a Faculty of Health Science , University of Malta . Msida , Malta.
b Academisch Medisch Centrum Geneeskunde Amsterdam , Noord-Holland , The Netherlands.
Acta Oncol. 2019 Feb;58(2):200-208. doi: 10.1080/0284186X.2018.1529422. Epub 2018 Oct 30.
To assess the impact of training and interprofessional collaboration on the interobserver variation in the delineation of the lung gross tumor volume (GTVp) and lymph node (GTVln).
Eight target volume delineations courses were organized between 2008 and 2013. Specialists and trainees in radiation oncology were asked to delineate the GTVp and GTVln on four representative CT images of a patient diagnosed with lung cancer individually prior each course (baseline), together as group (interprofessional collaboration) and post-training. The mean delineated volume and local standard deviation (local SD) between the contours for each course group were calculated and compared with the expert delineations.
A total 410 delineations were evaluated. The average local SD was lowest for the interprofessional collaboration (GTVp = 0.194 cm, GTVln = 0.371 cm) followed by the post-training (GTVp = 0.244 cm, GTVln = 0.607 cm) and baseline delineations (GTVp = 0.274 cm, GTVln: 0.718 cm). The mean delineated volume was smallest for the interprofessional (GTVp = 4.93 cm, GTVln = 4.34 cm) followed by the post-training (GTVp = 5.68 cm, GTVln = 5.47 cm) and baseline delineations (GTVp = 6.65 cm, GTVln = 6.93 cm). All delineations were larger than the expert for both GTVp and GTVln (p < .001).
Our findings indicate that image interpretational differences can lead to large interobserver variation particularly when delineating the GTVln. Interprofessional collaboration was found to have the greatest impact on reducing interobserver variation in the delineation of the GTVln. This highlights the need to develop a clinical workflow so as to ensure that difficult cases are reviewed routinely by a second radiation oncologist or radiologist so as to minimize the risk of geographical tumor miss and unnecessary irradiation to normal tissue.
评估培训和跨专业协作对肺部大体肿瘤体积（GTVp）和淋巴结（GTVln）勾画的观察者间变异性的影响。
2008 年至 2013 年期间组织了 8 次靶区勾画课程。要求放射肿瘤学的专家和学员在每次课程前（基线）、集体作为一个团队（跨专业协作）以及培训后，分别对 4 名诊断为肺癌患者的代表性 CT 图像上的 GTVp 和 GTVln 进行勾画。计算每个课程组勾画的平均体积和轮廓之间的局部标准差（局部 SD），并与专家勾画进行比较。
共评估了 410 次勾画。跨专业协作的平均局部 SD 最低（GTVp=0.194cm，GTVln=0.371cm），其次是培训后（GTVp=0.244cm，GTVln=0.607cm）和基线勾画（GTVp=0.274cm，GTVln：0.718cm）。跨专业协作的平均勾画体积最小（GTVp=4.93cm，GTVln=4.34cm），其次是培训后（GTVp=5.68cm，GTVln=5.47cm）和基线勾画（GTVp=6.65cm，GTVln=6.93cm）。所有勾画均大于专家勾画的体积（GTVp 和 GTVln，p<0.001）。
我们的研究结果表明，图像解释差异会导致观察者间变异性较大，特别是在勾画 GTVln 时。跨专业协作被发现对减少 GTVln 勾画的观察者间变异性影响最大。这突出表明需要制定临床工作流程，以确保困难病例由第二位放射肿瘤学家或放射科医生定期复查，从而最大限度地降低肿瘤位置勾画错误和对正常组织不必要照射的风险。
