, there is a need for label-efficient algorithms that can exploit easily available unlabeled or weakly-labeled data. Our aims for this study were to evaluate whether transfer learning can improve ICH segmentation performance and to compare a variety of transfer learning approaches that harness unlabeled and weakly-labeled data. Three self-supervised and three weakly-supervised transfer learning approaches were explored. To be used in our comparisons, we also manually labeled a dataset of 51 CT scans. We demonstrate that transfer learning improves ICH segmentation performance on both datasets. Unlike most studies on ICH segmentation our work relies exclusively on publicly available datasets, allowing for easy comparison of performances in future studies. To further promote comparison between studies, we also present a new public dataset of ICH-labeled CT scans, Seq-CQ500.

Academic achievement after a CT examination toward the head in childhood: Follow up of a randomized controlled trial.

INTRODUCTION: Increasing use of CT examinations has led to concerns of possible negative cognitive effects for children. The objective of this study is to examine if the ionizing radiation dose from a CT head scan at the age of 6-16 years affects academic performance and high school eligibility at the end of compulsory school. MATERIALS AND METHODS: A total of 832 children, 535 boys and 297 girls, from a previous trial where CT head scan was randomized on patients presenting with mild traumatic brain injury, were followed. Age at inclusion was 6-16 years (mean of 12.1), age at follow up 15-18 years (mean of 16.0), and time between injury and follow up one week up to 10 years (mean of 3.9). Participants' radiation exposure status was linked with the total grade score, grades in mathematics and the Swedish language, eligibility for high school at the end of compulsory school, previously measured GOSE-score, and their mothers' education level. The Chi-Square Test, Student's t-Test and factorial logistics were used to analyze data. RESULTS: Although estimates of school grades and high school eligibility were generally higher for the unexposed, the results showed no statistically significant differences between the exposed and unexposed participants in any of the aforementioned variables. CONCLUSIONS: Any effect on high school eligibility and school grades from a CT head scan at the age of 6-16 years is too small to be detected in a study of more than 800 patients, half of whom were randomly assigned to CT head scan exposure.

Brain cancer after radiation exposure from CT examinations of children and young adults: results from the EPI-CT cohort study.

BACKGROUND: The European EPI-CT study aims to quantify cancer risks from CT examinations of children and young adults. Here, we assess the risk of brain cancer. METHODS: We pooled data from nine European countries for this cohort study. Eligible participants had at least one CT examination before age 22 years documented between 1977 and 2014, had no previous diagnosis of cancer or benign brain tumour, and were alive and cancer-free at least 5 years after the first CT. Participants were identified through the Radiology Information System in 276 hospitals. Participants were linked with national or regional registries of cancer and vital status, and eligible cases were patients with brain cancers according to WHO International Classification of Diseases for Oncology. Gliomas were analysed separately to all brain cancers. Organ doses were reconstructed using historical machine settings and a large sample of CT images. Excess relative risks (ERRs) of brain cancer per 100 mGy of cumulative brain dose were calculated with linear dose-response modelling. The outcome was the first reported diagnosis of brain cancer after an exclusion period of 5 years after the first electronically recorded CT examination. FINDINGS: We identified 948 174 individuals, of whom 658 752 (69%) were eligible for our study. 368 721 (56%) of 658 752 participants were male and 290 031 (44%) were female. During a median follow-up of 5·6 years (IQR 2·4-10·1), 165 brain cancers occurred, including 121 (73%) gliomas. Mean cumulative brain dose, lagged by 5 years, was 47·4 mGy (SD 60·9) among all individuals and 76·0 mGy (100·1) among people with brain cancer. A significant linear dose-response relationship was observed for all brain cancers (ERR per 100 mGy 1·27 [95% CI 0·51-2·69]) and for gliomas separately (ERR per 100 mGy 1·11 [0·36-2·59]). Results were robust when the start of follow-up was delayed beyond 5 years and when participants with possibly previously unreported cancers were excluded. INTERPRETATION: The observed significant dose-response relationship between CT-related radiation exposure and brain cancer in this large, multicentre study with individual dose evaluation emphasises careful justification of paediatric CTs and use of doses as low as reasonably possible. FUNDING: EU FP7; Belgian Cancer Registry; La Ligue contre le Cancer, L'Institut National du Cancer, France; Ministry of Health, Labour and Welfare of Japan; German Federal Ministry of Education and Research; Worldwide Cancer Research; Dutch Cancer Society; Research Council of Norway; Consejo de Seguridad Nuclear, Generalitat de Catalunya, Spain; US National Cancer Institute; UK National Institute for Health Research; Public Health England.

MRI Markers of Small Vessel Disease and the APOE Allele in Cognitive Impairment.

Objective: The apolipoprotein E (APOE) ε4 allele is the main genetic risk factor for dementia and Alzheimer's disease (AD), but the underlying mechanism for the increased risk is not well understood. Cerebral small vessel disease (SVD) is prevalent among patients with cognitive impairment and is thought to play an important role in the pathophysiology of dementia. We aimed to investigate the association between the APOE ε genotype and magnetic resonance imaging (MRI) markers of SVD in a memory clinic population. Material and Methods: This is a cross-sectional study with a total of 520 patients undergoing dementia investigation, including an MRI brain scan and APOE genotyping in all patients enrolled, and cerebrospinal fluid (CSF) analysis for routine AD biomarkers in 399 patients. MR images were assessed for markers of SVD: cerebral microbleeds (CMBs), cortical superficial siderosis, intracerebral hemorrhage, white matter hyperintensities, lacunar infarcts, and enlarged perivascular spaces. Results: Apolipoprotein E carriers with AD had a higher number of CMBs when looking at all brain regions and lobar brain regions (p < 0.001). A lower number of CMBs were seen in APOE ε2 (p < 0.05), ε3 and ε3/3 carriers (p < 0.001) when looking at all brain regions. A higher number of CMBs in deep and infratentorial regions were seen in APOE ε2 and ε3 (p < 0.05). In APOE ε4/4 carriers, CMBs, cortical superficial siderosis, white matter hyperintensities, and enlarged perivascular spaces were associated with lower levels of CSF amyloid ß (Aß) 42 in the whole cohort, and in individuals with AD and mild cognitive impairment (p < 0.05). Conclusion: Apolipoprotein E ε4 is associated with MRI markers of SVD related to amyloid pathology, specifically CMBs and Aß42 plaque formation in the brain, as reflected by decreased CSF Aß42 levels, whereas APOE ε3 and ε2 are associated with the markers of hypertensive arteriopathy, as reflected by the association with CMBs in deep and infratentorial brain regions.

Staff and Facility Utilization in Direct Patient Transfer to the Comprehensive Stroke Center: Testing a Real-Time Location System for Automatic Patient Pathway Characterization.

Introduction: Starting reperfusion therapies as early as possible in acute ischemic strokes are of utmost importance to improve outcomes. The Comprehensive Stroke Centers (CSCs) can use surveys, shadowing personnel or perform journal analysis to improve logistics, which can be labor intensive, lack accuracy, and disturb the staff by requiring manual intervention. The aim of this study was to measure transport times, facility usage, and patient-staff colocalization with an automated real-time location system (RTLS). Patients and Methods: We tested IR detection of patient wristbands and staff badges in parallel with a period when the triage of stroke patients was changed from admission to the emergency room (ER) to direct admission to neuroradiology. Results: In total, 281 patients were enrolled. In 242/281 (86%) of cases, stroke patient logistics could be detected. Consistent patient-staff colocalizations were detected in 177/281 (63%) of cases. Bypassing the ER led to a significant decrease in median time neurologists spent with patients (from 15 to 9 min), but to an increase of the time nurses spent with patients (from 13 to 22 min; p = 0.036). Ischemic stroke patients used the most staff time (median 25 min) compared to hemorrhagic stroke patients (median 13 min) and stroke mimics (median 15 min). Discussion: Time spent with patients increased for nurses, but decreased for neurologists after direct triage to the CSC. While lower in-hospital transport times were detected, time spent in neuroradiology (CT room and waiting) remained unchanged. Conclusion: The RTLS could be used to measure the timestamps in stroke pathways and assist in staff allocation.

One hundred years of neuroradiology in Acta Radiologica: a Swedish perspective.

This year, Acta Radiologica marks its 100th anniversary. In this article, the authors present some of the highlights from the close collaboration between Swedish neuroradiology and Acta Radiologica over the last 100 years.

Cerebrospinal Fluid Metals and the Association with Cerebral Small Vessel Disease.

BACKGROUND: Brain metal homeostasis is essential for brain health, and deregulation can result in oxidative stress on the brain parenchyma. OBJECTIVE: Our objective in this study was to focus on two hemorrhagic MRI manifestations of small vessel disease [cerebral microbleeds (CMBs) and cortical superficial siderosis (cSS)] and associations with cerebrospinal fluid (CSF) iron levels. In addition, we aimed to analyze CSF biomarkers for dementia and associations with CSF metal levels. METHODS: This is a cross-sectional study of 196 patients who underwent memory clinic investigation, including brain MRI. CSF was collected and analyzed for metals, amyloid-ß (Aß) 42, total tau (T-tau), and phosphorylated tau (P-tau), and CSF/serum albumin ratios. Statistical analyses were performed using generalized linear models. RESULTS: No significant difference was found between CSF metal levels across diagnostic groups. Higher iron and copper levels were associated with higher CSF levels of Aß42, T-tau, P-tau, and CSF/serum albumin ratios (p < 0.05). Zinc was associated with higher CSF/serum albumin ratios. There was no significant association between CMBs or cSS and CSF iron levels. An increase in CSF iron with the number of CMBs was seen in APOEɛ4 carriers. CONCLUSION: CSF iron levels are elevated with cerebral microbleeds in APOEɛ4 carriers, with no other association seen with hemorrhagic markers of small vessel disease. The association of elevated CSF iron and copper with tau could represent findings of increased neurodegeneration in these patients.

Diagnostic performance of a new multicontrast one-minute full brain exam (EPIMix) in neuroradiology: A prospective study.

BACKGROUND: Clinical MRI protocols are time-consuming; hence, new faster techniques are needed. One new fast multicontrast MRI technique, called echo planar image mix (EPIMix) (including contrasts T1 -FLAIR, T2 -weighted, diffusion-weighted images [DWI], apparent diffusion coefficient [ADC], T2 *-weighted, and T2 -FLAIR images) needs to be tested. PURPOSE: To assess if EPIMix has comparable diagnostic performance as routine clinical brain MRI. STUDY TYPE: Prospective. POPULATION: A consecutive series of 103 patients' brain MRI (January 2018 to May 2018). FIELD STRENGTH/SEQUENCE: 1.5 T or 3T. EPIMix and routine clinical protocol (clinical MRI included all or some of the contrasts T1 -FLAIR, T2 -weighted, DWI, T2 *-weighted, T2 -FLAIR, 3D-FSE). ASSESSMENT: Two neuroradiologists assessed EPIMix and clinical scans and categorized the images as abnormal or normal and described diagnosis, artifacts, diagnostic confidence image quality, and comparison of imaging time. STATISTICAL TESTS: Pivot tables with diagnostic performance calculated by receiver operating characteristics (ROC) and the area under curve (AUC). Disease categorization and image quality measures were evaluated. The study protocol is published at ClinicalTrials.gov NCT03338270. RESULTS: After exclusion of 21 patients, 82 patients had a routine clinical MRI with comparable contrasts to EPIMix and were evaluated. The diagnostic performance to categorize a full brain MRI investigation as abnormal or normal was comparable between EPIMix (AUC 0.99 (95% confidence interval [CI] 0.97-1.00) and 0.99 (95% CI 0.97-1.00)) and routine clinical MRI (n = 82). Sensitivity was 95% (95% CI 88-95) and 93% (95% CI 86-98), and specificity 100% (95% CI 97-100) and 100% (95% CI 90-100). Disease categorization was congruent between EPIMix and clinical routine MRI in 90% (reader 2) and 93% (reader 1). Image quality was generally rated lower for EPIMix (P < 0.001). Imaging time was 78 seconds for EPIMix and for the same contrasts 12 minutes 29 seconds for conventional 3T MRI. DATA CONCLUSION: EPIMix has comparable diagnostic performance (disease identification and categorization) for most patients investigated in clinical routine. Level of Evidence 2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:1824-1833.

Cognitive function following head CT in childhood: a randomized controlled follow-up trial.

Background The question has been raised whether low dose radiation toward the brain in childhood can affect cognitive functions. Purpose To examine if a head computed tomography (CT) examination in childhood affect later cognitive functions. Material and Methods A total of 147 participants (67 girls/women, 80 boys/men) from a previous randomized controlled trial on management strategies after mild head injury (head CT examination or in-hospital observation) were followed up. Participants were aged 6-16 years (mean age = 11.2 ± 2.8) at first inclusion and 11-24 years (mean age = 17.8 ± 2.9) at follow-up. Computerized neuropsychological measures used for the assessment were motor speed and coordination, reaction time, selective attention, visuospatial ability, verbal and non-verbal short-term and long-term memory, and executive function tests from the neurocognitive test battery EuroCog and the Wechsler Memory Scale III. Results were analyzed with Student's t-tests and multivariate analyses adjusting for sex, age at time of injury/exposure, and age at assessment were performed with Factorial ANOVAs. Results The exposed and unexposed groups did not differ in any of the neuropsychological measures and results did not change when sex, age at time of injury/exposure, and age at assessment were included in the analyses. Conclusion A head CT examination at the age of 6-16 years does not seem to affect later cognitive functions.

Risk of Meningioma after CT of the Head.

Purpose To investigate the association between exposure to head computed tomography (CT) and subsequent risk of meningioma. Materials and Methods The study was approved by the local ethics committee. A cohort of 26 370 subjects was retrospectively collected from a radiology archive of CT examinations of the head performed from 1973 through 1992. For comparison, an age- and sex-matched cohort of 96 940 subjects who were not exposed to CT (unexposed cohort) was gathered. The risk of meningioma was assessed by using data from the Swedish Cancer Registry; however, one-third of patients with meningioma had to be excluded because they either had a prevalent meningioma or other brain tumor at the first CT examination or had undergone radiation treatment to the head. Hazard ratios (HRs) were calculated from time of exposure to the occurrence of meningioma or death or until December 31, 2010, with logistic regression. Results Comparison of exposed and unexposed cohorts showed that there was no statistically significant increase in the risk of meningioma after exposure to CT of the head (HR: 1.49; 95% confidence interval: 0.97, 2.30; P = .07). If incident cases at the time of the first CT examination were not excluded, the risk of meningioma would have been falsely increased (HR: 2.28; 95% confidence interval: 1.56, 3.33; P = .0001). Conclusion When prevalent cases of meningioma at first exposure to CT of the head are excluded, no statistically significant increase in risk of meningioma was found among exposed subjects compared with unexposed control subjects. © RSNA, 2017.

Stomach Cancer Following Hodgkin Lymphoma, Testicular Cancer and Cervical Cancer: A Pooled Analysis of Three International Studies with a Focus on Radiation Effects.

To further understand the risk of stomach cancer after fractionated high-dose radiotherapy, we pooled individual-level data from three recent stomach cancer case-control studies. These studies were nested in cohorts of five-year survivors of first primary Hodgkin lymphoma (HL), testicular cancer (TC) or cervical cancer (CX) from seven countries. Detailed data were abstracted from patient records and radiation doses were reconstructed to the site of the stomach cancer for cases and to the corresponding sites for matched controls. Among 327 cases and 678 controls, mean doses to the stomach were 15.3 Gy, 24.7 Gy and 1.9 Gy, respectively, for Hodgkin lymphoma, testicular cancer and cervical cancer survivors, with an overall mean dose of 10.3 Gy. Risk increased with increasing radiation dose to the stomach cancer site (P < 0.001) with no evidence of nonlinearity or of a downturn at the highest doses (≥35 Gy). The pooled excess odds ratio per Gy (EOR/Gy) was 0.091 [95% confidence interval (CI): 0.036-0.20] with estimates of 0.049 (95% CI: 0.007-0.16) for Hodgkin lymphoma, 0.27 (95% CI: 0.054-1.44) for testicular cancer and 0.096 (95% CI: -0.002-0.39) for cervical cancer (P homogeneity = 0.25). The EOR/Gy increased with time since exposure (P trend = 0.004), with an EOR/Gy of 0.38 (95% CI: 0.12-1.04) for stomach cancer occurring ≥20 years postirradiation corresponding to odds ratios of 4.8 and 10.5 at radiation doses to the stomach of 10 and 25 Gy, respectively. Of 111 stomach cancers occurring ≥20 years after radiotherapy, 63.8 (57%) could be attributed to radiotherapy. Our findings differ from those based on Japanese atomic-bomb survivors, where the overall EOR/Gy was higher and where there was no evidence of an increase with time since exposure. By pooling data from three studies, we demonstrated a clear increase in stomach cancer risk over a wide range of doses from fractionated radiotherapy with the highest risks occurring many years after exposure. These findings highlight the need to directly evaluate the health effects of high-dose fractionated radiotherapy rather than relying on the data of persons exposed at low and moderate acute doses.

Thrombectomy in acute ischemic stroke: estimations of increasing demands.

BACKGROUND: New recommendations for mechanical thrombectomy in acute ischemic stroke suggest that thrombectomy should be considered for eligible patients with a large artery occlusion in the anterior circulation within 6 hours of stroke onset. The resources are unevenly spread and, in order to be able to meet a potentially increased demand, we have estimated the future need for thrombectomy. METHODS: The new treatment recommendations are similar to those that have been in use at the Karolinska University Hospital since 2007. Using our local thrombectomy data (2009-2011), we calculated the proportion of thrombectomies performed at our hospital by level of stroke severity according to the National Institutes of Health Stroke Scale score (0-5, 6-11, 12-19, and 20-35). We then estimated the total number of potential thrombectomies expected in Sweden by extrapolating our treatment proportions to the rest of Sweden through the use of data from the Swedish National Stroke Registry. RESULTS: The number of potential thrombectomies would have been more than five times higher (1268 estimated compared with 232 actually reported in the National Stroke Registry) if the new recommendations for thrombectomy in acute ischemic stroke had been implemented in 2013 (the year from which we had the most recent available data from the Swedish Stroke Registry). CONCLUSIONS: When the new recommendations are implemented broadly, there may be a substantial increase in demand for thrombectomies. Our study highlights the need for policymakers and healthcare professionals to prepare for the increasing demands for advanced endovascular stroke treatment.

Increased pancreatic cancer risk following radiotherapy for testicular cancer.

BACKGROUND: Pancreatic cancer risk is elevated among testicular cancer (TC) survivors. However, the roles of specific treatments are unclear. METHODS: Among 23 982 5-year TC survivors diagnosed during 1947-1991, doses from radiotherapy to the pancreas were estimated for 80 pancreatic cancer patients and 145 matched controls. Chemotherapy details were recorded. Logistic regression was used to estimate odds ratios (ORs). RESULTS: Cumulative incidence of second primary pancreatic cancer was 1.1% at 30 years after TC diagnosis. Radiotherapy (72 (90%) cases and 115 (80%) controls) was associated with a 2.9-fold (95% confidence interval (CI) 1.0-7.8) increased risk. The OR increased linearly by 0.12 per Gy to the pancreas (P-trend<0.001), with an OR of 4.6 (95% CI 1.9-11.0) for ⩾25 Gy vs <25 Gy. Radiation-related risks remained elevated ⩾20 years after TC diagnosis (P=0.020). The risk increased with the number of cycles of chemotherapy with alkylating or platinum agents (P=0.057), although only one case was exposed to platinum. CONCLUSIONS: A dose-response relationship exists between radiation to the pancreas and subsequent cancer risk, and persists for over 20 years. These excesses, although small, should be considered when radiotherapy with exposure to the pancreas is considered for newly diagnosed patients. Additional data are needed on the role of chemotherapy.