Diffusion-weighted MRI for staging and evaluation of response in diffuse large B-cell lymphoma: a pilot study

Abstract

Purpose To compare diffusion-weighted magnetic resonance imaging (DW-MRI) with positron emission tomography/computed tomography (PET/CT) for staging and evaluating treatment response in patients with diffuse large B-cell lymphoma (DLBCL). Materials and Methods Institutional review board approval was obtained for this study; all subjects gave informed consent. Twelve patients were imaged before treatment and 8 of these also were imaged after two cycles of chemotherapy using both DW-MRI and PET/CT. Up to six target lesions were selected at baseline for response assessment based on International Working Group criteria (nodes >1.5 cm long diameter and extranodal lesions >1cm long diameter). For pretreatment staging, visual analysis of the numbers of nodal and extranodal lesions based on PET/CT was performed. For interim response assessment after cycle 2 of chemotherapy, residual tumor sites were assessed visually and percentage changes in target lesion size, maximum standardized uptake value (SUVmax) and apparent diffusion coefficient (ADC) from pretreatment values were calculated. Results In 12 patients studied pretreatment, there were 46 nodal and 16 extranodal sites of lymphomatous involvement. Agreement between DW-MRI and PET/CT for overall lesion detection was 97% (60/62 tumor sites; 44/46 nodal and 16/16 extranodal lesions) and for Ann Arbor stage it was 100%. In the 8 patients who had interim assessment, 5 of their 49 tumor sites remained abnormal on visual analysis of both DW-MRI and PET/CT and there was one false-positive on DW-MRI. Of their 24 target lesions, mean pretreatment ADC value, tumor size and SUVmax were 772 μm2/s, 21.3 cm2 and 16.9 g/mL, respectively. At interim assessment of the same 24 target lesions, ADC values increased by 85% tumor size decreased by 74%, and SUVmax decreased by 83% (all p<0.01 versus baseline). Conclusion DW-MRI provides results comparable to those of PET/CT for staging and early response assessment in patients with DLBCL.

Evaluation of Diffusion-Weighted Magnetic Resonance Imaging for Follow-up and Treatment Response Assessment of Lymphoma: Results of an 18F-FDG-PET/CT–Controlled Prospective Study in 64 Patients

“…The results of our study suggest that DWI-MRI is almost equal to 18F-FDG PET/CT for follow-up and therapy response assessment in patients with lymphoma, in accordance with the results of previous smaller-sized studies (13)(14)(15)(16)(17)(18)(19)(20). This is of interest, because only the image pattern, but not the underlying information (i.e., tumor property) assessed is similar between the two techniques: DWI visualizes intercellular space narrowing, and thus, cell density (35); whereas 18F-FDG-PET visualizes glucose metabolism, which in turn has been shown to correlate with cell proliferation (36,37).…”

“…[13][14][15][16][17][18][19], or a retrospective design (20). In addition, these studies included almost exclusively patients with diffuse large B-cell lymphoma (DLBCL) and Hodgkin lymphoma-there are practically no data for indolent nonHodgkin lymphomas (NHL).…”

“…In addition, these studies included almost exclusively patients with diffuse large B-cell lymphoma (DLBCL) and Hodgkin lymphoma-there are practically no data for indolent nonHodgkin lymphomas (NHL). Finally, almost all previous studies focused on treatment-induced changes of apparent diffusion coefficients (ADC) in target lesions (14)(15)(16)(17)(18)(19); only a single study in 15 DLBCL patients directly compared DWI with 18F-FDG-PET/ CT in terms of detection of residual lymphoma after therapy (13), albeit without further subcategorization of the response status (i.e., complete or partial remission, stable disease, or progression).…”

PET Scan in Hodgkin Lymphoma

“…Thus, these data did not support the replacement of FDG-PET with DW-MRI for response evaluation in lymphoma patients [175]. In other cohorts, DW-MRI provided results comparable with or complementary to those of PET/CT for staging and early response assessment in DLBCL [178][179][180]. There is also pilot data showing that the accuracy of DWI was significantly higher than that with PET/CT for mediastinal and hilar lymphadenopathy in differentiating between malignant and benign conditions [177].…”

Diagnostic accuracy of diffusion‐weighted imaging‐ magnetic resonance imaging compared to positron emission tomography/computed tomography in evaluating and assessing pathological response to treatment in adult patients with lymphoma: A systematic review

“…All studies in this systematic review were prospective studies. Three papers limited their study to DLBCL (Lin et al, 20 Siegel et al, 21 Wu et al 19 ), whereas the remaining studies contained more than one type of lymphoma. Three papers limited their study to DLBCL (Lin et al, 20 Siegel et al, 21 Wu et al 19 ), whereas the remaining studies contained more than one type of lymphoma.…”