Diffusion‐weighted MRI in early chemotherapy response evaluation of patients with diffuse large B‐cell lymphoma – a pilot study: comparison with 2‐deoxy‐2‐fluoro‐ D‐glucose‐positron emission tomography/computed tomography

Abstract

To determine the feasibility of diffusion-weighted MRI (DWI) in the evaluation of the early chemotherapeutic response in patients with aggressive non-Hodgkin's lymphoma (NHL), eight patients with histologically proven diffuse large B-cell lymphoma were imaged by MRI, including DWI, and positron emission tomography/computed tomography (PET/CT) before treatment (E1), and after 1 week (E2) and two cycles (E3) of chemotherapy. In all patients, whole-body screening using T(1) - and T(2) -weighted images in the coronal plane was performed. To quantitatively evaluate the chemotherapeutic response, axial images including DWI were acquired. Apparent diffusion coefficient (ADC) maps were reconstructed, and the ADC value of the tumor was measured. In addition, the tumor volume was estimated on axial T(2) -weighted images. The maximum standardized uptake value (SUV(max) ) and active tumor volume were measured on fused PET/CT images. Lymphomas showed high signal intensity on DW images and low signal intensity on ADC maps, except for necrotic foci. The mean pre-therapy ADC was 0.71 × 10(-3) mm(2) /s; it increased by 77% at E2 (p < 0.05) and 24% more at E3 (insignificant); the total increase was 106% (p < 0.05). The mean tumor volume by MRI was 276 mL at baseline; it decreased by 58% at E2 (p < 0.05) and 65% more at E3 (p < 0.05), giving a total decrease of 84% (p < 0.05). All the imaged pre-therapy tumors were strongly positive on PET/CT, with a mean SUV(max) of 20. The SUV(max) decreased by 60% at E2 (p < 0.05) and 59% more at E3 (p < 0.05), giving a total decrease of 83% (p < 0.05). The active tumor burden decreased by 66% at E2 (p < 0.05). At baseline, both central and peripheral tumor ADC values correlated inversely with SUV(max) (p < 0.05), and also correlated inversely with active tumor burden on PET/CT and with tumor volume on MRI at E2 (p < 0.05). In conclusion, the results of DWI in combination with whole-body MRI were comparable with those of integrated PET/CT.

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).…”

Diffusion-Weighted Imaging for Predicting and Monitoring Primary Central Nervous System Lymphoma Treatment Response

“…17 ADC has shown promise in the prognostication of response to therapy for non-Hodgkin lymphoma, even if not technically in the central nervous system. 18 DWI-derived ADC values provide an opportunity to quantitatively and serially follow treatment-induced changes in PCNSL, and specifically, ADCmin values were more powerful than ADC mean or ADC 25% values. 5 Here, we aimed to confirm the validity of ADCmin measurement as an imaging biomarker of therapy response in immunocompetent patients with PCNSL.…”

Evaluation of Whole Body DiffusionWeighted Imaging in the Staging and Treatment Response of Lymphoma Compared With Fluoride-Oxyglucose (FDG) PET/CT as a Reference Standard

“…3,4 However, PET/CT is expensive, time-consuming, requires exposure to ionizing radiation and is not widely available as it involves the use of a cyclotron. 5 In addition, FDG is not entirely cancer-specific; brown fat, muscle tissue and other factors such as infection, inflammation and granulomatous disease can also demonstrate increased FDG uptake. On the other hand, magnetic resonance imaging (MRI) although expensive, does not involve exposure to ionizing radiation, is more widely available and provides excellent soft tissue contrast.…”