ABSTRACT
Objective:To evaluate the application value of SPECT lung perfusion imaging in guiding radiotherapy path, optimizing the radiotherapy plan for lung cancer and protecting lung function during radiotherapy for locally advanced non-small cell lung cancer.Methods:In this study, 84 patients with stage Ⅲ non-resectable non-small cell lung cancer were randomly divided into the control group ( n=44) and observation group ( n=40). In the control group, radiotherapy plan based on conventional CT images was delivered, and two plans based on the lung function information suggested by conventional CT and SPECT lung perfusion imaging: P1 and P2 were given in the observation group. All patients in the observation group were finally treated according to the P2 plan. The incidence of radiation pneumonitis, and changes in lung function before and after radiotherapy were statistically compared between two groups. The dose-volume parameters of P1 and P2 were statistically compared. Results:After the plan was optimized, the incidence of radiation pneumonitis in the observation group was significantly reduced and the decline of lung function was significantly improved (both P≤0.001). The functional dose parameters were significantly improved in the P2 plans (both P<0.05), whereas the irradiation dose of organs at risk did not significantly change ( P>0.05). Conclusion:SPECT lung perfusion imaging optimizes the intensity-modulated radiotherapy plan, which can reduce the functional lung dose and increase the tumor radiotherapy dose without increasing the irradiation dose of other organs at risk.
ABSTRACT
Functional imaging plays an important role in lung cancer radiotherapy.Functional imaging techniques include single photon emission computed tomography,positron emission tomography,magnetic resonance imaging,and computed tomography.Using lung function information provided by these techniques for lung cancer radiotherapy can better protect the normal function of lung tissue,optimize the radiotherapy program,and reduce the incidence of radiation pneumonitis.With the development of perfusion and imaging technology,functional imaging technology is expected to be widely used in the precise radiotherapy of lung cancer in the future.
ABSTRACT
This study was aimed to identify pET21b-HPV16E2/BL21(DE3) strain and to optimize the expression of human papillomavirus type 16 (HPV16) E2 protein by orthogonal analysis. Four influence factors on two levels were selected to increase the target protein quantity. The four factors were induction time, induction temperature, inductor concentration and cell density. The quantity of HPV16 E2 protein was used as the evaluation parameter. Induced by IPTG, HPV16 E2 protein was analyzed by SDS-PAGE and Western Blot. Target protein was analyzed by GIS imaging system to quantify the protein level. SPSS13. 0 software was applied to analyze the result. Data showed that the expression strain pET211rHPV16 E2/BL21(DE3) was identified correctly. HPV16 E2 protein expressed mainly at insoluble form. The 42KD protein band was identified by SDS-PAGE and Western blot. Orthogonal test was applied on influence factor analysis and expression optimization successfully. Main influence factors were inductor concentration and induction temperature. The optimimum condition of maximum expression quantity was 37 degrees C, 7h, 1.0 mmol/L IPTG and OD600 1.0. In this experiment, orthogonal test could not only be used to analyze the influential factors and promote the target protein expression, but also be used to provide a better experiment method for molecular biological study.