Brain Activation Patterns Characterizing Different Phases of Motor Action: Execution, Choice and Ideation.

Motor behaviour is controlled by a large set of interacting neural structures, subserving the different components involved in hierarchical motor processes. Few studies have investigated the neural substrate of higher-order motor ideation, i.e. the mental operation of conceiving a movement. The aim of this functional magnetic resonance imaging study was to segregate the neural structures involved in motor ideation from those involved in movement choice and execution. An index finger movement paradigm was adopted, including three different conditions: performing a pre-specified movement, choosing and executing a movement and ideating a movement of choice. The tasks involved either the right or left hand, in separate runs. Neuroimaging results were obtained by comparing the different experimental conditions and computing conjunction maps of the right and left hands for each contrast. Pre-specified movement execution was supported by bilateral fronto-parietal motor regions, the cerebellum and putamen. Choosing and executing finger movement involved mainly left fronto-temporal areas and the anterior cingulate. Motor ideation activated almost exclusively left hemisphere regions, including the inferior, middle and superior frontal regions, middle temporal and middle occipital gyri. These findings show that motor ideation is controlled by a cortical network mainly involved in abstract thinking, cognitive and motor control, semantic and visual imagery processes

Application of Possibilistic C-Means for fault detection in Nuclear Power Plant data

none6noThis paper describes a classification method for automatic fault detection in nuclear power plant (NPP) data. The method takes as input time series associated to specific parameters and realizes signal classification by using a clustering algorithm based on possibilistic C-means (PCM). This approach is applied to time series recorded in a CANDU® power plant and is validated by comparison with results provided by a classification method based on principal component analysis (PCA).Perasso, Annalisa; Campi, Cristina; Toraci, Cristian; Benvenuto, Francesco; Piana, Michele; Massone, Anna MariaPerasso, Annalisa; Campi, Cristina; Toraci, Cristian; Benvenuto, Francesco; Piana, Michele; Massone, Anna Mari

A Brief Report on the Role of SPECT/TC in the Optimization of Radiotherapy Treatment with Radical Intent for Unresectable Stage III NSCLC

Background: The standard treatment for locally advanced non-small cell lung cancer (LA-NSCLC) is represented by concomitant chemo-radiotherapy followed by consolidation with durvalumab that ensures a 5-year survival of 46%. However, the risk of radiotherapy-induced pneumonia (RIP) is almost 10–15%. Complete cardiological examination is also usually performed during the cardiopulmonary pre-treatment evaluation and pulmonary function testing is one of the most used tool to predict the risk of RIP development. Aim: The aim of this study is to investigate the impact of Tc-99 macroaggregated albumin (MAA) lung perfusion scan with single photon emission-computed tomography/computed tomography (SPECT/CT) in the preliminary assessment of lung functions and its potential role for the optimization of the radiotherapy treatment planning. Methods: Descriptive and statistical analysis were performed on eight patients affected by unresectable stage III LA-NSCLC treated with chemo-radiotherapy. Before starting radiotherapy, patients underwent lung perfusion SPECT/CT. The SPECT/CT images were firstly co-registered with the simulation CT scan ones, then a specific region of interest (ROI) of lung volumes was created to represent the areas with a perfusion of at least 20% 40%, 60% and 80% of maximum perfusion, respectively. Finally, optimization of the standard treatment plan was performed with the aim of preserving the better perfused lung volumes. The dosimetric correlations of both plans were made comparing pulmonary V20 and V5, mean pulmonary, esophagus and heart dose. Results: From the DVH comparative analysis of the two treatment plans (standard one versus SPECT optimized one) obtained for each patient, the data confirmed an equal coverage of the target volume while respecting all lungs, heart and esophagus dose constraints. At the same time, SPECT-optimized plans allowed to reduce the average dose to the better perfused lung volumes. Conclusions: Lung perfusion scintigraphy could be considered a preliminary assessment tool to explore lung functions and stratify the risk of RIP development. SPECT/TC may also be proposed as a dose painting tool to optimize radiotherapy treatment plans. Only prospective analysis will be enable us to confirm the real reduction of RIP risk in lung areas with an optimal perfusion

Adoption of Hybrid MRI-Linac Systems for the Treatment of Brain Tumors: A Systematic Review of the Current Literature Regarding Clinical and Technical Features

Background Possible advantages of magnetic resonance (MR)-guided radiation therapy (MRgRT) for the treatment of brain tumors include improved definition of treatment volumes and organs at risk (OARs) that could allow margin reductions, resulting in limited dose to the OARs and/or dose escalation to target volumes. Recently, hybrid systems integrating a linear accelerator and an magnetic resonance imaging (MRI) scan (MRI-linacs, MRL) have been introduced, that could potentially lead to a fully MRI-based treatment workflow. Methods We performed a systematic review of the published literature regarding the adoption of MRL for the treatment of primary or secondary brain tumors (last update November 3, 2022), retrieving a total of 2487 records; after a selection based on title and abstracts, the full text of 74 articles was analyzed, finally resulting in the 52 papers included in this review. Results and discussion Several solutions have been implemented to achieve a paradigm shift from CT-based radiotherapy to MRgRT, such as the management of geometric integrity and the definition of synthetic CT models that estimate electron density. Multiple sequences have been optimized to acquire images with adequate quality with on-board MR scanner in limited times. Various sophisticated algorithms have been developed to compensate the impact of magnetic field on dose distribution and calculate daily adaptive plans in a few minutes with satisfactory dosimetric parameters for the treatment of primary brain tumors and cerebral metastases. Dosimetric studies and preliminary clinical experiences demonstrated the feasibility of treating brain lesions with MRL. Conclusions The adoption of an MRI-only workflow is feasible and could offer several advantages for the treatment of brain tumors, including superior image quality for lesions and OARs and the possibility to adapt the treatment plan on the basis of daily MRI. The growing body of clinical data will clarify the potential benefit in terms of toxicity and response to treatment

Anal squamous cell carcinoma: Impact of radiochemotherapy evolution over years and an explorative analysis of MRI prediction of tumor response in a mono-institutional series of 131 patients

Introduction: Radiochemotherapy (RCHT) for the treatment of anal squamous cell carcinoma (ASCC) has evolved dramatically, also thanks to intensitymodulated RT (IMRT) and 3D image guidance (3D IGRT). Despite most patients presenting fair outcomes, unmet needs still exist. Predictors of poor tumor response are lacking; acute toxicity remains challenging; and local relapse remains the main pattern of failure.Patients and methods: Between 2010 and 2020, ASCC stages I-III treated with 3D conformal radiotherapy or IMRT and CDDP-5FU or Mytomicine-5FU CHT were identified. Image guidance accepted included 2D IGRT or 3D IGRT. The study endpoints included freedom from locoregional recurrence (FFLR), colostomy free survival (CFS), freedom from distant metastasis (FFDM), overall survival (OS), and acute and late toxicity as measured by common terminology criteria for adverse events (CTCAE) version 5.0. An exploratory analysis was performed to identify possible radiomic predictors of tumor response. Feature extraction and data analysis were performed in Python (TM), while other statistics were performed using SPSS (R) v.26.0 software (IBM (R)).Results: A total of 131 patients were identified. After a median FU of 52 months, 83 patients (63.4%) were alive. A total of 35 patients (26.7%) experienced locoregional failure, while 31 patients (23.7%) relapsed with distant metastasis. Five year FFLR, CFS, DMFS and PS resulted 72.3%, 80.1%, 74.5% and 64.6%. In multivariate analysis, 2D IGRT was associated with poorer FFLR, OS, and CFS (HR 4.5, 4.1, and 5.6, respectively); 3DcRT was associated with poorer OS and CFS (HR 3.1 and 6.6, respectively). IMRT reduced severe acute gastro-intestinal (GI) and severe skin acute toxicity in comparison with 3DcRT. In the exploratory analysis, the risk of relapse depended on a combination of three parameters: Total Energy, Gray Level Size Zone Matrix's Large Area High Gray Level Emphasis (GLSZM's LAHGLE), and GTV volume.Conclusions: Advances in radiotherapy have independently improved the prognosis of ASCC patients over years while decreasing acute GI and skin toxicity. IMRT and daily 3D image guidance may be considered standard of care in the management of ASCC. A combination of three pre-treatment MRI parameters such as low signal intensity (SI), high GLSZM's LAHGLE, and GTV volume could be integrated in risk stratification to identify candidates for RT dose-escalation to be enrolled in clinical trials