Nakayama Michihiro, Nomura Kenta, Kamieda Sho, Yoshida Ippei, Fujiya Atsushi, Uno Takahiro, Okizaki Atsutaka
Asahikawa Medical University Faculty of Medicine, Department of Radiology, Asahikawa, Japan.
Asahikawa Medical University Hospital, Division of Radiology, Asahikawa, Japan.
Mol Imaging Radionucl Ther. 2025 Aug 1. doi: 10.4274/mirt.galenos.2025.71542.
A Iodine-131 (I) whole body scan (WBS) is performed to evaluate the treatment response after radioactive iodine (RAI) therapy. Despite the clinical relevance of RAI-refractory differentiated thyroid cancer, a consensus on its precise definition remains lacking. This study investigates the potential utility of hepatic I accumulation as an early predictor for tumor recurrence or progression after RAI administration.
Of 814 patients receiving care at our institution, we enrolled 225 patients who exhibited no accumulation of RAI in the remnant tissues or other lesions on I WBS. We quantified the hepatic uptake ratio [defined as (hepatic uptake/background uptake (H/B)] from WBS. All patients were categorized into group A (H/B ≤1.5) and group B (H/B >1.5), and we assessed between-group differences. The Kaplan-Meier method and Log-rank test were used to analyze the progression-free survival (PFS). Using the Cox proportional hazards model, we identified independent prognostic factors from among the seven known prognostic factors, i.e., H/B, thyroglobulin, sex, age, stage, total I dose, and final therapeutic dose.
The 5-year and median PFS were 98.8% and 114.7 months in group A (n: 171) compared with 24.1% and 42.7% months in group B (n: 54), respectively. Group B showed a significant correlation with poor prognosis (p<0.00001). Of the seven prognostic factors, H/B exhibited the highest impact on patient outcomes (hazards ratio for recurrence/disease progression, 42.156; 95% confidence interval: 8.750-203.106).
Quantitative evaluation of hepatic uptake on I WBS provides a marker that may help identify patients with differentiated thyroid cancer who are at a high risk of disease progression/recurrence immediately after RAI therapy.
进行碘-131（I）全身扫描（WBS）以评估放射性碘（RAI）治疗后的治疗反应。尽管RAI难治性分化型甲状腺癌具有临床相关性，但对其精确定义仍缺乏共识。本研究探讨肝脏I摄取作为RAI给药后肿瘤复发或进展的早期预测指标的潜在效用。
在我们机构接受治疗的814例患者中，我们纳入了225例在I WBS上残余组织或其他病变中未显示RAI摄取的患者。我们从WBS中量化肝脏摄取率[定义为（肝脏摄取/本底摄取（H/B）]。所有患者分为A组（H/B≤1.5）和B组（H/B>1.5），并评估组间差异。采用Kaplan-Meier法和Log-rank检验分析无进展生存期（PFS）。使用Cox比例风险模型，我们从七个已知的预后因素中确定独立的预后因素，即H/B、甲状腺球蛋白、性别、年龄、分期、总I剂量和最终治疗剂量。
A组（n = 171）的5年和中位PFS分别为98.8%和114.7个月，而B组（n = 54）分别为24.1%和42.7个月。B组与不良预后显著相关（p<0.00001）。在七个预后因素中，H/B对患者预后的影响最大（复发/疾病进展的风险比，42.156；95%置信区间：8.750 - 203.106）。
I WBS上肝脏摄取的定量评估提供了一个标志物，可能有助于识别RAI治疗后立即有疾病进展/复发高风险的分化型甲状腺癌患者。
