Xiao Canran, Xu Ruoxin, Luo Yao, Xu Zeqing, Tang Caihua
Department of Nuclear Medicine, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, China.
Department of Nuclear Medicine, Chongqing University Cancer Hospital, Chongqing, 400030, China.
Ann Nucl Med. 2025 Feb;39(2):167-175. doi: 10.1007/s12149-024-01984-8. Epub 2024 Sep 23.
The efficacy of a second radioactive iodine-131 (I) treatment in patients with differentiated thyroid cancer (DTC) who did not achieve an excellent response (ER) following initial I therapy remains controversy and the population that would derive limited benefit from it is currently unclear.
The aim of this retrospective study was to assess the efficacy of the second I treatment in DTC patients with non-ER after the initial I therapy, and to identify potential risk factors associated with non-benefit of the second I treatment.
127 DTC patients who underwent two I treatments following thyroidectomy were included in this study, and the therapeutic response was evaluated after each I treatment. Beneficial treatment was defined as an improvement in therapy response grade (e.g. from indeterminate response to ER) after the second I treatment, while unbeneficial treatment was defined as no change or a downgrade in therapy response grade. The potential risk factors associated with the non-benefit of the second I treatment were identified using univariate and multivariate logistic regression models.
Following the second I treatment, therapy responses of 55.12% (70/127) of patients were reclassified to a better grade indicating treatment benefit, while 44.88% (57/127) showed no change or were reclassified to a worse grade suggesting no benefit from treatment. The non-benefit of the second I treatment was significantly associated with potential risk factors including stimulated thyroglobulin (sTg) level ≥ 11.46 ng/mL before the second I treatment, primary tumor size > 2 cm, status T2 or higher, N1b status and ATA high risk.
The study results demonstrated that more than half of DTC patients could potentially benefit from a second I therapy. However, over 40% of patients exhibited no benefit in response to the second I treatment, suggesting potential overtreatment for this subgroup. Therefore, clinicians should exercise meticulous and precise decision-making based on identified risk factors when considering the necessity of a second I treatment.
对于分化型甲状腺癌（DTC）患者，在首次碘 - 131（I）治疗后未获得良好反应（ER）的情况下，第二次放射性碘 - 131（I）治疗的疗效仍存在争议，目前尚不清楚哪些人群能从该治疗中获得有限的益处。
这项回顾性研究的目的是评估首次I治疗后未达到ER的DTC患者接受第二次I治疗的疗效，并确定与第二次I治疗无获益相关的潜在风险因素。
本研究纳入了127例甲状腺切除术后接受两次I治疗的DTC患者，每次I治疗后评估治疗反应。有益治疗定义为第二次I治疗后治疗反应等级改善（例如从不明确反应变为ER），而无益治疗定义为治疗反应等级无变化或降低。使用单因素和多因素逻辑回归模型确定与第二次I治疗无获益相关的潜在风险因素。
第二次I治疗后，55.12%（70/127）的患者治疗反应重新分类为更好的等级，表明治疗有益，而44.88%（57/127）的患者无变化或重新分类为更差的等级，表明治疗无获益。第二次I治疗无获益与潜在风险因素显著相关，包括第二次I治疗前刺激甲状腺球蛋白（sTg）水平≥11.46 ng/mL、原发肿瘤大小>2 cm、T2或更高分期、N1b分期以及ATA高风险。
研究结果表明，超过一半的DTC患者可能从第二次I治疗中获益。然而，超过40%的患者对第二次I治疗无反应，提示该亚组可能存在过度治疗。因此，临床医生在考虑第二次I治疗的必要性时，应根据已确定的风险因素进行细致而精确的决策。
