FDG PET/CT versus CT, MR Imaging, and⁶⁷Ga Scintigraphy in the Posttherapy Evaluation of Malignant Lymphoma

Abstract

Malignant lymphoma is the most common form of hematologic cancer, yet because of advanced methods of assessment, the traditional histology-based classification of lymphoma is insufficient for understanding lymphoma imaging. Still, radiologists should be familiar with the imaging findings in lymphoma. Integrated positron emission tomography (PET)-computed tomography (CT) allows improved diagnostic accuracy, and uptake of 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG) can help predict response during treatment. The sensitivity and specificity of FDG PET are superior to those of gallium 67 scintigraphy in all but indolent lymphoma. Both magnetic resonance (MR) imaging and CT allow excellent assessment of bone texture, but FDG PET is superior in demonstrating bone marrow metabolic activity. Thus, FDG PET is important in both the primary diagnosis and the evaluation of therapy in lymphoma. It may be difficult to determine whether residual abnormalities seen after the completion of chemotherapy-radiation therapy represent residual tumor or fibrotic tissue, but PET/CT may allow more accurate diagnosis than MR imaging or CT, thereby helping identify patients who require more intensive treatment. Some diagnostic pitfalls are encountered at FDG PET. However, anatomic CT helps localize and define disease and avoid these potential pitfalls.

Ocena przydatności badań opóźnionych 18F-FDG PET/CT w różnicowaniu zmian łagodnych i złośliwych

“…kilovoltage peak) i rozdzielczości przestrzennej 5mm. Akwizycję PET całego ciała oraz regionu głowy i szyi przeprowadzono badając kolejne odcinki ciała z czasem akwizycji 1min 30 s na odcinek, przy zastosowaniu korekty pochłaniania i korekty rozpadu promieniotwórczego [28][29][30][31][32].…”

Diagnostic and Treatment Response Imaging in Lymphomas

“…Several studies have shown that standardized uptake value correlates with the degree of malignancy in lymphomas, and in patients with NHL and an standardized uptake value greater than 10 are quite likely to have aggressive disease (Okada M et al, 2010). The degree of FDG uptake by lymphoma cells may be a biomarker for disease biology: e.g.…”

18-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in the Management of Aggressive Non-Hodgkin's B-Cell Lymphoma

“…HL and the more aggressive forms of NHL share similar radiologic imaging patterns with the near universal use of combined FDG-PET/CT for assessment [6, 7]. Combined FDG-PET/CT is now considered the most accurate tool for diagnosis, assessment of treatment response, and prognosis in patients with aggressive NHL [8]. There are a number of caveats that one must be aware of when interpreting FDG-PET/CT in the setting of lymphoma.…”