21 research outputs found
Magnetic resonance imaging, computed tomography, and 68Ga-DOTATOC positron emission tomography for imaging skull base meningiomas with infracranial extension treated with stereotactic radiotherapy - a case series
<p>Abstract</p> <p>Introduction</p> <p>Magnetic resonance imaging (MRI) and computed tomography (CT) with <sup>68</sup>Ga-DOTATOC positron emission tomography (<sup>68</sup>Ga-DOTATOC-PET) were compared retrospectively for their ability to delineate infracranial extension of skull base (SB) meningiomas treated with fractionated stereotactic radiotherapy.</p> <p>Methods</p> <p>Fifty patients with 56 meningiomas of the SB underwent MRI, CT, and <sup>68</sup>Ga-DOTATOC PET/CT prior to fractionated stereotactic radiotherapy. The study group consisted of 16 patients who had infracranial meningioma extension, visible on MRI ± CT (MRI/CT) <it>or </it>PET, and were evaluated further. The respective findings were reviewed independently, analyzed with respect to correlations, and compared with each other.</p> <p>Results</p> <p>Within the study group, SB transgression was associated with bony changes visible by CT in 14 patients (81%). Tumorous changes of the foramen ovale and rotundum were evident in 13 and 8 cases, respectively, which were accompanied by skeletal muscular invasion in 8 lesions. We analysed six designated anatomical sites of the SB in each of the 16 patients. Of the 96 sites, 42 had infiltration that was delineable by MRI/CT and PET in 35 cases and by PET only in 7 cases. The mean infracranial volume that was delineable in PET was 10.1 ± 10.6 cm<sup>3</sup>, which was somewhat larger than the volume detectable in MRI/CT (8.4 ± 7.9 cm<sup>3</sup>).</p> <p>Conclusions</p> <p><sup>68</sup>Ga-DOTATOC-PET allows detection and assessment of the extent of infracranial meningioma invasion. This method seems to be useful for planning fractionated stereotactic radiation when used in addition to conventional imaging modalities that are often inconclusive in the SB region.</p
The Role of Ethnic Directors in Corporate Social Responsibility: Does Culture matter? The Cultural Trait Theory Perspectives
This paper investigates the effect of cultural differences between ethnic directors on corporate social responsibility (CSR) of Public Liability Companies (PLCs) in Nigeria. Using the cultural trait theory, the study focuses on how the ethnic directors are influenced when making decisions concerning CSR. Adopting multiple regression analysis of data, the study investigates the three major ethnic groups (Yoruba, Igbo and Hausa) and finds cultural differences between the ethnic directors affect the adoption of CSR. Empirical results indicate that ethnic directors (Yoruba, Igbo and Hausa) were positively and significantly related to CSR. The paper contributes to the corporate governance and CSR debate concerning how ethnic directors’ decisions impact on CSR activities, particularly on the directors who are individualistic and collectivists towards CSR
Financial and corporate social performance in the UK listed firms: the relevance of non-linearity and lag effects
Using environmental, social and governance scores compiled by Reuters Datastream for each company’s corporate social performance (CSP), we examine the relationship between CSP and corporate financial performance (CFP) of 314 UK listed companies over the period 2002–2015. We further evaluate the relationship between prior and subsequent CFP and prior and subsequent CSP. Based on the system-GMM estimation method, we provide direct evidence that suggests that while CFP and CSP can be linked linearly; however, when we examine the impact of CSP on CFP, the association is more non-linear (cubic) than linear. Our results suggest that firms periodically adjust their level of commitment to society, in order to meet their target CSP. The primary contributions of this paper are testing (1) the non-monotonous relationship between CSP and CFP, (2) the lagged relationship between the two and the optimality of CSP levels, and (3) the presence of a virtuous circle. Our results further suggest that CSP contributes to CFP better during post-crisis years. Our findings are robust to year-on-year changes in CFP and CSP, financial versus non-financial firms, and the intensity of corporate social responsibility (CSR) engagement across industries
Growth pattern analysis of sphenoid wing meningiomas
Structured radiological and anatomical analysis of the SWM growth pattern may influence the surgical strategy and facilitate the management and prognostication of patients with SWM
Meningiomas and hormonal receptors: immunohistochemical study in typical and non-typical tumors Meningiomas e receptores hormonais: estudo imuno-histoquímico em tumores típicos e não típicos
The authors assessed 116 cases of meningiomas classified as typical, atypical and anaplastic and they used an immunohistochemical technique for estrogen and progesterone receptors attempting to determine if there is any difference between typical and non-typical tumors in relation to hormone receptors. The immunohistochemical technique to estrogen receptors was negative in all meningiomas studied. Progesterone receptors were detected in 58.3% of typical, and in 48.2% of non-typical meningiomas. This difference was not statistically significant. However, individually considering the criteria used for selection of non-typical tumours, those that concurrently displayed brain invasion and increased mitotic activity or necrosis, as well as the summation of those three features, were predominantly negative for progesterone receptors (respectively p=0.038; p=0.001; and p=0.044). The authors conclude that estrogen receptors were not present in meningiomas; that progesterone receptors in isolation are not enough to predict a higher tumoral malignancy but can be useful associated with other histological features.<br>Os autores avaliam 116 meningiomas classificados em típicos, atípicos ou anaplásicos usando técnica imuno-histoquímica para receptores de estrógeno (ER) e progesterona (PR) com o objetivo de determinar se existe diferença entre tumores típicos e não típicos em relação aos receptores hormonais. Todos os tumores estudados foram negativos para ER. Os receptores de progesterona foram detectados em 58,3% dos meningiomas típicos e em 48,2% dos tumores não-típicos. Essa diferença não foi estatisticamente significativa. Entretanto, considerando os critérios utilizados para seleção dos não-típicos, os tumores que apresentavam, de forma concomitante, invasão do sistema nervoso central e aumento da taxa mitótica ou necrose, bem como a soma das três características, foram predominantemente negativos para PR (p=0,038; 0,01 e 0,044, respectivamente). Os autores concluem que: ERs não estão presentes em meningiomas; PRs estão presentes na maioria dos meningiomas; a negatividade para PR isoladamente não é suficiente para predizer maior malignidade mas pode ser útil se associada a outras características histológicas