Role of fluorine‐18 fluoro‐deoxyglucose positron emission tomography scan in the evaluation and follow‐up of patients with low‐grade lymphomas

Abstract

BACKGROUND Fluorine‐18 fluoro‐deoxyglucose positron emission tomography (FDG‐PET) scanning has excellent sensitivity and specificity for staging non‐Hodgkin lymphomas, but to the authors' knowledge few studies to date have evaluated FDG‐PET in low‐grade lymphomas only. METHODS A retrospective study was performed on patients with biopsy‐proven nontransformed and transformed follicular lymphoma (FL), B‐cell small‐cell lymphocytic lymphoma (SLL/CLL), or marginal zone lymphoma (MZL) who underwent PET and computed tomography (CT) scans within 3 weeks. Standard uptake values (SUV) of all abnormal foci were measured. RESULTS In FL, PET demonstrated 94% sensitivity and 100% specificity for staging. PET was more specific than CT for detecting recurrence or assessing therapeutic responses (91% vs. 50%). FDG avidity among patients with WHO Grades 1, 2, and 3 disease was not significantly different (analysis of variance [ANOVA]). For MZL staging, PET had moderate sensitivity (71%) and outperformed CT alone in the depiction of extranodal sites (85% vs. 57% sensitivity). In SLL/CLL, PET sensitivity was 53% and underestimated disease extent in 5 of 19 patients (26%) compared with CT. PET did not affect initial management but confirmed suspected recurrences in 75% of patients. Nontransformed FL had a higher SUV (ANOVA, P<.05) compared with MZL and SLL/CLL. SUV was higher in transformed than in nontransformed tumors (P<.001, Student t test). CONCLUSIONS PET usefulness in staging low‐grade lymphomas varies depending on histology. PET sensitivity is excellent in FL and moderate in MZL. PET is more specific than CT for follow‐up in all types. PET has limited usefulness for SLL/CLL staging. However, a suggestive pattern of hazy and mild uptake was often noted in positive scans. In all low‐grade lymphomas, the emergence of foci of intense uptake should raise suspicion of conversion to high‐grade disease. Cancer 2006. © 2006 American Cancer Society.

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. Hoffmann et al reported similar results in 7 patients with primary duodenal FL.…”

“…This is similar to the clinical observation that outcomes do not differ significantly between these 2 categories. 17 However, this information would be important for patients with grade 3 FL, because it is believed that these patients to have a more aggressive clinical course and to need more aggressive treatment. However, neither the disease site detection rate nor the SUV differed between grade 3 and grades 1 or 2.…”

“…1,2 There have been several reports comparing the usefulness of 18 F-FDG-PET with conventional imaging modalities, such as computed tomography (CT) and 67 Ga for detecting tumors, [10][11][12][13] and examining the relations between 18 F-FDG-PET and histologic subtypes based on the World Health Organization (WHO) classification system. [15][16][17][18] However, those studies were not systematic, and they involved relatively small numbers of patients. [9][10][11][12][13][14] Comparisons between 18 F-FDG-PET and conventional imaging modalities using large numbers of patients would help to further our understanding of the biologic differences between lymphoma cell types, establish guidelines for the selection of appropriate clinical management, and verify the clinical relevance of lymphoma classification systems.…”

Small Lymphocytic Lymphoma Obscuring Microscopic Tonsillar Squamous Cell Carcinoma: an Unknown Occurrence with a Known Primary

“…Microscopic primary tumors as the one presented here likely account for many PET false negatives. The reported PET accuracy in detecting CLL/SLL is even lower [29]. None of the two neoplasms were identified by PET in our patient, either at the primary site or in the cervical lymph nodes.…”

SIE, SIES, GITMO revised guidelines for the management of follicular lymphoma

“…Published literature includes 10 retrospective analyses [9][10][11][12][13][14][15][16][17][18] and 1 prospective one [19]: pooled analysis of 356 patients revealed that 24% were upstaged from Stage I-II to Stage III-IV. Baseline PET also showed to have a high prognostic value, irrespective of FLIPI [10,11,17,19].…”