RPS 2416 - Current advances in lymphoma imaging

Author Block: M. Kassube, P. F. Linden, K. Rejeski, G. Sheikh, R. Werner, M. Subklewe, J. Ricke, W. G. Kunz, M. Winkelmann; Munich/DE
Purpose: CAR T-cell therapy (CART) has transformed treatment for relapsed or refractory llymphomas. While Ann Arbor staging remains important for risk stratification, tumor burden (TB) may offer additional prognostic insight. The differential impact of TB in early- (I/II) versus advanced-stage (III/IV) disease remains unclear in the context of CART. We assessed the added prognostic value of Lugano-based sum of product diameters (SPD) in stage I/II compared with stage III/IV patients for progression-free (PFS) and overall survival (OS).
Methods or Background: This study was conducted on a cohort of 103 patients treated with CART. Tumor burden at baseline was quantified using SPD according tu Lugano Criteria. Patients were stratified by Ann Arbor stage and SPD levels. PFS and OS were analyzed using Kaplan-Meier curves and log-rank tests.
Results or Findings: Median age was 67 years; 38% female. Patients with Stage III/IV disease had significantly higher baseline SPD compared to Stage I/II (median SPD: 6,088 mm² vs. 1,504 mm²; p<0.001). Survival analysis demonstrated significantly inferior PFS (p<0.001) and OS (p=0.018) in patients with advanced disease. The subdivision of the early stage patients according to their median SPD of 1,504 mm2 resulted in a significant separation of the two groups. The early stage patients with a low SPD showed a significantly longer OS and a slightly longer PFS than those with a high SPD. Interestingly, stage I/II patients with higher TB showed a similar overall survival curve as the advanced stage patients.
Conclusion: Baseline tumor burden, as measured by SPD, had a prognostic value in early-stage lymphoma patients undergoing CART. In this subgroup, higher SPD was associated with inferior OS and slightly inferior PFS. In contrast, SPD did not show a prognostic impact among patients with advanced-stage disease.
Limitations: Monocentric, retrospective study.
Funding for this study: BZKF, FöFoLe (LMU Munich)
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: All medical records and imaging studies underwent review with approval from the LMU Munich Institutional Review Board (LMU Ethics Committee, project number 19-817).

Author Block: P. F. Linden, M. Kassube, K. Rejeski, G. Sheikh, R. Werner, M. Subklewe, J. Ricke, W. G. Kunz, M. Winkelmann; München/DE
Purpose: CD19-directed chimeric antigen receptor T-cell therapy (CART) has improved outcomes in relapsed/refractory (r/r) B-cell lymphomas. However, long-term survival impact is difficult to assess using conventional endpoints such as progression-free survival (PFS1). Second progression-free survival (PFS2) has been proposed as a more comprehensive endpoint, but has not been studied in CART. This study evaluates associations among PFS1, PFS2, and overall survival (OS).
Methods or Background: We analyzed patients with r/r lymphomas treated with CART at our center. PFS1 was defined as time to first progression, PFS2 as time to second progression. To avoid overfitting, patients in whom death was the event for both PFS1 and PFS2 were excluded. Associations among PFS1, PFS2, and OS were assessed by linear regression and Spearman correlation. Tumor burden prior to CART was calculated as the sum of product of diameters (SPD). Box plots explored SPD outcome associations. Kaplan–Meier estimates were used for survival endpoints.
Results or Findings: Of 140 patients, 51 were excluded (death as event for PFS1: n=13; PFS2: n=38). Median PFS1, PFS2, and OS were 9, 14, and 18 months. PFS2 differed significantly from PFS1 (p=0.044) and was more comparable to OS (p=0.256). PFS2 correlated more strongly with OS (r=0.91) than PFS1 (r=0.77), suggesting superior reflection of outcomes. Patients with shorter PFS1 had higher baseline tumor burden; this association was more pronounced when stratified by median PFS2. Patients with two progressions had shorter OS than those with one, progression-free patients achieved the longest OS.
Conclusion: PFS2 shows strong association with OS in CD19 CART recipients, supporting its use as an efficacy endpoint to capture long-term benefit. Incorporating PFS2 into trial design and real-world assessments may improve evaluation of therapeutic benefit and guide treatment sequencing in CART.
Limitations: Retrospective, monocentric study
Funding for this study: BZKF,FöFoLe
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: All medical records and imaging studies underwent review with approval from the LMU Munich Institutional Review Board (LMU Ethics Committee, project number 19-817).

Author Block: H-J. Meyer, V. Sotikova, T. Denecke, M. Merz; Leipzig/DE
Purpose: B-cell maturation antigen (BCMA)-directed chimeric antigen receptor (CAR) T-cell therapy has shown significant promise for patients with relapsed or refractory multiple myeloma (RRMM). Despite its efficacy, treatment is frequently complicated by adverse events such as cytokine release syndrome and hematologic toxicities, including severe thrombocytopenia. Identifying reliable prognostic markers is essential to improve patient risk stratification, optimizing treatment strategies, and managing complications effectively. While various prognostic markers have been explored, spleen size has not been extensively studied in this context.
Methods or Background: This study aims to evaluate spleen size as a prognostic marker in RRMM patients receiving CAR T-cell therapy. Specifically, we examine its association with thrombocytopenia, metabolic tumor volume, soluble BCMA (sBCMA) levels, progression-free survival (PFS), and overall survival (OS). Additionally, we compare spleen size to established prognostic markers, including baseline sBCMA, EASIX, and CAR-HEMATOTOX scores, to determine its predictive value. The association of spleen size, assessed via computed tomography imaging, with clinical outcomes was evaluated.
Results or Findings: Splenomegaly (spleen size >340 cm³) was found to be significantly associated with severe and prolonged thrombocytopenia, higher metabolic tumor volumes, and elevated sBCMA levels. In our cohort, splenomegaly emerged as an independent prognostic factor for both PFS and OS, showing stronger associations than other markers such as sBCMA, EASIX, and CAR-HEMATOTOX scores.
Conclusion: Spleen size may serve as a promising prognostic marker in CAR T-cell therapy for RRMM patients, providing a simple and readily accessible tool for enhancing risk stratification. This finding could inform monitoring strategies and optimize healthcare resource management for these patients.
Limitations: The present study has to address the limitation of its retrospective design. The measurement of the spleen sizes were performed by one reader with potential small reader bias.
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: University Hospital of Leipzig, 361/22-ek

Author Block: M. Kassube, P. Achhammer, P. F. Linden, K. Rejeski, G. Sheikh, M. Subklewe, J. Ricke, W. G. Kunz, M. Winkelmann; Munich/DE
Purpose: CD19-directed CAR T-cell therapy improves outcomes in relapsed/refractory (r/r) B-cell non-Hodgkin lymphoma (NHL). However, relapse remains common, particularly with extranodal disease. Organ-specific involvement may affect prognosis, yet spatial response data are limited. Radiologic assessment enables evaluation at the organ level. We aimed to identify organ systems whose involvement is linked to poor response or early relapse after CAR T-cell therapy.
Methods or Background: This retrospective study included 153 patients with r/r B-cell NHL treated with CD19 CAR T-cells. Baseline and follow-up imaging (FDG-PET/CT or contrast-enhanced CT) at day 30 (FU1) and 3 months (FU2) was analyzed. Extranodal lesions were documented by frequency, size, and number per organ system. Depth of response (DoR) was assessed by percentage change in sum of product diameters (SPD) according to Lugano criteria.
Results or Findings: Responses were heterogeneous across organ systems. Nodal disease showed stronger reductions compared with extranodal sites (median DoR –89.4% vs. –90.4%). Significant decreases in lesion size occurred from baseline to FU2 in both nodal (p<0.001) and extranodal sites (p<0.001). Among the five most frequently involved extranodal organs, muscle and pleura demonstrated significant reductions (muscle: p=0.020; pleura: p=0.008). Bone and lung showed favorable responses (≈–67% SPD) without reaching statistical significance. In contrast, hepatic lesions responded least, with an average reduction of –29%.
Conclusion: Radiologic assessment reveals organ-specific heterogeneity after CD19 CAR T-cell therapy, with lymphoid tissues exhibiting more profound responses than non-lymphoid sites. Specific extranodal involvement, especially of the liver, may limit therapeutic durability and should be validated in future studies.
Limitations: Limitations include the single-center design.
Funding for this study: This study received no external funding and was conducted with institutional resources only.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: All medical records and imaging studies underwent review with approval from the LMU Munich Institutional Review Board (LMU Ethics Committee, project number 19-817)

Author Block: F. Abubacker Sulaiman, R. Praveenkumar; Chennai/IN
Purpose: To evaluate the patterns of bone marrow (BM) metabolic activity on ^18F-FDG PET/CT in patients with lymphoma and solid tumors, and to correlate them with clinical, hematologic, and histopathologic parameters for assessing diagnostic and prognostic significance.
Methods or Background: A prospective study was conducted on 90 patients—45 with histologically confirmed lymphoma and 45 with solid malignancies (breast, lung, and gastrointestinal cancers). All patients underwent baseline ^18F-FDG PET/CT before therapy initiation. Bone marrow metabolic activity was visually graded and quantitatively assessed using mean and maximum standardized uptake values (SUVmean, SUVmax) measured in vertebral and pelvic marrow. Patterns of BM uptake (diffuse, focal, or heterogeneous) were correlated with complete blood counts, inflammatory markers, and marrow biopsy findings when available. Statistical analysis included Pearson’s correlation and ROC analysis for predictive accuracy.
Results or Findings: In lymphoma, focal or multifocal marrow uptake correlated strongly with biopsy-confirmed infiltration (sensitivity 91%, specificity 86%), while diffuse uptake was commonly reactive. Higher BM SUVmean correlated with advanced stage and elevated LDH levels (r = 0.72, p < 0.001). In solid tumors, diffuse marrow hypermetabolism was associated with anemia and elevated CRP rather than metastatic infiltration. ROC analysis identified an optimal SUVmean cutoff of 2.9 for predicting marrow involvement in lymphoma (AUC = 0.93).
Conclusion: 18F-FDG PET/CT provides a non-invasive, reliable assessment of bone marrow metabolism, enabling differentiation between reactive and infiltrative changes in both lymphoma and solid tumors, thereby improving staging accuracy and treatment planning.
Limitations: Single-center design, limited histopathologic confirmation, and potential influence of hematopoietic stimulation or infection on FDG uptake. Multicentric validation is recommended.
Funding for this study: No external funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Institutional ethical committee approval was obtained.

Author Block: B. Baysal, H. Ardalı Çakır, M. Gezgin, B. Canitez, I. Erdogan Ozunal, M. Tiglioglu, E. Ozturk, H. S. Uslu; Istanbul/TR
Purpose: This study investigates the diagnostic performance of whole-body magnetic resonance imaging (WB-MRI) with diffusion-weighted imaging (DWI) compared with 18F-FDG PET/CT in detecting lesions in multiple myeloma and examines the relationship of imaging findings with serum parameters and bone marrow involvement.
Methods or Background: This retrospective study included newly diagnosed multiple myeloma patients who underwent both WB-MRI and 18F-FDG PET/CT. Demographic, laboratory, and imaging data were collected. Lesion presence in the cranial, cervical, thoracic, lumbar, pelvic, costal–sternal–scapular–clavicular, and extremity regions was compared between modalities using the McNemar test, and the relationship of imaging findings with immunoglobulin subtypes was evaluated.
Results or Findings: Twenty eight newly diagnosed multiple myeloma patients (mean age, 66.1 ± 10.9 years; 53.6% female) were evaluated. IgG was the most frequent heavy chain subtype (46.4%), followed by IgA (32.1%), while 21.4% had no heavy chain; kappa light chain predominated (57.1%). MRI identified marrow involvement as diffuse (35.7%), focal (32.1%), micronodular (14.3%), or absent (17.9%). Compared with PET/CT, MRI showed higher sensitivity in cervical (p = 0.001), pelvic (p = 0.031), and extremity (p = 0.008) regions, with a nonsignificant trend in the cranium (p = 0.063). No significant differences were observed in thoracic, lumbar, or costal–sternal–scapular–clavicular regions. PET/CT revealed more cervical lesions in IgA patients and more lumbar lesions in IgA and heavy chain–negative groups, while MRI detection did not differ by heavy or light chain subtype.
Conclusion: Whole-body MRI with diffusion-weighted imaging demonstrated higher sensitivity than 18F-FDG PET/CT in multiple myeloma, particularly in the cervical spine, pelvis, and long bones. These findings suggest that WB-MRI may serve as a prominent diagnostic tool, while PET/CT provides complementary metabolic insights.
Limitations: The main limitations are the small sample size and retrospective design.
Funding for this study: No funding was received for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Currently in the process

Author Block: F. Maccioni, L. Bottino, L. Busato, A. Valenti, M. Rutigliano, C. Catalano; Rome/IT
Purpose: This study aims to assess the performance of whole-body DWI MRI (WB-DWI MRI), for staging and monitoring lymphomas. WB-DWI MRI was prospectively compared to PET/CT. The ultimate goal is to propose WB-DWI MRI as a viable alternative or complementary tool to PET/CT, especially in younger patients.
Methods or Background: In this single-center study, 71 patients with HL or DLBCL prospectively underwent both ^18F-FDG PET/CT and WB-MRI (within 15 days). Inclusion required histological confirmation, age ≥18, and ≤2 chemotherapy cycles. Exclusion criteria included contraindications to MRI, other neoplasms, or delayed imaging. WB-MRI included T1, T2, and DWI sequences (b-values: 50–800 s/mm²). Qualitative analysis included assessment of 10 different lymphnodal stations and 3 extranodal organans (liver, spleen, bone marrow) and quantitative parameters (SUVmax/ SUVmean vs. DWI/ADC). PET/CT and WB-MRI images were independently evaluated for qualitative and quantitative parameters (SUVmax/ SUVmean; ADCmin/ADCmean). Statistical analyses included concordance (Cohen’s κ), predictive values (PPV/NPV), and correlation tests. Strong inverse correlations were found between SUV and ADC values.
Results or Findings: PET/CT and WB-MRI showed excellent agreement (Cohen’s κ = 0.91; PPV/NPV: 0.96/0.97), including 100% concordance in extranodal sites.
Conclusion: Quantitative analysis demonstrated an inverse correlation between ADC and SUV values, reflecting tumor cellularity. Whole-body DWI-MRI, a radiation-free modality, showed high concordance with PET/CT, supporting its integration as a complementary tool for lymphoma management, particularly in younger or radiation-sensitive patients.
Limitations: Limited number of patients.
Funding for this study: None
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Local ethics committee

Author Block: Z. Tan, S. Gui, J. Wang; Wuhan/CN
Purpose: To develop spectral CT-based nomogram for predicting response and prognosis in lymphoma patients after first-line therapy.
Methods or Background: The baseline clinical and spectral CT data of 91 lymphoma patients were retrospectively analyzed. Patients were assessed for therapy response using the Lugano criteria and were categorized into complete response (CR) and non-complete response (non-CR) groups. Spectral CT parameters of each patient's largest lesion, including the arterial phase (AP) and venous phase (VP) were measured. Univariable and multivariable logistic regression were performed to identify independent predictors of response. In addition, the model was visualized using a clinical model, spectral CT model, and nomograms, and its performance was assessed via receiver operating characteristic curves. Overall survival and progression-free survival (PFS) in patients with different parameters were estimated using the Kaplan-Meier method.
Results or Findings: In the multivariate analysis, B symptoms, Ki-67, iodine concentration (IC), normalized IC at AP, and arterial enhancement fraction based on IC (AEF-IC) were identified as independent predictor factors for CR. The nomogram incorporating all five independent predictors outperformed spectral CT and the clinical model with the highest AUC of 0.856 (95% CI: 0.767-0.921). AEF-IC, the clinical model, spectral CT model, and nomogram were associated with PFS, and the nomogram had the strongest association with unfavorable PFS, with a hazard ratio of 4.725 (95% CI: 2.275-9.817, P<0.001).
Conclusion: Spectral CT and the clinical models were useful in predicting efficacy and PFS in lymphoma patients. Combining spectral CT parameters and clinical characteristics in a nomogram improved predictive performance.
Limitations: A retrospective study conducted at a single center with a small sample size that used a spectral CT scanner from a specific manufacturer, the results may lack generalizability.
Funding for this study: This spectral CT-based nomogram integrating clinical characteristics is a non-invasive and easily obtainable tool for accurately predicting first-line treatment response and prognosis, thereby aiding clinicians in performing personalized treatment planning in lymphoma patients.
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: