scholarly journals [18F]-Fluciclovine PET discrimination of recurrent intracranial metastatic disease from radiation necrosis

2020 ◽  
Author(s):  
Ephraim Edward Parent ◽  
Dhruv Patel ◽  
Jonathon A Nye ◽  
Li Zhuo ◽  
Jeffrey Olson ◽  
...  
Keyword(s):  
Metastatic Disease ◽  
Recurrent Disease ◽  
Radiation Necrosis ◽  
Brain Parenchyma ◽  
Normal Brain ◽  
Time Activity ◽  
Time Points ◽  
Contralateral Normal Brain ◽  
Intracranial Metastatic Disease ◽  
Time Point

Abstract Background Stereotactic radiosurgery (SRS) is often the primary treatment modality for patients with intracranial metastatic disease. Despite advances in magnetic resonance imaging, including use of perfusion and diffusion sequences and molecular imaging, distinguishing radiation necrosis from progressive tumor remains a diagnostic and clinical challenge. We investigated the sensitivity and specificity of 18F-fluciclovine PET to accurately distinguish radiation necrosis from recurrent intracranial metastatic disease in patients who had previously undergone SRS. Methods Fluciclovine PET imaging was performed in 8 patients with a total of 15 lesions that had previously undergone SRS and had subsequent MRI and clinical features suspicious for recurrent disease. The SUVmax of each lesion and the contralateral normal brain parenchyma were summated and evaluated at 4 different time points (5 minutes, 10 minutes, 30 minutes, and 55 minutes). Lesions were characterized as either recurrent disease (11 of 15 lesions) or radiation necrosis (4 of 15 lesions) and confirmed with histopathological correlation (7 lesions) or through serial MRI studies (8 lesions). Results Time activity curve analysis found statistically greater radiotracer accumulation for all lesions, including radiation necrosis, when compared to contralateral normal brain. While the mean and median SUVmax for recurrent disease was statistically greater than that of radiation necrosis at all time points, the difference was more significant at the earlier time points (p = 0.004 at 5 min – 0.025 at 55 min). Using a SUVmax threshold of ≥ 1.3, fluciclovine PET demonstrated a 100% accuracy in distinguishing recurrent disease from radiation necrosis up to 30 minutes after injection and an accuracy of 87% (sensitivity = 0.91, specificity = 0.75) at the last time point of 55 minutes. However, tumor to brain ratios (TBRmax) were not significantly different between recurrent disease and radiation necrosis at any time point due to variable levels of fluciclovine uptake in the background brain parenchyma. Conclusions Fluciclovine PET may play an important role in distinguishing active intracranial metastatic lesions from radiation necrosis in patients previously treated with SRS but needs to be validated in larger studies.

scholarly journals [18F]-Fluciclovine PET discrimination of recurrent intracranial metastatic disease from radiation necrosis

2020 ◽  
Author(s):  
Ephraim Edward Parent ◽  
Dhruv Patel ◽  
Jonathon A Nye ◽  
Li Zhuo ◽  
Jeffrey Olson ◽  
...  
Keyword(s):  
Metastatic Disease ◽  
Recurrent Disease ◽  
Radiation Necrosis ◽  
Brain Parenchyma ◽  
Normal Brain ◽  
Time Activity ◽  
Time Points ◽  
Contralateral Normal Brain ◽  
Intracranial Metastatic Disease ◽  
Time Point

Abstract Background Stereotactic radiosurgery (SRS) is often the primary treatment modality for patients with intracranial metastatic disease. Despite advances in magnetic resonance imaging, including use of perfusion and diffusion sequences and molecular imaging, distinguishing radiation necrosis from progressive tumor remains a diagnostic and clinical challenge. We investigated the sensitivity and specificity of 18F-fluciclovine PET to accurately distinguish radiation necrosis from recurrent intracranial metastatic disease in patients who had previously undergone SRS. Methods Fluciclovine PET imaging was performed in 8 patients with a total of 15 lesions that had previously undergone SRS and had subsequent MRI and clinical features suspicious for recurrent disease. The SUVmax of each lesion and the contralateral normal brain parenchyma were summated and evaluated at 4 different time points (5 minutes, 10 minutes, 30 minutes, and 55 minutes). Lesions were characterized as either recurrent disease (11 of 15 lesions) or radiation necrosis (4 of 15 lesions) and confirmed with histopathological correlation (7 lesions) or through serial MRI studies (8 lesions). Results Time activity curve analysis found statistically greater radiotracer accumulation for all lesions, including radiation necrosis, when compared to contralateral normal brain. While the mean and median SUVmax for recurrent disease was statistically greater than that of radiation necrosis at all time points, the difference was more significant at the earlier time points (p = 0.004 at 5 min – 0.025 at 55 min). Using a SUVmax threshold of ≥1.3, fluciclovine PET demonstrated a 100% accuracy in distinguishing recurrent disease from radiation necrosis up to 30 minutes after injection and an accuracy of 87% (sensitivity = 0.91, specificity = 0.75) at the last time point of 55 minutes. However, tumor to brain ratios (TBRmax) were not significantly different between recurrent disease and radiation necrosis at any time point due to variable levels of fluciclovine uptake in the background brain parenchyma. Conclusions Fluciclovine PET may play an important role in distinguishing active intracranial metastatic lesions from radiation necrosis in patients previously treated with SRS but needs to be validated in larger studies.

scholarly journals [18F]-Fluciclovine PET discrimination of recurrent intracranial metastatic disease from radiation necrosis

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ephraim E. Parent ◽  
Dhruv Patel ◽  
Jonathon A. Nye ◽  
Zhuo Li ◽  
Jeffrey J. Olson ◽  
...  
Keyword(s):  
Metastatic Disease ◽  
Recurrent Disease ◽  
Radiation Necrosis ◽  
Brain Parenchyma ◽  
Normal Brain ◽  
Time Activity ◽  
Time Points ◽  
Contralateral Normal Brain ◽  
Intracranial Metastatic Disease ◽  
Time Point

Abstract Background Stereotactic radiosurgery (SRS) is often the primary treatment modality for patients with intracranial metastatic disease. Despite advances in magnetic resonance imaging, including use of perfusion and diffusion sequences and molecular imaging, distinguishing radiation necrosis from progressive tumor remains a diagnostic and clinical challenge. We investigated the sensitivity and specificity of 18F-fluciclovine PET to accurately distinguish radiation necrosis from recurrent intracranial metastatic disease in patients who had previously undergone SRS. Methods Fluciclovine PET imaging was performed in 8 patients with a total of 15 lesions that had previously undergone SRS and had subsequent MRI and clinical features suspicious for recurrent disease. The SUVmax of each lesion and the contralateral normal brain parenchyma were summated and evaluated at four different time points (5 min, 10 min, 30 min, and 55 min). Lesions were characterized as either recurrent disease (11 of 15 lesions) or radiation necrosis (4 of 15 lesions) and confirmed with histopathological correlation (7 lesions) or through serial MRI studies (8 lesions). Results Time activity curve analysis found statistically greater radiotracer accumulation for all lesions, including radiation necrosis, when compared to contralateral normal brain. While the mean and median SUVmax for recurrent disease were statistically greater than those of radiation necrosis at all time points, the difference was more significant at the earlier time points (p = 0.004 at 5 min–0.025 at 55 min). Using a SUVmax threshold of ≥ 1.3, fluciclovine PET demonstrated a 100% accuracy in distinguishing recurrent disease from radiation necrosis up to 30 min after injection and an accuracy of 87% (sensitivity = 0.91, specificity = 0.75) at the last time point of 55 min. However, tumor-to-background ratios (TBRmax) were not significantly different between recurrent disease and radiation necrosis at any time point due to variable levels of fluciclovine uptake in the background brain parenchyma. Conclusions Fluciclovine PET may play an important role in distinguishing active intracranial metastatic lesions from radiation necrosis in patients previously treated with SRS but needs to be validated in larger studies.

Radiotherapy for Brain Tumors: Current Practice and Future Directions

2020 ◽  
Vol 16 (3) ◽  
pp. 182-195
Author(s):  
Sarah Baker ◽  
Natalie Logie ◽  
Kim Paulson ◽  
Adele Duimering ◽  
Albert Murtha
Keyword(s):  
Brain Tumors ◽  
Treatment Strategies ◽  
Brain Parenchyma ◽  
Benign Tumors ◽  
Tumor Control ◽  
Normal Brain ◽  
Neurocognitive Deficits ◽  
Close Proximity ◽  
Recent Developments ◽  
High Level

Radiotherapy is an important component of the treatment for primary and metastatic brain tumors. Due to the close proximity of critical structures and normal brain parenchyma, Central Nervous System (CNS) radiotherapy is associated with adverse effects such as neurocognitive deficits, which must be weighed against the benefit of improved tumor control. Advanced radiotherapy technology may help to mitigate toxicity risks, although there is a paucity of high-level evidence to support its use. Recent advances have been made in the treatment for gliomas, meningiomas, benign tumors, and metastases, although outcomes remain poor for many high grade tumors. This review highlights recent developments in CNS radiotherapy, discusses common treatment toxicities, critically reviews advanced radiotherapy technologies, and highlights promising treatment strategies to improve clinical outcomes in the future.

scholarly journals Cytotoxicity assessment of different doses of ozonated water on dental pulp cells

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ferdiye Küçük ◽  
Sibel Yıldırım ◽  
Serap Çetiner
Keyword(s):  
Cell Viability ◽  
Repeated Measures ◽  
Dental Pulp ◽  
Control Group ◽  
Dental Pulp Cells ◽  
Time Points ◽  
Significant Difference ◽  
Pulp Cells ◽  
Time Point ◽  
Ozonated Water

Abstract Background The purpose of this study was to assess the cytotoxicity of various concentrations of ozonated water (OW) on human primary dental pulp cells. Methods Human primary dental pulp cells were isolated from exfoliated primary canine teeth of an 11-year-old patient with good systemic and oral health. Afterwards, cells were divided into 6 experimental groups; four groups of OW in concentrations of 2 mg/L, 4 mg/L, 8 mg/L, and 16 mg/L, untreated control group, and cell culture without cells. Cytotoxicity was evaluated after exposure for 5-min exposure using Mosmann’s Tetrazolium Toxicity (MTT) assay at 0 h and 48 h time points. Data were analyzed using a repeated measures analysis of variance and Post-hoc tests were performed using Bonferroni correction for multiple comparisons. Results All experimental groups showed proliferation at 0 h time point. However, all groups also experienced a decrease in overtime at 48 h time point (p < 0.05). At both time points 2 mg/L OW showed the highest cell viability as well as proliferation. At 0 h time point, the increase in cell viability for all experimental groups was found statistically significant when compared to positive control group (p < 0.05). At 48 h time point, although 8 mg/L and 16 mg/L OW showed statistically significant reduction in compare to 0 h time point, 2 mg/L and 4 mg/L OW groups didn’t experience any statistically significant difference (p < 0.05). Conclusion Considering our findings, due to ozonated water's induced a higher proliferation rate of dental pulp cells, indicating their biocompatibility and a possible adjuvant on irrigating agent in regenerative endodontic procedures.

scholarly journals Levels of physical activity in four domains and affective wellbeing before and during the Covid-19 pandemic

2021 ◽  
Vol 79 (1) ◽  
Author(s):  
Eliane S. Engels ◽  
Michael Mutz ◽  
Yolanda Demetriou ◽  
Anne K. Reimers
Keyword(s):  
Mental Health ◽  
Physical Activity ◽  
Protective Factor ◽  
Total Sample ◽  
Poor Mental Health ◽  
German Population ◽  
Time Points ◽  
Sport And Exercise ◽  
Over Time ◽  
Time Point

Abstract Background Latest studies indicated that the general mental health level is low during the pandemic. Probably, this deterioration of the mental health situation is partly due to declines in physical activity. The aim of this study was to investigate differences in and the association between affective wellbeing and levels of different domains of physical activity at three time points before and during the pandemic. Method We used a nationwide online panel with a trend data design encompassing a total sample of N = 3517, representing the German population (> 14 years). Four different activity domains (sport and exercise, light outdoor activity, housework/gardening, active travel) and affective wellbeing (positive and negative affect) were assessed at three time points before and during the Covid-19 pandemic (October 2019, March 2020, October 2020). Results Multivariate analyses of variance (MANOVA) indicate differences regarding affective wellbeing over the three time points with the lowest values at the second time point. Levels of activity in the four domains differed significantly over time with the strongest decrease for sport and exercise from the first to the second time point. Partial correlations indicated that the relationships between sport and exercise and positive affect were most consistent over time. Conclusions Overall, our findings suggest that physical activity plays a particularly important role in the pandemic period as a protective factor against poor mental health. Especially sports and exercise seem to be supportive and should be encouraged, e.g. by providing additional support in finding adequate outdoor, home-based or digital substitutes.

scholarly journals Propagation of Voltage Deviations in a Power System

Electronics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 949
Author(s):  
Tomasz Okon ◽  
Kazimierz Wilkosz
Keyword(s):  
Power System ◽  
Case Studies ◽  
Measurement Data ◽  
Theoretical Background ◽  
Original Method ◽  
Operational Experience ◽  
Remedial Measures ◽  
Time Points ◽  
General Candidate ◽  
Time Point

The paper deals with voltage profiles in a power system. The analysis of these profiles is important due to the requirement that the Root-Mean-Squared (RMS) values of nodal voltages should be within certain ranges, as well as to ensure desired power flows in a power system. In both cases, it is desirable to indicate points in a power system where it is reasonable to apply remedial measures to meet the requirements for RMS values of nodal voltages, or to effectively control the power flows in a power system. In general, candidate nodes for remediation are established based on operational experience or measurement data from a certain time point (sometimes from several time points). The paper presents a method that provides a basis for determining the aforementioned candidate nodes based on the behavior of a system over a certain period of time, which is an unquestionable advantage of this proposal. In order to achieve the abovementioned goal, the method provides for the analysis of propagation of voltage RMS value deviations in a power system. The analysis of correlational relationships between the RMS values of nodal voltages is used for this. After presentation of the theoretical background, the new original method is described in the paper. Then, case studies showing the utilization of that method are presented. At the end of the paper, features of the proposed method are enumerated.

scholarly journals Knee Muscle Strength Recovery in the Early Period After ACL Reconstruction

2014 ◽  
Vol 2 (11_suppl3) ◽  
pp. 2325967114S0014
Author(s):  
Gulcan Harput ◽  
Hasan Erkan Kılınc ◽  
Hamza Özer ◽  
Gül Baltacı ◽  
Carl G. Mattacola
Keyword(s):  
Acl Reconstruction ◽  
Early Period ◽  
Quadriceps Strength ◽  
Isometric Strength ◽  
Time Points ◽  
Hamstring Muscles ◽  
Significant Difference ◽  
Isometric Torque ◽  
Over Time ◽  
Time Point

Objectives: The aim of this study was to investigate quadriceps and hamstrings isometric strength at 4, 8 and 12 week time points following ACL Reconstruction (ACLR) and to document the strength changes of these muscles over time. The primary hypothesis was that there would be significant increases in quadriceps and hamstring muscle strengths between the 4th, 8th and 12th weeks following ACLR. The secondary hypothesis was that the quadriceps index would be higher than hamstring index at 12th week after ACLR. Methods: Thirty patients (Mean ± SD [age, 29.1±2.3yrs; weight, 77.3±13.2kg; height, 172.1±7.1cm; BMI, 21.2±3.5kg/m2, time to surgery: 7.1±7.2 months]) who underwent ACLR with Hamstring Tendon Autograft (HTG) were enrolled in this study. The isometric strength of quadriceps and hamstring muscles was measured on an isokinetic dynamometer at 60° knee flexion angle at 4th, 8th and 12th weeks after surgery. The recovery of quadriceps and hamstring muscles strength following rehabilitation was expressed as a Quadriceps Index (QI) and Hamstring Index (HI) and calculated with the following formula:[(maximum voluntary isometric torque of the involved limb / maximum voluntary isometric torque by uninvolved limb) × 100]. Torque output of the involved and uninvolved limbs and quadriceps and hamstring indexes were used for the statistical analysis. A repeated measures of ANOVA was used to determine the strength changes of quadriceps and hamstrings over time. Results: Quadriceps and Hamstrings strengths significantly increased over time for both involved (Quadriceps: F (2,46)=58.3, p<0.001, Hamstring: F (2,46)=35.7, p<0.001) and uninvolved limb (Quadriceps: F(2,46)=17.9, p<0.001, Hamstring: F(2,46)=56.9, p=0.001 ). Quadriceps strength was higher at 12th week when compared to the 8 and 4 week time points for the involved limb (p<0.001), and it was higher at 8th week when compared to 4 week time point for the involved limb (p<0.001). For the uninvolved limb, quadriceps strength was also higher at 12th week when compared to the 8 (p=0.02) and 4 week time point (p<0.001), and higher at 8 week when compared to the 4 week time point (p=0.02). Hamstring strength was higher at 12 week when compared to the 8 and 4 week time points (p<0.001) and it was higher at 8 week when compared to 4 week time point for the involved limb (p<0.001). For the uninvolved limb hamstring strength was also higher at 12 week when compared to 4 week time point (p=0.01). There was no significant difference between the 4 and 8 week time points (p>0.05) or between the 8 and 12 week time points (p=0.07). Quadriceps and hamstring indexes significantly changed from 4th weeks (QI:57.9, HI:54.4 ) to 8th weeks (QI:78.8, HI:69.9 ) and from 8th weeks to 12th weeks (QI:82, HI:75.7 ) (p<0.001); however, there was no difference between indexes at the 12-week time point (p=0.17). Conclusion: Isometric strength of quadriceps and hamstring muscles for the involved and uninvolved limb increased during the early period of ACLR. The results of this study could be a baseline for clinicians while prescribing a rehabilitation protocol for ACLR patients with HTG to better appreciate expected strength changes of the muscles in the early phase.

scholarly journals Virus isolation studies suggest short-term variations in abundance in natural cyanophage populations of the Indian Ocean

2006 ◽  
Vol 86 (3) ◽  
pp. 499-505 ◽  
Author(s):  
Martha R.J. Clokie ◽  
Andrew D. Millard ◽  
Jaytry Y. Mehta ◽  
Nicholas H. Mann
Keyword(s):  
Indian Ocean ◽  
Surface Waters ◽  
Molecular Diversity ◽  
Virus Isolation ◽  
Short Term ◽  
Distinct Subgroup ◽  
Time Points ◽  
The Indian Ocean ◽  
Long Timescales ◽  
Time Point

Cyanophage abundance has been shown to fluctuate over long timescales and with depth, but little is known about how it varies over short timescales. Previous short-term studies have relied on counting total virus numbers and therefore the phages which infect cyanobacteria cannot be distinguished from the total count.In this study, an isolation-based approach was used to determine cyanophage abundance from water samples collected over a depth profile for a 24 h period from the Indian Ocean. Samples were used to infect Synechococcus sp. WH7803 and the number of plaque forming units (pfu) at each time point and depth were counted. At 10 m phage numbers were similar for most time-points, but there was a distinct peak in abundance at 0100 hours. Phage numbers were lower at 25 m and 50 m and did not show such strong temporal variation. No phages were found below this depth. Therefore, we conclude that only the abundance of phages in surface waters showed a clear temporal pattern over a short timescale. Fifty phages from a range of depths and time points were isolated and purified. The molecular diversity of these phages was estimated using a section of the phage-encoded psbD gene and the results from a phylogenetic analysis do not suggest that phages from the deeper waters form a distinct subgroup.

Abstract T P234: Multiparametric Assessment of Longitudinal Changes in Tissue Microstructure in Normal and Abnormal Brain Tissue in Patients with Small Vessel Disease

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Maria D Valdes-Hernandez ◽  
Paul A Armitage ◽  
Eleni Sakka ◽  
Susana Munoz Maniega ◽  
Natalie A Royle ◽  
...  
Keyword(s):  
White Matter ◽  
Brain Tissue ◽  
Small Vessel Disease ◽  
Brain Mri ◽  
Mean Diffusivity ◽  
Tissue Loss ◽  
Minor Stroke ◽  
Normal Brain ◽  
Limited Information ◽  
Time Points

Background: Volume measures of normal brain tissue and white matter hyperintensities (WMH) between two time points gives limited information about the complex dynamics of tissue change. We evaluated two quantitative parameters that characterise the microstructure of normal-appearing white matter (NAWM), deep grey matter (DGM) and WMH on brain images obtained at presentation with minor stroke and at 1 year to investigate the microstructural changes. Methods: From 182 brain MRI datasets of patients with minor stroke obtained at baseline and 1 year, we extracted the WMH, DGM and NAWM, and separated WMH into less-intense and intense WMH, using validated semi-automatic methods and validated criteria. We registered the binary structural masks to diffusion space and performed a voxel-wise subtraction of the combined masks at both time points. Then we measured fractional anisotropy (FA) and mean diffusivity (MD)(valuex10 -9 m 2 /s) in each tissue mask at baseline and 1 year. Results: WMH volume median increase was 1.4ml (IQR 6.98) mainly due to changes in less-intense WMH: 0.94ml (7.13). WMH that were visible at both time points, ie damage that remained after a year, had the lowest FA= 0.21(0.06) and highest MD=1.05(0.12) at baseline, and were mainly intense WMH at baseline (FA=0.12(0.03), MD=1.55(0.27)). WMH seen only at follow-up, ie that were NAWM at baseline, had the highest FA=0.30(0.06) and lowest MD=0.85 (0.06) at baseline. WMH that were observed only at baseline had intermediate FA=0.26(0.08) and MD=0.90(0.10). NAWM FA=0.26(0.03), MD=0.78(0.04) and DGM FA=0.23(0.03), MD=0.79(0.06) did not change between time points. Conclusions: WMH at baseline can partially evolve to normal-appearing tissues, remain or precede tissue loss. Differentiation between severe and subtle damage and spatial analysis are necessary to characterise the dynamic of WMH evolution.

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