Department of Radiology, The Royal Marsden Hospital, 203 Fulham Rd, London, England, SW3 6JJ, UK.
Department of Radiology, The Royal Marsden Hospital, Downs Rd, Sutton, England, SM2 5PT, UK.
Eur Radiol. 2022 Sep;32(9):6514-6525. doi: 10.1007/s00330-022-08714-6. Epub 2022 Apr 6.
Invasive lobular breast carcinomas (ILC) account for approximately 15% of breast cancer diagnoses. They can be difficult to diagnose both clinically and radiologically, due to their infiltrative growth pattern. The pattern of metastasis of ILC is unusual, with spread to the serosal surfaces (pleura and peritoneum), retroperitoneum and gastrointestinal (GI)/genitourinary (GU) tracts and a higher rate of leptomeningeal spread than IDC. Routine staging and response assessment with computed tomography (CT) can be undertaken quickly and measurements can be reproduced easily, but this is challenging with metastatic ILC as bone-only/bone-predominant patterns are frequently seen and assessment of the disease status is limited in these scenarios. Functional imaging such as whole-body MRI (WBMRI) allows the assessment of bone and soft tissue disease by providing functional information related to differences in cellular density between malignant and benign tissues. A number of recent studies have shown that WBMRI can detect additional sites of disease in metastatic breast cancer (MBC), resulting in a change in systemic anti-cancer therapy. Although WBMRI and fluorodeoxyglucose-positron-emission tomography-computed tomography (FDG-PET/CT) have a comparable performance in the assessment of MBC, WBMRI can be particularly valuable as a proportion of ILC are non-FDG-avid, resulting in the underestimation of the disease extent. In this review, we explore the added value of WBMRI in the evaluation of metastatic ILC and compare it with other imaging modalities such as CT and FDG-PET/CT. We also discuss the spectrum of WBMRI findings of the different metastatic sites of ILC with CT and FDG-PET/CT correlation. KEY POINTS: • ILC has an unusual pattern of spread compared to IDC, with metastases to the peritoneum, retroperitoneum and GI and GU tracts, but the bones and liver are the commonest sites. • WBMRI allows functional assessment of metastatic disease, particularly in bone-only and bone-predominant metastatic cancers such as ILC where evaluation with CT can be challenging and limited. • WBMRI can detect more sites of disease compared with CT, can reveal disease progression earlier and provides the opportunity to change ineffective systemic treatment sooner.
浸润性小叶乳腺癌（ILC）约占乳腺癌诊断的 15%。由于其浸润性生长模式，无论是在临床还是影像学上，都难以诊断。ILC 的转移模式不同寻常，会扩散到浆膜表面（胸膜和腹膜）、腹膜后和胃肠道（GI）/泌尿生殖系统（GU），并且软脑膜扩散的发生率高于 IDC。使用计算机断层扫描（CT）进行常规分期和反应评估可以快速进行，并且可以轻松地重复测量，但在转移性 ILC 中，这具有挑战性，因为经常看到仅骨/以骨为主的模式，并且在这些情况下评估疾病状态受到限制。全身磁共振成像（WBMRI）等功能成像可以通过提供与恶性和良性组织之间细胞密度差异相关的功能信息来评估骨和软组织疾病。最近的一些研究表明，WBMRI 可以在转移性乳腺癌（MBC）中检测到更多的疾病部位，从而改变全身抗癌治疗。尽管 WBMRI 和氟代脱氧葡萄糖正电子发射断层扫描-计算机断层扫描（FDG-PET/CT）在评估 MBC 方面具有相当的性能，但 WBMRI 特别有价值，因为一部分 ILC 是非 FDG-avid 的，导致疾病范围的低估。在这篇综述中，我们探讨了 WBMRI 在评估转移性 ILC 中的附加价值，并将其与 CT 和 FDG-PET/CT 等其他成像方式进行了比较。我们还讨论了 WBMRI 与 CT 和 FDG-PET/CT 相关的 ILC 不同转移部位的影像学表现。要点： • ILC 的播散模式与 IDC 不同，转移到腹膜、腹膜后和 GI 和 GU 道，但骨骼和肝脏是最常见的部位。 • WBMRI 允许对转移性疾病进行功能评估，特别是在 CT 评估具有挑战性和局限性的情况下，如 ILC 中仅骨/以骨为主的转移性癌症。 • WBMRI 与 CT 相比，可以检测到更多的疾病部位，可以更早地发现疾病进展，并提供更早改变无效全身治疗的机会。
