Positron Emission Tomography (PET) for Staging Low-Grade Non-Hodgkin's Lymphomas (NHL)

Abstract

Although positron emission tomography (PET) imaging is now recognized as a useful tool for staging intermediate and high-grade non-Hodgkin's lymphoma (NHL), few data are available regarding its accuracy in low grade NHL. We therefore studied 36 patients with histologically proven low-grade NHL. Whole-body 2-(fluorine-18) fluoro-2-deoxy-D-glucose (FDG) PET was performed at the time of initial diagnosis (n = 21) or for disease recurrence (n = 15) prior to any treatment. PET results were compared to those of physical examination and computed tomography (CT). PET studies were read without knowledge of any clinical data. Any focus of increased activity was described and given a probability of malignancy using a 5 point-scale (0: normal to 4: definitively malignant). An individual biopsy was available for a total of 31 lesions. The sensitivity and specificity were 87% and 100% for FDG-PET, 100% and 100% for physical examination and 90% and 100% for CT respectively. In addition, 42 of 97 peripheral lymph node lesions observed by FDG-PET were clinically undetected, whereas the physical examination detected 23 additional nodal lesions. PET and CT both indicated 12 extranodal lymphomatous localizations. FDG-PET showed 7 additional extranodal lesions while 5 additional unconfirmed lesions were observed on CT. Regarding bone marrow infiltration, PET and biopsy were concordant in 24 patients with 11 true positive (TP) and 13 true negative (TN). However PET was FN in 11 patients and no biopsy was performed in one patient. The combination PET/CT/physical examination seems to be more sensitive than the conventional approach for staging low grade NHL. Its sensitivity however is unacceptably low for diagnosing bone marrow infiltration.

The usefulness of 18F‐fluorodeoxyglucose positron emission tomography (18F‐FDG‐PET) and a comparison of 18F‐FDG‐pet with 67gallium scintigraphy in the evaluation of lymphoma

“…17,23,24 In the current study, 18 F-FDG-PET detected disease sites with high accuracy in FL, which was in agreement with previous reports. 16,17 However, it should be noted that 18 F-FDG-PET failed to detect sites in all 3 patients who had FL in the duodenum.…”

“…Previous reports also have reported its limited usefulness for staging in SLL, with a sensitivity of approximately 50%. 17,23,24 To our knowledge, there has been only 1 report regarding the utility of 18 F-FDG-PET in SMZL, in which the PET scan showed homogenous but increased uptake (SUV 5 4.2) in the spleen. 17 Con- 10-12 but low in indolent lymphomas (range, 41-56%).…”

The role of 18F‐FDG PET/CT imaging in Waldenstrom macroglobulinemia

“…Whole body positron emission tomography (PET) with fluorine-18-fluorodeoxyglucose ( 18 F-FDG) is a functional imaging modality that has become the clinical standard for staging and assessing treatment response in patients with both Hodgkin and aggressive non-Hodgkin lymphoma [10][11][12][13][14]. Combined FDG-PET/CT has also been shown to be more accurate than PET alone or CT alone in the staging, restaging of patients with indolent lymphomas [13,15,16].…”

“…Combined FDG-PET/CT has also been shown to be more accurate than PET alone or CT alone in the staging, restaging of patients with indolent lymphomas [13,15,16]. To our knowledge, to date, no study has investigated the value of FDG-PET specifically in the patient population of WM.…”

Utilidad de la deoxiglucosa marcada con flúor-18 (FDG) en el manejo de los linfomas

“…Además, en 80% de 105 de esos casos hubo concordancia con el informe de biopsia de médu-la ósea. La FDG, según Najjar y cols 9 , tiene sensibilidad de 83% y especificidad de 100%, similar a la obtenida con tomografía computada (TC) en la evaluación de linfomas de bajo grado.…”