Kist Jakob W, de Keizer Bart, Stokkel Marcel P M, Hoekstra Otto S, Vogel Wouter V
Department of Nuclear Medicine, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
BMC Cancer. 2014 Jun 5;14:405. doi: 10.1186/1471-2407-14-405.
After initial treatment of differentiated thyroid carcinoma (DTC) patients are followed with thyroglobulin (Tg) measurements to detect recurrences. In case of elevated levels of Tg and negative neck ultrasonography, patients are treated 'blindly' with Iodine-131 (131I). However, in up to 50% of patients, the post-therapy scan reveals no 131I-targeting of tumor lesions. Such patients derive no benefit from the blind therapy but are exposed to its toxicity. Alternatively, iodine-124 (124I) Positron Emission Tomography/Computed Tomography (PET/CT) has become available to visualize DTC lesions and without toxicity. In addition to this, 18F-fluorodeoxyglucose (18F-FDG) PET/CT detects the recurrent DTC phenotype, which lost the capacity to accumulate iodine. Taken together, the combination of 124I and 18F-FDG PET/CT has potential to stratify patients for treatment with 131I.
METHODS/DESIGN: In a multicenter prospective observational cohort study the hypothesis that the combination of 124I and 18F-FDG PET/CT can avoid futile 131I treatments in patients planned for 'blind' therapy with 131I, is tested.One hundred patients planned for 131I undergo both 124I and 18F-FDG PET/CT after rhTSH stimulation. Independent of the outcome of the scans, all patients will subsequently receive, after thyroid hormone withdrawal, the 131I therapy. The post 131I therapeutic scintigraphy is compared with the outcome of the 124I and 18F-FDG PET/CT in order to evaluate the diagnostic value of the combined PET modalities.This study primary aims to reduce the number of futile 131I therapies. Secondary aims are the nationwide introduction of 124I PET/CT by a quality assurance and quality control (QA/QC) program, to correlate imaging outcome with histopathological features, to compare 124I PET/CT after rhTSH and after withdrawal of thyroid hormone, and to compare 124I and 131I dosimetry.
This study aims to evaluate the potential value of the combination of 124I and 18F-FDG PET/CT in the prevention of futile 131I therapies in patients with biochemically suspected recurrence of DTC. To our best knowledge no studies addressed this in a prospective cohort of patients. This is of great clinical importance as a futile 131I is a costly treatment associated with morbidity and therefore should be restricted to those likely to benefit from this treatment.
Clinicaltrials.gov identifier: NCT01641679.
分化型甲状腺癌（DTC）患者在初始治疗后，需通过检测甲状腺球蛋白（Tg）来监测复发情况。当Tg水平升高且颈部超声检查结果为阴性时，患者会接受碘 - 131（¹³¹I）的“盲目”治疗。然而，高达50%的患者在治疗后的扫描中显示肿瘤病灶无¹³¹I摄取。这些患者无法从盲目治疗中获益，却要承受其毒性。另外，碘 - 124（¹²⁴I）正电子发射断层扫描/计算机断层扫描（PET/CT）已可用于可视化DTC病灶且无毒性。除此之外，¹⁸F - 氟脱氧葡萄糖（¹⁸F - FDG）PET/CT可检测出失去碘摄取能力的复发性DTC表型。综上所述，¹²⁴I与¹⁸F - FDG PET/CT联合应用有潜力对患者进行分层，以确定是否适合接受¹³¹I治疗。
方法/设计：在一项多中心前瞻性观察队列研究中，对¹²⁴I与¹⁸F - FDG PET/CT联合应用能否避免对计划接受¹³¹I“盲目治疗 ”的患者进行无效的¹³¹I治疗这一假设进行检验。100例计划接受¹³¹I治疗的患者在重组人促甲状腺素（rhTSH）刺激后，同时接受¹²⁴I和¹⁸F - FDG PET/CT检查。无论扫描结果如何，所有患者在甲状腺激素撤药后均随后接受¹³¹I治疗。将¹³¹I治疗后的闪烁扫描结果与¹²⁴I和¹⁸F - FDG PET/CT的结果进行比较，以评估联合PET检查方法的诊断价值。本研究的主要目的是减少无效¹³¹I治疗的次数。次要目的包括通过质量保证和质量控制（QA/QC）计划在全国范围内引入¹²⁴I PET/CT，将影像学结果与组织病理学特征相关联，比较rhTSH刺激后和甲状腺激素撤药后的¹²⁴I PET/CT，并比较¹²⁴I和¹³¹I的剂量测定。
本研究旨在评估¹²⁴I与¹⁸F - FDG PET/CT联合应用在预防生化检查怀疑有DTC复发患者的无效¹³¹I治疗方面的潜在价值。据我们所知，尚无研究在前瞻性患者队列中对此进行探讨。这具有重要的临床意义，因为无效的¹³¹I治疗成本高昂且伴有发病率，因此应仅限于可能从该治疗中获益的患者。
Clinicaltrials.gov标识符：NCT01641679。
