Muratet J P, Daver A, Minier J F, Larra F
Médecine Nucléaire, Centre Paul Papin, Angers, France.
J Nucl Med. 1998 Sep;39(9):1546-50.
The therapeutic outcome after (131)I first ablative treatment in patients operated on for nonmedullary differentiated thyroid carcinoma was compared after both the currently used scanning dose of 111 MBq (131)I and a scanning dose of 37 MBq (131)I.
Two-hundred twenty-nine consecutive patients with no known metastases were retrospectively studied. They were divided in two populations according to the scanning dose (127 patients with 111 MBq and 102 patients with 37 MBq). All patients received 111 or 37 MBq (131)I for diagnostic purposes and 3.7 GBq (131)I for ablative therapy 9 days later. To assess the efficacy of the treatment, all patients were studied with (131)I and with thyroglobulin plasma assays 6-17 mo later.
Successful outcome was significantly more frequent after a scanning dose of 37 MBq (131)I than after a scanning dose of 111 MBq (76% versus 50%, p < 0.001). The treatment efficacy was particularly enhanced after 37 MBq in patients with associated lymphocytic thyroiditis.
In patients with no known metastases, our data suggest that the impairment of the treatment efficacy observed after a scanning dose of 111 MBq (131)I is related to a stunning effect on the thyroid remnants. The threshold amount above which this effect begins to occur in thyroid remnants could be between 37 and 111 MBq (131)I. Consequently, a scanning dose of only 37 MBq (131)I could be recommended before first ablative treatment. The absence of metastatic patients in our study prevents any conclusion about the possible stunning of the neoplastic tissue. Nevertheless, we must suspect such an effect and try to avoid it, especially during follow-up after first radioiodine therapy. For instance, one may consider postponing radioiodine treatment several weeks or even months after scanning dose administration or using only thyroglobulin measurement for patients who are likely to receive a subsequent radioiodine treatment.
对接受非髓样分化型甲状腺癌手术的患者进行首次（131）I消融治疗后，比较了目前使用的111 MBq（131）I扫描剂量和37 MBq（131）I扫描剂量后的治疗效果。
回顾性研究了229例无已知转移的连续患者。根据扫描剂量将他们分为两组（127例接受111 MBq的患者和102例接受37 MBq的患者）。所有患者均接受111或37 MBq（131）I用于诊断目的，并在9天后接受3.7 GBq（131）I进行消融治疗。为评估治疗效果，在6至17个月后对所有患者进行了（131）I和甲状腺球蛋白血浆检测。
37 MBq（131）I扫描剂量后的成功结果显著多于111 MBq扫描剂量后（76%对50%，p<0.001）。在伴有淋巴细胞性甲状腺炎的患者中，37 MBq后治疗效果尤其增强。
在无已知转移的患者中，我们的数据表明，111 MBq（131）I扫描剂量后观察到的治疗效果受损与甲状腺残余组织的顿抑效应有关。甲状腺残余组织中开始出现这种效应的阈值量可能在37至111 MBq（131）I之间。因此，在首次消融治疗前可推荐仅37 MBq（131）I的扫描剂量。我们研究中没有转移性患者，因此无法就肿瘤组织可能的顿抑得出任何结论。然而，我们必须怀疑这种效应并尽量避免，尤其是在首次放射性碘治疗后的随访期间。例如，对于可能接受后续放射性碘治疗的患者，可考虑在给予扫描剂量后推迟数周甚至数月进行放射性碘治疗，或仅使用甲状腺球蛋白测量。
