Weber Wolfgang A, Gatsonis Constantine A, Mozley P David, Hanna Lucy G, Shields Anthony F, Aberle Denise R, Govindan Ramaswamy, Torigian Drew A, Karp Joel S, Yu Jian Q Michael, Subramaniam Rathan M, Halvorsen Robert A, Siegel Barry A
Memorial Sloan Kettering Cancer Center, New York, New York
Department of Biostatistics and Center for Statistical Sciences, Brown University, Providence, Rhode Island.
J Nucl Med. 2015 Aug;56(8):1137-43. doi: 10.2967/jnumed.114.147728. Epub 2015 Apr 23.
PET/CT with the glucose analog (18)F-FDG has several potential applications for monitoring tumor response to therapy in patients with non-small cell lung cancer (NSCLC). A prerequisite for many of these applications is detailed knowledge of the repeatability of quantitative parameters derived from (18)F-FDG PET/CT studies.
The repeatability of the (18)F-FDG signal was evaluated in 2 prospective multicenter trials. Patients with advanced NSCLC (tumor stage III-IV) underwent two (18)F-FDG PET/CT studies while not receiving therapy. Tumor (18)F-FDG uptake was quantified by measurement of the maximum standardized uptake value within a lesion (SUVmax) and the average SUV within a small volume of interest around the site of maximum uptake (SUVpeak). Analysis was performed for the lesion in the chest with the highest (18)F-FDG uptake and a size of at least 2 cm (target lesion) as well as for up to 6 additional lesions per patient. Repeatability was assessed by Bland-Altman plots and calculation of 95% repeatability coefficients (RCs) of the log-transformed SUV differences.
Test-retest repeatability was assessed in 74 patients (34 from the ACRIN 6678 trial and 40 from the Merck MK-0646-008 trial). SUVpeak was 11.57 ± 7.89 g/mL for the ACRIN trial and 6.89 ± 3.02 for the Merck trial. The lower and upper RCs were -28% (95% confidence interval [CI], -35% to -23%) and +39% (95% CI, 31% to 54%) in the ACRIN trial, indicating that a decrease of SUVpeak by more than 28% or an increase by more than 39% has a probability of less than 2.5%. The corresponding RCs from the Merck trial were -35% (95% CI, -42% to -29%) and +53% (95% CI, 41% to 72%). Repeatability was similar for SUVmax of the target lesion, averaged SUVmax, and averaged SUVpeak of up to 6 lesions per patient.
The variability of repeated measurements of tumor (18)F-FDG uptake in patients with NSCLC is somewhat larger than previously reported in smaller single-center studies but comparable to that of gastrointestinal malignancies in a previous multicenter trial. The variability of measurements supports the definitions of tumor response according to PET Response Criteria in Solid Tumors.
使用葡萄糖类似物（18）F-FDG的PET/CT在监测非小细胞肺癌（NSCLC）患者的肿瘤治疗反应方面有多种潜在应用。这些应用中的许多的一个先决条件是详细了解从（18）F-FDG PET/CT研究中得出的定量参数的可重复性。
在2项前瞻性多中心试验中评估了（18）F-FDG信号的可重复性。晚期NSCLC（肿瘤分期为III-IV期）患者在未接受治疗时进行了两次（18）F-FDG PET/CT研究。通过测量病变内的最大标准化摄取值（SUVmax）和最大摄取部位周围小感兴趣体积内的平均SUV（SUVpeak）来量化肿瘤（18）F-FDG摄取。对胸部FDG摄取最高且大小至少为2 cm的病变（靶病变）以及每位患者最多6个其他病变进行分析。通过Bland-Altman图和计算对数转换后的SUV差异的95%可重复性系数（RC）来评估可重复性。
在74例患者中评估了重测可重复性（ACRIN 6678试验中的34例和默克MK-0646-008试验中的40例）。ACRIN试验中SUVpeak为11.57±7.89 g/mL，默克试验中为6.89±3.02。ACRIN试验中较低和较高的RC分别为-28%（95%置信区间[CI]，-35%至-23%）和+39%（95%CI，31%至54%），这表明SUVpeak降低超过28%或增加超过39%的概率小于2.5%。默克试验中的相应RC为-35%（95%CI，-42%至-29%）和+53%（95%CI，41%至72%）。靶病变的SUVmax、平均SUVmax以及每位患者多达6个病变的平均SUVpeak的可重复性相似。
NSCLC患者肿瘤（18）F-FDG摄取重复测量的变异性比先前在较小的单中心研究中报告的略大，但与先前多中心试验中胃肠道恶性肿瘤的变异性相当。测量的变异性支持根据实体瘤PET反应标准对肿瘤反应的定义。
