Nuclear Medicine Department, Clinic University Hospital, Barcelona, Spain.
Eur J Nucl Med Mol Imaging. 2013 Apr;40(4):496-504. doi: 10.1007/s00259-012-2320-8. Epub 2013 Jan 23.
Interim (18)F-FDG PET performed early during the course of therapy in diffuse large B-cell lymphoma (DLBCL) is a good predictor of outcome. However, interpretation criteria for interim PET for the evaluation of tumour response are still not clearly defined. The study aim was to assess whether interim PET can predict overall survival (OS) and progression-free survival (PFS) in DLBCL patients following three different sets of parameters, two qualitative (visual) methods and one semiquantitative.
A total of 50 newly diagnosed DLBCL patients were prospectively enrolled in this study. All patients had a PET/CT scan at diagnosis and an interim PET/CT scan after the second or third cycle of chemotherapy. Three methods of evaluation for the interim PET/CT were used: a qualitative three-point scoring (3-PS) method, a qualitative 5-PS method and a semiquantitative method (ΔSUVmax). The degree of correlation between therapy response seen on FDG PET and PFS and OS was determined.
The analysis of the visual 3-PS method showed no statistically significant difference in PFS and OS. The estimated 5-year PFS and OS were 79 % and 92 %, respectively, in patients with an interim PET scan showing uptake not greater than in the liver versus 50 % in patients with uptake greater than in the liver, and this difference was statistically significant. The optimal cut-off value of ΔSUVmax that could predict the PFS and OS difference in patients with DLBCL was 76 % (95 % CI 62.7-89.2 %) and 75 % (95 % CI, 54.6-95.4 %), respectively.
Our results support the use of liver uptake as an indicator in the qualitative evaluation of interim PET, or a ΔSUVmax greater than 75 % in semiquantitative analysis. Interim PET may predict PFS and OS and could be considered in the prognostic evaluation of DLBCL.
在弥漫性大 B 细胞淋巴瘤（DLBCL）治疗过程中早期进行（18）F-FDG PET 是预后的良好预测指标。然而，用于评估肿瘤反应的中期 PET 的解释标准仍未明确界定。本研究旨在评估在三种不同参数（两种定性（视觉）方法和一种半定量）下，中期 PET 是否可以预测 DLBCL 患者的总生存期（OS）和无进展生存期（PFS）。
本研究前瞻性纳入了 50 例新诊断的 DLBCL 患者。所有患者在诊断时均进行了 PET/CT 扫描，并在化疗第 2 或第 3 周期后进行了中期 PET/CT 扫描。使用三种方法评估中期 PET/CT：定性三分法（3-PS）、定性五分法（5-PS）和半定量方法（ΔSUVmax）。确定 FDG PET 上看到的治疗反应与 PFS 和 OS 之间的相关性程度。
分析视觉 3-PS 方法显示，在 PFS 和 OS 方面无统计学差异。在中期 PET 扫描摄取不大于肝脏的患者中，估计 5 年 PFS 和 OS 分别为 79%和 92%，而摄取大于肝脏的患者中分别为 50%，差异具有统计学意义。可以预测 DLBCL 患者 PFS 和 OS 差异的 ΔSUVmax 的最佳截断值分别为 76%（95%CI 62.7-89.2%）和 75%（95%CI，54.6-95.4%）。
我们的结果支持在定性评估中期 PET 时将肝脏摄取用作指标，或在半定量分析中使用 ΔSUVmax 大于 75%。中期 PET 可预测 PFS 和 OS，可在 DLBCL 的预后评估中考虑使用。
