背景:转移性分化型甲状腺癌(DTC)代表一组分子异质性癌症,具有不同的放射性碘(RAI)和[18F]-氟脱氧葡萄糖(FDG)摄取模式,可能与所谓的“翻转”现象的去分化程度相关。然而,RAI和FDG摄取模式是否与分子状态或转移部位相关尚不清楚.材料和方法:回顾性分析2008年至2022年期间接受放射性131碘全身扫描(WBS)和FDG-PET成像的转移性DTC患者(n=46)。纳入标准包括1年内可获得的FDG-PET和WBS研究。两名失明的放射科医生解释了甲状腺外部位包括肺在内的碘或FDG摄取的研究,淋巴结,还有骨头.病例按BRAFV600E突变状态分层,组织学,以及肿瘤基因型和组织学的组合。数据采用McNemar卡方检验。结果:肺转移FDG摄取明显高于碘摄取(WBS:52%,FDG:84%,p=0.04),但淋巴结或骨转移没有发现显着差异。肺转移FDG摄取在乳头状模式亚组中明显更普遍(WBS:37%,FDG:89%,p=0.02)比卵泡模式子队列(WBS:75%,FDG:75%,p=1.00)。同样,具有肺转移的BRAFV600E+肿瘤也表现出FDG摄取的优势(WBS:29%,FDG:93%,p=0.02)比BRAFV600E-肿瘤(WBS:83%,FDG:83%,p=1.00)伴肺转移。乳头状组织学在肺转移中具有较高的FDG摄取(WBS:39%,FDG:89%,p=0.03)与卵泡组织学相比(WBS:69%,FDG:77%,p=1.00)。乳头状型疾病患者,BRAFV600E+突变,与滤泡型疾病相比,或乳头状组织学在所有转移部位的两种摄取方式之间的一致性降低,BRAFV600E-突变,或卵泡组织学。无论分子状态或组织学如何,所有患者的淋巴结摄取均呈低一致性。结论:FDG-PET和放射性碘摄取的模式取决于分子状态和转移部位,具有乳头状组织学或BRAFV600E突变的患者在远处转移中表现为FDG摄取增加。扩大队列的进一步研究可以确定哪些患者可以从特定的成像模式中受益,以识别和监测转移。
Background: Metastatic differentiated thyroid cancer (DTC) represents a molecularly heterogeneous group of cancers with varying radioactive iodine (RAI) and [18F]-fluorodeoxyglucose (FDG) uptake patterns potentially correlated with the degree of de-differentiation through the so-called \"flip-flop\" phenomenon. However, it is unknown if RAI and FDG uptake patterns correlate with molecular status or metastatic site. Materials and Methods: A retrospective analysis of metastatic DTC patients (n = 46) with radioactive 131-iodine whole body scan (WBS) and FDG-PET imaging between 2008 and 2022 was performed. The inclusion criteria included accessible FDG-PET and WBS studies within 1 year of each other. Studies were interpreted by two blinded radiologists for iodine or FDG uptake in extrathyroidal sites including lungs, lymph nodes, and bone. Cases were stratified by BRAF V600E mutation status, histology, and a combination of tumor genotype and histology. The data were analyzed by McNemar\'s Chi-square test. Results: Lung metastasis FDG uptake was significantly more common than iodine uptake (WBS: 52%, FDG: 84%, p = 0.04), but no significant differences were found for lymph or bone metastases. Lung metastasis FDG uptake was significantly more prevalent in the papillary pattern sub-cohort (WBS: 37%, FDG: 89%, p = 0.02) than the follicular pattern sub-cohort (WBS: 75%, FDG: 75%, p = 1.00). Similarly, BRAF V600E+ tumors with lung metastases also demonstrated a preponderance of FDG uptake (WBS: 29%, FDG: 93%, p = 0.02) than BRAF V600E- tumors (WBS: 83%, FDG: 83%, p = 1.00) with lung metastases. Papillary histology featured higher FDG uptake in lung metastasis (WBS: 39%, FDG: 89%, p = 0.03) compared with follicular histology (WBS: 69%, FDG: 77%, p = 1.00). Patients with papillary pattern disease, BRAF V600E+ mutation, or papillary histology had reduced agreement between both modalities in uptake at all metastatic sites compared with those with follicular pattern disease, BRAF V600E- mutation, or follicular histology. Low agreement in lymph node uptake was observed in all patients irrespective of molecular status or histology. Conclusions: The pattern of FDG-PET and radioiodine uptake is dependent on molecular status and metastatic site, with those with papillary histology or BRAF V600E+ mutation featuring increased FDG uptake in distant metastasis. Further study with an expanded cohort may identify which patients may benefit from specific imaging modalities to recognize and surveil metastases.