Staged operations for a hypervascular mixed germ cell tumor with growing teratoma syndrome: a case report.

INTRODUCTION: A mixed germ cell tumor with a teratoma component can become enlarged following chemotherapy, and such an event is diagnosed as growing teratoma syndrome. Removing large, hypervascular tumors including a tumor encased by developed vasculatures from the pineal region is challenging during a single operation. CASE REPORT: A 15-year-old male underwent chemotherapy for mixed germ cell tumors according to the KSPNO G082 protocol. This case of a mixed germ cell tumor with growing teratoma syndrome was recognized very early during chemotherapy. The tumor was completely removed during the staged operations. First, the anteriorly located tumor on the third ventricle was removed via the transcallosal interforniceal approach, and 1 month later, the occipital transtentorial approach was used for the pineal tumor with decreased vascularity. CONCLUSION: Performing staged operations could be recommended for large hypervascular pineal tumors, which can be safely removed during the second operation once vascularity has decreased.

Multiple craniospinal tumors in a pediatric patient with neurofibromatosis type 2: a case report.

INTRODUCTION: Neurofibromatosis type 2 (NF-2) is an inherited disease, linked with abnormalities in the NF-2 gene, which is located on chromosome 22 and involved in merlin production. Many craniospinal tumors are common in individuals with NF-2. We present a case of NF-2 with the rapid symptomatic progression of multiple craniospinal tumors. CASE REPORT: A 12-year-old male complained of headache and hearing impairment in the right ear for 7 months. Brain magnetic resonance imaging (MRI) revealed a right frontal meningioma, bilateral vestibular and trigeminal schwannomas, and a brainstem tumor. He was diagnosed with NF-2 and underwent brain surgery and radiotherapy for chordoid meningioma. He complained of right leg motor weakness 5 months post-surgery. The spine MRI showed multiple heterogeneously enhanced masses spreading over the entire spinal cord. The symptomatic intradural extramedullary mass at the cervicothoracic area was removed and the histological finding was schwannoma. His leg motor weakness was relieved after surgery. At the 6-month follow-up, brain MRI revealed the progression of the vestibular schwannoma, trigeminal schwannoma, and brainstem tumor. The patient was treated with bevacizumab (5 mg/kg) every 2 weeks for 6 months. For 2 years, all of the craniospinal tumors were stable without neurological deterioration after the completion of chemotherapy. CONCLUSION: Meningiomas and schwannomas grow slowly in most patients with NF-2, but these multiple craniospinal tumors can show sudden rapid growth and manifest as neurological symptoms in a pediatric patient. These tumors could be controlled with local symptomatic and systemic bevacizumab treatments.

Reliability and Validity of the Korean Child Sensory Profile-2.

IMPORTANCE: The Korean Child Sensory Profile-2 (K-CSP-2) is a tool for assessing sensory processing that was recently culturally adapted for use with Korean children. OBJECTIVE: To investigate the test-retest and interrater reliability and the convergent and discriminant validity of the K-CSP-2. DESIGN: Cross-sectional study. SETTING: Community settings in South Korea. PARTICIPANTS: Caregivers of 102 children with autism spectrum disorder (ASD) and 156 typically developing (TD) children ages 3-14 yr. OUTCOMES AND MEASURES: The K-CSP-2 was tested for reliability and validity using the Korean version of the Sensory Profile (K-SP) and the Korean Behavior Assessment System for Children-2 (K-BASC-2). RESULTS: The K-CSP-2 demonstrated good test-retest and interrater reliability. The K-CSP-2 was correlated with the K-SP and the K-BASC-2. Children with ASD had higher K-CSP-2 scores than TD children. The discriminant analysis classified children with ASD and TD children with an overall accuracy of 89%. CONCLUSIONS AND RELEVANCE: The K-CSP-2 can be used to assess the sensory processing of Korean children consistently across time and raters. The instrument maintains the quadrant factors of the K-SP and relates to adaptive and maladaptive behaviors. The K-CSP-2 can distinguish children with ASD from TD children. What This Article Adds: Korean occupational therapy practitioners can use the K-CSP-2 to identify sensory processing patterns and to support the evaluation of children with ASD.

The Application of Magnetic Resonance Imaging-Deformed 11C-Methionine-Positron Emission Tomography Images in Stereotactic Radiosurgery.

BACKGROUND: Although 11C-methionine positron emission tomography (MET-PET) images can be fused with magnetic resonance (MR) images using planning software for gamma knife radiosurgery (GKR), the stereotactic information has limited value in patients with recurrent malignant brain tumor due to the difference in imaging protocols between MET-PET and MR images. The aim of this study was to evaluate the clinical application of MR imaging (MRI)-deformed MET-PET images in GKR using a deformable registration tool. METHODS: We examined the enhanced MR stereotactic images, MET-PET and MRI-deformed MET-PET images without stereotactic information for 12 newly developed metastatic brain tumors. MET-PET and MRI-deformed MET-PET images were co-registered with the MR stereotactic images using radiosurgery planning software. Visual analysis was performed to determine whether the MET-PET and MR images matched better after using the deformable registration tool. In addition, the matching volume between MR and MET-PET images was compared before and after applying this tool. The matching volume was calculated as the metabolic tumor volume on the MET-PET images, including the MR-enhanced volume. The matching percentage was calculated as the matching volume divided by the MR-enhanced volume, multiplied by 100. RESULTS: Visual analysis revealed that the MRI-deformed MET-PET images provided the same axial plane as that of the MR images, with the same window level, enabling easy identification of the tumor with the radiosurgery planning software. The mean matching percentage of the MET-PET/MR fusion images was 61.1% (range 24.7-94.7) and that of the MRI-deformed MET-PET/MR fusion images was 63.4% (range 20.8-94.3). No significant difference was found in the matching percentage between the two types of fusion images (p = 0.754). CONCLUSIONS: The MRI-deformed MET-PET images enable utilization of the functional information when planning a treatment in GKR without significant volume change.

Metabolic alterations in a rat model of hepatic ischaemia reperfusion injury: In vivo hyperpolarized 13 C MRS and metabolic imaging.

BACKGROUND & AIMS: Despite a number of studies addressing the pathophysiology of hepatic IRI, a gold standard test for early diagnosis and evaluation of IRI remains elusive. This study investigated the metabolic alterations in a rat model of hepatic IRI using the in vivo hyperpolarized ¹³C MRS and metabolic imaging. METHODS: Hyperpolarized 13 C MRS with IVIM-DWI was performed on the liver of 7 sham-operated control rats and 7 rats before and after hepatic IRI. RESULTS: The hepatic IRI-induced rats showed significantly higher ratios of [1-13 C] alanine/pyruvate, [1-13 C] alanine/tC, [1-13 C] lactate/pyruvate and [1-13 C] lactate/tC compared with both sham-operated controls and rats before IRI, whereas [1-13 C] pyruvate/tC ratio was decreased in IRI-induced rats. In IVIM-DWI study, apparent diffusion coefficient (ADC), f and D values in rats after hepatic IRI were significantly lower than those of rats before IRI and sham-operated controls. The levels of [1-13 C] alanine and [1-13 C] lactate were negatively correlated with ADC, f and D values, whereas the level of [1-13 C] pyruvate was positively correlated with these values. CONCLUSIONS: The levels of [1-13 C] alanine, [1-13 C] lactate and [1-13 C] pyruvate in conjunction with IVIM-DWI will be helpful to evaluate the hepatic IRI as well as these findings can be useful in understanding the biochemical mechanism associated with hepatic damage.

Disseminated juvenile xanthogranuloma occurring after treatment of Langerhans cell histiocytosis: a case report.

CASE PRESENTATION: An 11-year-old boy presented with a complaint of a painful temporal mass. Brain magnetic resonance imaging (MRI) showed a 3-cm-sized, homogeneously enhancing mass in the greater wing of the left sphenoid bone, which was diagnosed as Langerhans cell histiocytosis (LCH). Chemotherapy with vincristine and prednisolone was performed for 1 year. After 1 year and 11 months off treatment, he developed symptoms such as polydipsia and polyuria. Brain MRI showed thickening of the pituitary stalk with enhancement, suggestive of LCH involvement, and no recurrence in the sphenoid bone. After 4 years and 4 months off treatment, he developed multiple, subcutaneous, asymptomatic, and yellowish variable-sized papules on his face, posterior neck, and back, which were pathologically diagnosed as juvenile xanthogranuloma (JXG). Brain MRI revealed multifocal enhancing skull lesions in the left parietal, right frontal, and left occipital bones, which were also diagnosed as JXG. After 5 years and 8 months off treatment, the number of variable-sized skin lesions was increased without changes in the lesions in the skull and pituitary stalk. CONCLUSION: We report a case of disseminated JXG occurring after treatment of LCH. These clinical co-presentations suggested a close relationship between their pathogenesis.

Visual outcome after endoscopic third ventriculostomy for hydrocephalus.

PURPOSE: Hydrocephalus-related symptoms are mostly improved after successful endoscopic third ventriculostomy (ETV). However, visual symptoms can be different. This study was focused on visual symptoms. We analyzed the magnetic resonance images (MRI) of the orbit and visual outcomes. METHODS: From August 2006 to November 2016, 50 patients with hydrocephalus underwent ETV. The male-to-female ratio was 33:17, and the median age was 61 years (range, 5-74 years). There were 18 pediatric and 32 adult patients. Abnormal orbital MRI findings included prominent subarachnoid space around the optic nerves and vertical tortuosity of the optic nerves. We retrospectively analyzed clinical symptoms, causes of hydrocephalus, ETV success score (ETVSS), ETV success rate, ETV complications, orbital MRI findings, and visual impairment score (VIS). RESULTS: The median duration of follow-up was 59 months (range, 3-113 months). The most common symptoms were headache, vomiting, and gait disturbance. Visual symptoms were found in 6 patients (12%). The most common causes of hydrocephalus were posterior fossa tumor in 13 patients, pineal tumor in 12, aqueductal stenosis in 8, thalamic malignant glioma in 7, and tectal glioma in 4. ETVSS was 70 in 3 patients, 80 in 34 patients, and 90 in 13 patients. ETV success rate was 80%. ETVSS 70 showed the trend in short-term survival compared to ETVSS 90 and 80. ETV complications included epidural hematoma requiring operation in one patient, transient hemiparesis in two patients, and infection in two patients. Preoperative abnormal orbital MRI findings were found in 18 patients and postoperative findings in 7 patients. Four of six patients with visual symptoms had abnormal MR findings. Three patients did not show VIS improvement, including two with severe visual symptoms. CONCLUSIONS: Patients with severe visual impairment were found to have bad outcomes. The visual symptoms related with increased intracranial pressure should be carefully monitored and controlled to improve outcomes.

Pediatric brainstem abscess with hemorrhage mimicking diffuse intrinsic pontine glioma: a case report.

PURPOSE: We report a rare case of brainstem abscess with hemorrhage mimicking diffuse intrinsic pontine glioma (DIPG). METHODS: A 7-month-old baby girl presented with lethargy and poor oral feeding. She had the mild fever for 1 month. Brain computed tomography revealed the hypodense lesion in the pons. Brain magnetic resonance images (MRI) showed around 1.4-cm-sized rim-enhanced mass with perilesional edema and internal hemorrhage in the pons. The cerebral blood volume was increased in the rim-enhanced area. The provisional diagnosis was DIPG, but the mass did not show the expansile mass with encasement of the basilar artery on the ventral pons. RESULTS: The biopsy was done via the floor of the fourth ventricle, and the pathologic findings showed the many inflammatory cells and CD68-immunopositive macrophage which were compatible with abscess. The antibiotics with ceftriaxone and metronidazole were administrated for 11 weeks, and the follow-up MRI showed the slightly small enhanced lesion without central necrotic area. Three years later, follow-up MRI revealed the encephalomalacic change and atrophy of the pons. She had the stable neurologic deficit of left facial palsy and right hemiparesis. CONCLUSION: The biopsy could be necessary for pontine lesions without typical radiologic findings of DIPG.

Progressive Multiple Cavernous Angiomas after Radiotherapy in a Pediatric Patient with Medulloblastoma: A Case Report.

BACKGROUND: We report a case of progressive multiple cavernous angiomas. PATIENT AND METHOD: A 16-year-old boy presented with a 2-month history of headache and dizziness. Six years earlier, he underwent surgery for cerebellar medulloblastoma and subsequent chemoradiotherapy according to the M-051 protocol of the Korean Society of Pediatric Neuro-Oncology. Follow-up brain magnetic resonance imaging (MRI) revealed a tiny hemorrhage on the cerebellum 3 months after 23.4-Gy craniospinal and 32.4-Gy boost radiotherapy. RESULT: The multiple hemorrhagic lesions had progressively developed on the whole brain without any symptoms for 6 years. On admission, MRI revealed a 1.5-cm enlarged mass with subacute hemorrhage on the right frontal area. The mass was totally removed and diagnosed as cavernous angioma. However, 5 months later, the patient complained of a headache. MRI revealed 1.4- and 0.7-cm enlarged masses on the left frontal and right temporal areas with internal hemorrhage, respectively. The left frontal mass was totally removed, and the histopathological finding was suggestive of cavernous angioma. CONCLUSION: This case showed early-developed multiple hemorrhagic lesions after radiotherapy, which had been progressive and were associated with some symptomatic cavernous angiomas. Pediatric patients with brain radiotherapy should undergo radiological check-up to identify vascular lesions, especially symptomatic patients.

Cavernous hemangioma of the third ventricle: a case report and review of the literature.

BACKGROUND: Although cavernous hemangiomas (CHs) can be found anywhere in the central nervous system, CHs of the third ventricle have been reported in only 29 patients (including our case). In the current case report, we discuss the clinical characteristics and surgical outcome of CHs of the third ventricle. CASE PRESENTATION: A 64-year-old female was admitted to our emergency room with a sudden decreased level of consciousness. Brain imaging studies demonstrated a multi-lobulated hemorrhagic mass in the third ventricle. The lesion was removed via the transcallosal-interforniceal approach and pathologically diagnosed as CH. Postoperatively, the patient had a transient neurological deficit due to hypothalamic injury and recovered to the normal status at 2 months after the operation. In the review of 29 cases, the mean age of the patients was 40 years with a slight female preponderance (female/male, 17/12). The majority of the patients complained of a mass effect with signs of increased intracranial pressure; only one case was asymptomatic. Gross total resection was achieved in 81% of the cases. Around 80% of the patients were asymptomatic or improved from the initial symptoms. Mortality rate was 6.9% and the most common complication was hydrocephalus. CONCLUSIONS: As demonstrated in the review of the previous reports, the outcome is favorable after surgical excision for CH of the third ventricle. Hence, surgical excision appears to be the treatment of choice for CH located in the third ventricle, which tends to grow rapidly resulting in a mass effect.

Electroencephalography-based classification of Alzheimer's disease spectrum during computer-based cognitive testing.

Alzheimer's disease (AD) is a progressive disease leading to cognitive decline, and to prevent it, researchers seek to diagnose mild cognitive impairment (MCI) early. Particularly, non-amnestic MCI (naMCI) is often mistaken for normal aging as the representative symptom of AD, memory decline, is absent. Subjective cognitive decline (SCD), an intermediate step between normal aging and MCI, is crucial for prediction or early detection of MCI, which determines the presence of AD spectrum pathology. We developed a computer-based cognitive task to classify the presence or absence of AD pathology and stage within the AD spectrum, and attempted to perform multi-stage classification through electroencephalography (EEG) during resting and memory encoding state. The resting and memory-encoding states of 58 patients (20 with SCD, 10 with naMCI, 18 with aMCI, and 10 with AD) were measured and classified into four groups. We extracted features that could reflect the phase, spectral, and temporal characteristics of the resting and memory-encoding states. For the classification, we compared nine machine learning models and three deep learning models using Leave-one-subject-out strategy. Significant correlations were found between the existing neurophysiological test scores and performance of our computer-based cognitive task for all cognitive domains. In all models used, the memory-encoding states realized a higher classification performance than resting states. The best model for the 4-class classification was cKNN. The highest accuracy using resting state data was 67.24%, while it was 93.10% using memory encoding state data. This study involving participants with SCD, naMCI, aMCI, and AD focused on early Alzheimer's diagnosis. The research used EEG data during resting and memory encoding states to classify these groups, demonstrating the significance of cognitive process-related brain waves for diagnosis. The computer-based cognitive task introduced in the study offers a time-efficient alternative to traditional neuropsychological tests, showing a strong correlation with their results and serving as a valuable tool to assess cognitive impairment with reduced bias.

Low-temperature pulverization-specific Sargassum horneri extract accelerates wound healing and attenuates inflammation in a mouse burn model.

Burn injuries, affecting local skin disruption as well as inducing systemic inflammatory responses, are presented as a global public health problem. To enhance the effects of burn wound healing, treatment must simultaneously regulate both re-epithelialization and hyperinflammation. Extracts of Sargassum horneri (S. horneri) have shown a potential to enhance skin wound healing through antioxidative properties, immune enhancement, and modulation of inflammatory responses. However, despite its promising application for burn wound healing, specific investigation into S. horneri-derived compounds for enhancing wound healing has not yet been conducted. In this research, we investigated the burn wound-healing effect of the low-temperature pulverization-specific S. horneri extract (LPSHE), which could not be detected using the room-temperature grinding method. In a mouse burn model with third-degree burn injuries, LPSHE accelerated re-epithelialization by promoting the increase in F-actin formation and reduced burn-induced ROS levels. Additionally, LPSHE significantly regulated hyperinflammation by reducing pro-inflammatory cytokines. Further investigation into molecular mechanisms using HaCaT keratinocytes also demonstrated beneficial effects on burn wound healing. Taken together, our findings suggested that LPSHE is a promising therapeutic candidate for enhancing burn wound healing. Furthermore, this research underscored the importance of low-temperature pulverization in discovering novel natural compounds from marine organisms.

Psychometric properties of Korean Infant Sensory Profile 2.

OBJECTIVES: This study aimed to evaluate test-retest reliability and convergent validity of the Korean Infant Sensory Profile 2 (K-ISP2) and explore whether the sensory processing of infants differs according to age, gender, and culture. MATERIALS AND METHODS: Participants were 140 Korean caregivers of infants aged 0-6 months. They completed the K-ISP2 and the Korean version of 'What My Baby Is Like' (K-WBL), a scale for measuring infant temperament, for convergent validity. The K-ISP2 was re-administrated for test-retest reliability with a mean interval of 16 days. RESULTS: The K-ISP2 showed good test-retest reliability (ICC = .84) and significant but weak convergent validity with the K-WBL (amenability/persistence, r = -.28, p < .001; adaptability, r = -.30, p < .001; reactivity, r = .24, p = .004; activity, r = .20, p = .02). There were no significant age and gender differences in the K-ISP2 total score. The K-ISP2 total score was similar to that of the Infant Sensory Profile 2 (ISP2). CONCLUSIONS: This study provides reliability and validity evidence of the K-ISP2. Normative data of K-ISP2 total score can be established regardless of age or gender. The ISP2 has showed similar psychometric properties for populations of both Korea and the United States.KEY MESSAGESSensory processing is a fundamental component for adaptive responses to environment and begins to develop before birth.The Korean Infant Sensory Profile 2 (K-ISP2) can be used to assess sensory processing patterns of Korean infants, with evidence of reliability and validity.Total scores of the K-ISP2 can be interpreted with one normative data set regardless of age and gender.

Hemodynamic changes in the portal vein with age: evaluation using four-dimensional flow MRI.

Aging process is associated with gradual change of liver function and structure. The goal of this study was to evaluate age-related hemodynamic changes in the portal vein (PV) using four-dimensional (4D) flow MRI in healthy adults. A total of 120 healthy subjects were enrolled and categorized into groups A (n = 25, 30-39 years), B (n = 31, 40-49 years), C (n = 34, 50-59 years), and D (n = 30, 60-69 years). All subjects underwent 4D flow data acquisition using a 3-T MRI system to measure the hemodynamic parameters in the main PV. The clinical characteristics and 4D flow parameters were compared among the groups using analysis of variance and analysis of covariance after controlling for significant covariates, accordingly. The outcome metric applying the age-related quadratic model to estimate the age at which 4D flow parameters are the highest (the peak age) as well as the rates of age-related 4D flow changes was estimated. The average area, average through-plane velocity, peak velocity magnitude, average net flow, peak flow, and net forward volume in group D were significantly lower than those in groups A, B and C (P < 0.05). Group C showed significantly lower values of the average through-plane velocity and peak velocity magnitude than those of group B (P < 0.05). The peak age computed was approximately 43-44 years of age for all 4D flow parameters. The rates of age-related 4D flow changes for all 4D flow parameters were negatively correlated with age (P < 0.05). The volume and velocity of the blood flow through the PV peaked at approximately 43-44 years of age and decreased significantly after 60 years of age.

Radiologic Follow-up of Ruptured Arachnoid Cysts With or Without Hemorrhage: Five Case Reports and a Review of the Literature.

Arachnoid cysts are usually asymptomatic and discovered incidentally. However, cysts may occasionally rupture because of minor head trauma. We describe the radiologic follow-up of 5 patients with ruptured arachnoid cysts featuring spontaneous resolution, subdural hygroma formation, and cystic and subdural hemorrhage. From January 2004 through July 2020, 5 patients (1.3%) with ruptured arachnoid cysts were evaluated out of 388 patients with arachnoid cysts encountered at our institution at that time. The 5 patients were all male, and they ranged in age from 6-17 years (median, 12 years). The median duration of radiologic follow-up was 3.5 years (range, 2.3-10.1 years). All of the ruptured arachnoid cysts were overlying the temporal lobe with Galassi type II. The median cyst diameter was 4.9 cm (range, 4.4-8.9 cm). Four patients had a history of recent minor head trauma. There were no particular neurologic symptoms in their past medical history in all patients. In the follow-up, two patients' cysts resolved spontaneously without hemorrhage. One patient's cyst resolved post-burr-hole drainage for chronic subdural hemorrhage. Another patient, whose cyst led to a hemorrhage and chronic subdural hemorrhage, recovered following a craniotomy, hematoma removal, and cyst fenestration. Another patient, presenting with hygroma, cystic hemorrhage, and chronic subdural hemorrhage, was treated with burr-hole drainage. Three patients recovered postoperatively. Arachnoid cysts rarely rupture, and surgical intervention is required for some cases associated with hemorrhage. Postoperatively, all patients had good outcomes without complications in this series.

Evaluation of PVC-Type Insulation Foam Material for Cryogenic Applications.

With the International Maritime Organization (IMO) reinforcing environmental regulations on the shipbuilding industry, the demand for fuels, such as liquefied natural gas (LNG) and liquefied petroleum gas (LPG), has soared. Therefore, the demand for a Liquefied Gas Carrier for such LNG and LPG also increases. Recently, CCS carrier volume has been increasing, and damage to the lower CCS panel has occurred. To withstand liquefied gas loads, the CCSs should be fabricated using a material with improved mechanical strength and thermal performance compared with the conventional material. This study proposes a polyvinyl chloride (PVC)-type foam as an alternative to commercial polyurethane foam (PUF). The former material functions as both insulation and a support structure primarily for the LNG-carrier CCS. To investigate the effectiveness of the PVC-type foam for a low-temperature liquefied gas storage system, various cryogenic tests, namely tensile, compressive, impact, and thermal conductivity, are conducted. The results illustrate that the PVC-type foam proves stronger than PUF in mechanical performance (compressive, impact) across all temperatures. In the tensile test, there are reductions in strength with PVC-type foam but it meets CCS requirements. Therefore, it can serve as insulation and improve the overall CCS mechanical strength against increased loads under cryogenic temperatures. Additionally, PVC-type foam can serve as an alternative to other materials in various cryogenic applications.

Cryogenic Reliability Evaluation of Glass Fabric-Reinforced Composites Using Novel Slip-Prevention Method.

Glass fabric-reinforced composites are the main insulating material components of the secondary barrier of cargo containment systems (CCSs), because they prevent liquefied natural gas (LNG) leakage during transport. Nevertheless, it is difficult to evaluate the material performance of glass fabric-reinforced composites at cryogenic temperatures (-163 °C) because it takes approximately 7 days to prepare the test specimens and because the slip-based test frequently fails. Although glass fabric-reinforced composites for the secondary barrier of LNG CCSs show various structural vulnerabilities, enhancing their material performance is significantly limited owing to the reasons mentioned above. This study evaluated the structural vulnerabilities and failure characteristics of glass fabric-reinforced composites by using the slip-prevention test method to determine the level difference and adhesive vacancies. The failure surface and the thermal expansion of the composites were also observed, to analyze their mechanical characteristics. By adopting our proposed test procedure, the failure rate of the experiment decreased by approximately 80%, and the sample preparation time for manufacturing was significantly shortened, to 1 day.

Influence of Silica-Aerogel on Mechanical Characteristics of Polyurethane-Based Composites: Thermal Conductivity and Strength.

Polyurethane foam (PUF) has generally been used in liquefied natural gas (LNG) carrier cargo containment systems (CCSs) owing to its excellent mechanical and thermal properties over a wide range of temperatures. An LNG CCS must be designed to withstand extreme environmental conditions. However, as the insulation material for LNGC CCSs, PUF has two major limitations: its strength and thermal conductivity. In the present study, PUFs were synthesized with various weight percentages of porous silica aerogel to reinforce the characteristics of PUF used in LNG carrier insulation systems. To evaluate the mechanical strength of the PUF-silica aerogel composites considering LNG loading/unloading environmental conditions, compressive tests were conducted at room temperature (20 °C) and a cryogenic temperature (-163 °C). In addition, the thermal insulation performance and cellular structure were identified to analyze the effects of silica aerogels on cell morphology. The cell morphology of PUF-silica aerogel composites was relatively homogeneous, and the cell shape remained closed at 1 wt.% in comparison to the other concentrations. As a result, the mechanical and thermal properties were significantly improved by the addition of 1 wt.% silica aerogel to the PUF. The mechanical properties were reduced by increasing the silica aerogel content to 3 wt.% and 5 wt.%, mainly because of the pores generated on the surface of the composites.

The Tumor Control According to Radiation Dose of Gamma Knife Radiosurgery for Small and Medium-Sized Brain Metastases from Non-Small Cell Lung Cancer.

OBJECTIVE: The effectiveness of gamma knife radiosurgery (GKR) in the treatment of brain metastases is well established. The aim of this study was to evaluate the efficacy and safety of maximizing the radiation dose in GKR and the factors influencing tumor control in cases of small and medium-sized brain metastases from non-small cell lung cancer (NSCLC). METHODS: We analyzed 230 metastatic brain tumors less than 5 mL in volume in 146 patients with NSCLC who underwent GKR. The patients had no previous radiation therapy for brain metastases. The pathologies of the tumors were adenocarcinoma (n=207), squamous cell carcinoma (n=18), and others (n=5). The radiation doses were classified as 18, 20, 22, and 24 Gy, and based on the tumor volume, the tumors were categorized as follows : small-sized (less than 1 mL) and medium-sized (1-3 and 3-5 mL). The progression-free survival (PFS) of the individual 230 tumors and 146 brain metastases was evaluated after GKR depending on the pathology, Eastern Cooperative Oncology Group (ECOG) performance score (PS), tumor volume, radiation dose, and anti-cancer regimens. The radiotoxicity after GKR was also evaluated. RESULTS: After GKR, the restricted mean PFS of individual 230 tumors at 24 months was 15.6 months (14.0-17.1). In small-sized tumors, as the dose of radiation increased, the tumor control rates tended to increase (p=0.072). In medium-sized tumors, there was no statistically difference in PFS with an increase of radiation dose (p=0.783). On univariate analyses, a statistically significant increase in PFS was associated with adenocarcinomas (p=0.001), tumors with ECOG PS 0 (p=0.005), small-sized tumors (p=0.003), radiation dose of 24 Gy (p=0.014), synchronous lesions (p=0.002), and targeted therapy (p=0.004). On multivariate analyses, an improved PFS was seen with targeted therapy (hazard ratio, 0.356; 95% confidence interval, 0.150-0.842; p=0.019). After GKR, the restricted mean PFS of brain at 24 months was 9.8 months (8.5-11.1) in 146 patients, and the pattern of recurrence was mostly distant within the brain (66.4%). The small and medium-sized tumors treated with GKR showed radiotoxicitiy in five out of 230 tumors (2.2%), which were controlled with medical treatment. CONCLUSION: The small-sized tumors were effectively controlled without symptomatic radiation necrosis as the radiation dose was increased up to 24 Gy. The medium-sized tumors showed potential for symptomatic radiation necrosis without signifcant tumor control rate, when greater than 18 Gy. GKR combined targeted therapy improved the tumor control of GKR-treated tumors.

Differentiating Radiation Necrosis from Brain Tumor Using Hyperpolarized Carbon-13 MR Metabolic Imaging.

PURPOSE: Differentiation between radiation-induced necrosis and tumor recurrence is crucial to determine proper management strategies but continues to be one of the central challenges in neuro-oncology. We hypothesized that hyperpolarized 13C MRI, a unique technique to measure real-time in vivo metabolism, would distinguish radiation necrosis from tumor on the basis of cell-intrinsic metabolic differences. The purpose of this study was to explore the feasibility of using hyperpolarized [1-13C]pyruvate for differentiating radiation necrosis from brain tumors. PROCEDURES: Radiation necrosis was initiated by employing a CT-guided 80-Gy single-dose irradiation of a half cerebrum in mice (n = 7). Intracerebral tumor was modeled with two orthotopic mouse models: GL261 glioma (n = 6) and Lewis lung carcinoma (LLC) metastasis (n = 7). 13C 3D MR spectroscopic imaging data were acquired following hyperpolarized [1-13C]pyruvate injection approximately 89 and 14 days after treatment for irradiated and tumor-bearing mice, respectively. The ratio of lactate to pyruvate (Lac/Pyr), normalized lactate, and pyruvate in contrast-enhancing lesion was compared between the radiation-induced necrosis and brain tumors. Histopathological analysis was performed from resected brains. RESULTS: Conventional MRI exhibited typical radiographic features of radiation necrosis and brain tumor with large areas of contrast enhancement and T2 hyperintensity in all animals. Normalized lactate in radiation necrosis (0.10) was significantly lower than that in glioma (0.26, P = .004) and LLC metastatic tissue (0.25, P = .00007). Similarly, Lac/Pyr in radiation necrosis (0.18) was significantly lower than that in glioma (0.55, P = .00008) and LLC metastasis (0.46, P = .000008). These results were consistent with histological findings where tumor-bearing brains were highly cellular, while irradiated brains exhibited pathological markers consistent with reparative changes from radiation necrosis. CONCLUSION: Hyperpolarized 13C MR metabolic imaging of pyruvate is a noninvasive imaging method that differentiates between radiation necrosis and brain tumors, providing a groundwork for further clinical investigation and translation for the improved management of patients with brain tumors.