中华放射肿瘤学杂志
中華放射腫瘤學雜誌
중화방사종류학잡지
CHINESE JOURNAL OF RADIATION ONCOLOGY
2011年
3期
236-239
,共4页
固体水模体%水等效
固體水模體%水等效
고체수모체%수등효
SoIid Water phantom%Water equivalent
目的 对两种固体模体的水等效性及相关校准因子进行检测.方法 对美国MED-TEC公司虚拟水和德国PTW公司RW3两种同体模体不同深度处进行X线、电子线照射测量,得到深度电离量曲线与水模体中的进行比较,而水等效因子两种模体直接比较.按照国际原子能机构定义得到不同能量电子线深度比例因子(Cpl)与注量比例因子(hpl),比较两种模体间差异.结果 两种固体模体与水模体的深度电离量平均偏差在6 MV X线时为0.42%和0.16%(t:-6.15.P=0.001和t=-1.65,P=0.419),10 MV X线时为0.21%和0.31%(t=1.73,P=0.135和t:2.30.P=0.061),6 MeV电子线时为17.4%和14.5%(t=-1.37,P=0.208和t=-1.47,P=0.179),15 MeV 电子线时为7.0%和6.0%(t=-0.58,P=0.581和t=-0.90,P=0.395).两模体水等效因子变化均较大,但在参考测量点附近接近1,在6 MV X线时F=58.54、P=0.000,10 MV X线时F=0.21、P=0.662,6 MeV电子线时F=0.97、P=0.353,15 MeV电子线时F=0.14、P=0.717.随着电子线能量增加Cpl值增加(F=26.40,P=0.014)而hpl值减少(F=7.45,P=0.072).结论 若假设固体体模为完全水等效则会引入系统误差,因而在临床应用中要慎重.
目的 對兩種固體模體的水等效性及相關校準因子進行檢測.方法 對美國MED-TEC公司虛擬水和德國PTW公司RW3兩種同體模體不同深度處進行X線、電子線照射測量,得到深度電離量麯線與水模體中的進行比較,而水等效因子兩種模體直接比較.按照國際原子能機構定義得到不同能量電子線深度比例因子(Cpl)與註量比例因子(hpl),比較兩種模體間差異.結果 兩種固體模體與水模體的深度電離量平均偏差在6 MV X線時為0.42%和0.16%(t:-6.15.P=0.001和t=-1.65,P=0.419),10 MV X線時為0.21%和0.31%(t=1.73,P=0.135和t:2.30.P=0.061),6 MeV電子線時為17.4%和14.5%(t=-1.37,P=0.208和t=-1.47,P=0.179),15 MeV 電子線時為7.0%和6.0%(t=-0.58,P=0.581和t=-0.90,P=0.395).兩模體水等效因子變化均較大,但在參攷測量點附近接近1,在6 MV X線時F=58.54、P=0.000,10 MV X線時F=0.21、P=0.662,6 MeV電子線時F=0.97、P=0.353,15 MeV電子線時F=0.14、P=0.717.隨著電子線能量增加Cpl值增加(F=26.40,P=0.014)而hpl值減少(F=7.45,P=0.072).結論 若假設固體體模為完全水等效則會引入繫統誤差,因而在臨床應用中要慎重.
목적 대량충고체모체적수등효성급상관교준인자진행검측.방법 대미국MED-TEC공사허의수화덕국PTW공사RW3량충동체모체불동심도처진행X선、전자선조사측량,득도심도전리량곡선여수모체중적진행비교,이수등효인자량충모체직접비교.안조국제원자능궤구정의득도불동능량전자선심도비례인자(Cpl)여주량비례인자(hpl),비교량충모체간차이.결과 량충고체모체여수모체적심도전리량평균편차재6 MV X선시위0.42%화0.16%(t:-6.15.P=0.001화t=-1.65,P=0.419),10 MV X선시위0.21%화0.31%(t=1.73,P=0.135화t:2.30.P=0.061),6 MeV전자선시위17.4%화14.5%(t=-1.37,P=0.208화t=-1.47,P=0.179),15 MeV 전자선시위7.0%화6.0%(t=-0.58,P=0.581화t=-0.90,P=0.395).량모체수등효인자변화균교대,단재삼고측량점부근접근1,재6 MV X선시F=58.54、P=0.000,10 MV X선시F=0.21、P=0.662,6 MeV전자선시F=0.97、P=0.353,15 MeV전자선시F=0.14、P=0.717.수착전자선능량증가Cpl치증가(F=26.40,P=0.014)이hpl치감소(F=7.45,P=0.072).결론 약가설고체체모위완전수등효칙회인입계통오차,인이재림상응용중요신중.
Objective To investigate the water equivalent of two solid water phantoms.Methods The X-ray and electron beam depth-ion curves were measured in water and two solid water phantoms,RW3 and Virtual Water.The water-equivalency correction factors for the two solid water phantoms were compared.We measured and calculated the range sealing factors and the fluence correction factors for the two solid water phantoms in the case of electron beams. Results The average differenee between the measurled ionization in solid water phantoms and water was 0.42%and 0.16%on 6 MV X-ray(t=-6.15.P=0.001and t=-1.65,P=0.419)and 0.21%and 0.31%on 10 MV X-ray(t=1.728,P=0.135 and t=-2.296,P=0.061),with 17.4%and 14.5%on 6 MeV electron beams(t=-1.37.P=0.208 and t=-1.47,P=0.179)and 7.0%and 6.0%on 15 MeV electron beams(t=-0.58.P=0.581 and t=-0.90,P=0.395).The water-equivalency correction factors for the two solid water Dhantoms varied slightly largely,F=58.54,P=0.000 on 6 MV X-ray,F=0.211.P=0.662 on 10 MV X.ray,F=0.97.P=0.353 on 6 MeV electron beams,F=0.14,P=0.717 on 15 MeV electron beams.However,they were almost equal to 1 near the referenee depths.The two solid water phantoms showed a similar tread of Cpl increasing(F=26.40,P=0.014)and hpl decreasing(F=7.45,P=0.072)with increasing energy.Conclusion The solid water phantom should undergo a quality control test before being clinical use.
