RESUMO
Objective To apply a simple fixator to salivary gland scintigraphy to evaluate its effect on body position movement. Methods Totally 30 female patients complaining xerostomia were randomly and equally divided into a conventional scan group and a simple fixator group,who were injected with Technetium Tc-99m Pertechnetate intravenously. In the conventional scan group the patients had their necks fixed with the bracket and cushion,while in the other group the fixation was executed with the single fixator. SPECT imager was used for dynamic salivary gland scintigraphy, and two nuclear medicine physicians evaluated the maximum shift of the parotid gland along left-right(X)and head-foot(Y)axes in series of dynamic images. SPSS 16.0 software was used for data analysis. Results In the conventional scan group the maximum shift was(6.6±4.6)mm at X axis and(5.2±3.4)mm at Y axis;in the single fixator group the maximum shift was(3.2± 1.6)mm at X axis and(3.0±1.3)mm at Y axis.There were significant differences between the maximum shifts in the two groups (P=0.012,X axis;P=0.027,Y axis).Conclusion The single fixator assists in salivary gland scintigraphy,and alleviates the body position movement during dynamic acquisition and provides data support for functional parameter calculation and result determination.
RESUMO
Objective To analyze the effects of position shift and dose adjustment on the pass rate of IMRT dose verification to facilitate to obtain rapidly high-pass-rate IMRT dose verification report.Methods At first,the dose unit of measuring dose map image and planning Dose Profile was unified.Secondly,the planning Dose Profile was moved at lateral and cephal-ocaudal directions respectively in contrast mode so as to determine the position error with the maximum pass rate.Thirdly,the highest pass rate point of dose verification was found in the range of dose adjustment.Fourthly,the plan report with the highest pass rate of dose verification was found out by adjusting position error and dose coefficient.Results The highest pass rate was obtained in case the displacement was-3 mm at lateral direction or +3 mm at cephal-ocaudal direction;high pass rate was got when dose adjustment coefficient was 1.02;high pass rate was achieved in case the displacement was-3 mm at lateral direction,+2 mm at cephal-ocaudal direction and the dose adjustment coefficient was 1.02,which was significantly different from those with other combined values (P＜0.05).Conclusion The dose verification technique is convenient and quick when used to obtain a high-pass-rate dose verification report.