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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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Related in: MedlinePlus

Diffusion-weighted images with b values of 50 and 800 s/mm2 (b50 and b800) and their corresponding ADC map in a 24-year-old patient with gastric involvement of diffuse large B-cell lymphoma. In addition to sub-diaphragmatic disease, DWI depicted an additional enlarged lymph node (arrow) on both b50 and b800 diffusion-weighted images over left lower neck (no abnormal FDG uptake, PET image not shown). DWI upstaged the patient based on size criteria alone. However, this lymph node shows no restricted diffusion (isointense to muscle) on the ADC map. Therefore, with combined ADC analysis, this lymph node can be considered negative, and the patient would have been correctly staged.
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Figure 3: Diffusion-weighted images with b values of 50 and 800 s/mm2 (b50 and b800) and their corresponding ADC map in a 24-year-old patient with gastric involvement of diffuse large B-cell lymphoma. In addition to sub-diaphragmatic disease, DWI depicted an additional enlarged lymph node (arrow) on both b50 and b800 diffusion-weighted images over left lower neck (no abnormal FDG uptake, PET image not shown). DWI upstaged the patient based on size criteria alone. However, this lymph node shows no restricted diffusion (isointense to muscle) on the ADC map. Therefore, with combined ADC analysis, this lymph node can be considered negative, and the patient would have been correctly staged.

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)

Diffusion-weighted images with b values of 50 and 800 s/mm2 (b50 and b800) and their corresponding ADC map in a 24-year-old patient with gastric involvement of diffuse large B-cell lymphoma. In addition to sub-diaphragmatic disease, DWI depicted an additional enlarged lymph node (arrow) on both b50 and b800 diffusion-weighted images over left lower neck (no abnormal FDG uptake, PET image not shown). DWI upstaged the patient based on size criteria alone. However, this lymph node shows no restricted diffusion (isointense to muscle) on the ADC map. Therefore, with combined ADC analysis, this lymph node can be considered negative, and the patient would have been correctly staged.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2967138&req=5

Figure 3: Diffusion-weighted images with b values of 50 and 800 s/mm2 (b50 and b800) and their corresponding ADC map in a 24-year-old patient with gastric involvement of diffuse large B-cell lymphoma. In addition to sub-diaphragmatic disease, DWI depicted an additional enlarged lymph node (arrow) on both b50 and b800 diffusion-weighted images over left lower neck (no abnormal FDG uptake, PET image not shown). DWI upstaged the patient based on size criteria alone. However, this lymph node shows no restricted diffusion (isointense to muscle) on the ADC map. Therefore, with combined ADC analysis, this lymph node can be considered negative, and the patient would have been correctly staged.
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