The aims of this study are twofold:1) To examine if other MRI parameters, different from the ones currently used for DWIBS, improve image quality of DWIBS2) To examine if the accuracy of DWIBS is good enough (especially its sensitivity) to correctly rule out bone marrow involvement in patients with malignant lymphoma.
1) Cancer is a major health problem worldwide. Imaging plays an important and growing role in the management of cancer patients. Diffusion-weighted magnetic resonance imaging (MRI) provides functional information not available from conventional (anatomical) MRI and can be used for the detection and characterization of pathologic processes, including malignant tumors. The recently developed diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) sequence now allows acquisition of diffusion-weighted images of the entire body. DWIBS may play an important role in whole-body oncological imaging, including staging, assessment of therapeutic response and detection of tumor recurrence. However, optimization of the DWIBS sequence is first necessary to assess and exploit its full potential.2) Bone marrow involvement is of crucial importance in staging of malignant lymphoma (Hodgkin s disease [HD] and non-Hodgkin lymphoma [NHL]), since it signifies advanced-stage disease and, thus, may affect both treatment and prognosis. Unilateral bone marrow biopsy is the established method for the detection of bone marrow involvement. However, bone marrow biopsy is a painful procedure and has a risk of complications (bleeding, infection). Another disadvantage of unilateral bone marrow biopsy is the possibility of missing focal bone marrow involvement. Moreover, sometimes only a small sample can be obtained, which may be inconclusive. In addition, experience teaches that it can take over a week before the results of bone marrow biopsy are known to the hematologist.Bone marrow involvement is found in only 5-15% of patients with HD, and in 25-40% of patients with NHL. A diagnostic test with a high sensitivity (and thus a low false-negative rate) would be of great value to prevent patients from undergoing an unnecessary, uninformative biopsy. DWIBS is a non-invasive, radiation free, functional whole-body imaging modality and may therefore be an excellent alternative to bone marrow biopsy.The aims of this study are:1) To examine if other MRI parameters, different from the ones currently used for DWIBS, improve image quality of DWIBS2) To examine if DWIBS is able to correctly rule out bone marrow involvement in patients with malignant lymphomaTo answer these questions we will:1) Investigate different MRI/DWIBS parameters (field strengths, b-values, and fat-suppression techniques) in 15 healthy volunteers and assess their effect on contrast-to-noise ratios (AppCNRs, a measure of image quality).The calculated AppCNRs of each type of DWIBS-scan will be compared to one another using the t-test for matched pairs.2) Perform a prospective, diagnostic cohort study in 250 eligible patients (8 years and older) with a histologically proven Hodgkin s disease or non-Hodgkin lymphoma, who will undergo DWIBS on top of the protocollar imaging routinely done (including unilateral bone marrow biopsy).The challenge of this study will be to show that DWIBS is able to rule out bone marrow involvement in patients with malignant lymphoma. Testing of this hypothesis will be performed by calculating the sensitivity (and specificity) of DWIBS for bone marrow involvement in patients with malignant lymphoma, using unilateral bone marrow biopsy as the gold standard. |
