Objective To evaluate the dose distributions with different dose rates, and approach a reference to the dose rate for radiation. Methods Three classic static intensity modulated radiotherapy (IMRT) plans of prostate cancer, lymphoma and nasopharyngeal carcinoma were chosen for the study. For each plan, the dose verification of three different dose rates (100, 300 and 600 MU/min) was performed with the Varian 600CD linear accelarator by using the 2-DICA of I'mRT Matrixx. With the Pinncale planning system, each segment was used as a beam to form another IMRT plan. The OmniPro-I'mRT V1.6 was applied to compare the segments in the two IMRT plans, and then the actual weights were obtained. The simulated plans at different dose rate were designed when setting the weights back into the planning system. Results With the increase of dose rate, the passing ratio of the verification decreased and the D_(max), D_(min), D_(mean) and D_(95) of the planning tumor volume increased. The high dose area expanded significantly in target regions, and the 95% isodose line extended. At the dose rate of 600 MU/min, The D_(95) of GTV_(nd) in nasopharyngeal carcinoma increased by 5.33% than the original plan with the V_(110) up to 19. 38%. The irradiation dose of the organs at risk (OARs) increased. For the case of lymphoma, the V_(20) of the lungs in the original plan and the three simulated plans were 31.77%, 32. 11%, 32.60% and 33.26%, respectively. For the case of nasopharyngeal carcinoma, the V_(30) of the right parotid were 48.75%, 49. 56%, 51.65% and 53.91%, respectively. Conclusions With the increase of dose rate in static IMRT , the actual dose distribution deviates the original plan , and the high dose area and the OARs dose increases. The higher dose rate is suboptimal when the dose of the OARs is proximate to the tolerance limit.

Objective To evaluate the efficacy and safety of efavirenz-based therapy in patients with human immunodeficiency virus (HIV)/hepatitis C virus (HCV) co-infection. Methods Fiftythree HIV/HCV co-infected patients received efavirenz-based therapy were followed up for 7 years.The changes of CD4+ T lymphocyte count, HIV virus load, hepatic function, hepatic fibrosis index,blood lipid, blood glucose, blood uric acid and blood routine were observed. The comparison of means before and after treatment was performed by t-test. Results The HIV RNA levels at baseline and endpoint were (4. 56±0. 88) lg copy/mL and (1.70±1.10) lg copy/mL, respectively (t=14. 781, P＜0.01). The peripheral blood CD4+ T lymphocyte counts were ( 188.37±151.14)×106/L and (445.18±314.25)×106/L, respectively (t=5.362, P＜0.01).The alanine aminotransferase (ALT) levels were (36.6±16.3) U/L and (57.2±9.9) U/L, respectively (t=7.864, P＜0. 01).The glycocholic acid levels were (444.22±476.74) mg/L and (556.88±733.05) mg/L, respectively (t=0.938, P＜0.05). The Ⅳ-collagen(Ⅳ-C) levels were (45.13±8.25) ng/mL and (47.88±4.51) ng/mL, respectively (t= 2.129, P＜0.05). The riacylglycerol levels were (1.57±0.65)mmol/L and (2.51±1.29) mmol/L, respectively (t=4.737, P＜0.01). The blood uric acid levels were (298.5±48.2) mmol/L and (495.1±89.4) mmol/L, respectively (t= 14.092, P＜0.01).Conclusions The efavirenz-based therapy is efficacious in HIV/HCV co-infected patients, but it could cause liver injury and metabolic disorder.