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Merkel cell carcinoma (MCC) is a rare primary neuroendocrine carcinoma of the skin, which is named for its ultrastructure and immunophenotype similar to Merkel cells in the skin. It has been found that the integration of MCC with the oncogenic Merkel cell polyomavirus (MCPyV) may drive tumorigenesis or cause somatic mutations to the development of MCC because of ultraviolet ray-induced DNA damage. However, the pathogenesis of MCC is still unclear. This article introduces the current research progress of the pathogenesis of MCC, hoping to provide theoretical guidance for follow-up researches.
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In the recent years, the damage of the spleen has been increased due to trauma or neoplastic diseases. Traditional view holds the point that the damaged spleen should be completely removed, but with the development of spleen surgery, the important physiological function of the spleen has been widely recognized, and partial splenectomy has been well recognized by the surgeons. This paper summarized the clinical experience in partial splenectomy and raised some technical points.
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Objective To apply 3D printing technology to fabricate patient-specific silicone tissue compensators for the chest wall and compare the advantages and clinical characteristics between conventional bolus and 3D-printed PLA materials. Methods The chest wall data of two breast cancer patients undergoing mastectomy were obtained based upon the CT images. A patient-specific 3D printing silicone rubber bolus (3D-SRB) was designed and fabricated. The conformability of 3D-SRB,3D-PLA and conventional bolus to the chest wall were validated. Ecipse8. 6 planning system was adopted to statistically compare the dosimetric parameters of virtual plan with those after using three tissue compensators. Results The 3D-SRB was successfully designed and fabricated with a similar hardness to conventional bolus. During the process of validating conformability and radiotherapy planning,3D-SRB and 3D-PLA were superior to conventional bolus in terms of conformability to chest wall and planning dosimetric distribution.3D-SRB was advantageous in repeatability, conformability and comfortable experience compared with 3D-PLA. Regarding dosimetric parameters,3D-SRB yielded the highest repeatability with the virtual plan, followed by 3D-PLA and conventional bolus. Conclusion It is applicable to utilize 3D-SRB as the patient-specific compensators for the chest wall,which is of significance in clinical practice.
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Objective To evaluate the lung exposure dose-volume (DVH) parameters and other indicators of lung perfusion imaging before and after three-dimensional conformal or intensity modulated radiation therapy for lung cancer patients,and combined with clinical factors,to explore relationship with radiation pneumonitis occurred.Methods 18 patients were selected for data analysis.Lung perfusion scintigraphy was detected before and after three-dimensional conformal or intensity modulated radiation therapy for lung cancer.Lung perfusion changes were compared before and after irradiation.Evaluation of radiation pneumonitis was assessed by the Radiation Therapy Oncology Group (RTOG) acute radiation pneumonitis standard.After the CT and SPECT lung perfusion images were transferred to Varian,the Eclipse 3D treatment planning system,image fusion after dose curve projected onto the SPECT images,and the DVH was converted into a f-DVH diagram.Analysis of pulmonary perfusion imaging changes before and after radiotherapy combined with lung irradiation dose volume parameters and radiation pneumonitis.Results In the whole group,33.3 ％ (6/18) cases occurred more than 2 radiation pneumonitis.Before and after radiotherapy,the damage to the lung perfusion was more than 2 radiation pneumonitis incidence [62.5 ％ (5/8)],and impaired pulmonary perfusion improvement was 10.0 ％ (1/10).DVH parameters to V5 severe RP forecasted high accuracy.In curve for each patient,boundary values of V5,V10 and V20 were 53 ％,41％ and 27 ％.Before and after radiotherapy it was found that lung perfusion changes and the whole lung V5 portfolio were the strongest predictors for radiation pneumonitis after radiotherapy.Conclusion Pulmonary perfusion imaging in patients with lung cancer is able to reflect changes in the function of ipsilateral lung perfusion before and after radiotherapy.Changes in the ipsilateral lung perfusion detected before and after radiotherapy combined with V5 are expected to serve as indicators to predict radiation pneumonitis.