Roach Dale, Holloway Lois C, Jameson Michael G, Dowling Jason A, Kennedy Angel, Greer Peter B, Krawiec Michele, Rai Robba, Denham Jim, De Leon Jeremiah, Lim Karen, Berry Megan E, White Rohen T, Bydder Sean A, Tan Hendrick T, Croker Jeremy D, McGrath Alycea, Matthews John, Smeenk Robert J, Ebert Martin A
Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia.
Ingham Institute for Applied Medical Research, Sydney, New South Wales, Australia.
J Med Imaging Radiat Oncol. 2019 Apr;63(2):264-271. doi: 10.1111/1754-9485.12844. Epub 2019 Jan 4.
This study quantified inter-observer contouring variations for multiple male pelvic structures, many of which are of emerging relevance for prostate cancer radiotherapy progression and toxicity response studies.
Five prostate cancer patient datasets (CT and T2-weighted MR) were distributed to 13 observers for contouring. CT structures contoured included the clinical target volume (CTV), seminal vesicles, rectum, colon, bowel bag, bladder and peri-rectal space (PRS). MR contours included CTV, trigone, membranous urethra, penile bulb, neurovascular bundle and multiple pelvic floor muscles. Contouring variations were assessed using the intraclass correlation coefficient (ICC), Dice similarity coefficient (DSC), and multiple additional metrics.
Clinical target volume (CT and MR), bladder, rectum and PRS contours showed excellent inter-observer agreement (median ICC = 0.97; 0.99; 1.00; 0.95; 0.90, DSC = 0.83 ± 0.05; 0.88 ± 0.05; 0.93 ± 0.03; 0.81 ± 0.07; 0.80 ± 0.06, respectively). Seminal vesicle contours were more variable (ICC = 0.75, DSC = 0.73 ± 0.14), while colon and bowel bag contoured volumes were consistent (ICC = 0.97; 0.97), but displayed poor overlap (DSC = 0.58 ± 0.22; 0.67 ± 0.21). Smaller MR structures showed significant inter-observer variations, with poor overlap for trigone, membranous urethra, penile bulb, and left and right neurovascular bundles (DSC = 0.44 ± 0.22; 0.41 ± 0.21; 0.66 ± 0.21; 0.16 ± 0.17; 0.15 ± 0.15). Pelvic floor muscles recorded moderate to strong inter-observer agreement (ICC = 0.50-0.97), although large outlier variations were observed.
Inter-observer contouring variation was significant for multiple pelvic structures contoured on MR.
本研究对多位观察者在勾画多个男性盆腔结构轮廓时的差异进行了量化，其中许多结构与前列腺癌放疗进展及毒性反应研究的相关性日益凸显。
将五个前列腺癌患者数据集（CT和T2加权磁共振成像）分发给13位观察者进行轮廓勾画。CT勾画的结构包括临床靶区（CTV）、精囊、直肠、结肠、肠袋、膀胱和直肠周间隙（PRS）。磁共振成像轮廓包括CTV、三角区、膜部尿道、阴茎球部、神经血管束和多块盆底肌肉。使用组内相关系数（ICC）、骰子相似系数（DSC）和多个其他指标评估轮廓勾画差异。
临床靶区（CT和磁共振成像）、膀胱、直肠和PRS轮廓显示出观察者间的高度一致性（ICC中位数分别为0.97；0.99；1.00；0.95；0.90，DSC分别为0.83±0.05；0.88±0.05；0.93±0.03；0.81±0.07；0.80±0.06）。精囊轮廓的变异性更大（ICC = 0.75，DSC = 0.73±0.14），而结肠和肠袋的勾画体积一致（ICC分别为0.97；0.97），但重叠性较差（DSC分别为0.58±0.22；0.67±0.21）。较小的磁共振成像结构显示出观察者间的显著差异，三角区、膜部尿道、阴茎球部以及左右神经血管束的重叠性较差（DSC分别为0.44±0.22；0.41±0.21；0.66±0.21；0.16±0.17；0.15±0.15）。盆底肌肉记录到观察者间的一致性为中等至强（ICC = 0.50 - 0.97），尽管观察到有较大的异常值差异。
对于磁共振成像上勾画的多个盆腔结构，观察者间的轮廓勾画差异显著。
