摘要 目的 比较4DCT呼吸周期八分法、四分法与传统十分法重建模式对肺孤立灶靶区构建的影响,探讨八分法、四分法在4DCT模拟定位中的可行性。方法 24例肺孤立灶行4DCT扫描,按3种呼吸周期均分法进行图像重建及ITV构建,比较ITV10、ITV8、ITV4大小和中心点位置及三维方向运动度。Friedman M法非参数检验差异。结果 ITV10、ITV8、ITV4大小分别为(9.09±12.29)、(9.10±12.47)、(8.98±12.61) cm3(P=0.001),ITV10与ITV8相近(P=0.721),ITV10与ITV4不同(P=0.002)。ITV10、ITV8、ITV4中心点坐标分别为x轴(12.22±7.71)、(12.23±7.71)、(12.22±7.71)(P=0.668);y轴:(43.30±29.38)、(43.30±29.40)、(43.31±29.39)(P=0.643);z轴:(5.66±3.67)、(5.66±3.67)、(5.66±3.67)(P=0.878)。3种重建模式下肿瘤中心在三维方向的运动度分别为x轴:(0.69±0.56)、(0.69±0.68)、(0.79±0.51) mm (P=0.356);y轴:(3.13±3.78)、(3.13±4.05)、(3.19±4.06) mm (P=0.978);z轴:(1.18±1.31)、(1.03±1.32)、(1.16±1.34) mm (P=0.302)。结论 肺孤立灶4DCT模拟定位呼吸周期八分法与十分法重建模式下ITV大小、中心点位置及三维方向的运动度均相近,八分法减少了重建图像的数量和靶区勾画负荷,在4DCT模拟定位中具有可行性。
Abstract：Objective To explore the influence of different reconstruction modes with time-weighted respiratory phases on the internal tumor volume (ITV) of solitary pulmonary lesion (SPL), and to evaluate the feasibilities of 8 and 4 equal time-weighted respiratory phases in 4DCT simulation. Methods 24 patients with SPL underwent 4D scanning. Images were reconstructed with 10, 8 and 4 equal time-weighted phases of the respiratory cycles, respectively. Gross tumor volumes (GTVs) were delineated on the three sets of reconstructed images and fused into ITVs, which were ITV10, ITV8 and ITV4 respectively. The differences of volumes, centroid of the ITVs and motions of GTV centroids in three-dimensional directions were compared. Statistical analysis was performed using the Friedman M test. Results The volumes of ITV10, ITV8 and ITV4 were (9.09±12.29) cm3,(9.10±12.47) cm3 and (8.98±12.61) cm3(P=0.001), respectively. There were no differences between the volumes of ITV10 and ITV8 after the Bonferroni correction (P=0.721), while the opposite between those of ITV10 and ITV4(P=0.002). The differences of centroid positions of ITV10, ITV8 and ITV4 in x-, y-and z-axes were all less than 1 mm ((12.22±7.71),(12.23±7.71),(12.22±7.71),Px=0.668);(43.30±29.38),(43.30±29.40),(43.31±29.39),Py=0.643;(5.66±3.67),(5.66±3.67),(5.66±3.67),Pz=0.878), similar to the motions of GTV centroids in three reconstructed modes ((0.69±0.56),(0.69±0.68),(0.79±0.51) mm,Px=0.356;(3.13±3.78),(3.13±4.05),(3.19±4.06) mm,Py=0.978;(1.18±1.31),(1.03±1.32),(1.16±1.34) mm,Pz=0.302). Conclusions There were no differences in volumes, centroid positions and motions between ITV10 and ITV8. The quantity of reconstruction images and GTV delineations according to 8 time-weighted phases were both less than conventional 10 phases. 8 time-weighted respiratory phases mode was feasible in 4DCT simulation for SPL.
Shang Dongping,Ling Minghuan,Li Yanchi et al. Comparison of internal tumor volume based on different reconstruction modes of 4DCT for solitary pulmonary lesion[J]. Chinese Journal of Radiation Oncology, 2015, 24(5): 556-559.
[1] 王金之,李建彬,戚焕鹏,等.基于放疗中重复四维CT的食管癌大体肿瘤体积与位移的相关性[J].中华放射肿瘤学杂志,2014,23(1):36-39.DOI:10.3760/cma.j.issn.1004-4221.2014.01.010. [2] 孙宗文,陈明,邓上武.四维CT在肺癌个体化放疗中的应用[J].中华放射肿瘤学杂志,2008,17(1):71-74. [3] Simon L,Giraud P, Serviis V, et al. Lung volume assessment for a cross-comparison of two breathing-adapted technique in radiotherapy[J].Int J Radiat Oncol Biol Phys, 2005,63(2):602-609.DOI:10.1016/j.ijrobp.2005.05.020. [4] Roland T, Hales R, Mcnutt T,et al. A method for deriving a 4D-interpolated balanced planning target for mobile tumor radiotherapy[J].Med Phys,2012,39(1):195-205.DOI:10. 1118/1.3666774. [5] Cheung PC, Sixel KE, Tirona R, et al. Reproducibility of lung tumor position and reduction of lung mass within the planning target volume using active breathing control (ABC)[J]. Int J Radiat Oncol Biol Phys,2003,57(5):1437-1442. [6] Wang L, Hayes S, Paskalev K, et al. Dosimetric comparison of stereotactic body radiotherapy using 4DCT and multiphase CT images for treatment planning of lung cancer:evaluation of the impact on daily dose coverage[J]. Radiother Oncol,2009,91(3):314-324.DOI:10.1016/j.radonc.2008.11.018. [7] Shih HA, Jiang SB, Aljarrah KM, et al. Internal target volume determined with expansion margins beyond composite gross tumor volume in three dimensional conformal radiotherapy for lung cancer[J]. Int J Radiat Oncol Biol Phys,2004,60(2):613-622. [8] 李奉祥,李建彬,张英杰,等.基于三维与四维CT勾画的非小细胞肺癌大体肿瘤体积的比较[J].中华放射肿瘤学杂志,2011,20(4):275-276.DOI:10.3760/cma.j.issn.1004-4221.2011.04.003. [9] Hof H, Rhein B, Haering P, et al. 4D-CT-based target volume definition in stereotactic radiotherapy of lung tumors:comparison with a conventional technique using individual margins[J].Radiother Oncol,2009,93(3):419-423.DOI:10.1016/j.radonc.2009.08.040. [10] Underberg RW, Lagerwaard FJ, Slotman BJ, et al. Benefit of respiration-gated stereotactic radiotherapy for stage Ⅰ lung cancer:an analysis of 4DCT datasets[J]. Int J Radiat Oncol Biol Phys,2005,62(2):554-560. [11] 尚东平,李明焕,李建彬,等.四维CT技术确定肺内孤立性病灶靶体积的应用[J].中华放射肿瘤学杂志,2011,20(5):417-419.DOI:10.3760/cma.j.issn.1004-4221.2011.05.016. [12] 鞠瀟,周宗玫.四维CT在肺癌放疗中的临床应用现状[J].中华放射肿瘤学杂志,2011,20(6):531-534.DOI:10.3760/cma.j.issn. 1004－4221.2011.06.025. [13] 李奉祥,李建彬,张英杰,等.基于四维CT勾画非小细胞肺癌大体肿瘤靶体积的三种方法比较[J].中华放射肿瘤学杂志,2011,20(2):101-105.DOI:10.3760/cma.j.issn.1004-4221.2011.02.005
2015, Vol. 24 
