Al-Nahhas A, Win Z, Al-Sayed Y, Khan S, Singh A, Rubello D, Gishen P
Department of Nuclear Medicine, Hammersmith Hospital, London, UK.
Q J Nucl Med Mol Imaging. 2007 Sep;51(3):251-9. Epub 2007 Jun 1.
Lymphoma has become one of the most successfully treated malignancies. The success of treatment and long-term prognosis depend on accurate staging in which imaging plays a pivotal role. In addition to staging, imaging assists in the evaluation of early and late response to therapy, detecting disease activity in a residual mass and locating sites of recurrence. The mainstay of imaging remains computed tomography (CT), which has replaced lymphangiography, and staging laparotomy. Magnetic resonance imaging (MRI) has additional value in detecting disease in bone marrow, the musculoskeletal and central nervous system. Recent technical developments in CT and MRI have improved acquisition times and resolution, but the main drawback of cross-sectional imaging techniques is their reliance on size criteria to define disease, with consequent failure to detect disease in small lymph nodes and exclude disease in large, but treated, masses. Diffuse visceral involvement is likewise difficult to detect by both modalities. Functional imaging with nuclear medicine techniques offers an answer to these problems. Imaging with the fluorinated glucose analogue, [18F]FDG positron emission tomography (PET), can detect metabolically active disease by its increased glycolysis that is proportional to mitotic activity. It can separate high from low-grade tumors and aid in prognostication. Recent publications suggest that imaging with [18F]FDG PET should be an important component in staging; assessment of response to therapy and restaging. Like other imaging modalities, it has its own drawbacks including inability to detect very small lesions (<5 mm) and reduced specificity due to increased uptake in metabolically active inflammatory and infective tissues. The new generation of hybrid PET-CT combines anatomical and functional imaging and is considered the state-of-the-art imaging technique for the assessment of lymphoma and other malignancies.
淋巴瘤已成为治疗最为成功的恶性肿瘤之一。治疗的成功及长期预后取决于准确分期，而影像学在其中起着关键作用。除分期外，影像学有助于评估治疗的早期和晚期反应，检测残留肿块中的疾病活性以及确定复发部位。影像学的主要手段仍是计算机断层扫描（CT），它已取代了淋巴管造影和分期剖腹术。磁共振成像（MRI）在检测骨髓、肌肉骨骼和中枢神经系统疾病方面具有额外价值。CT和MRI的最新技术发展改善了采集时间和分辨率，但横断面成像技术的主要缺点是依赖大小标准来定义疾病，从而无法检测到小淋巴结中的疾病，也无法排除大的但已接受治疗的肿块中的疾病。弥漫性内脏受累同样难以通过这两种方式检测到。核医学技术的功能成像为这些问题提供了答案。使用氟化葡萄糖类似物[18F]FDG正电子发射断层扫描（PET）成像，可以通过其增加的糖酵解来检测代谢活跃的疾病，这种糖酵解与有丝分裂活性成正比。它可以区分高级别和低级别肿瘤，并有助于预后评估。最近的出版物表明，[18F]FDG PET成像应成为分期、评估治疗反应和再分期的重要组成部分。与其他成像方式一样，它也有自身的缺点，包括无法检测到非常小的病变（<5mm）以及由于代谢活跃的炎症和感染组织摄取增加而导致特异性降低。新一代的PET-CT融合了解剖学和功能成像，被认为是评估淋巴瘤和其他恶性肿瘤的最先进成像技术。
