Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto, ON, Canada.
Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto, ON, Canada.
Int J Radiat Oncol Biol Phys. 2014 Aug 1;89(5):1076-1083. doi: 10.1016/j.ijrobp.2014.04.042. Epub 2014 Jul 8.
Radiographic changes after lung stereotactic body radiation therapy (SBRT) have been categorized into 4 groups: modified conventional pattern (A), mass-like fibrosis; (B), scar-like fibrosis (C), and no evidence of increased density (D). The purpose of this study was to assess the interrater reliability of this categorization system in patients with early-stage non-small cell lung cancer (NSCLC).
Seventy-seven patients were included in this study, all treated with SBRT for early-stage (T1/2) NSCLC at a single institution, with a minimum follow-up of 6 months. Six experienced clinicians familiar with post-SBRT radiographic changes scored the serial posttreatment CT images independently in a blinded fashion. The proportion of patients categorized as A, B, C, or D at each interval was determined. Krippendorff's alpha (KA), Multirater kappa (M-kappa), and Gwet's AC1 (AC1) scores were used to establish interrater reliability. A leave-one-out analysis was performed to demonstrate the variability among raters. Interrater agreement of the first and last 20 patients scored was calculated to explore whether a training effect existed.
The number of ratings ranged from 450 at 6 months to 84 at 48 months of follow-up. The proportion of patients in each category was as follows: A, 45%; B, 16%; C, 13%; and D, 26%. KA and M-kappa ranged from 0.17 to 0.34. AC1 measure range was 0.22 to 0.48. KA increased from 0.24 to 0.36 at 12 months with training. The percent agreement for pattern A peaked at 12 month with a 54% chance of having >50% raters in agreement and decreased over time, whereas that for patterns B and C increased over time to a maximum of 20% and 22%, respectively.
This post-SBRT radiographic change categorization system has modest interrater agreement, and there is a suggestion of a training effect. Patterns of fibrosis evolve after SBRT and alternative categorization systems should be evaluated.
肺部立体定向体放射治疗（SBRT）后的放射学改变可分为 4 组：改良常规模式（A）、块状纤维化；（B）、瘢痕样纤维化（C）和无密度增加证据（D）。本研究旨在评估该分类系统在早期非小细胞肺癌（NSCLC）患者中的组间可靠性。
本研究纳入了 77 例患者，均在一家医疗机构接受 SBRT 治疗早期（T1/2）NSCLC，随访时间至少 6 个月。6 名熟悉 SBRT 后放射学改变的经验丰富的临床医生以盲法独立对治疗后系列 CT 图像进行评分。确定每个时间点 A、B、C 或 D 分类患者的比例。Krippendorff's alpha（KA）、Multirater kappa（M-kappa）和 Gwet's AC1（AC1）评分用于确定组间可靠性。进行了一次留一法分析，以显示评分者之间的变异性。计算了评分的前 20 名和最后 20 名患者之间的组间一致性，以探讨是否存在培训效果。
评分次数从 6 个月的 450 次到 48 个月的 84 次不等。每个类别的患者比例如下：A，45%；B，16%；C，13%；和 D，26%。KA 和 M-kappa 范围为 0.17 至 0.34。AC1 测量范围为 0.22 至 0.48。KA 在 12 个月时从 0.24 增加到 0.36，同时进行了培训。A 型的百分比一致率在 12 个月时达到峰值，有 54%的机会有>50%的评分者一致，随着时间的推移而下降，而 B 型和 C 型的一致率则随着时间的推移而增加，分别达到最高的 20%和 22%。
这种 SBRT 后放射学改变分类系统的组间一致性适中，并且存在培训效果的提示。SBRT 后纤维化模式演变，应评估替代分类系统。
