Study on the Imaging Differences of Small Volume Tumors by Motion
LIU Lingling1,2,3, FEI Zhenle4, CUI Xiangli1,3, LI Jie1,3, NIU Zhenyang4, WANG Hongzhi1,2,3
1. Institute of Health and Medical Technology (Anhui Province Key Laboratory of Medical Physics and Technology), Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei Anhui 230031, China; 2. Science Island Branch, Graduate School of USTC, Hefei Anhui 230026, China; 3. Radiotherapy Center, Hefei Cancer Hospital, Chinese Academy of Sciences, Hefei Anhui 230031, China; 4. Cancer Diagnosis and Treatment Center, No.901 Hospital of Joint Logistics Support Force of PLA, Hefei Anhui 230031, China
Abstract:Objective To explore the influence of motion on the target volume of a small tumor by using respiratory motion platform and CT imaging. Methods Stereo lithography appearance (SLA) photosensitive resin was used to 3D print 9 solid spheres with diameters ranging from 10 to 50 mm and interval 5 mm to simulate the tumors. The spheres were fixed on the QUASAR respiratory motion platform. The platform drove the spheres into sinusoidal motion to emulate the respiratory motion of human head and feet direction. Images of spheres corresponding to breathing amplitudes of 0 to 15 mm were captured using CT scans with layer
thicknesses of 2, 3 and 5 mm. The images were transferred to the treatment planning system, and the spheres were reconstructed
individually. Results The volume deviation of 9 spheres was 8.43%~120% only when the scanning table moved. The effect of the
movement of the scanning couch and the breathing motion on the volume of the tumor target was dependent on the size of the tumor
and the amplitude of motion. The movement led to deviations of 38.5% to 505% in the volume of the 10-mm-diameter sphere, which
was with the greatest dependence on amplitude and layer thickness. In relation, for the spheres with diameters from 15 to 50 mm,
the deviations in the volume were ranged from 1.05% to 45.6% when the breathing amplitude was less than 1.5 mm, from -6.41%
to 72.4% when the breathing amplitude was between 2 and 3.5 mm, and from -23.5% to 139% when the breathing amplitude was
between 4 and 15 mm. On the other hand, the effect of breathing movement on the volume of the tumor target area was dependent
on its volume and respiratory amplitude. The deviations in the sphere volume ranged from -26.9% to 175% when the diameter of the
sphere was smaller than 20 mm. If the diameter of the sphere was between 20 and 50 mm, the deviations in the sphere volume ranged
from -10% to 10% when the breathing amplitude was within 2 mm, from -20% to 20% when the breathing amplitude was between 2
and 5 mm, and from -29.9% to 113% when the breathing amplitude was beyond 5 mm. Conclusion The smaller the tumor volume,
the greater the influence of the motion range and the scanning thickness. The influence of the movement of the scanning couch and
the breathing motion on the volume of the small tumor should not be ignored. For small tumors with a diameter of less than 50 mm, it
is recommended to do breathing exercise management and choose thin-slice scanning.
刘苓苓1,2,3,费振乐4,崔相利1,3,李洁1,3,牛振洋4,王宏志1,2,3. 运动对小体积肿瘤影像学差异的研究[J]. 中国医疗设备, 2022, 37(4): 1-5.
LIU Lingling1,2,3, FEI Zhenle4, CUI Xiangli1,3, LI Jie1,3, NIU Zhenyang4, WANG Hongzhi1,2,3. Study on the Imaging Differences of Small Volume Tumors by Motion. China Medical Devices, 2022, 37(4): 1-5.