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Whole-body diffusion-weighted imaging in lymphoma.

Lin C, Itti E, Luciani A, Haioun C, Meignan M, Rahmouni A - Cancer Imaging (2010)

Bottom Line: DWI is capable of combining anatomical and functional information and is becoming a valuable tool in oncology, in particular for staging purposes.DWI may prove to be a useful biomarker in clinical decision making for patients with lymphoma.Large-scaled prospective studies are needed to confirm these preliminary results.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Centre Hospitalo-Universitaire Henri Mondor, Avenue du Marechal de Lattre de Tassigny, Créteil, France.

ABSTRACT
The current evidence regarding the usefulness of whole-body diffusion-weighted magnetic resonance imaging (DWI) in lymphoma is reviewed. DWI is capable of combining anatomical and functional information and is becoming a valuable tool in oncology, in particular for staging purposes. DWI may prove to be a useful biomarker in clinical decision making for patients with lymphoma. Large-scaled prospective studies are needed to confirm these preliminary results.

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Whole-body FDG-PET image in maximal intensity projection (left), transverse integrated FDG-PET/CT images (middle two columns) and diffusion-weighted b800 images with ADC map (right) in a 42-year-old patient with diffuse large B-cell lymphoma. DWI and PET/CT show focal lesions (arrows) involving both kidneys. However, the mass protruding into the left renal pelvis (open arrow) is obscured by the physiologic FDG excretion on PET; it is clearly depicted on DWI because of excellent lesion-to-normal renal parenchyma contrast. Note that another lesion on the left kidney (arrowhead on b800 image) and a lymph node (arrowhead on PET image) were both detected by the other imaging technique on adjacent slices (images not shown).
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Figure 4: Whole-body FDG-PET image in maximal intensity projection (left), transverse integrated FDG-PET/CT images (middle two columns) and diffusion-weighted b800 images with ADC map (right) in a 42-year-old patient with diffuse large B-cell lymphoma. DWI and PET/CT show focal lesions (arrows) involving both kidneys. However, the mass protruding into the left renal pelvis (open arrow) is obscured by the physiologic FDG excretion on PET; it is clearly depicted on DWI because of excellent lesion-to-normal renal parenchyma contrast. Note that another lesion on the left kidney (arrowhead on b800 image) and a lymph node (arrowhead on PET image) were both detected by the other imaging technique on adjacent slices (images not shown).

Mentions: We have conducted a prospective pilot study of 15 patients with histologically proven diffuse large B-cell lymphoma (DLBCL) using the whole-body respiratory-gated DWI[26]. Among them, 2 patients had concomitant DLBCL and a follicular lymphoma component. FDG-PET is currently a powerful whole-body functional imaging modality and has been shown to be more accurate than contrast-enhanced CT for lymphoma staging in terms of nodal and extranodal involvement[28–30]. In our study, FDG-PET/CT was taken as the reference standard because pathological proof for each lymph node region or organ suspected to have disease involvement is practically and ethically not possible[23,26]. For lymph node involvement, based on the International Working Group (IWG) Cheson’s size criteria alone[31], DWI findings matched PET/CT findings in 277 node regions (94%), yielding sensitivity and specificity of 90% and 94%[26]. Among the 82 lymph node regions that were considered positive on both DWI (size criteria alone) and PET/CT, the lymph nodes were visually hypointense to muscle on ADC maps (restricted diffusion) in 73 regions (89%) (Fig. 2). Not all PET-positive lymph nodes had low ADC values. Small lymph nodes adjacent to the lungs and the heart may show falsely high ADC values probably related to heart motion[26], and are not well visualized on DWIBS images with high b values[23]. Although it is known that size criteria lack the desired accuracy for characterizing lymph nodes[23,32], our preliminary results show that for pretreatment staging purposes, the ability of DWI for detection of lymph node involvement based on size criteria alone (i.e., node larger than 1 cm on its longest transverse diameter) was comparable with that of FDG-PET/CT. Studies of whole-body MRI using only T2-weighted images (again with size-based analysis) for pediatric lymphoma staging also corroborated this point[33,34]. In our study, when visual ADC analysis was combined with the size measurement, the specificity of DWI increased to 100% but sensitivity decreased to 81%[26] (Fig. 3). Regarding extranodal organ involvement, whole-body DWI agreed with PET/CT in all 20 organs recorded (100%). All organ lesions showed restricted diffusion therefore combining visual ADC analysis would not change the diagnostic performance of DWI for extranodal disease detection[26]. DWI was not able to depict diffuse spleen involvement in one patient because normal spleen already showed restricted diffusion. However, small focal splenic lesions were identified on the respiratory-gated DWI[26]. DWI can be more sensitive than PET in depicting hepatic and renal involvement in some cases[26] (Fig. 4). There was agreement with Ann Arbor stages in 14 (93%) of the 15 patients.Figure 2


Whole-body diffusion-weighted imaging in lymphoma.

Lin C, Itti E, Luciani A, Haioun C, Meignan M, Rahmouni A - Cancer Imaging (2010)

Whole-body FDG-PET image in maximal intensity projection (left), transverse integrated FDG-PET/CT images (middle two columns) and diffusion-weighted b800 images with ADC map (right) in a 42-year-old patient with diffuse large B-cell lymphoma. DWI and PET/CT show focal lesions (arrows) involving both kidneys. However, the mass protruding into the left renal pelvis (open arrow) is obscured by the physiologic FDG excretion on PET; it is clearly depicted on DWI because of excellent lesion-to-normal renal parenchyma contrast. Note that another lesion on the left kidney (arrowhead on b800 image) and a lymph node (arrowhead on PET image) were both detected by the other imaging technique on adjacent slices (images not shown).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2967138&req=5

Figure 4: Whole-body FDG-PET image in maximal intensity projection (left), transverse integrated FDG-PET/CT images (middle two columns) and diffusion-weighted b800 images with ADC map (right) in a 42-year-old patient with diffuse large B-cell lymphoma. DWI and PET/CT show focal lesions (arrows) involving both kidneys. However, the mass protruding into the left renal pelvis (open arrow) is obscured by the physiologic FDG excretion on PET; it is clearly depicted on DWI because of excellent lesion-to-normal renal parenchyma contrast. Note that another lesion on the left kidney (arrowhead on b800 image) and a lymph node (arrowhead on PET image) were both detected by the other imaging technique on adjacent slices (images not shown).
Mentions: We have conducted a prospective pilot study of 15 patients with histologically proven diffuse large B-cell lymphoma (DLBCL) using the whole-body respiratory-gated DWI[26]. Among them, 2 patients had concomitant DLBCL and a follicular lymphoma component. FDG-PET is currently a powerful whole-body functional imaging modality and has been shown to be more accurate than contrast-enhanced CT for lymphoma staging in terms of nodal and extranodal involvement[28–30]. In our study, FDG-PET/CT was taken as the reference standard because pathological proof for each lymph node region or organ suspected to have disease involvement is practically and ethically not possible[23,26]. For lymph node involvement, based on the International Working Group (IWG) Cheson’s size criteria alone[31], DWI findings matched PET/CT findings in 277 node regions (94%), yielding sensitivity and specificity of 90% and 94%[26]. Among the 82 lymph node regions that were considered positive on both DWI (size criteria alone) and PET/CT, the lymph nodes were visually hypointense to muscle on ADC maps (restricted diffusion) in 73 regions (89%) (Fig. 2). Not all PET-positive lymph nodes had low ADC values. Small lymph nodes adjacent to the lungs and the heart may show falsely high ADC values probably related to heart motion[26], and are not well visualized on DWIBS images with high b values[23]. Although it is known that size criteria lack the desired accuracy for characterizing lymph nodes[23,32], our preliminary results show that for pretreatment staging purposes, the ability of DWI for detection of lymph node involvement based on size criteria alone (i.e., node larger than 1 cm on its longest transverse diameter) was comparable with that of FDG-PET/CT. Studies of whole-body MRI using only T2-weighted images (again with size-based analysis) for pediatric lymphoma staging also corroborated this point[33,34]. In our study, when visual ADC analysis was combined with the size measurement, the specificity of DWI increased to 100% but sensitivity decreased to 81%[26] (Fig. 3). Regarding extranodal organ involvement, whole-body DWI agreed with PET/CT in all 20 organs recorded (100%). All organ lesions showed restricted diffusion therefore combining visual ADC analysis would not change the diagnostic performance of DWI for extranodal disease detection[26]. DWI was not able to depict diffuse spleen involvement in one patient because normal spleen already showed restricted diffusion. However, small focal splenic lesions were identified on the respiratory-gated DWI[26]. DWI can be more sensitive than PET in depicting hepatic and renal involvement in some cases[26] (Fig. 4). There was agreement with Ann Arbor stages in 14 (93%) of the 15 patients.Figure 2

Bottom Line: DWI is capable of combining anatomical and functional information and is becoming a valuable tool in oncology, in particular for staging purposes.DWI may prove to be a useful biomarker in clinical decision making for patients with lymphoma.Large-scaled prospective studies are needed to confirm these preliminary results.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Centre Hospitalo-Universitaire Henri Mondor, Avenue du Marechal de Lattre de Tassigny, Créteil, France.

ABSTRACT
The current evidence regarding the usefulness of whole-body diffusion-weighted magnetic resonance imaging (DWI) in lymphoma is reviewed. DWI is capable of combining anatomical and functional information and is becoming a valuable tool in oncology, in particular for staging purposes. DWI may prove to be a useful biomarker in clinical decision making for patients with lymphoma. Large-scaled prospective studies are needed to confirm these preliminary results.

Show MeSH
Related in: MedlinePlus