Department of Nuclear Medicine, Faculty of Medicine, Henri Becquerel Cancer Center and Rouen University Hospital, & QuantIF - LITIS (EA 4108), University of Rouen, Rouen, France.
Eur J Nucl Med Mol Imaging. 2013 Sep;40(9):1345-55. doi: 10.1007/s00259-013-2450-7. Epub 2013 May 29.
FDG PET has been suggested to have predictive value in the prognosis of oesophageal carcinoma. However, the retrospective studies reported in the literature have shown discordant results. Additionally, only four studies have evaluated FDG PET during chemoradiotherapy (CRT) in patients with different histological lesions. The purpose of this study was to investigate the predictive value of FDG PET performed early during CRT (on day 21) in a population of patients with oesophageal squamous cell carcinoma.
Included in this prospective study were 57 patients with a histological diagnosis of squamous cell carcinoma of the oesophagus. Of these 57 patients, 48 (84%) were evaluated (aged 63 ± 11 years; 44 men, 4 women). Each patient underwent FDG PET (4.5 MBq/kg) before CRT, according to the Herskovic protocol (t0; PET₁) and on day 21 ± 3 from the start of CRT (d21; PET₂). The response assessment included a clinical examination, CT scan or FDG PET and histological analysis 3 months and 1 year after PET₁. The patients were classified as showing a complete response (CR) or a noncomplete response. A quantitative analysis was carried out for PET₁ and PET₂ using the following parameters: SUVmax, SUVmean (with SUVmean40 as the 3-D volume at an SUVmax threshold of 40% and SUVmeanp as that defined by a physician), tumour volume (TV, with TV40 defined as the TV at 40% of SUVmax, and TVp as that defined by a physician); and the total lesion glycolysis (TLG, SUVmean × TV, with TLG₄₀ defined as the TLG at 40% of SUVmax, and TLGp as that defined by a physician). The differences in responses at 3 months and 1 year between PET₁ (t0) and PET₂ (d21) were assessed in terms of variations in SUV, TV and TLG using a repeated measures of variance (ANOVA).
SUVmax, SUVmean and TLG decreased significantly between PET₁ (t0) and PET₂ (d21; p < 0.0001). The TV significantly decreased only when assessed as TVp (p = 0.02); TV₄₀ did not decrease significantly. With respect to the predictive value of PET₁, only TV40_1 and TVp_1 values, and therefore TLG40_1 and TLGp_1, but not the SUV values, were significantly lower in patients with CR at 3 months. SUVmax1, TVp_1 and TLGp_1 were significantly lower in patients with CR at 1 year. With respect to the predictive value of PET₂, only TV40_2 and TVp_2 values, and therefore TLG40_2 and TLGp_2, but not the SUV values, were significantly lower in patients with CR at 3 months. None of the PET₂ parameters had significant value in predicting patient outcome at 1 year. The changes in SUVmax, TV₄₀, TVp, TLG₄₀ and TLGp between PET₁ and PET₂ had no relationship to patient outcome at 3 months or 1 year.
This prospective, multicentre study performed in a selected population of patients with oesophageal squamous cell cancer demonstrates that the parameters derived from baseline PET₁ are good predictors of response to CRT. Specifically, a high TV and TLG are associated with a poor response to CRT at 3 months and 1 year, and a high SUVmax is associated with a poor response to CRT at 1 year. FDG PET performed during CRT on day 21 appears to have less clinical relevance. However, patients with a large functional TV on day 21 of CRT have a poor clinical outcome (ClinicalTrials.gov NCT 00934505).
FDG PET 已被证明对食管癌的预后具有预测价值。然而，文献中的回顾性研究结果存在差异。此外，只有四项研究评估了不同组织学病变患者在放化疗期间的 FDG PET。本研究旨在探讨在食管鳞状细胞癌患者中，放化疗早期（第 21 天）进行 FDG PET 的预测价值。
本前瞻性研究纳入了 57 例组织学诊断为食管鳞状细胞癌的患者。其中 48 例（84%）进行了评估（年龄 63±11 岁；男性 44 例，女性 4 例）。每位患者均按照 Herskovic 方案在放化疗前（t0；PET₁）和放化疗开始后第 21 天±3 天（d21；PET₂）进行 FDG PET（4.5MBq/kg）。反应评估包括临床检查、CT 扫描或 FDG PET 和组织学分析，分别在 PET₁后 3 个月和 1 年进行。患者被分为完全缓解（CR）或非完全缓解。对 PET₁和 PET₂使用以下参数进行定量分析：SUVmax、SUVmean（SUVmean40 是 SUVmax 阈值为 40%的 3-D 体积，SUVmeanp 是医生定义的体积）、肿瘤体积（TV，TV40 是 SUVmax 的 40%的 TV，TVp 是医生定义的 TV）；总病变糖酵解（TLG，SUVmean×TV，TLG₄₀ 是 SUVmax 的 40%的 TLG，TLGp 是医生定义的 TLG）。使用方差重复测量（ANOVA）评估 3 个月和 1 年时 PET₁（t0）和 PET₂（d21）之间反应的差异，即 SUV、TV 和 TLG 的变化。
SUVmax、SUVmean 和 TLG 在 PET₁（t0）和 PET₂（d21）之间显著降低（p<0.0001）。仅当评估 TVp 时，TV 显著降低（p=0.02）；TV₄₀ 没有显著降低。就 PET₁的预测价值而言，仅在 3 个月时，CR 患者的 TV40_1 和 TVp_1 值，因此 TLG40_1 和 TLGp_1 值，而不是 SUV 值，显著降低。SUVmax1、TVp_1 和 TLGp_1 在 1 年时 CR 患者显著降低。就 PET₂的预测价值而言，仅在 3 个月时，CR 患者的 TV40_2 和 TVp_2 值，因此 TLG40_2 和 TLGp_2 值，而不是 SUV 值，显著降低。PET₂的任何参数在预测 1 年的患者结局时均无显著价值。SUVmax、TV₄₀、TVp、TLG₄₀ 和 TLGp 之间在 PET₁和 PET₂ 之间的变化与 3 个月或 1 年的患者结局无关。
本前瞻性、多中心研究在选定的食管鳞状细胞癌患者人群中进行，表明基线 PET₁ 的参数是放化疗反应的良好预测指标。具体而言，高 TV 和 TLG 与 3 个月和 1 年时 CRT 反应不良相关，高 SUVmax 与 1 年时 CRT 反应不良相关。放化疗第 21 天进行的 FDG PET 似乎具有较少的临床相关性。然而，放化疗第 21 天 CRT 时具有较大功能 TV 的患者具有较差的临床结局（ClinicalTrials.gov NCT 00934505）。
