Comparison of gross tumor volume of primary oesophageal cancer based on contrast-enhanced three-dimensional, four-dimensional, and cone beam computed tomography

Chao-Yue Hu; Jian-Bin Li; Jin-Zhi Wang; Wei Wang; Feng-Xiang Li; Yan-Luan Guo

doi:10.18632/oncotarget.21520

Comparison of gross tumor volume of primary oesophageal cancer based on contrast-enhanced three-dimensional, four-dimensional, and cone beam computed tomography

Oncotarget. 2017 Oct 5;8(56):95577-95585. doi: 10.18632/oncotarget.21520. eCollection 2017 Nov 10.

Authors

Chao-Yue Hu^{1

2}, Jian-Bin Li², Jin-Zhi Wang², Wei Wang², Feng-Xiang Li², Yan-Luan Guo²

Affiliations

¹ School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciences, Jinan, Shandong Province, China.
² Department of Radiation Oncology, Shandong Cancer Hospital Affiliated to Shandong University, Shandong Academy of Medical Sciences, Jinan, Shandong Province, China.

Abstract

Background: To explore motion information included in 3DCT, 4DCT and CBCT by comparing volumetric and positional differences of GTV.

Results: Independent of tumor location, significant differences were observed among volumes [IGTV₁₀ > (IGTV_CBCT or IGTV_MIP) > (GTV_3D or GTV_4D50)]. The underestimations or overestimations between IGTV₁₀ and IGTV_CBCT were larger than those between IGTV₁₀ and IGTV_MIP (p < 0.001-0.011; p < 0.001-0.023). For upper oesophageal tumors, GTV_4D50/IGTV_CBCT negatively correlated with motion vector (r = -0.756, p = 0.011). In AP direction, the centroid coordinates of IGTV_CBCT differed from GTV_3D, GTV_4D50, IGTV_MIP and IGTV₁₀ (p = 0.006, 0.013, 0.038, and 0.010). For middle oesophageal tumors, IGTV₁₀/IGTV_CBCT positively correlated with motion vector (r = 0.695, p = 0.006). The centroid coordinates of IGTV_CBCT differed from those of IGTV₁₀ (p = 0.046) in AP direction. For distal oesophageal tumors, the centroid coordinates of IGTV_CBCT showed significant differences to those of IGTV_MIP (p = 0.042) in LR direction. For both middle and distal tumors, the degrees of associations of IGTV₁₀ outside IGTV_CBCT significantly correlated with the motion vector (r = 0.540, p = 0.046; r = 0.678, p = 0.031).

Materials and methods: Thirty-four oesophageal cancer patients underwent 3DCT, 4DCT and CBCT. GTV_3D, GTV_4D50, internal GTV_MIP (IGTV_MIP) and IGTV_CBCT were delineated on 3DCT, 4DCT₅₀, 4DCT_MIP and CBCT. GTVs from 10 respiratory phases were combined to produce GTV₁₀. Differences in volume, position for different targets, correlation between volume ratio and motion vector were evaluated. The motion vector was the spatial moving of the target centroid position.

Conclusions: IGTV_CBCT encompasses more motion information than GTV_3D and GTV_4D50 for upper oesophageal tumors, but slightly less than IGTV₁₀ for middle and distal oesophageal tumors. IGTV_CBCT incorporated similar motion information to IGTV_MIP. However, motion information encompassed in CBCT and MIP cannot replace each other.

Keywords: cone beam computed tomography; four-dimensional computed tomography; gross tumor volume; oesophageal cancer; three-dimensional computed tomography.