1,721,051 research outputs found
PET/CT in radiation oncology
No full textThe progressive integration of positron emission tomography/computed tomography (PET/CT) imaging in radiation therapy has its rationale in the biological intertumoral and intratumoral heterogeneity of ma- lignant lesions that require the individual adjustment of radiation dose to obtain an effective local tumor control in cancer patients. PET/CT provides information on the biological features of tumor lesions such as metabolism, hypoxia, and proliferation that can identify radioresistant regions and be exploited to optimize treatment plans. Here, we provide an overview of the basic principles of PET-based target vol- ume selection and definition using 18F-fluorodeoxyglucose (18F-FDG) and then we focus on the emerging strategies of dose painting and adaptive radiotherapy using different tracers. Previous studies provided consistent evidence that integration of 18F-FDG PET/CT in radiotherapy planning improves delineation of target volumes and reduces the uncertainties and variabilities of anatomical delineation of tumor sites. PET-based dose painting and adaptive radiotherapy are feasible strategies although their clinical imple- mentation is highly demanding and requires strong technical, computational, and logistic efforts. Further prospective clinical trials evaluating local tumor control, survival, and toxicity of these emerging strate- gies will promote the full integration of PET/CT in radiation oncology
Opsoclonus-myoclonus syndrome in patients with locked-in syndrome: a therapeutic porthole with gabapentin
No full textNeuropsicologia e sindromi psichiatriche.
No full textModelli neurobiologici delle maggiori malattie mentali: Depressione, Disturbi Ansiosi, Schizofrenia e disturbi somatoform
Action observation improves motor imagery: specific interactions between simulative processes
No full textThe role of the right premotor cortex and temporo-parietal junction in defensive responses to visual threats
No full textPrevious neuroimaging studies demonstrated that several brain areas are involved in detecting threats and activating defensive responses to threatening stimuli. The right premotor cortex (PM) is mainly activated during freezing, whereas the right temporoparietal junction (TPJ) is involved in attentional orienting towards threat. The aim of the present study was to test the possibility to modulate attentional orienting and defensive responses to threatening stimuli by interfering with the activity of the right TPJ and PM with cathodal. The results demonstrated that after sham stimulation the participants were slower to respond to threatening than to non-threatening stimuli, consistent with the idea that the experimental paradigm induced a freeze-like response to threatening stimuli. Active tDCS over PM reversed this response pattern, whereas TPJ stimulation wiped out the difference between responses to threatening and non-threatening stimuli. Our findings demonstrated that inhibitory stimulation of PM favours active defensive responses to threatening stimuli whereas TPJ inhibitory stimulation reduces attentional prioritizing of threatening stimuli. In conclusion, our study showed that it is possible to modulate responses to threatening stimuli by interfering with activity of at least two cortical regions of the brain network involved in dealing with threats
Normal tissue complication probability (NTCP) models for modern radiation therapy
No full textMathematical models of normal tissue complication probability (NTCP) able to robustly predict radiation-induced morbidities (RIM) play an essential role in the identification of a personalized optimal plan, and represent the key to maximizing the benefits of technological advances in radiation therapy (RT). Most modern RT techniques pose, however, new challenges in estimating the risk of RIM. The aim of this report is to schematically review NTCP models in the framework of advanced radiation therapy techniques. Issues relevant to hypofractionated stereotactic body RT and ion beam therapy are critically reviewed. Reirradiation scenarios for new or recurrent malignances and NTCP are also illustrated. A new phenomenological approach to predict RIM is suggested
Visual and kinesthetic motor imagery in adults with different degrees of self-reported motor coordination difficulties
No full text: Developmental Coordination Disorder (DCD) involves difficulties in performing coordinated movements with fine and/or gross motor skills deficits. Several studies showed that DCD is characterized by motor imagery deficits as well. Here we investigated in neurotypical adults (N = 334) the relationships between the ease of imaging two main motor imagery components, that is the visual and the kinesthetic one, self-reported motor coordination difficulties and handwriting speed. Self-reported motor difficulties were measured by the Adult Developmental Co-ordination Disorders/Dyspraxia Checklist (ADC) and scores were used to distinguish three groups: participants at risk of DCD (with both relevant childhood and current motor coordination difficulties); with motor coordination difficulties (relevant current but not childhood difficulties); without motor coordination difficulties (neither current nor childhood difficulties). The main results showed more kinesthetic and visual imagery difficulties in participants at risk of DCD than in those both with and without motor coordination difficulties. Interestingly, the relationships between the two imagery components and motor difficulties were different in the three groups, depending on: 1) the developmental phase (childhood or adulthood) to which motor coordination difficulties referred, and 2) the point of view (self or other), from which images were judged. Instead, no relationship was found between imagery abilities and handwriting speed. Thus, a nuanced pattern of the ease of imaging motor imagery emerged in adults with different degrees of self-reported motor coordination difficulties. These findings could be relevant for the assessment of people candidate to undergo a motor imagery training
Monochannel Preference in Autism Spectrum Conditions Revealed by a Non-Visual Variant of Rubber Hand Illusion
No full textIndividuals with autism spectrum conditions (ASC) are less susceptible to multisensory delusions, such as rubber hand illusion (RHI). Here, we investigate whether a monochannel variant of RHI is more effective in inducing an illusory feeling of ownership in ASC. To this aim, we exploit a non-visual variant of the RHI that, excluding vision, leverages only on the somatosensory channel. While the visual-tactile RHI does not alter the perceived hand position in ASC individuals, the tacto-tactile RHI effectively modulates proprioception to a similar extent as that found in typical development individuals. These findings suggest a more effective integration of multiple inputs originating from the same sensory channel in ASC, revealing a monochannel preference in this population
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