Molecular Imaging and Therapy, Hoag Family Cancer Institute, Newport Beach, California
Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York.
J Nucl Med. 2021 Mar;62(3):326-331. doi: 10.2967/jnumed.120.247882. Epub 2020 Jul 17.
Invasive lobular carcinoma (ILC) demonstrates lower conspicuity on F-FDG PET than the more common invasive ductal carcinoma. Other molecular imaging methods may be needed for evaluation of this malignancy. As ILC is nearly always (95%) estrogen receptor (ER)-positive, ER-targeting PET tracers such as 16α-F-fluoroestradiol (F-FES) may have value. We reviewed prospective trials at Memorial Sloan Kettering Cancer Center using F-FES PET/CT to evaluate metastatic ILC patients with synchronous F-FDG and F-FES PET/CT imaging, which allowed a head-to-head comparison of these 2 PET tracers. Six prospective clinical trials using F-FES PET/CT in patients with metastatic breast cancer were performed at Memorial Sloan Kettering Cancer Center from 2008 to 2019. These trials included 92 patients, of whom 14 (15%) were of ILC histology. Seven of 14 patients with ILC had F-FDG PET/CT performed within 5 wk of the research F-FES PET/CT and no intervening change in management. For these 7 patients, the F-FES and F-FDG PET/CT studies were analyzed to determine the total number of tracer-avid lesions, organ systems of involvement, and SUV of each organ system for both tracers. In the 7 comparable pairs of scans, there were a total of 254 F-FES-avid lesions (SUV, 2.6-17.9) and 111 F-FDG-avid lesions (SUV, 3.3-9.9) suggestive of malignancy. For 5 of 7 (71%) ILC patients, F-FES PET/CT detected more metastatic lesions than F-FDG PET/CT. In the same 5 of 7 patients, the SUV of F-FES-avid lesions was greater than the SUV of F-FDG-avid lesions. One patient had F-FES-avid metastases with no corresponding F-FDG-avid metastases. There were no patients with F-FDG-avid distant metastases without F-FES-avid distant metastases, although in one patient liver metastases were evident on F-FDG but not on F-FES PET. F-FES PET/CT compared favorably with F-FDG PET/CT for detection of metastases in patients with metastatic ILC. Larger prospective trials of F-FES PET/CT in ILC should be considered to evaluate ER-targeted imaging for clinical value in patients with this histology of breast cancer.
浸润性小叶癌（ILC）在 F-FDG PET 上的显影低于更常见的浸润性导管癌。可能需要其他分子成像方法来评估这种恶性肿瘤。由于 ILC 几乎总是（95%）雌激素受体（ER）阳性，因此 ER 靶向 PET 示踪剂，如 16α-F-氟雌二醇（F-FES）可能具有价值。我们回顾了纪念斯隆凯特琳癌症中心使用 F-FES PET/CT 评估转移性 ILC 患者的前瞻性试验，这些患者同时进行 F-FDG 和 F-FES PET/CT 成像，这使得这两种 PET 示踪剂可以进行头对头比较。 2008 年至 2019 年，纪念斯隆凯特琳癌症中心共进行了 6 项使用 F-FES PET/CT 治疗转移性乳腺癌患者的前瞻性临床试验。这些试验共纳入 92 例患者，其中 14 例（15%）为 ILC 组织学。14 例 ILC 患者中有 7 例在研究 F-FES PET/CT 后 5 周内进行了 F-FDG PET/CT 检查，且在此期间无治疗干预。对于这 7 例患者，对 F-FES 和 F-FDG PET/CT 研究进行了分析，以确定两种示踪剂的总示踪剂阳性病变数量、受累器官系统和每个器官系统的 SUV。 在这 7 对可比较的扫描中，共有 254 个 F-FES 阳性病变（SUV，2.6-17.9）和 111 个 F-FDG 阳性病变（SUV，3.3-9.9）提示恶性肿瘤。在 7 例 ILC 患者中的 5 例中，F-FES PET/CT 检测到的转移性病变多于 F-FDG PET/CT。在这 5 例相同的患者中，F-FES 阳性病变的 SUV 大于 F-FDG 阳性病变的 SUV。1 例患者有 F-FES 阳性转移灶，而无相应的 F-FDG 阳性转移灶。虽然在一名患者中，F-FDG 显示肝脏转移，但 F-FES PET 未显示，但没有患者 F-FDG 阳性的远处转移灶无 F-FES 阳性的远处转移灶。F-FES PET/CT 与 F-FDG PET/CT 相比，在检测转移性 ILC 患者的转移灶方面具有优势。应考虑对 ILC 患者进行更大规模的 F-FES PET/CT 前瞻性试验，以评估 ER 靶向成像在这种乳腺癌组织学中的临床价值。
