Objective To compare the analytical result of different kinds of film dose analysis software for the same gamma knife,analyze the reasons of difference caused,and explore the measurements and means for quality control and quality assurance during testing gamma knife and analyzing its result.Methods To test the Moon Deity gamma knife with Kodak EDR2 film and γ-Star gamma knife with GAFCHROMIC(R) EBT film,respectively.All the validation films are scanned to proper imagine format for dose analysis software by EPSON PERFECTION V750 PRO scanner.Then imagines of Moon Deity gamma knife are analyzed with Robot Knife Adjuvant 1.09 and Fas-09 1.0,and imagines of γ-Star gamma knife with Fas-09 and MATLAB 7.0.Results There is no significant difference in the maximum deviation of radiation field size ( Full Width at Half Maximum,FWHM) and its nominal value between Robot Knife Adjuvant and Fas-09 for Moon Deity gamma knife (t = -2.133,P ＞0.05).The analysis on the radiation field' s penumbra region width of collimators which have different sizes indicated that the differences are significant (t = - 8.154,P ＜ 0.05 ).There is no significant difference in the maximum deviation of FWHM and its nominal value between Fas-09 and MATLAB for γ-Star gamma knife ( t = - 1.384,P ＞0.05 ).However,following national standards,analysis of φ4 mm width of collimators can obtain different results according to the two kinds software,and the result of Fas-09 is not qualified while MATLAB is qualified.The analysis on the radiation field' s penumbra region width of collimators which have different sizes indicates that the differences are significant ( t = 3.074,P ＜ 0.05 ).The imagines are processed with Fas-09.The analysis of imagine in the pre-and the post-processing indicates that there is no significant difference in the maximum deviation of FWHM and its nominal value ( t = 0.647,P ＞ 0.05 ),and the analytical result of the radiation field' s penumbra region width indicates that there is no significant difference as well ( t = -0.627,P ＞ 0.05 ).Conclusion The study shows that different kinds of film dose analysis software may have some differences in analysis of the same gamma knife validation film,and the results may lead to the different decisions in accordance with national standard.

Objective To introduce a new method of trans-superior limb of cerebellopontine fissure approach for exploring and managing superomedial responsible vessels of facial nerve of patients with hemifacial spasm.Methods Clinical data of 21 patients with hemifacial spasm among 183 consecutive patients were analyzed retrospectively in our hospital from February 2009 to December 2013.Dissection of the superior limb of the cerebellopontine fissure was performed to explore the distribution and the severity of compression of the superomedial responsible vessels of the facial nerve,and microvascular decompression was performed.Results Neurovascular compression was found in all of the patients,primary responsible vessels were found in 13 patients,and secondary responsible vessels were found in 8 patients.Complete spasm alleviation was achieved immediately after operation in 18 patients,and complete spasm alleviation was achieved in all of the patients 3 months after operation.No severn complications occurred and no patient died.No recurrence was noted after an average 56 months of follow-up.Conclusion The trants-superior limb of cerebellopontine fissure approach could avoid the defects of standard suboccipital retrosigrnoidal approach,which allows easy identification and management of the superomedial responsible vessels of the facial nerve of patients with hemifacial spasm;thus,high consistent successful rate and low complication rate could be found.

Objective To assess the value of magnetic resonance imaging compilation(MAGiC)sequence in predicting lympho-vascular space invasion(LVSI)in early cervical cancer.Methods The data of 48 patients with cervical cancer confirmed by pathology were collected retrospectively,and classified into LVSI-positive group(n=29)and LVSI-negative group(n=19)according to postop-erative pathological results.MAGiC sequence images of patients were obtained before injecting contrast agents,then the region of interest(ROI)was delineated along the largest dimension edge of the lesion,and T1,T2 and proton density(PD)values were automatically generated by the software.Predictors were screened by univariate analysis and receiver operating characteristic(ROC)curves were drawn to assess their diagnostic efficacy for predicting LVSI in cervical cancer.Results Significant differences were found in T1 and PD values between LVSI-positive and LVSI-negative groups(P=0.003,P=0.017).There were no significant differences in T2 values between the two groups(P=0.414).The area under the curve(AUC)for T1 and PD values to predict LVSI status were 0.73 and 0.721,respectively.Conclusion LVSI-positive group of cervical cancer has lower T1 and PD values than LVSI-negative group based on MAGiC sequence.The MAGiC sequence has a certain application value for predicting LVSI status in early cervical cancer.