Dosimetric feasibility of direct post-operative MR-Linac-based stereotactic radiosurgery for resection cavities of brain metastases

BACKGROUND

Post-operative radiosurgery (SRS) of brain metastases patients is typically planned on a post-recovery MRI, 2-4 weeks after resection. However, the intracranial metastasis may (re-)grow in this period. Planning SRS directly on the post-operative MRI enables shortening this time interval, anticipating the start of adjuvant systemic therapy, and so decreasing the chance of extracranial progression. The MRI-Linac (MRL) allows the simultaneous execution of the post-operative MRI and SRS treatment. The aim of this work was investigating the dosimetric feasibility of MRL-based post-operative SRS.

METHODS

MRL treatments based on the direct post-operative MRI were simulated, including thirteen patients with resectable single brain metastases. The gross tumor volume (GTV) was contoured on the direct post-operative scans and compared to the post-recovery MRI GTV. Three plans for each patient were created: a non-coplanar VMAT CT-Linac plan (ncVMAT) and a coplanar IMRT MRL plan (cIMRT) on the direct post-operative MRI, and a ncVMAT plan on the post-recovery MRI as the current clinical standard.

RESULTS

Between the direct post-operative and post-recovery MRI, 15.5 % of the cavities shrunk by > 2 cc, and 46 % expanded by ≥ 2 cc. Although the direct post-operative cIMRT plans had a higher median gradient index (3.6 vs 2.7) and median V3Gy of the skin (18.4 vs 1.1 cc) compared to ncVMAT plans, they were clinically acceptable.

CONCLUSION

Direct post-operative MRL-based SRS for resection cavities of brain metastases is dosimetrically acceptable, with the advantages of increased patient comfort and logistics. Clinical benefit of this workflow should be investigated given the dosimetric plausibility.

RADT-08. DOSIMETRIC FEASIBILITY OF DIRECT POST-OPERATIVE MRI-LINAC-BASED STEREOTACTIC RADIOSURGERY FOR RESECTION CAVITIES OF BRAIN METASTASES

Background

Post-operative stereotactic radiosurgery (SRS) of patients with brain metastases with single resection cavities is typically planned on a post-recovery MRI, 4-6 weeks after resection. However, meanwhile the intracranial metastasis may (re-)grow, and postponing adjuvant systemic treatment increases chance on extracranial progression as well. Anticipating direct post-operative SRS to minimize this interval would enable rapid start of systemic therapy. In this study, we considered treatment with MRI-Linac (MRL) SRS, because of the possibility to execute the post-operative MRI and SRS treatment combined on the MRL instead of on two separate systems, improving logistics and increasing patient comfort. However, it is unclear whether MRL-based SRS may be feasible from a dosimetric perspective. This study aims to shed light on the dosimetric feasibility of MRL-based SRS.

METHODS

We simulated MRL treatments including thirteen patients with resectable single brain metastases treated with single fraction CT-Linac (CTL) SRS. We therefore contoured direct post-operative gross tumor volumes (GTV) and compared them to post-recovery MRI GTV. Next, we compared a non-coplanar VMAT technique for CTL (ncVMAT) to a coplanar IMRT technique for MRL (cIMRT), creating three plans per patient: a ncVMAT plan and a cIMRT plan for the direct post-operative GTV, and a post-recovery ncVMAT plan as current clinical standard. RESULTSCompared to GTVs defined on direct post-operative MRI, on post-recovery MRI 15.5% of cavities shrunk by > 2cc, and 46% expanded by > 2cc. Although direct post-operative ncVMAT plans had lower median gradient index and higher median V3Gy of the skin, they were clinically acceptable according to clinical guidelines.

CONCLUSION

Although slightly inferior to non-coplanar CTL plans, direct post-operative MRL-based SRS for resection cavities of brain metastases is dosimetrically acceptable, at the trade-off between increased patient comfort and logistics. Additionally, MRL-based SRS enables substantially earlier start with adjuvant systemic therapies, thereby maximizing tumor control.

Sensory processing sensitivity and axonal microarchitecture: identifying brain structural characteristics for behavior

Previous research using functional MRI identified brain regions associated with sensory processing sensitivity (SPS), a proposed normal phenotype trait. To further validate SPS, to characterize it anatomically, and to test the usefulness in psychology of methodologies that assess axonal properties, the present study correlated SPS proxy questionnaire scores (adjusted for neuroticism) with diffusion tensor imaging (DTI) measures. Participants (n = 408) from the Human Connectome Project were studied. Voxelwise analysis showed that mean- and radial diffusivity correlated positively with SPS scores in the right and left subcallosal and anterior-ventral cingulum bundle, and the right forceps minor of the corpus callosum, all frontal cortex areas generally underlying emotion, motivation, and cognition. Further analyses showed correlations throughout medial frontal cortical regions in the right and left ventromedial prefrontal cortex, including the superior longitudinal fasciculus, inferior fronto-occipital fasciculus, uncinate, and arcuate fasciculus. Fractional anisotropy was negatively correlated with SPS scores in white matter (WM) of the right premotor/motor/somatosensory/supramarginal gyrus regions. Region of interest (ROI) analysis showed small effect sizes (- 0.165 to 0.148) in WM of the precuneus and inferior frontal gyrus. Other ROI effects were found in the dorsal-, ventral visual pathways and primary auditory cortex. The results reveal that in a large group of participants, axonal microarchitectural differences can be identified with SPS traits that are subtle and in the range of typical behavior. The results suggest that the heightened sensory processing in people who show that SPS may be influenced by the microstructure of WM in specific cortical regions. Although previous fMRI studies had identified most of these areas, the DTI results put a new focus on brain areas related to attention and cognitive flexibility, empathy, emotion, and first levels of sensory processing, as in primary auditory cortex. Psychological trait characterization may benefit from DTI methodology by identifying influential brain systems for traits.

Quantifying the post-radiation accelerated brain aging rate in glioma patients with deep learning

BACKGROUND AND PURPOSE

Changes of healthy appearing brain tissue after radiotherapy (RT) have been previously observed. Patients undergoing RT may have a higher risk of cognitive decline, leading to a reduced quality of life. The experienced tissue atrophy is similar to the effects of normal aging in healthy individuals. We propose a new way to quantify tissue changes after cranial RT as accelerated brain aging using the BrainAGE framework.

MATERIALS AND METHODS

BrainAGE was applied to longitudinal MRI scans of 32 glioma patients. Utilizing a pre-trained deep learning model, brain age is estimated for all patients' pre-radiotherapy planning and follow-up MRI scans to acquire a quantification of the changes occurring in the brain over time. Saliency maps were extracted from the model to spatially identify which areas of the brain the deep learning model weighs highest for predicting age. The predicted ages from the deep learning model were used in a linear mixed effects model to quantify aging of patients after RT.

RESULTS

The linear mixed effects model resulted in an accelerated aging rate of 2.78 years/year, a significant increase over a normal aging rate of 1 (p < 0.05, confidence interval = 2.54-3.02). Furthermore, the saliency maps showed numerous anatomically well-defined areas, e.g.: Heschl's gyrus among others, determined by the model as important for brain age prediction.

CONCLUSION

We found that patients undergoing RT are affected by significant post-radiation accelerated aging, with several anatomically well-defined areas contributing to this aging. The estimated brain age could provide a method for quantifying quality of life post-radiotherapy.

Testing the Limit Range of Motion Safety Function of Upper Limb Rehabilitation Robots with an Anthropometrically Adjustable and Sensorized Dummy Limb. IEEE Int Conf Rehabil Robot 2022;2022:1-6. [PMID: 36176113 DOI: 10.1109/icorr55369.2022.9896575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Arm type or exoskeleton type rehabilitation robots move the patient's upper limb through one or more, either free or restrained connection points. The rehabilitation robot is unsafe if it moves the patient's upper limb beyond the limits of the anatomical joint ranges. A validation toolkit was developed to assess the risks of "limit anatomical joint range of movement" and "limit anatomical joint overreaching" during the regular operation of a rehabilitation robot. The validation toolkit includes an anthropometrically adjustable and sensorised dummy limb attached to the RACA (rehabilitation, assessment, compensation, or alleviation) rehabilitation robot; and a software tool for off-line risk assessment and reporting.

POS1566-PARE BEYOND MEDICATION – SELF MANAGEMENT AS A COMPLEMENTARY APPROACH FOR TREATING RMDS

Background

Upon diagnosis Rheumatoid Patients declare that the feeling that prevails is fear. Fear over the unknown over their health condition, their professional future, and their personal and social life. The person experiences a vicious cycle. Loss of control leads to anxiety which triggers pain which enhances psychological distress, thus the person feels completely helpless.

Objectives

The Self-Management education workshop is offered as a complementary aid, next to the arranged medical plan and the medications prescribed. The primary goal of the Workshop is for patients to accept their new reality which is, living with RMD. Further on, grounds for change are set. Patients within the program are taught in great detail how to engage new healthy, daily activities, such as appropriate exercise, appropriate use of medications, healthier nutrition, communicating effectively their fatigue, anxiety and psychological distress to family and friends. Patients are also taught, how to communicate to health professionals their condition, seek for information so as to evaluate new treatments, and demand the right for shared decision over their treatment. Moreover they receive information about the Cyprus League of people with Rheumatism, the social and psychological help provided, practicalities that concerns them, availability of Doctors, and new medications. Information, provides a strong Know-how, to deal with everyday problems. Such achievement enhances the confidence that a new well-being could be within the persons reach.

Methods

Participants meet for two hours once a week, for five weeks. Two trained leaders conduct the workshop, one being a health professional and one patient. Participants are to the maximum 15. Major rules of a therapeutic group apply, such as empathy, confidentiality, respect in every sharing, time keeping, simple language. All activities are Interactive. Discussions, questions and answers, brain storming, action-planning exercises and feedback, role playing, problem-solving techniques, and decision making. Moreover, symptom management activities are included, such as exercise, relaxation, communication, healthy eating, medication management, and managing sleep and fatigue. During the workshop, participants experience rapport, and trust thus they are motivated to manage the challenges associated with their condition.

Results

Participants demonstrated significant improvements in exercise, ability to do social and household activities, less depression, less fear and frustration about their health, reduction in symptoms like pain, improve mobility, increase energy, and boost confidence in their ability to manage their condition. Results of every workshop are scientifically documented.

Conclusion

Self-Management workshops are often described by new coming participants as “render of last hope”. The structure and the facilitators create a safe environment for the patient to release the pain, seek knowledge, express the despair, set all the nightmares free. Acceptance, Respect, Rapport, Trust, knowledge aid the participants to experience the rebirth of hope. Self-Management workshops, are designed to complement clinical treatment and when delivered with empathy, lead RMD patients to physical and psychological well-being.

References

[1]Private practice, Self-Management education workshops at the Cyprus League of people with Rheumatism.

Disclosure of Interests

None declared

CT fractional flow reserve: an alternative to stress ECHO for gatekeeping to invasive coronary angiography

Funding Acknowledgements

Type of funding sources: None.

Introduction

Stress echocardiography (SE) can assess the significance of moderate/severe stenoses found on CT coronary angiography (CTCA), as a gatekeeper to invasive coronary angiography (ICA). In 2017, the UK National Institute for Health and Care Excellence (NICE), recommended CT fractional flow reserve (CTFFR) on all patients with coronary stenoses on CTCA to reduce downstream ICA and reduce costs.

Aim

We describe our experience of using CTFFR and compare this with previously accepted practice of judicious use of SE in patients with moderate/severe CTCA stenosis, and subsequent rate of ICA.

Method

An electronic patient record identified patients undergoing CTFFR between January 2019 and March 2020, and CTCA between January 2017 and June 2018, at our centre. We assessed downstream testing following CT evidence of moderate/severe stenoses and undertook a cost analysis per patient (PP) with the following NHS tariffs; CTCA=£220, CTFFR=£530, SE=£177, ICA=£1000.

Results

140 patients were referred for CTFFR with 125 analysed (rejection rate 11%) of which 81 had moderate/severe stenoses. The baseline audit comprised 652 patients undergoing CTCA of which 92 had moderate/severe stenoses.

Moderate CTCA stenosis: Baseline audit

58 had moderate stenosis, 18 (31%) underwent SE, with 1 positive and subsequent ICA. 36 (62%) were referred directly for ICA. In total 17 (46%) were revascularised. Cost of £1224 PP.

CTFFR audit

44 had moderate stenosis, with 35 negative and 9 positive CTFFR.  9 (26%) and 7 (78%) following negative and positive CTFFR respectively, were subsequently referred for ICA. In total 16 (36%) were referred for ICA, and 44% revascularised. Cost of £1425 PP.

Severe CTCA stenosis: Baseline audit

34 had severe stenosis, 1 (3%) underwent SE. 33 (97%) were referred directly for ICA. In total 18 (60%) were revascularised. Cost of £1418 PP.

CTFFR audit

37 had severe stenoses, with 10 negative CTFFR and 27 positive CTFFR.  5 (50%) and 22 (81%) following negative and positive CTFFR respectively were referred for ICA. In total 27 (73%) were referred for ICA and 70% revascularised. Cost of £1719 PP.

Importantly 14 patients underwent ICA following negative CTFFR with 29% revascularised.

Conclusion

CTFFR use in all patients with moderate/severe stenosis reduced the rate of downstream ICA compared with previous judicious use of SE, albeit at greater cost and similar revascularisation rates. A small number of patients underwent ICA despite negative CTFFR due to clinical concerns.

The NICE guidance recommending CTFFR on all patients with moderate/severe CTCA stenosis reduces ICA. However, assuming equal efficacy, based on the non-invasive arm of the Platform trial1, SE would achieve this at lower cost. Notably, CTFFR benefits from completing assessment within a single visit, which is pertinent in the COVID-19 era and negates inherent delays between multiple tests.

Irradiation of the Subventricular Zone and Subgranular Zone in High- and Low-Grade Glioma Patients: an Atlas-based Analysis on Overall Survival

Background

Neural stem cells in the subventricular zone (SVZ) and subgranular zone (SGZ) are hypothesized to support growth of glioma. Therefore, irradiation of the SVZ and SGZ might reduce tumor growth and might improve overall survival (OS). However, it may also inhibit the repair capacity of brain tissue. The aim of this retrospective cohort study is to assess the impact of SVZ and SGZ radiotherapy doses on OS of patients with high-grade (HGG) or low-grade (LGG) glioma.

Methods

We included 273 glioma patients who received radiotherapy. We created an SVZ atlas, shared openly with this work, while SGZ labels were taken from the CoBrA atlas. Next, SVZ and SGZ regions were automatically delineated on T1 MR images. Dose and OS correlations were investigated with Cox regression and Kaplan-Meier analysis.

Results

Cox regression analyses showed significant hazard ratios for SVZ dose (univariate: 1.029/Gy, P < .001; multivariate: 1.103/Gy, P = .002) and SGZ dose (univariate: 1.023/Gy, P < .001; multivariate: 1.055/Gy, P < .001) in HGG patients. Kaplan-Meier analysis showed significant correlations between OS and high-/low-dose groups for HGG patients (SVZ: respectively 10.7 months (>30.33 Gy) vs 14.0 months (<30.33 Gy) median OS, P = .011; SGZ: respectively 10.7 months (>29.11 Gy) vs 15.5 months (<29.11 Gy) median OS, P < .001). No correlations between dose and OS were found for LGG patients.

Conclusion

Irradiation doses on neurogenic areas correlate negatively with OS in patients with HGG. Whether sparing of the SVZ and SGZ during radiotherapy improves OS, should be subject of prospective studies.

Diffusion kurtosis imaging of white matter in bipolar disorder

White matter pathology likely contributes to the pathogenesis of bipolar disorder (BD). Most studies of white matter in BD have used diffusion tensor imaging (DTI), but the advent of more advanced multi-shell diffusion MRI imaging offers the possibility to investigate other aspects of white matter microstructure. Diffusion kurtosis imaging (DKI) extends the DTI model and provides additional measures related to diffusion restriction. Here, we investigated white matter in BD by applying whole-brain voxel-based analysis (VBA) and a network-based connectivity approach using constrained spherical deconvolution tractography to assess differences in DKI and DTI metrics between BD (n = 25) and controls (n = 24). The VBA showed lower mean kurtosis in the corona radiata and posterior association fibers in BD. Regional differences in connectivity were indicated by lower mean kurtosis and kurtosis anisotropy in streamlines traversing the temporal and occipital lobes, and lower mean axial kurtosis in the right cerebellar, thalamo-subcortical pathways in BD. Significant differences were not seen in DTI metrics following FDR-correction. The DKI findings indicate altered connectivity across cortical, subcortical and cerebellar areas in BD. DKI is sensitive to different microstructural properties and is a useful complementary technique to DTI to more fully investigate white matter in BD.

Assessment of soil quality in agroecosystems based on soil fauna

Soil arthropods respond sensitively to land management practices and correlate with beneficial soil functions. The aim of this research was to determine soil quality using the QBS index in different types of crops and influence of soil variables (pH soil, soil moisture, potassium, phosphorus and nitrogen) on soil arthropods. Between the years 2018 and 2020, we studied different types of crops (Brassica napus, Pisum sativum, Triticum aestivum, T. spelta, Zea mays, Grass mixture and Hordeum vulgare) and recorded 14 taxa. Our results suggest a higher QBS index value in crops grass mixture, Pisum sativum, Triticum aestivum, T. spelta. The EMI value grew with increasing values of soil moisture, soil pH, phosphorus, potassium and nitrogen; indicating the presence of soil arthropods occurring in higher quality soil. Our results suggest that agricultural intensification affects soil arthropods, which are important for the production of biomass, which also affects crop yields.

Assessment of soil quality in agroecosystems based on soil fauna

Soil arthropods respond sensitively to land management practices and correlate with beneficial soil functions. The aim of this research was to determine soil quality using the QBS index in different types of crops and influence of soil variables (pH soil, soil moisture, potassium, phosphorus and nitrogen) on soil arthropods. Between the years 2018 and 2020, we studied different types of crops (Brassica napus, Pisum sativum, Triticum aestivum, T. spelta, Zea mays, Grass mixture and Hordeum vulgare) and recorded 14 taxa. Our results suggest a higher QBS index value in crops grass mixture, Pisum sativum, Triticum aestivum, T. spelta. The EMI value grew with increasing values of soil moisture, soil pH, phosphorus, potassium and nitrogen; indicating the presence of soil arthropods occurring in higher quality soil. Our results suggest that agricultural intensification affects soil arthropods, which are important for the production of biomass, which also affects crop yields.

Morphological changes after cranial fractionated photon radiotherapy: Localized loss of white matter and grey matter volume with increasing dose

PURPOSE

Numerous brain MR imaging studies have been performed to understand radiation-induced cognitive decline. However, many of them focus on a single region of interest, e.g. cerebral cortex or hippocampus. In this study, we use deformation-based morphometry (DBM) and voxel-based morphometry (VBM) to measure the morphological changes in patients receiving fractionated photon RT, and relate these to the dose. Additionally, we study tissue specific volume changes in white matter (WM), grey matter (GM), cerebrospinal fluid and total intracranial volume (TIV).

METHODS AND MATERIALS

From our database, we selected 28 patients with MRI of high quality available at baseline and 1 year after RT. Scans were rigidly registered to each other, and to the planning CT and dose file. We used DBM to study non-tissue-specific volumetric changes, and VBM to study volume loss in grey matter. Observed changes were then related to the applied radiation dose (in EQD2). Additionally, brain tissue was segmented into WM, GM and cerebrospinal fluid, and changes in these volumes and TIV were tested.

RESULTS

Performing DBM resulted in clusters of dose-dependent volume loss 1 year after RT seen throughout the brain. Both WM and GM were affected; within the latter both cerebral cortex and subcortical nuclei show volume loss. Volume loss rates ranging from 5.3 to 15.3%/30 Gy were seen in the cerebral cortical regions in which more than 40% of voxels were affected. In VBM, similar loss rates were seen in the cortex and nuclei. The total volume of WM and GM significantly decreased with rates of 5.8% and 2.1%, while TIV remained unchanged as expected.

CONCLUSIONS

Radiotherapy is associated with dose-dependent intracranial morphological changes throughout the entire brain. Therefore, we will consider to revise sparing of organs at risk based on future cognitive and neurofunctional data.

Return to work and quality of life after trauma: A systematic review

Background

Globally, one-tenth of the disability-adjusted life-years (DALYs) are due to injuries. Injuries can reduce employment opportunities and significantly affect the quality of life (QOL). Most research on these outcomes tend to focus on specific mechanisms of injury like road traffic crashes or falls, or body regions affected such as brain or limbs. But rarely do patients come with just body region injured nor does the healthcare system only treat one specific mechanism of injury. Therefore, we aimed to assess and provide a systematic overview of current knowledge about return to work (RTW) and QOL among adult injured patients up to 1-year after discharge.

Methods

We conducted a systematic review of the literature published since 2010 on RTW and QoL among injured patients. Three databases (MEDLINE, EMBASE, the Cochrane Library) were used. Meta-analysis was performed based on outcome, measurement tool, and the effect measure. Methodological quality of the studies were evaluated using the Joanna Briggs Institute (JBI) Critical Appraisal Tool Checklist.

Results

41 articles were included in this review. More than one-third (36%) of patients had not yet returned to back to work even after 1-year. Those who did get back to work took an average time of more than 3 months. The QOL scores of the injured patients had not reached the general population or pre-injury levels even up to a year post-discharge. Women and the elderly tended have poorer outcomes and were under-represented in the studies. Over 75% of the included studies were from high-income countries (HICs) and had higher methodological quality. There were no studies from low-income countries (LICs).

Conclusions

RTW and QOL continue to remain a challenge even up to year since discharge after an injury, more so among women and the elderly. Health policy and practice should address this burden. Future studies should focus on building of high-quality evidence from LMICs on RTW and QOL among injury survivors.

Key messages

Return to work and quality of life were significantly low even after 1-year in trauma patients, especially among elderly and females. Larger representation of elderly, females, and participants from low- and middle-income setting in future long-term research on trauma patients.

OS03.4.A Irradiation of the subventricular and subgranular zone and overall survival in high-grade glioma patients

BACKGROUND

Previous research has shown that neural stem cells (NSCs) in the subventricular zone (SVZ) may support the growth of glioma by recruiting new cells to the tumor. NSCs are located in the SVZ as well as in the subgranular zone (SGZ) of the hippocampus, the two neurogenic niches of the brain. This might indicate that irradiation of the SVZ and SGZ, and thereby damaging NSCs, reduces tumor growth and improves overall survival (OS). However, irradiation may also inhibit the repair capacity of healthy brain tissue by these neurogenic niches. Therefore, we investigated the effects of SVZ and SGZ irradiation dose on OS, in a cohort of high-grade glioma patients.

MATERIAL AND METHODS

We have retrospectively selected 221 patients (2014–2020) with WHO grade III and IV gliomas that underwent radiotherapy. Next to clinical baseline characteristics, T1 weighted MRI- and CT-images were collected. The SVZ and SGZ regions on the individual T1 images were delineated via non-linear registration of brain atlases. SVZ labels were created in 0.5mm isotropic MNI T1 and T2 templates, while SGZ atlas labels were available via the Hippocampus and Subfields CoBrA atlas. Next, the mean dose from the acquired SVZ and SGZ labels were extracted. The relationship between SVZ doses, SGZ doses and OS were examined using the Cox proportional hazards model and the Kaplan-Meier method (using the Log Rank test for significance).

RESULTS

For the mean dose in the SVZ, the hazard ratio (HR) was 1.024 per Gy (P = 0.002, [95% confidence interval, 1.009–1.040]) and the mean SGZ dose had a HR of 1.021 per Gy (P&lt; 0.001, [95% confidence interval, 1.012–1.031]). These results were then corrected for the following covariates: sex, age, total intracranial volume and extent of surgery. This resulted in a HR of 1.031 per Gy (P = 0,001, [95% confidence interval, 1.014–1.050]) for the mean SVZ dose, and a HR of 1.025 per Gy (P&lt; 0.001, [95% confidence interval, 1.015–1.036]) for the mean SGZ dose. Patients whose SVZ received greater than the median SVZ dose (= 31.3 Gy) showed a significant decrease in OS compared to patients who received less than the median dose (10.7 months vs 13.5 months median OS, P = 0.001). Patients whose SGZ received greater than the median SGZ dose (= 31.9) showed a significant decrease in OS compared to patients who received less than the median dose (10.7 months vs 15.1 months median OS, P&lt; 0.001).

CONCLUSION

Here, we present a large cohort of high-grade glioma patients, in which we show a statistically significant decrease in overall survival with increasing radiation dose on the SGZ and SVZ. This correlation suggests that both neurogenic niches might need to be spared during radiotherapy treatment to improve overall survival even in high-grade glioma patients. Modern radiotherapy planning and delivery options are available to implement this.

P14.23 Relation between neurological deficits and location of postsurgical ischemia in glioma resection

BACKGROUND

Postoperative ischemia is a known complications of glioma resection and can lead to neurological deficits. New or worsened postoperative deficits are often transient, but some patients experience persisting effects after surgery. Neuroanatomical location of ischemia is suspected to play an important role in the development as well as persistence of neurological deficits. Therefore, the aim of this study was to investigate the spatial relation between postoperative ischemia and short-term and long-term neurological deficits.

MATERIAL AND METHODS

Postoperative ischemia was defined as new confluent areas of diffusion restriction on DWI in a retrospective database of 144 adult WHO grade II-IV supratentorial glioma patients, who received MRI within 3 days after resection in 2012–2014. New or worsened neurological deficits of any grade at discharge and after 3 months was assessed in relation to postoperative ischemia by an experienced neuro-oncologist. We manually delineated ischemic lesions and spatially normalized these to stereotaxic MNI space. Next, we performed voxel-based analysis (VBA) to identify locations of ischemia associated with new or worsened neurological deficits and corrected for multiple comparisons using family-wise error correction to eliminate false positive results. Delineations were labeled using the Harvard-Oxford cortical and subcortical atlases and a white matter atlas (XTRACT).

RESULTS

Any new or worsened neurological deficits were present in 44 (30.5%) cases at discharge and in 27 (20.9%) cases after 3 months, of which respectively 26 (18%) and 21 (16.3%) were related to ischemia. Volume of ischemia was significantly associated with deficits at discharge (P = 0.003) and after 3 months (P = 0.039). No areas of ischemia were associated with a lack of new or worsened deficits. A statistically significant cluster of 42.96cc was associated with deficits at discharge and encompassed the right frontal, insular and tempo-occipital regions. Voxels associated only with deficits at discharge included lateral occipital cortices and supramarginal gyri. A cluster of 17.68cc in the right frontal and insular lobes was significantly associated with deficits after 3 months. Overlapping areas included the right thalamus, caudate nucleus, putamen, globus pallidum, insular cortex, middle and inferior temporal gyri, corticospinal tract and superior thalamic radiation.

CONCLUSION

Transient and persisting new or worsened deficits after glioma resection were significantly associated with volume of postoperative ischemia. Ischemic lesions in right frontal and insular regions, including the basal nuclei, corticospinal tract and superior thalamic radiation were significantly associated with persisting neurological deficits after 3 months, while temporo-occipital lesions were associated with transient deficits only found at discharge.

P14.30 Voxelwise analysis of spatial distribution of postoperative ischemia in diffuse glioma

BACKGROUND

Surgical treatment of diffuse glioma is performed to reduce tumor mass effect and to pave the way for adjuvant (chemo)radiotherapy. As a complication of surgery, ischemic lesions are often found in the postoperative setting. Not only can these lesion induce neurological deficits, but their volume has also been associated with reduced survival time. Prior studies suggest areas with a singular vascular supply to be more prone to postoperative ischemic lesions, although the precise cause is yet unknown. The aim of this study was to explore the volumetric and spatial distributions of postoperative ischemic lesions and their relation to arterial territories in glioma patients.

MATERIAL AND METHODS

We accessed a retrospective database of 144 adult cases with WHO grade II-IV supratentorial gliomas, who received surgery and postoperative MRI within 3 days in 2012–2014. We identified 93 patients with postoperative ischemia, defined as new confluent diffusion restriction on DWI. Ischemic lesions were manually delineated and spatially normalized to stereotaxic MNI space. Voxel-based analysis (VBA) was performed to compare presence and absence of postoperative ischemia. False positive results were eliminated by family-wise error correction. Areas of ischemia were labeled using an arterial territory map, the Harvard-Oxford cortical and subcortical atlases and the XTRACT white matter atlas.

RESULTS

Median volume of confluent ischemia was 3.52cc (IQR 2.15–5.94). 23 cases had only ischemic lesion in the left hemisphere, 46 in the right hemisphere and 24 bilateral. Median volume was 3.08cc (IQR 1.35–5.72) in left-sided lesions and 2.47cc (1.01–4.24) in right-sided lesions. Volume of ischemic lesions was not associated with survival after 1, 2 or 5 years. A cluster of 125.18cc was found to be significantly associated with development of postoperative ischemia. 73% of this cluster was situated in the arterial territory of the right middle cerebral artery (MCA), limited by the border of the posterior cerebral artery (PCA), and the watershed area between the right MCA and the right anterior cerebral artery (ACA). Significant areas were located in the frontal lobes, spanning into the right temporo-occipital region, and predominantly included right and left thalamus, caudate nucleus, putamen, pallidum, as well as right temporal gyri and insular cortex, and parts of the right corticospinal tract, longitudinal fasciculi and superior thalamic radiation.

CONCLUSION

We found slightly more and larger ischemic lesions in the right than left hemisphere after glioma resection. A statistically significant cluster of voxels of postoperative ischemia was found in the territory of the right MCA and watershed area of the right ACA. Exploration of the spatial distribution of these lesions could help elucidate their etiology and form the basis for predicting clinically relevant postoperative ischemia.

The influence of relief morphometric characteristics upon the occurrence of the species Cordulegaster bidentata in the particular conditions of the Western Carpathians

The study concerns a monitoring survey of Cordulegaster bidentata Selys, 1843 (Odonata, Cordulegastridae), which is considered near threatened in the European Red List of Dragonflies, in order to show its habitat preferences and clarify the influence of slope and orientation of slopes on the occurrence of the species. Investigations of water habitats were carried out during the period from 2019 to 2020 in the Kysuce Region in northwest Slovakia. The protocol consists of looking for larvae and characterizing larval micro-habitat of C. bidentata so as to show their habitat preferences and clarify the influence of slope and orientation of slopes on the occurrence of the species. We sampled 32 watercourses (epicrenal, hypocrenal, rheocren, heleocren, epirhithral, metarhithral) at altitudes 420–950 m above sea level. A total of 79 larvae and 10 imagines (7♂ 3♀) of C. bidentata were found at 12 streams. In the present study, C. bidentata clearly preferred first-order stream sections, the slopes were steep and the proportion of small sediment grain sizes was high. The results show that the number of C. bidentata larvae grew with the increasing percentage of forests around streams. We also confirmed the trend for the number of C. bidentata larvae to increase with increasing values of slope and altitude of watercourses. Most of the individuals were recorded at the south and southwest oriented streams; we did not record larvae on the north and northwest oriented slopes. We assume that more suitable conditions for development of population exist in the streams on the south and southwest oriented slopes. The preference for watercourses oriented south and southwest ensures optimal conditions for the development of the population of this dragonfly species. The finding of larvae at the stages of instars shows the permanent occurrence of the species in the Kysuce Region.

ESC 2019 guidelines on chronic coronary syndromes: can calcium scoring improve the risk underestimation associated with the updated pre-test probability risk score?

Funding Acknowledgements

Type of funding sources: None.

Introduction

The European Society of Cardiology (ESC) published an updated stable chest pain guideline in 2019. It recommends the use of an updated pre-test probability (PTP) risk score (RS) to assess the likelihood of coronary artery disease (CAD), to try and reduce the risk overestimation associated with previous risk scores. We sought to assess the performance of the 2019 PTPRS in a contemporary cohort of patients undergoing CT coronary angiography (CTCA). Furthermore, we focussed on patients with PTPRS &lt;15%, and assessed the utility of CT calcium scores as a discriminator of risk.

Methods

652 patients who were investigated with CTCA for stable chest pain between January 2017 and May 2018 were included in a retrospective analysis. CTCA reported CAD degree of stenosis as normal/minimal stenosis, mild (30-50%), moderate (50-70%), or severe (&gt;70%). ESC 2019 pre-test probability risk scores were retrospectively calculated and compared.

Results

A total of 652 patients underwent CTCA between 01 January 2017 and 31 May 2018, of which 330 were male and 322 were female, with an average age of 55 years ±11 years.

Using the ESC 2019 PTPRS there were no patients with PTPRS &gt;85%. 2 patients had PTPRS 50-85%; one patient had moderate stenosis and one mild stenosis on CTCA. 

There were 267 patients with PTPRS 15-50%; 23 (9%) patients had severe CTCA stenosis, 37 (14%) a moderate stenosis, and 34 (13%) a mild stenosis.

A further 379 patients had PTPRS &lt;15%; 11 (3%) had severe stenosis and 20 (5%) moderate stenosis. A further 27 (7%) patients had mild CTCA stenosis. 

A total of 357 of 379 patients with PTPRS &lt;15% based on ESC 2019 had a CT calcium score. 236 patients were found to have a calcium score of zero, and 121 patients had a score greater than zero, with a range between 1 and 930. Of patients with zero calcium score, only 1 (0.4%) patient had severe stenosis, 2 (0.8%) moderate stenoses and 6 (2.5%) mild stenosis. In contrast, in patients with positive calcium scores, 10 (8%) had severe stenosis, 18 (15%) moderate stenosis, and 22 (18%) mild stenosis.

Conclusions

The ESC 2019 PTPRS classified this as an overall low risk cohort. The downward risk modification of PTPRS has led to a large number of patients being classified as low risk with PTPRS &lt;15%. No or deferred investigation is recommended by the ESC in this cohort. However, the use of CT calcium scores  in patients with PTPRS &lt;15%, detected the majority of patients with any degree of CAD. CT calcium scores are a simple and low cost risk modifier, and may help identify patients who may benefit from primary prevention as per SCOT-Heart. Patients with calcium score greater than zero could be investigated with CTCA.

Rapid detection and differentiation of mobile colistin resistance (mcr-1 to mcr-10) genes by real-time PCR and melt-curve analysis

BACKGROUND

The emergence of multi-drug-resistant (MDR) micro-organisms prompted new interest in older antibiotics, such as colistin, that had been abandoned previously due to limited efficacy or high toxicity. Over the years, several chromosomal-encoded colistin resistance mechanisms have been described; more recently, 10 plasmid-mediated mobile colistin resistance (mcr) genes have been identified. Spread of these genes among MDR Gram-negative bacteria is a matter of serious concern; therefore, reliable and timely mcr detection is paramount.

AIM

To design and validate a multiplex real-time polymerase chain reaction (PCR) assay for detection and differentiation of mcr genes.

METHODS

All available mcr alleles were downloaded from the National Center for Biotechnology Information Reference Gene Catalogue, aligned with Clustal Omega and primers designed using Primer-BLAST. Real-time PCR monoplexes were optimized and validated using a panel of 120 characterized Gram-negative strains carrying a wide range of resistance genes, often in combination. Melt-curve analysis was used to confirm positive results.

FINDINGS

In-silico analysis enabled the design of a 'screening' assay for detection of mcr-1/2/6, mcr-3, mcr-4, mcr-5, mcr-7, mcr-8 and mcr-9/10, paired with an internal control assay to discount inhibition. A 'supplementary' assay was subsequently designed to differentiate mcr-1, mcr-2, mcr-6, mcr-9 and mcr-10. Expected results were obtained for all strains (100% sensitivity and specificity). Melt-curve analysis showed consistent melting temperature results. Inhibition was not observed.

CONCLUSIONS

The assay is rapid and easy to perform, enabling unequivocal mcr detection and differentiation even when more than one variant is present. Adoption by clinical and veterinary microbiology laboratories would aid the surveillance of mcr genes amongst Gram-negative bacteria.

ESC 2019 guidelines on chronic coronary syndromes: could calcium scoring improve detection of coronary artery disease in patients with low risk score. Findings from a retrospective cohort of patients in a district general hospital

BACKGROUND

The European Society of Cardiology (ESC) published an updated stable chest pain guideline in 2019, recommending the use of an updated pre-test probability (PTP) risk score (RS) to assess the likelihood of coronary artery disease (CAD). We sought to compare the 2019 and 2013 PTPRS in a contemporary cohort of patients.

METHODS

612 patients who were investigated with computed tomography coronary angiography (CTCA) for stable chest pain were included in a retrospective analysis.

RESULTS

There were 255 patients with 2019 PTPRS 15-50% with a 9% yield of severe CAD on CTCA, compared with 402 patients and a 4% yield using the 2013 PTPRS (p = 0.01). 355 patients had a 2019 PTPRS of <15%, with 3% found to have severe CAD, compared with 67 patients and none with severe CAD using the 2013 PTPRS (p = 0.14). 336 of patients with 2019 PTPRS of <15% had a calcium score as part of the CTCA. 223 of these had a zero calcium score and only one had severe CAD. In comparison, 113 patients had a positive calcium score, and 10 (9%) had severe CAD (p < 0.001).

DISCUSSION

The ESC 2019 PTPRS classifies more patients as at lower risk of CAD and hence reduces the risk overestimation associated with the 2013 PTPRS. However, in patients with a 2019 PTPRS of <15%, who would not be investigated, the use of the calcium score detected the majority of patients with significant CAD, who may benefit from secondary prevention and an associated mortality benefit as per the SCOT-Heart trial.

[What is evidence-based in the treatment of sepsis?]

BACKGROUND

The term sepsis was redefined in 2016 as a life-threatening organ dysfunction caused by an inadequate host response to an infection. The German S3 guidelines for the treatment of sepsis were published in 2018.

OBJECTIVE

What is evidence-based in the treatment of patients with sepsis?

MATERIAL AND METHODS

Discussion of the S3 guidelines and inclusion of study results after 2018.

RESULTS

The cornerstones for the treatment of sepsis continue to consist of early hemodynamic stabilization, anti-infection treatment and organ support procedures. Supportive and extracorporeal treatments are controversially discussed and continue to be intensively investigated.

CONCLUSION

Despite an improved understanding of the pathophysiology, there is still no effective causal sepsis treatment, i.e. directed against the pathological host reaction. The treatment of patients with sepsis is therefore still based on the basic principles of correction of volume deficits, anti-infective agents, source control and organ support, including the symptomatic treatment of vasoplegia with catecholamines.

Long-term Survival with 18-Fluorodeoxyglucose Positron Emission Tomography-directed Therapy in Non-small Cell Lung Cancer with Synchronous Solitary Brain Metastasis

AIMS

At diagnosis, <1% of patients with non-small cell lung cancer (NSCLC) have synchronous solitary brain metastasis (SSBM). In prior cohorts without 18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) staging, definitive treatment to intracranial and intrathoracic disease showed a 5-year overall survival (OS) of 11-21%. We investigated the long-term survival outcomes for patients with SSBM NSCLC, diagnosed in the FDG-PET/CT era and treated definitively with local therapies to both intracranial and intrathoracic sites of disease.

MATERIALS AND METHODS

This retrospective study assessed patients staged with FDG-PET/CT who received definitive lung and SSBM treatment from February 1999 to December 2017. A lung-molecular graded prognostic assessment (lung-molGPA) score was assigned for each patient using age, performance status score, and, where carried out, molecular status. Overall survival and progression-free survival (PFS) were calculated using Kaplan-Meier methods. Cox proportional hazard models determined OS and PFS prognostic factors.

RESULTS

Forty-nine patients newly diagnosed with NSCLC and SSBM had a median age of 63 years (range 34-76). The median follow-up of all patients was 3.9 years. Thirty-three patients (67%) had ≥T2 disease, 23 (47%) had ≥N2. At 2 years, 45% of first failures were intracranial only (95% confidence interval 30-59). At 3 and 5 years, OS was 45% (95% confidence interval 32-63) and 30% (95% confidence interval 18-51), respectively. In ≥N1 disease, 5-year OS was 34% (95% confidence interval 18-63). The 3- and 5-year PFS was 8% (95% confidence interval 3-22) and 0%, respectively. Higher lung-molGPA was associated with longer OS (hazard ratio 0.26, 95% confidence interval 0.11-0.61, P = 0.002). Higher lung-molGPA (hazard ratio 0.33, 95% confidence interval 0.15-0.71, P = 0.005) and lower N-stage (hazard ratio 1.56, 95% confidence interval 1.13-2.15, P = 0.007) were associated with longer PFS.

CONCLUSIONS

Definitive treatment of patients with NSCLC and SSBM staged with FDG-PET/CT can result in 5-year survivors, including those with ≥N1 disease.

[Treatment of severe COVID-19 courses in intensive care medicine]

Die durch die „coronavirus disease 2019“ (COVID-19) ausgelöste Pandemie hat die Intensivmedizin in den Fokus der Öffentlichkeit gerückt. Die Sterblichkeit der Erkrankten eskaliert v. a. in dem Moment, in dem die intensivmedizinischen Versorgungsmöglichkeiten enden. In der täglichen intensivmedizinischen Praxis werden die Herausforderungen durch die Besonderheiten der Infektion mit dem „severe acute respiratory syndrome coronavirus 2“ (SARS-CoV-2) und ihrer Behandlung deutlich. Diese bestehen in der Entwicklung und Therapie von Lungen‑, Multiorganversagen sowie des schweren Inflammationssyndroms. Zu diesen schweren Verläufen ist noch wenig Evidenz darüber vorhanden, welche Interventionen am effektivsten sind. Neben Erkenntnissen, die aus der raschen Durchführung klinischer Studien gewonnen wurden, stützt sich die Behandlung daher auch auf Analogien zu anderen Syndromen wie der Sepsis und dem Makrophagenaktivierungssyndrom.

Indirect frontocingulate structural connectivity predicts clinical response to accelerated rTMS in major depressive disorder

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is an established treatment for major depressive disorder (MDD), but its clinical efficacy remains rather modest. One reason for this could be that the propagation of rTMS effects via structural connections from the stimulated area to deeper brain structures (such as the cingulate cortices) is suboptimal.

METHODS

We investigated whether structural connectivity — derived from diffusion MRI data — could serve as a biomarker to predict treatment response. We hypothesized that stronger structural connections between the patient-specific stimulation position in the left dorsolateral prefrontal cortex (dlPFC) and the cingulate cortices would predict better clinical outcomes. We applied accelerated intermittent theta burst stimulation (aiTBS) to the left dlPFC in 40 patients with MDD. We correlated baseline structural connectivity, quantified using various metrics (fractional anisotropy, mean diffusivity, tract density, tract volume and number of tracts), with changes in depression severity scores after aiTBS.

RESULTS

Exploratory results (p < 0.05) showed that structural connectivity between the patient-specific stimulation site and the caudal and posterior parts of the cingulate cortex had predictive potential for clinical response to aiTBS.

LIMITATIONS

We used the diffusion tensor to perform tractography. A main limitation was that multiple fibre directions within voxels could not be resolved, which might have led to missing connections in some patients.

CONCLUSION

Stronger structural frontocingular connections may be of essence to optimally benefit from left dlPFC rTMS treatment in MDD. Even though the results are promising, further investigation with larger numbers of patients, more advanced tractography algorithms and classic daily rTMS treatment paradigms is warranted.

CLINICAL TRIAL REGISTRATION

http://clinicaltrials.gov/show/NCT01832805

Effect of radiation therapy on cerebral cortical thickness in glioma patients: Treatment-induced thinning of the healthy cortex

Background

With overall survival of brain tumors improving, radiation induced brain injury is becoming an increasing issue. One of the effects of radiation therapy (RT) is thinning of the cerebral cortex, which could be one of the factors contributing to cognitive impairments after treatment. In healthy brain, cortex thickness varies between 1 and 4.5 mm. In this study, we assess the effect of RT on the thickness of the cerebral cortex and relate the changes to the local dose.

Methods

We identified 28 glioma patients with optimal scan quality. Clinical CTs and MRIs at baseline and 1 year post-RT were collected and coregistered. The scans were processed via an automated image processing pipeline, which enabled measuring changes of the cortical thickness, which were related to local dose.

Results

Three areas were identified where significant dose-dependent thinning occurred, with thinning rates of 5, 6, and 26 μm/Gy after 1 year, which corresponds to losses of 5.4%, 7.2%, and 21.6% per 30 Gy per year. The first area was largely located in the right inferior parietal, supramarginal, and superior parietal regions, the second in the right posterior cingulate and paracentral regions, and the third almost completely in the right lateral orbital frontal region.

Conclusions

We have identified three areas susceptible to dose-dependent cortical thinning after radiation therapy. Should future prospective studies conclude that irradiation of these areas lead to cognitive decline, they need to be spared in order to prevent this debilitating consequence of treatment.

Kinetic study of hydrogen lateral diffusion at high temperature in a directly-bonded InP-SiO2/Si substrate

Hybrid integration of III-V materials onto silicon by direct bonding technique is a mature and promising approaches to develop advanced photonic integrated devices into the silicon photonics platform. In this approach, the III-V material stack is grown on an InP wafer in a unique epitaxial step prior to the direct bonding process onto the silicon-on-insulator wafer. Currently, no additional epitaxial regrowth steps are implemented after bonding. This can be seen as a huge limitation as compared to the III-V on III-V wafer mature technology where multi-regrowth steps are most often implemented. In this work, we have studied the material behavior of an InP membrane on silicon (InPoSi) under epitaxial regrowth conditions by metal-organic vapor phase epitaxy (MOVPE). MOVPE requires high-temperature elevation, typically above 600 °C. We show for the first time the appearance of voids at 400 °C in an InP seed (100 nm) directly-bonded onto a thermally oxidized Si substrate despite the use of a thick SiO₂ oxide (200 nm) at the bonding interface. This phenomenon is explained by a weakening of the bonding interface while high-pressurized hydrogen is present. A kinetic study of the hydrogen lateral diffusion is carried out, enabling the assessment of its lateral diffusion length. To overcome the void formation, highly efficient outgassing trenches after bonding are demonstrated. Finally, high-quality AlGaInAs-based multi-quantum well (MQW) heterostructure surrounded by two InP layers was grown by MOVPE on InPoSi template patterned with outgassing trenches. This process is not only compatible with MOVPE regrowth conditions (650 °C under PH₃) but also with conventional fabrication processes used for photonic devices.

P1589 Yield of invasive coronary angiography following the UK NICE 2016 guideline expansion of CT coronary angiography

Results

In total 652 patients underwent CTCA (mean age 55 yrs; 330 male). 92 patients were found to have moderate or severe stenosis. 69 of them were referred directly to ICA, with 63 undergoing ICA and confirming severe CAD in 40 patients, a yield of 63%. 18 patients with moderate stenosis were referred for stress echo (SE) with one positive result. In total 35 patients went on to be revascularised.

62 patients were found to have mild stenosis. The majority of patients (n = 462) had normal/minimal stenosis. There were 36 inconclusive studies.

The ESC RS was calculated retrospectively with the following results:

70 patients had an ESC RS &lt;15% and 2 (3%) were found to have moderate stenosis. 427 patients had an ESC RS 15-50%; 17 (4%) had severe stenosis and 32 (8%) moderate stenosis. 149 patients had an ESC RS 50-85%; 17 (11%) were found to have severe stenosis and 23 (15%) moderate stenosis. Lastly 2 patients had an ESC RS &gt;85% and one had moderate stenosis.

Conclusions

Our results demonstrate that CTCA is an effective first line test for most patients with new stable chest pain as the majority were found to have normal/minimal disease. In the patients that went on to have ICA, CTCA had a relatively high yield of detecting severe CAD (63%). This was achieved with some use of SE as a gatekeeper to ICA, particularly in patients with moderate CTCA stenosis. SE should be used more after CTCA in patients with moderate stenosis, as a gatekeeper to ICA.

The ESC RS was predictive of significant CAD but overestimated the likelihood of CAD.

Abstract P1589 Figure. Severe CTCA stenosis of the LAD

P1487 Anomalous right coronary artery from mid left anterior descending artery

55-year-old male with history of transient ischaemic attack, excised gastro-intestinal stromal tumour, and osteoarthritis presented to rapid access chest pain clinic with history of atypical chest pain. There were no resting electrocardiographic changes. In accordance with NICE stable chest pain guidelines, a CT coronary angiogram was requested to further assess for any underlying coronary artery disease. This showed normal origin of left main stem (LMS) from left coronary sinus of aorta, however there was an anomalous origin of the right coronary artery (RCA) as a branch from the mid portion of left anterior descending artery (LAD). This was deemed to be an incidental finding with a benign course and not the cause of his symptoms.

Coronary anomalies have a reported incidence of 1.3% at invasive coronary angiography (1), and a reported incidence of 0.014-0.066% of single coronary artery (2). Anomalous RCA usually courses from the LMS and courses between the aorta and pulmonary artery. We present an extremely rare variant of single coronary artery arising from the mid LAD without any associated congenital or structural abnormality, on CT coronary angiography (the gold standard for demonstrating coronary anatomy). This is rarely reported in the literature and is a benign coronary anomaly.

Abstract P1487 Figure.