摘要
目的测量不同运动频率和不同运动幅度下,用PET影像勾画GTV的大小,探讨不同运动状态对PET影像中病灶体积的影响。方法使用自行研制的二维运动平台系统及体模,模拟不同频率及幅度的呼吸运动,在不同运动状态下对体模进行PET-CT扫描,利用PET图像勾画GTV并计算其大小。结果静止状态下GTV(GTV0)为(7.90±0.21)cm3,运动频率为16次/min、18次/min及20次/min状态下GTV分别为(11.56±2.62)cm3(GTV16)、(12.51±3.57)cm3(GTV18)及(11.86±3.27)cm3(GTV20)。GTV0、GTV16、GTV18及GTV20之间差异有统计学意义,P均<0.01。z轴方向运动幅度为1.0、1.5及2.0cm状态下GTV分别为(11.44±3.68)cm3(GTVz-1.0)、(11.64±3.47)cm3(GTVz-1.5)、(12.83±2.02)cm3(GTVz-2.0)。x轴方向运动幅度为0.5、1.0及1.5cm状态下GTV分别为(9.68±2.32)cm3(GTVx-0.5)、(14.41±3.19)cm3(GTVx-1.0)、(11.83±1.92)cm3(GTVx-1.5)。在z轴和x轴运动方向上,各GTV差异有统计学意义。结论不同呼吸频率和运动幅度对PET图像勾画靶区均会产生较大影响,在采用PET影像制定放疗计划时建议采取门控技术等有效措施尽量减少这种影响,使得到的生物靶区尽可能地接近靶区的实际情况。
OBJECTIVE : To evaluate the effect of respiratory motion on GTV contoured with PET image, using a 2D respiratory motion phantom system. METHODS: Twentyeight kinds of respiratory motions were simulated by using a respiratory motion phantom system. The phantom was scanned by PET-CT machine under different motion conditions, then the PET images were obtained. GTV was contoured by using PET images. RESULTS; GTV under static condition (GTV0) was (7.90 ± 0. 21) cm^3. GTV with motion frequencies of 16 per minute, 18 per minute and 20 per minute were (11.56 ± 2.62) cm^3(GTV16), (12.51 ± 3.57) cm^3(GTV18) and 11.86 ± 3.27 cm^3(GTV20), respectively. The differences among GTV0, GTV16, GTV18 and GTV20 were significant (all P〈0.01). GTV with motion amplitudes of 1.0 cm, 1.5 and 2.0 cm on z axis were (11.44±3.68) cm^3 (GTVz-1.0), 11.64±3.47 cm^3(GTVz-1.3) and (12.83±2.02) cm^3 (GTVz-2.0 ), respectively. GTV with motion amplitudes of 0.5 cm, 1.0 cm and 1.5 cm on x axis were (9.68 ± 2.32) cm^3(GTVx-0.5), (14.41 ± 3.19) cm^3(GTVx-1.0) and (11.83 ± 1.92) cm^3 (GTVx-1.5) respectively. The differences of GTV on z axis and x axis were significant (all P〈0.01). CONCLUSION: GTV contoured with PET image will be severely effected by respiratory motion which will impact on radiation treatment planning. The gating technique should be used in order to decrease this kind of effect when GTV is contoured with PET image.
出处
《中华肿瘤防治杂志》
CAS
2007年第7期548-550,共3页
Chinese Journal of Cancer Prevention and Treatment