Nuclear Medicine Service, Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA.
J Nucl Med. 2010 Sep;51(9):1361-7. doi: 10.2967/jnumed.110.075960. Epub 2010 Aug 18.
The objective of this study was to determine whether posttherapy (131)I SPECT/CT changed the need for additional cross-sectional imaging or modified the American Thyroid Association risk of recurrence classification. We performed planar imaging and SPECT/CT in a consecutive series of patients after (131)I therapy.
Planar imaging and SPECT/CT were performed on 148 consecutive patients with thyroid carcinoma (125 papillary, 2 follicular, 8 Hürthle cell, and 13 poorly differentiated) approximately 5 d after the therapeutic administration of 1,739-8,066 MBq (47-218 mCi) of (131)I. The indication for treatment was postsurgical ablation (n = 109) or recurrent or metastatic disease with rising thyroglobulin levels (n = 39). SPECT/CT scans were obtained for all subjects for 1 bed position (38 cm), which included the neck and upper chest. Additional SPECT/CT scans of the abdomen or pelvis were acquired if suggestive findings were noted on planar images. All patients were treated in real time, according to the standard of care in our practice. At that time, clinical decisions regarding thyroid tumor classification were made by our multidisciplinary group based on all data, including operative findings, pathology, imaging, and thyroglobulin levels. In a retrospective analysis, planar and SPECT/CT images were interpreted independently, and sites of uptake were categorized as likely benign, malignant, or equivocal. An experienced thyroid endocrinologist used a combination of surgical histopathology and scan findings to determine whether additional cross-sectional imaging was required and determined if the imaging findings changed the patient's risk category.
In 29 patients, 61 additional cross-sectional imaging studies were avoided using SPECT/CT, compared with medical decision making based on the planar images alone. In 7 of 109 postsurgical patients, SPECT/CT findings changed the initial American Thyroid Association risk of recurrence classification. The sensitivity of planar imaging and SPECT/CT for identification of focal (131)I uptake in the thyroid bed was similar in the postsurgical and recurrence cohorts. For metastatic disease in the neck, characterization of (131)I uptake by SPECT/CT in the postsurgical group was significantly better than that by planar scanning (P < 0.01). Among the 109 postsurgical patients, the characterization of iodine uptake in the lung, liver, and bone was also more accurate using SPECT/CT than planar scanning (P < 0.01). The CT portion of SPECT/CT demonstrated non-iodine-avid lesions in 32 of 148 patients.
SPECT/CT data provided information that reduced the need for additional cross-sectional imaging in 29 patients (20%) and significantly altered the initial risk of recurrence estimates in 7 of 109 patients (6.4%), thereby altering patient management recommendations with regard to frequency and intensity of follow-up studies.
本研究旨在确定治疗后碘-131（131）SPECT/CT 是否改变了对额外横断面成像的需求或修改了美国甲状腺协会（ATA）复发风险分类。我们对接受 131I 治疗后的连续一系列患者进行了平面成像和 SPECT/CT 检查。
对 148 例甲状腺癌（125 例乳头状、2 例滤泡状、8 例 Hurthle 细胞、13 例低分化）患者进行了 131I 治疗后 5 天左右的平面成像和 SPECT/CT 检查。治疗的指征是术后消融（n=109）或复发或转移性疾病伴甲状腺球蛋白水平升高（n=39）。所有患者均进行了 1 个床位位置（38cm）的 SPECT/CT 扫描，包括颈部和上胸部。如果平面图像上有提示性发现，则获取腹部或骨盆的额外 SPECT/CT 扫描。根据我们实践中的标准，所有患者均实时接受治疗。当时，我们的多学科小组根据所有数据（包括手术发现、病理学、影像学和甲状腺球蛋白水平）对甲状腺肿瘤分类做出临床决策。在回顾性分析中，独立解读平面和 SPECT/CT 图像，并将摄取部位归类为可能良性、恶性或不确定。一位经验丰富的甲状腺内分泌专家结合手术组织病理学和扫描结果，确定是否需要进行额外的横断面成像，并确定影像学结果是否改变了患者的风险类别。
与仅基于平面图像的医学决策相比，SPECT/CT 在 29 例患者中避免了 61 例额外的横断面成像研究。在 109 例术后患者中的 7 例中，SPECT/CT 结果改变了初始 ATA 复发风险分类。在术后和复发组中，平面成像和 SPECT/CT 检测甲状腺床焦点（131）I 摄取的敏感性相似。对于颈部的转移性疾病，SPECT/CT 对术后组（131）I 摄取的特征比平面扫描更好（P<0.01）。在 109 例术后患者中，SPECT/CT 对肺、肝和骨中的碘摄取的特征也比平面扫描更准确（P<0.01）。SPECT/CT 的 CT 部分在 148 例患者中的 32 例中显示了非碘摄取性病变。
SPECT/CT 数据提供的信息减少了 29 例患者（20%）对额外横断面成像的需求，并显著改变了 7 例患者（6.4%）的初始复发风险估计，从而改变了患者管理建议，包括随访研究的频率和强度。
