Complete metabolic response (CMR) on PET/CT was the sole independent predictor of overall survival in the PET substudy of the phase III GALLIUM trial (NCT01332968) in first-line treatment of high-tumor-burden follicular lymphoma. The aim of this analysis was to further investigate the outcome of patients not achieving CMR. Methods: Two international experts rereviewed PET/CT scans from patients failing to achieve CMR assessed by the Independent Review Committee masked otherwise to committee results. Metabolic response category and Deauville score were assigned. Progression-free survival (PFS) was investigator-assessed with contrast-enhanced CT. Kaplan–Meier methodology was used to estimate landmark PFS and time to next treatment from end of induction by Deauville score. Patients who experienced CT-based progressive disease at the end of induction were excluded. Results: Fifty-four patients were reviewed. Six had CMR, 37 had a partial metabolic response, 2 had no metabolic response, and 9 had progressive metabolic disease. Patients were reassigned to CMR because ¹⁸F-FDG uptake was considered inflammatory (n = 2), was considered incidental neoplasia (n = 2), or was visually close to liver uptake but quantitatively lower (n = 2). There was a trend for shorter PFS and time to next treatment for patients with a Deauville score of 5 than a score of 4. High-grade mesenteric uptake at the end of induction was common, occurring in 20 patients with non-CMR, 14 of whom achieved CMR at all other sites. Only 3 of 14 (21%) patients with mesenteric uptake as the only site of disease experienced progression or death within 24 mo, whereas 4 of 6 patients (67%) with mesenteric and additional sites of ¹⁸F-FDG–avid disease experienced progression or death within 24 mo. All patients with early progression had measurable disease on contrast-enhanced CT at ¹⁸F-FDG–avid sites at the end of induction. Conclusion: After induction immunochemotherapy, CMR was assigned after reassessment in some patients, in whom increased ¹⁸F-FDG uptake was considered due to inflammation or incidental neoplasia rather than to lymphoma. Quantitative assessment to confirm the visual impression of residual uptake in lesions is suggested. Isolated mesenteric ¹⁸F-FDG uptake is likely a common false-positive finding at the end of induction and does not warrant changes in clinical management or disease surveillance unless there is measurable disease on contrast-enhanced CT or clinical suspicion of active disease.

在高肿瘤负荷滤泡性淋巴瘤的 III 期 GALLIUM 试验 (NCT01332968) 的 PET 子研究中，PET/CT 上的完全代谢反应 (CMR) 是总生存期的唯一独立预测因子。该分析的目的是进一步调查未达到 CMR 的患者的结果。方法：两位国际专家审查了独立审查委员会评估的未能达到 CMR 的患者的 PET/CT 扫描，该委员会的结果以其他方式掩盖了委员会的结果。分配了代谢反应类别和多维尔评分。研究者使用对比增强 CT 评估了无进展生存期 (PFS)。Kaplan-Meier 方法用于通过 Deauville 评分估计具有里程碑意义的 PFS 和从诱导结束到下一次治疗的时间。在诱导结束时出现基于 CT 的进展性疾病的患者被排除在外。结果：共审查了 54 名患者。6 人有 CMR，37 人有部分代谢反应，2 人没有代谢反应，9 人有进行性代谢疾病。患者被重新分配到 CMR，因为¹⁸ F-FDG 摄取被认为是炎症性的（n = 2)，被认为是偶然的肿瘤形成 ( n = 2)，或视觉上接近肝脏摄取但数量上较低 ( n = 2)。对于多维尔评分为 5 分的患者，与评分为 4 分的患者相比，PFS 和下一次治疗的时间有更短的趋势。诱导结束时高级别肠系膜摄取很常见，发生在 20 名非 CMR 患者中，14 名在所有其他站点都实现了 CMR。14 名肠系膜摄取作为唯一疾病部位的患者中只有 3 名 (21%) 在 24 个月内出现进展或死亡，而 6 名肠系膜和其他部位的¹⁸ F-FDG-avid 疾病患者中有 4 名 (67%) 出现进展或在 24 个月内死亡。所有早期进展的患者在对比增强 CT 上都有可测量的疾病诱导结束时有^{18 个F-FDG-avid 位点。}结论：诱导免疫化疗后，在重新评估某些患者后分配 CMR，其中¹⁸ F-FDG 摄取增加被认为是由于炎症或偶发肿瘤而不是淋巴瘤。建议进行定量评估以确认病变中残留摄取的视觉印象。孤立的肠系膜¹⁸ F-FDG 摄取可能是诱导结束时常见的假阳性发现，并且不需要改变临床管理或疾病监测，除非在增强 CT 上有可测量的疾病或临床怀疑活动性疾病。