Elhalawani Hesham, Elgohari Baher, Lin Timothy A, Mohamed Abdallah S R, Fitzgerald Thomas J, Laurie Fran, Ulin Kenneth, Kalpathy-Cramer Jayashree, Guerrero Thomas, Holliday Emma B, Russo Gregory, Patel Abhilasha, Jones William, Walker Gary V, Awan Musaddiq, Choi Mehee, Dagan Roi, Mahmoud Omar, Shapiro Anna, Kong Feng-Ming Spring, Gomez Daniel, Zeng Jing, Decker Roy, Spoelstra Femke O B, Gaspar Laurie E, Kachnic Lisa A, Thomas Charles R, Okunieff Paul, Fuller Clifton D
Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, TX 77030, USA.
Baylor College of Medicine, TX 77030, USA.
Clin Transl Radiat Oncol. 2019 Jan 6;15:83-92. doi: 10.1016/j.ctro.2019.01.001. eCollection 2019 Feb.
Target delineation variability is a significant technical impediment in multi-institutional trials which employ intensity modulated radiotherapy (IMRT), as there is a real potential for clinically meaningful variances that can impact the outcomes in clinical trials. The goal of this study is to determine the variability of target delineation among participants from different institutions as part of Southwest Oncology Group (SWOG) Radiotherapy Committee's multi-institutional quality assurance study in patients with Pancoast tumors as a "dry run" for trial implementation.
CT simulation scans were acquired from four patients with Pancoast tumor. Two patients had simulation 4D-CT and FDG-FDG PET-CT while two patients had 3D-CT and FDG-FDG PET-CT. Seventeen SWOG-affiliated physicians independently delineated target volumes defined as gross primary and nodal tumor volumes (GTV_P & GTV_N), clinical target volume (CTV), and planning target volume (PTV).Six board-certified thoracic radiation oncologists were designated as the 'Experts' for this study. Their delineations were used to create a simultaneous truth and performance level estimation (STAPLE) contours using ADMIRE software (Elekta AB, Sweden 2017). Individual participants' contours were then compared with Experts' STAPLE contours.
When compared to the Experts' STAPLE, GTV_P had the best agreement among all participants, while GTV_N showed the lowest agreement among all participants. There were no statistically significant differences in all studied parameters for all TVs for cases with 4D-CT versus cases with 3D-CT simulation scans.
High degree of inter-observer variation was noted for all target volume except for GTV_P, unveiling potentials for protocol modification for subsequent clinically meaningful improvement in target definition. Various similarity indices exist that can be used to guide multi-institutional radiotherapy delineation QA credentialing.
在采用调强放射治疗（IMRT）的多机构试验中，靶区勾画的变异性是一个重大技术障碍，因为存在临床意义上的差异，这可能会影响临床试验的结果。本研究的目的是确定不同机构参与者之间靶区勾画的变异性，这是西南肿瘤协作组（SWOG）放射治疗委员会针对潘科斯特瘤患者进行的多机构质量保证研究的一部分，作为试验实施的“预演”。
从4例潘科斯特瘤患者获取CT模拟扫描图像。2例患者进行了模拟4D-CT和FDG-FDG PET-CT检查，另外2例患者进行了3D-CT和FDG-FDG PET-CT检查。17名SWOG附属医生独立勾画靶区体积，定义为原发肿瘤大体体积和淋巴结转移瘤体积（GTV_P和GTV_N）、临床靶区体积（CTV）和计划靶区体积（PTV）。6名获得委员会认证的胸科放射肿瘤学家被指定为本研究的“专家”。使用ADMIRE软件（瑞典医科达公司，2017年）将他们的勾画结果用于创建同时真值和性能水平估计（STAPLE）轮廓。然后将个体参与者的轮廓与专家的STAPLE轮廓进行比较。
与专家的STAPLE轮廓相比，GTV_P在所有参与者中一致性最好，而GTV_N在所有参与者中一致性最低。对于4D-CT病例和3D-CT模拟扫描病例，所有靶区体积的所有研究参数均无统计学显著差异。
除GTV_P外，所有靶区体积均存在高度的观察者间差异，这揭示了为后续临床靶区定义的有意义改进而修改方案的可能性。存在各种相似性指数，可用于指导多机构放射治疗勾画质量保证认证。
