The relationship of body mass index to setup errors, dosimetric parameters and incidence of radiation pneumonitis in non-small cell lung cancer patients undergoing intensity-modulated radiation therapy: a single-center observational study.

BACKGROUND: The relationship among body mass index (BMI), setup error and radiation pneumonitis is not clearly illustrated. OBJECTIVE: The present study aimed to investigate the role of BMI in non-small cell lung cancer (NSCLC) patients' radiation treatment, focusing on its relationship with setup error of patient positioning, the dosimetric parameters of intensity-modulated radiation therapy (IMRT) and the incidence of radiation pneumonitis. METHODS: This prospective observational study included 523 cases of NSCLC patients during 2020-2022. Patients were divided into different groups by different BMI. The setup error was obtained by cone beam CT (CBCT) at three positions, lateral (LAT), longitudinal (LNG) and vertical (VRT). IMRT dosimetric parameters of V5, V20, and mean dose were collected. RESULTS: Patients with BMI ≥28 kg/m2 showed significantly higher absolute values of LAT, LNG and VRT, higher V5, V20, mean dose, as well as higher total incidence of radiation pneumonitis and grade III radiation pneumonitis compared with patients with BMI <24 kg/m2 or 24-28 kg/m2. Spearman's analysis demonstrated that the absolute values of LAT, LNG and VRT were positively correlated with BMI, and positive correlation existed among BMI, dosimetric parameters and setup errors. ROC curves showed that LAT in setup errors and V5 in dosimetric parameters had the best diagnostic value for prediction of radiation pneumonitis. Only BMI, LAT, V5 and V20 were the independent risk factors for radiation pneumonitis. CONCLUSIONS: Setup error caused by higher BMI might be associated with the dosimetric parameters, as well as the incidence of radiation pneumonitis in NSCLC patients.

Early evaluation of adjuvant effects on topramezone efficacy under different temperature conditions using chlorophyll fluorescence tests.

Proper selection of adjuvant applications is an important strategy to enhance herbicide efficacy and reduce active ingredient input especially under adverse environmental conditions. In this study, a two-factor split-plot-design experiment was conducted to evaluate the effects of two adjuvants on the efficacy of topramezone on the grassy weed species giant foxtail (Setaria faberi Herrm.) and the broadleaved weed species velvetleaf (Abutilon theophrasti Medik.) under three different temperature conditions. The two tested adjuvants were methylated seed oil (MSO) and organosilicone. Three temperature levels, 35/30°C, 25/20°C, and 15/10°C (day/night), were used in the laboratory and greenhouse experiment. Plant chlorophyll fluorescence measurements shortly after herbicide application and classic whole-plant bioassay methods were used to evaluate the herbicide efficacy among the different treatments. Results indicated that the maximum quantum efficiency (Fv/Fm) of the top leaf of the weeds treated with topramezone mixed with MSO was significantly lower than that of the weeds treated with topramezone mixed with organosilicone and without an adjuvant at 2-3 days after treatment under all three temperature levels. The herbicide response of the plants treated with topramezone mixed with organosilicone and topramezone alone was not significantly different. These results corresponded well with the results of the classic whole-plant test. MSO has been shown to be good at enhancing the efficacy of topramezone on these weed species under all three temperature conditions. The measurement of chlorophyll fluorescence is a promising technique for evaluating the effects of adjuvants on the efficacy of herbicides shortly after herbicide treatment.

miR-200c enhances sensitivity of drug-resistant non-small cell lung cancer to gefitinib by suppression of PI3K/Akt signaling pathway and inhibites cell migration via targeting ZEB1.

Acquired resistance to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) is a major obstacle in the treatment of non-small cell lung cancer (NSCLC) patients. We explored the role of miR-200c in modulating the sensitivity of gefitinib-resistant NSCLC cells and examined the underlying mechanism. The gefitinib-resistant cell line PC-9-ZD and its parental PC-9 cells were used. Growth inhibition was detected by MTT assay. The cell apoptosis was detected by Annexin V/PI assay. Cell migration was assessed by wound-healing assay. RT-PCR was used to detected levels of miR-200c and ZEB1. The PI3k, Bcl-2, Bax, caspase-3 and ZEB1 protein expression were detected using Western blot analysis, and TUNEL, Immunohistochemistry for xenograft model. PC-9-ZD cells had low level of miR-200c expression compared to its parental PC-9 cells. PC-9-ZD cells with miR-200c transfection were more sensitive to gefitinib treatment. Apoptosis induced by gefitinib was observed in PC-9-ZD cells with miR-200c transfection significantly. The levels of phosphorylated-Akt and Bcl-2 expression decreased and levels of Bax and Caspase-3 expression increased in PC-9-ZD cells with miR-200c transfection. Cell migration was inhibited and ZEB1 mRNA level and protein expression were significantly decreased in PC-9-ZD cells with miR-200c transfection. Further in gefitinib resistant xenograft model, miR-200c enhanced sensitivity of gefitinib and induced apoptosis significantly through PI3K/Akt signaling pathway and targeting ZEB1. These results provided insights into the functions of miR-200c and offered an alternate approach in treating gefitinib-resistance NSCLC.