ABSTRACT
Objective:To establish a novel clinical application process of the optical surface monitoring system (OSMS) in the cranial frameless stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT), and to assess the accuracy and effectiveness of the OSMS in the intra-fraction motion monitoring of both cranial phantoms and cranial SRT patients fixed using the Q-Fix encompass immobilization system.Methods:The deviations of OSMS in the real-time motion monitoring were assessed by determining the deviations between the displacement of the cranial SRS phantoms detected by the OSMS and the predefined displacement of the Varian Edge six degrees of freedom (6DoF) couch. The ability of the OSMS to conduct real-time monitoring of the head movement was also analyzed when one camera was blocked by the rotary gantry of the accelerator and when the couch was at non-zero angles. Moreover, ten patients who received 50 fractions of cranial frameless SRT were enrolled in this study. All the patients were fixed using the Q-Fix Encompass system, and their intra-fraction motion was monitored using the OSMS. The intra-fraction errors of OSMS real-time monitoring throughout the treatment were obtained from the OSMS logs. The patients received cone-beam computed tomography (CBCT) after the beam delivery, and the six-dimensional errors were obtained as intra-fraction motion errors of the CBCT.Results:For the cranial phantoms, there was a close correlation between the OSMS monitoring deviations and the predefined displacement in six dimensions. The OSMS-detected 3D vector deviations in the translational and rotational directions were (0.28±0.10) mm and (0.15±0.09)°, respectively when the angel both the gantry and couch was 0° and were (0.35±0.13) mm and(0.17±0.09)°, respectively, when one camera was blocked. The OSMS monitoring deviations with the couch at a non-zero degree were greater than those at zero degree. The maximum deviations occurred when the couch was at 270° and were (0.69±0.19) mm and (0.32±0.12)°, respectively, in the translational and rotational directions. For the cranial SRT patients fixed using the Q-Fix Encompass system, the OSMS and CBCT showed comparable intra-fractional motion deviations, which were (0.40±0.26) and (0.29±0.10) mm, respectively in the translational direction and were (0.33±0.20)°and (0.26±0.08)° in the rotational direction.Conclusions:The OSMS is an effective tool for optically guided radiotherapy, which allows for intra-fraction real-time motion monitoring with sub-millimeter accuracy. Therefore, to ensure the accurate preformation of cranial SRS/SRT, it is necessary to conduct the intra-fractional position monitoring using OSMS.
ABSTRACT
OBJECTIVE:To optimize the formulation and preparation technology of Propylthiouracil(PTU)solid lipid nanopar-ticles(PTU-SLN)and to evaluate the quality of PLN-SLN. METHODS:PTU-SLN was prepared by emulsion ultrasound dispersing method. The formulation of PTU-SLN was optimized by orthogonal design with the entrapment efficacy and particle size as index, using the amount of lipid material,soybean lecithin and poloxamer 188 and ultrasonic time as factors. The quality of prepared nanoparticles was evaluated with particle size,Zeta potential,entrapment efficiency,stability and in vitro drug release rate as in-dex. RESULTS:The optimal formulation and technology was as follows as lipid material 0.6 g,soybean lecithin 1.0 g,poloxamer 188 0.8 g,ultrasonic time 10 min. The obtained PTU-SLN was round and smooth in appearance and distributed evenly in particle size with average particle size of 93.5 nm,Zeta potential of -30.8 mV and average entrapment efficiency of 74.9%. Prepared nanoparticles had no significant change after placing for 15 d at 4 ℃. Accumulative release rate of PTU-SLN was 56.1% at 4 hour in vitro and reached 98.4% at 24 hour. CONCLUSIONS:PTU-SLN is prepared successfully and reasonable in technology,and can reach sustained-release effects.
ABSTRACT
OBJECTIVE:To study the effects of Clebopride(CBP)bioadhensive sustained-release tablets on experimental gas-tric ulcer and gastrointestinal motility disorder. METHODS:Gastric ulcer rat model was induced by ethanol and aspirin,and then divided into model group (normal saline),common tablet (CBP tablet 0.072 mg/kg) and sustained-release tablet high-dose and low-dose groups (CBP bioadhensive sustained-release tablet 0.072,0.036 mg/kg);normal rats were included in normal control group (normal saline);they were given relevant medicine intragastrically,twice a day for sustained-release tablet,three times a day for other. Ulcer area were observed 2 and 4 days after medication to calculate healing rate of ulcer(n=6). Gastrointestinal mo-tility disorder mice model was induced by atropine,and then divided into model group (normal saline),common tablet group (CBP tablet 0.1 mg/kg)and sustained-release tablet high-dose,medium-dose and low-dose groups(CBP bioadhensive sustained-re-lease tablet 0.1,0.05,0.025 mg/kg);normal mice were included in normal control group(normal saline);they were given rele-vant medicine intragastrically,once a day,for consecutive 3 days. The rate of gastric emptying and small intestinal propulsion were detected (n=6). RESULTS:Compared with normal control group,ulcer area of rats increased in model group;compared with model group,that of rats decreased in common tablet group and sustained-release tablet high-dose,low-dose groups,with statisti-cal significance (P<0.01);healing rates of gastric ulcer were 32.35%-48.24% 2 days after medication,and those were above 70% 4 days after medication. Compared with normal control group,the rate of gastric emptying and small intestinal propulsion in mice decreased in model group;compared with model group,those of mice increased in common tablet group and sustained-re-lease tablet high-dose,medium-dose,low-dose groups. The effects of sustained-release tablet high-dose and medium-dose groups were better than that of common tablet group;those difference had statistical significance (P<0.01 or P<0.05). CONCLU-SIONS:CBP bioadhensive sustained-release tablets have im-provement effects against gastric ulcer of rats and gastrointesti-nal motility disorder of mice.