False-Positive [18F]Fluorodeoxyglucose-Avid Lymph Nodes on Positron Emission Tomography–Computed Tomography After Allogeneic but Not Autologous Stem-Cell Transplantation in Patients With Lymphoma
Menée sur 251 patients atteints de lymphome et ayant reçu une greffe de cellules souches entre 2005 et 2009, cette étude montre que des ganglions lymphatiques sans lésion maligne peuvent être faussement détectés positifs par une tomographie numérique par émission de positrons à base de fluorodésoxyglucose (18F) chez les patients dont la greffe est allogénique, mais pas chez les patients dont la greffe est autologue
Purpose : Determine the clinical significance of [18F]fluorodeoxyglucose (FDG)–avid lesions in patients with lymphoma treated with stem-cell transplantation.
Methods : All patients who underwent stem-cell transplantation for lymphoma at Memorial Sloan-Kettering Cancer Center between January 2005 and December 2009 and had post-transplantation FDG positron emission tomography/computed tomography (PET/CT) examinations were included. PET/CT examinations were evaluated for FDG-avid lesions suggestive of disease. Clinical records, biopsy results, and subsequent imaging examinations were evaluated for malignancy.
Results : Two hundred fifty-one patients were identified, 107 with allogeneic and 144 with autologous stem-cell transplantation. Of allogeneic stem-cell transplantation recipients, 50 had FDG-avid lesions suggestive of lymphoma, defined as FDG-avidity greater than liver background. However, only 29 of these 50 demonstrated lymphoma on biopsy, whereas biopsy attempts were benign in the other 21 patients. Sensitivity analysis determined that a 1.5-cm short axis nodal measurement distinguished patients with malignant from nonmalignant biopsies. In 21 of 22 patients with FDG-avid lymph nodes ≤ 1.5 cm, biopsy attempts were benign. In the absence of treatment, these nodes either resolved or were stable on repeat imaging. Disease-free survival of patients with FDG-avid ≤ 1.5 cm lymph nodes was comparable with patients without FDG-avid lesions. In comparison, autologous stem-cell transplantation patients rarely demonstrated FDG-avid lesions suggestive of disease without malignant pathology.
Conclusion : Twenty percent (21 of 107) of patients with an allogeneic stem-cell transplantation demonstrated FDG-avid lymph nodes up to 1.5 cm in short axis on PET/CT, which did not represent active lymphoma. After allogeneic stem-cell transplantation of patients with lymphoma, benign FDG-avid ≤ 1.5 cm lymph nodes can mimic malignancy.
Journal of Clinical Oncology , résumé, 2013