Pancreatic ductal adenocarcinoma(PDAC) is expected to become the second leading cause of death from cancer by 2030. Despite intensive research in the field of therapeutics, the 5-year overall survival is approximately...Pancreatic ductal adenocarcinoma(PDAC) is expected to become the second leading cause of death from cancer by 2030. Despite intensive research in the field of therapeutics, the 5-year overall survival is approximately 8%, with only 20% of patients eligible for surgery at the time of diagnosis. The tumoral microenvironment(TME) of the PDAC is one of the main causes for resistance to antitumoral treatments due to the presence of tumor vasculature, stroma, and a modified immune response. The TME of PDAC is characterized by high stiffness due to fibrosis, with hypo microvascular perfusion, along with an immunosuppressive environment that constitutes a barrier to effective antitumoral treatment. While systemic therapies often produce severe side effects that can alter patients’ quality of life, locoregional therapies have gained attention since their action is localized to the pancreas and can thus alleviate some of the barriers to effective antitumoral treatment due to their physical effects. Local hyperthermia using radiofrequency ablation and radiation therapy-most commonly using a local high single dose-are the two main modalities holding promise for clinical efficacy. Recently, irreversible electroporation and focused ultrasound-derived cavitation have gained increasing attention. To date, most of the data are limited to preclinical studies, but ongoing clinical trials may help better define the role of these locoregional therapies in the management of PDAC patients.展开更多
Lorentz force electrical impedance tomography(LFEIT)inherits the merit of high resolution by ultrasound stimulation and the merit of high contrast through electromagnetic field detection.To reduce the instantaneous pe...Lorentz force electrical impedance tomography(LFEIT)inherits the merit of high resolution by ultrasound stimulation and the merit of high contrast through electromagnetic field detection.To reduce the instantaneous peak power of the stimulating signal to the transducer,the sinusoidal pulse and step-frequency technique is investigated in LFEIT.The theory of application of step-frequency technique in LFEIT is formulated with the direct demodulation method and the in-phase quadrature demodulation method.Compared with the in-phase quadrature demodulation method,the direct demodulation method has simple experimental setup but could only detect half of the range.Experiments carried out with copper foils confirmed that LFEIT using the step-frequency technique could detect the electrical conductivity variations precisely,which suggests an alternative method of realization of LFEIT.展开更多
基金Supported by the Labex DEVwe Can (Universitéde Lyon) and PCSI ITMO Cancer INSERM。
文摘Pancreatic ductal adenocarcinoma(PDAC) is expected to become the second leading cause of death from cancer by 2030. Despite intensive research in the field of therapeutics, the 5-year overall survival is approximately 8%, with only 20% of patients eligible for surgery at the time of diagnosis. The tumoral microenvironment(TME) of the PDAC is one of the main causes for resistance to antitumoral treatments due to the presence of tumor vasculature, stroma, and a modified immune response. The TME of PDAC is characterized by high stiffness due to fibrosis, with hypo microvascular perfusion, along with an immunosuppressive environment that constitutes a barrier to effective antitumoral treatment. While systemic therapies often produce severe side effects that can alter patients’ quality of life, locoregional therapies have gained attention since their action is localized to the pancreas and can thus alleviate some of the barriers to effective antitumoral treatment due to their physical effects. Local hyperthermia using radiofrequency ablation and radiation therapy-most commonly using a local high single dose-are the two main modalities holding promise for clinical efficacy. Recently, irreversible electroporation and focused ultrasound-derived cavitation have gained increasing attention. To date, most of the data are limited to preclinical studies, but ongoing clinical trials may help better define the role of these locoregional therapies in the management of PDAC patients.
基金Supported by the National Natural Science Foundation of China under Grant Nos 51137004 and 61427806the Scientific Instrument and Equipment Development Project of Chinese Academy of Sciences under Grant No YZ201507the China Scholarship Council Program under Grant No 201604910849
文摘Lorentz force electrical impedance tomography(LFEIT)inherits the merit of high resolution by ultrasound stimulation and the merit of high contrast through electromagnetic field detection.To reduce the instantaneous peak power of the stimulating signal to the transducer,the sinusoidal pulse and step-frequency technique is investigated in LFEIT.The theory of application of step-frequency technique in LFEIT is formulated with the direct demodulation method and the in-phase quadrature demodulation method.Compared with the in-phase quadrature demodulation method,the direct demodulation method has simple experimental setup but could only detect half of the range.Experiments carried out with copper foils confirmed that LFEIT using the step-frequency technique could detect the electrical conductivity variations precisely,which suggests an alternative method of realization of LFEIT.
