Bhutani M, Landgren O
Multiple Myeloma Section, Lymphoid Malignancies Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, 9000 Rockville Pike, Building 10/Room 13N240, 20892, Bethesda, MD, USA.
Radiologe. 2014 Jun;54(6):572, 574-81. doi: 10.1007/s00117-014-2694-7.
Emerging clinical trial data support treatment of high-risk smoldering multiple myeloma (SMM) upon diagnosis, and not only at the time of progression to symptomatic complications (multiple myeloma). Early detection of bone and/or bone marrow involvement by sensitive imaging modalities may help define SMM patients at a high risk of progression.
Current (2011) consensus guidelines recognize skeletal survey as a cornerstone modality for assessment of bone involvement at initial diagnosis and during follow-up of SMM. Skeletal survey has severe limitations related to underdetection of bone lesions and also provides no information on bone marrow abnormalities.
Modern imaging strategies such as fluorodeoxyglucose positron-emission tomography/CT (FDG PET/CT) and MRI, in conjunction with functional innovations, provide improved estimates of global abnormalities in the bone marrow and bone compartments. These methods have the potential to objectively quantify early transformation from SMM to multiple myeloma.
Although frequently used for staging and risk prognostication in multiple myeloma, modern imaging techniques have only been evaluated to a limited extent in SMM. Scant data in SMM indicate the prognostic value of two or more MRI-detected focal bone marrow abnormalities, which, if present, predict rapid progression to multiple myeloma. Data evaluating the role of FDG PET/CT in detecting early bone marrow abnormalities as an aid to predicting risk or directing treatment in SMM is currently lacking.
The superior specificity and sensitivity of modern imaging techniques compared to skeletal survey suggest that these should have a place in standard practice management of patients at a high risk of SMM progression. The model imaging of the future should be an all-in-one strategy offering high diagnostic performance for bone marrow abnormalities and low-volume bone lesions, as well as allowing monitoring by minimizing radiation exposure and the need for contrast agents.
Newer imaging techniques need to be validated in prospective clinical trials assessing the SMM to multiple myeloma transition, with the aim of enabling appropriate management decisions. Efforts are also needed to improve the costs and availability of whole-body MRI and/or FDG PET/CT, in order to facilitate their widespread adoption as first-line detection modalities. Future clinical trials of therapeutic agents using earlier detection strategies will have to be carefully designed and take into consideration the risk of lead-time and length-time biases, which might falsely demonstrate longer overall survival. The English full text version of this article is available at SpringerLink (under "Supplemental").
新出现的临床试验数据支持对高危冒烟型多发性骨髓瘤（SMM）在诊断时进行治疗，而不仅是在进展为有症状并发症（多发性骨髓瘤）时才治疗。通过敏感的成像方式早期检测骨骼和/或骨髓受累情况，可能有助于确定有高进展风险的SMM患者。
当前（2011年）的共识指南认可骨骼X线检查是SMM初始诊断及随访期间评估骨骼受累情况的基础检查方式。骨骼X线检查存在与骨病变漏诊相关的严重局限性，且无法提供有关骨髓异常的信息。
现代成像策略，如氟脱氧葡萄糖正电子发射断层扫描/计算机断层扫描（FDG PET/CT）和磁共振成像（MRI），结合功能创新，能更好地评估骨髓和骨腔的整体异常情况。这些方法有潜力客观量化SMM向多发性骨髓瘤的早期转变。
尽管现代成像技术常用于多发性骨髓瘤的分期和风险预后评估，但在SMM中仅得到有限评估。SMM中少量数据表明，MRI检测到两个或更多局灶性骨髓异常具有预后价值，若存在此类异常，则预示着快速进展为多发性骨髓瘤。目前缺乏评估FDG PET/CT在检测早期骨髓异常以辅助预测SMM风险或指导治疗方面作用的数据。
与骨骼X线检查相比，现代成像技术具有更高的特异性和敏感性，这表明这些技术在SMM高进展风险患者的标准实践管理中应占有一席之地。未来的理想成像模式应是一种一体化策略，对骨髓异常和小体积骨病变具有高诊断性能，同时通过减少辐射暴露和造影剂需求实现监测。
需要在前瞻性临床试验中验证更新的成像技术，这些试验旨在评估SMM向多发性骨髓瘤的转变，以便做出适当的管理决策。还需要努力降低全身MRI和/或FDG PET/CT的成本并提高其可及性，以促进它们作为一线检测方式的广泛应用。未来使用早期检测策略的治疗药物临床试验必须精心设计，并考虑提前期和长期偏差的风险，这可能会错误地显示更长的总生存期。本文的英文全文版本可在SpringerLink（“补充材料”项下）获取。
