ObjectiveTo estimate the radiation dose (RD) to the general public and nuclear medicine technicians from patients undergoing 99mTc-methoxy isobutyl isonitrile (MIBI) myocardial perfusion imaging. MethodsFrom January to June 2015, 55 patients including 30 males and 25 females aged between 25 and 87 years[averaging (63.6±15.1)years] ready to undergo myocardial perfusion scintigraphy with 99mTc-MIBI were prospectively recruited in this study. Approximately at hour 1.5 after injection of 99mTc-MIBI, whole-body dose-equivalent rate was measured with a radiation-survey meter at 0.3 meter and 1.0 meter from the patients. On the basis of human 99mTc-MIBI metabolic rate proposed by the International Commission of Radiological Protection and human social contact model proposed by the National Council on Radiation Protection and Measurements, the RDs to the general public from patients who had completed 99mTc-MIBI myocardial perfusion imaging and left nuclear medicine department were calculated. On the assumption that a nuclear medicine technician typically spent 5 minutes at a distance of 0.3 meter for positioning the patient, the technician's RD was also estimated. ResultsThe RD to a family member sleeping with the patient at night was predicted to be 42.88-160.55 μSv, to a family member contacting the patient at daytime 7.50-29.38 μSv, to a colleague 9.89-38.78 μSv and to a nearby passenger 124.48-466.06 μSv. The RD to a technician per 99mTc-MIBI myocardial perfusion imaging procedure was predicted to be 1.72-6.44 μSv. ConclusionThe predicted RDs to the general public and technicians from exposure of patients undergoing 99mTc-MIBI myocardial perfusion imaging are significantly lower than the regulatory dose limits.
Objective To explore the expression of long non-coding RNA (LncRNA) KCNQ1OT1 and its clinical significance in non-small cell lung cancer (NSCLC). Methods Eighty-nine NSCLC patients who underwent surgery were recruited in Sichuan Cancer Hospital from January 2011 to December 2013. Quantitative real-time PCR was used to detect the expression of LncRNA KCNQ1OT1 in tumor tissues and paracarcinoma tissues (5cm or above away from tumor). The relationship between LncRNA KCNQ1OT1 expression and clinicopathologic features was analyzed by univariate analysis and Cox regression analysis. Results The expression of LncRNA KCNQ1OT1 significantly increased in tumor tissues than that in paracarcinoma tissues (P < 001). The patients were divided into a high expression group and a low expression group according to the relative expression of LncRNA KCNQ1OT1. Univariate analysis showed that the differences between two groups were not significant in age, gender or histological type, but were significant in tumor size (χ2=12.619, P < 001), lymph node metastasis(χ2=10.298, P=0.001), TNM stage(χ2=7.199, P=0.007), and history of smoking(χ2=24.005, P < 001). Kaplan-Meier analysis showed the patients with high LncRNA KCNQ1OT1 expression had significantly lower overall survival time (20.0 months vs. 35.0 months, χ2=45.860, P < 001) and significantly lower progression-free survival time (12.0 months vs. 24.0 months, χ2=31.510, P < 001) than those with low LncRNA KCNQ1OT1 expression. Cox regression analysis revealed that the disease stage and the expression of LncRNA KCNQ1OT1 could be used as independent prognostic markers for poor prognosis. Conclusion LncRNA KCNQ1OT1 is highly expressed in tumor tissues and associated with the prognosis of NSCLC patients, thus can be used as a potential marker for predicting the prognosis of lung cancer.