12 research outputs found

    Allowing for crystalline structure effects in Geant4

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    International audienceIn recent years, the Geant4 toolkit for the Monte Carlo simulation of radiation with matter has seen large growth in its divers user community. A fundamental aspect of a successful physics experiment is the availability of a reliable and precise simulation code. Geant4 currently does not allow for the simulation of particle interactions with anything other than amorphous matter. To overcome this limitation, the GECO (GEant4 Crystal Objects) project developed a general framework for managing solid-state structures in the Geant4 kernel and validate it against experimental data. Accounting for detailed geometrical structures allows, for example, simulation of diffraction from crystal planes or the channeling of charged particle

    Channeling efficiency dependence on bending radius and thermal vibration amplitude of the model for the channeling of high-energy particles in straight and bent crystals implemented in Geant4

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    Monte Carlo simulations of the interaction of particles with matter are usually done with downloadable toolkits such as Geant4. A model suitable for the implementation into Geant4 for the interaction of high-energy particles in straight and bent crystals was developed and implemented. The model relies on the continuum potential approximation. The variation of the Geant4 model for the description of the orientational effect as a function of the physical parameters for the calculation of the interplanar potential is presented. The simulations are capable of reproducing the variation of the efficiency of channeling as a function of the thermal vibration amplitude and the bending radius of a bent Si strip. The study can be useful for the simulation of the channeling effect in experiments at GeV/c energies

    Predictors of unexpected nodal upstaging in patients with cT1-3N0 non-small cell lung cancer (NSCLC) submitted to thoracoscopic lobectomy

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    In the last decades, the use of video-assisted thoracoscopic surgery (VATS) lobectomy for the treatment of early stage non-small cell lung cancer is continuously growing. This is mainly due to the development of more advanced surgical devices, to the rising incidence of peripheral lung tumors and is also favored by the increased reliability of preoperative staging techniques. Despite this progress, postoperative unexpected nodal upstaging is still a relevant issue. Aim of this study is to identify possible predictors of unexpected nodal upstaging in patients affected by cT1-3N0 NSCLC submitted to VATS lobectomy

    Thymic Carcinoma With Thyroid Transcription Factor-1 Expression: An Insidious Pitfall

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    The expression of thyroid transcription factor-1 (TTF-1), commonly used as a marker of pulmonary and thyroid tumor, has been recently described in association with thymomas. Herein we report the clinicopathologic features of the first case of thymic carcinoma with nuclear expression of TTF-1, initially misdiagnosed as a lung tumor

    Predictors of nodal upstaging in patients with cT1‑3N0 non‑small cell lung cancer (NSCLC): results from the Italian VATS Group Registry

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    PURPOSE: Accurate staging of early non-small cell lung cancer is fundamental for selecting the best treatment. The aim of this study was to identify risk factors for nodal upstaging after video-assisted thoracoscopic lobectomy for clinical T1-3N0 tumors. METHODS: From 2014 to 2017, 3276 thoracoscopic lobectomies were recorded in the prospective database "Italian VATS Group". Linear and multiple logistic regression models were adapted to identify independent predictors of nodal upstaging and factors associated with progression in postoperative N status. RESULTS: Nodal upstaging was found in 417 cases (12.7%), including 206 cases (6.2%) of N1-positive nodes, 81 cases of N2 nodes (2.4%), and 130 cases (4%) of involvement of both N1 + N2 nodes. A total of 241 (7.3%) patients had single-station nodal involvement, whereas 176 (5.3%) had multiple-station involvement. In the final regression model, the tumor grade, histology, pathologic T status, and > 12 resected nodes were independent predictors of nodal upstaging. CONCLUSIONS: The number of resected lymph nodes seems to predict nodal upstaging better than the type of intraoperative lymph node management. Other preoperative risk factors correspond to those for which the current guidelines of the European Society of Thoracic Surgery recommend more extensive preoperative mediastinal staging

    Outcomes and prognostic factors of non-small-cell lung cancer with lymph node involvement treated with induction treatment and surgical resection

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    OBJECTIVES: Induction therapy (IT) has gained popularity in recent years, becoming a standard of treatment in resectable lymph node-positive NSCLC. IT aims to downstage the disease (shrinkage of tumour and clearance of lymph node-metastases), clear distant micrometastases and prolong survival. Potential disadvantages are increased morbidity and/or mortality after surgery and risk of progression of disease that could have been initially resected. The purpose of this study was to evaluate the outcomes and prognostic factors in a series of patients with lymph node-positive NSCLC receiving IT followed by surgery. METHODS: A total of 86 patients (75.6% males, median age 63 years) affected by NSCLC in clinical stage IIIA (n = 80) or IIIB (n = 6), with pathologically proven lymph node involvement, underwent platinum-based IT followed by surgery between 2000 and 2009. RESULTS: Eighty (93%) patients received a median of 3 cycles of chemotherapy, and 6 (7%) underwent induction chemoradiotherapy. Response to IT was complete in 3.5%, partial in 59.3% and stable disease in 37.2% of patients. Postoperative morbidity and mortality were 25.6 and 2.3%, respectively. At pathological evaluation, 38.4% of patients had a downstaging of disease with a complete lymph node clearance in 31.4%. Median overall survival was 23 months (5-year survival 33%). Univariate analysis found clinical stage (P = 0.02), histology (P = 0.01), response to IT (P = 0.02) and type of intervention (P = 0.047) to have predictive roles in survival. A better but not significant survival was also found for pN0 vs pN+ (P = 0.22), downstaged tumours (P = 0.08) and left side (P = 0.06). On multivariate analysis, clinical response to neoadjuvant therapy (P = 0.01) and age (P = 0.03) were the only independent predictors of survival. CONCLUSIONS: The use of IT for lymph node-positive NSCLC seems justified by low morbidity and/or mortality and good survival rates. Patients with response to IT showed greater benefit in the long term

    Does Induction Therapy Increase Anastomotic Complications in Bronchial Sleeve Resections?

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    BackgroundSleeve lobectomy represents a safe and effective treatment for central NSCLC to avoid the risks of pneumonectomy. Induction therapy (IT) may be indicated in advanced stages; however, the effect of IT on bronchial anastomoses remains uncertain. The purpose of the study was to evaluate the impact of IT on the complications of the anastomoses.MethodsBetween 2000 and 2012, 159 consecutive patients were submitted to sleeve lobectomy for NSCLC at our Institution. We retrospectively compared the results of patients who underwent IT before operation with those who received upfront surgery.ResultsIn the study period, 49 (30.8%) patients received IT (37 chemotherapy, 1 radiotherapy and 11 chemo-radiotherapy) and 110 (69.2%) patients were directly submitted to surgery (S). The two groups were comparable for sex, age, comorbidities, ASA score, pulmonary function, side, type of procedure and histology. Pathological stage was statistically higher for IT group (p=0.001). No differences between IT and S groups were observed in terms of post-operative mortality (2% vs 0%, p=NS), morbidity (45% vs 38%, p=NS), including early (6% vs 9%, p=NS) and long-term (16% vs 14%, p=NS) bronchial complication rates. Patients undergoing induction mediastinal radiotherapy, however, are at higher risk of bronchial complications.ConclusionIn our experience, the use of induction chemotherapy did not significantly increase mortality and morbidity rates, in particular, neither for early nor for late anastomotic complications. We, therefore, conclude that sleeve lobectomy after induction chemotherapy is safe and reliable procedure for the treatment of locally advanced NSCLC
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