Abstract
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Objectives The spleen is infrequently involved in hematological malignancies, upto 1/3 of Hodgkin’s pts (HL) may demonstrate splenic involvement, and a lesser number in DLBCL and other aggressive lymphomas (1). Accurate evaluation of splenic involvement is necessary because it alters staging, clinical management and prognosis. Though, CT has long been the mainstay of imaging in pts. with lymphomas, PET-CT is currently considered the modality of choice in FDG avid aggressive lymphomas. On CT various patterns of involvement have been described (2): 1. homogeneous splenomegaly without a focal lesion, 2. diffuse infiltration with miliary lesions less than 5 mm, 3. multiple focal nodular lesions (1−10 cm) and 4. large solitary mass. While splenomegaly favors involvement, and splenic size modestly correlates with prognosis (2), normal sized spleens do harbor viable tumor. Furthermore, non lymphomatous masses can falsely imply splenic involvement. Metabolic imaging with FDG-PET mainly evaluates FDG avid lesions in Hodgkin’s and other aggressive Non-Hodgkin’s Lymphomas - mainly DLBCL. In addition, the inherently quantitative nature of PET renders it an excellent tool for evaluating response to therapy.
Methods We have retrospectively evaluated the correlative morphologic and metabolic patterns of splenic involvement on combined concurrent FDG PET-CT and diagnostic contrast CT (diagCT) in 33 pts, with splenic involvement on PET-CT and/or diagCT, at initial diagnosis and on follow up, and biopsy (DLBCL=15, HL=11, misc. aggressive lymphomas=12.)
Results In an atlas format, the following will be demonstrated from our series. 1. Different morphologic and metabolic patterns of splenic involvement in HL and DLBCL will be demonstrated. 2. Correlation of findings on diagCT and PET-CT, and the clinical implications of their correlations will be enumerated. 3. Quantitative evaluation of splenic involvement by different methodologies 4. False positives, false negatives, limitation, and mimics will be displayed. 5. Correlation of morphologic and metabolic parameters with respect to response to therapy, and different morpho-metabolic prognostic biomarkers will be exemplified in our series.
Conclusions In our small series we have demonstrated the utility of combined diagCT and PET-CT in the evaluation of splenic involvement in Hodgkin's and other aggressive lymphomas. The various morpho-metabolic patterns, their clinical, therapeutic and prognostic implications are exemplified. RESEARCH SUPPORT: Not applicable