Kulkarni Bhudevi Soubhagya N, Bajwa Harjot, Chandrashekhar Mukka, Sharma Sunil Dutt, Singareddy Rohith, Gudipudi Dileep, Ahmad Shabbir, Kumar Alok, Sresty N V N Madusudan, Raju Alluri Krishnam
Basavatarakam Indo American Cancer Hospital and Research Center, Hyderabad 500035, Telangana, India.
Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad 500 085, Telangana, India.
Rep Pract Oncol Radiother. 2017 May-Jun;22(3):201-208. doi: 10.1016/j.rpor.2017.02.002. Epub 2017 Apr 22.
This study represents an enumeration and comparison of gross target volumes (GTV) as delineated independently on contrast-enhanced computed tomography (CT) and T1 and T2 weighted magnetic resonance imaging (MRI) in vestibular schwannomas (VS).
Multiple imaging in radiotherapy improves target localization.
42 patients of VS were considered for this prospective study with one patient showing bilateral tumor. The GTV was delineated separately on CT and MRI. Difference in volumes were estimated individually for all the 43 lesions and similarity was studied between CT and T1 and T2 weighted MRI.
The male to female ratio for VS was found to be 1:1.3. The tumor was right sided in 34.9% and left sided in 65.1%. Tumor volumes (TV) on CT image sets were ranging from 0.251 cc to 27.27 cc. The TV for CT, MRI T1 and T2 weighted were 5.15 ± 5.2 cc, 5.8 ± 6.23 cc, and 5.9 ± 6.13 cc, respectively. Compared to MRI, CT underestimated the volumes. The mean dice coefficient between CT versus T1 and CT versus T2 was estimated to be 68.85 ± 18.3 and 66.68 ± 20.3, respectively. The percentage of volume difference between CT and MRI (%VD: mean ± SD for T1; 28.84 ± 15.0, T2; 35.74 ± 16.3) and volume error (%VE: T1; 18.77 ± 10.1, T2; 23.17 ± 13.93) were found to be significant, taking the CT volumes as the baseline.
MRI with multiple sequences should be incorporated for tumor volume delineation and they provide a clear boundary between the tumor and normal tissue with critical structures nearby.
本研究旨在对前庭神经鞘瘤（VS）在对比增强计算机断层扫描（CT）以及T1加权和T2加权磁共振成像（MRI）上独立勾画的大体靶体积（GTV）进行计数和比较。
放射治疗中的多种成像可改善靶区定位。
本前瞻性研究纳入了42例VS患者，其中1例为双侧肿瘤。在CT和MRI上分别勾画GTV。对所有43个病灶分别估计体积差异，并研究CT与T1加权和T2加权MRI之间的相似性。
发现VS的男女比例为1:1.3。肿瘤位于右侧的占34.9%，位于左侧的占65.1%。CT图像集上的肿瘤体积（TV）范围为0.251立方厘米至27.27立方厘米。CT、MRI T1加权和T2加权的TV分别为5.15±5.2立方厘米、5.8±6.23立方厘米和5.9±6.13立方厘米。与MRI相比，CT低估了体积。CT与T1以及CT与T2之间的平均骰子系数分别估计为68.85±18.3和66.68±20.3。以CT体积为基线，发现CT和MRI之间的体积差异百分比（%VD：T1的均值±标准差为28.84±15.0，T2为35.74±16.3）和体积误差（%VE：T1为18.77±10.1，T2为23.17±13.93）具有显著性。
应采用多序列MRI进行肿瘤体积勾画，其能在肿瘤与附近关键结构的正常组织之间提供清晰边界。
