METHODS: 35 patients were included in this dual-center prospective study. FDG-PET using digital photon counting technology combined with CT scans were acquired before (T1) and after neo-adjuvant therapy (T2). Patients were staged and restaged based on standard protocol with ceCT and CA 19.9, while all PET/CT scans were stored securely and not included in clinical decision making. After the pancreatic resection, an expert team retrospectively assessed the CT tumor diameter, CA19-9, tumor FDG-uptake, and appearance of metastatic disease of all patients for both time points.
RESULTS: CA19-9 levels, CT tumor diameter, and tumor FDG-uptake on PET significantly decreased from T1 to T2 (p = 0.017, p = 0.001, and p < 0.0001). The change in FDG-uptake values showed a strong positive correlation with the change in CT tumor diameter and change in CA19-9 (R = 0.75 and R = 0.73, respectively). In addition, small-volume liver lesions were detected on digital PET/CT in 5/35 patients (14%), 4 of which were pathology confirmed at laparotomy. Only one of these five cases was detected on baseline staging ceCT (3%).
CONCLUSIONS: We found that adding digital PET/CT strengthens restaging after neo-adjuvant therapy based on the observed strong correlation with ceCT tumor diameter and Ca19.9. Also, digital PET/CT was found to detect occult metastatic disease not visualized on ceCT, that would have resulted in altered disease staging and therapeutic strategy in a substantial proportion of patients.
方法:这项双中心前瞻性研究纳入了35例患者。采用数字光子计数技术的FDG-PET结合CT扫描在新辅助治疗前(T1)和后(T2)采集。根据ceCT和CA19.9的标准协议对患者进行分期和重新分类,而所有PET/CT扫描均安全存储,不包括在临床决策中。胰腺切除术后,一个专家小组回顾性评估了CT肿瘤直径,CA19-9,肿瘤FDG摄取,以及两个时间点所有患者的转移性疾病的出现。
结果:CA19-9水平,CT肿瘤直径,从T1到T2,PET上的肿瘤FDG摄取显着降低(p=0.017,p=0.001,p<0.0001)。FDG摄取值的变化与CT肿瘤直径的变化和CA19-9的变化呈强正相关(分别为R=0.75和R=0.73)。此外,5/35例患者(14%)在数字PET/CT上检测到小体积肝脏病变,其中4例为剖腹手术病理证实。在基线分期ceCT中,仅检测到这5例病例中的1例(3%)。
结论:我们发现,根据观察到的与ceCT肿瘤直径和Ca19.9的强相关性,增加数字PET/CT可以增强新辅助治疗后的再融合。此外,发现数字PET/CT可检测未在CECT上显示的隐匿性转移性疾病,这将导致相当一部分患者的疾病分期和治疗策略发生改变。