RPS 616 - Haematologic malignancies: multimodality imaging

Author Block: A. Rossi¹, D. Bezzi¹, D. Diano¹, A. Prochowski Iamurri¹, A. Cattabriga², E. Antognoni¹, G. Feliciani¹, P. Caroli¹, C. Cerchione¹; ¹Meldola/IT, ²Bologna/IT
Purpose: This study aims to compare the diagnostic efficacy of Whole Body-Magnetic Resonance Imaging (WB-MRI) and 18F-Fluorodeoxyglucose Positron Emission Tomography (PET-CT) in detecting bone marrow infiltration (BMI) in myeloma patients and assess their impact on patient management.
Methods or Background: We prospectively enrolled myeloma patients from October 2020 to January 2024. Within a month, patients underwent 3T WB-MRI (following MY-RADS criteria) and PET-CT to assess BMI, para, and extramedullary disease. Clinical and laboratory data were collected. Two haematologists determined treatment plans using International Myeloma Working Group (IMWG) criteria based on all findings, which were then used to evaluate imaging performance.
Results or Findings: The cohort included 137 patients (73 male; mean age, 66 years), with 39 having High Risk-Smoldering Multiple Myeloma (SMM) and 98 with Multiple Myeloma (MM). WB-MRI sensitivity and specificity for BMI in MM were 100% and 97%, respectively, while PET-CT showed 89% sensitivity and 97% specificity (p=0.02). In SMM, BMI-positive patients had higher paraprotein levels (p=0.01); in MM, they had higher paraprotein (p=0.007) and lower hemoglobin (p=0.002). Clinical management changed in 54% of cases based on combined imaging results, with WB-MRI consistent with management changes in 97% compared to 61% for PET-CT (p < 0.001).
Conclusion: WB-MRI and PET-CT play key roles in evaluating myeloma patients. WB-MRI demonstrated superior sensitivity in detecting BMI and had a greater influence on therapeutic decision-making.
Limitations: No limitations were identified
Funding for this study: This study was partly funded by the Italian Ministry of Health for Institutional Research (Ricerca Corrente) within the research line "Innovative therapies, phase I-III clinical trials, and therapeutic strategy trials based on preclinical models, onco-immunological mechanisms, and nano vectors.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: the study was approved by C.E.R.O.M comitato etico della Romagna (AccuMRI trial IRST code 100.15)

Author Block: M. Winkelmann, P. Achhammer, V. Blumenberg, K. Rejeski, G. Sheikh, M. Brendel, J. Ricke, M. Subklewe, W. G. Kunz; Munich/DE
Purpose: CD19 specific CAR T-cell therapy (CART) is an effective treatment for relapsed or refractory (r/r) lymphoma. The maximum distance (Dmax) of lymphoma lesions holds potential as imaging biomarker in lymphoma treated with conventional therapies, but has not been studied in context of CART. We evaluated Dmax at baseline imaging as a prognostic tool for assessment of metabolic and overall response, progression-free survival (PFS) and overall survival (OS).
Methods or Background: Consecutive r/r lymphoma patients with (PET/)CT at baseline before CART were included. Dmax was measured in cm at BL. Patients were divided into three groups according to Dmax: low, intermediate and high. The sum of product diameters (SPD) according to Lugano criteria was used to represent tumor burden (TB). Overall response according to Lugano criteria and Deauville score were determined at follow-up imaging.
Results or Findings: 103 patients were included. Median baseline Dmax was 40.0 cm (IQR: 16.4 – 70.3 cm). Median TB was significantly higher in the intermediate and high risk group compared to the low risk group (p=0.005). Intermediate and high risk group showed significantly higher Ann Arbor stages (p<0.001). The survival analysis revealed a significantly (p=0.030) shorter PFS in the high-risk group compared to the other patients (91 vs 364 days), but no relevant differences in OS (p=0.151). In addition, no significant differences in Deauville score and ORR were detected.
Conclusion: Patients with high Dmax showed a shorter PFS, but no significant differences in OS. Dmax as an interval-scaled parameter represents a useful alternative to the Ann Arbor classification.
Limitations: Single center study, limited number of subjects. Few patients were excluded because of no measurable disease. Some patients had only CT without PET at FU, with a possible redistribution of Deauville score among Dmax-based groups.
Funding for this study: The work was supported by funding from the research program “Förderung für Forschung und Lehre (FöFoLe) project number 1147” of the Medical Faculty of Ludwig Maximilian University (LMU) Munich and the Bavarian Cancer Research Center (BZKF)
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: C. Neelsen¹, C. Sachpekidis¹, J. M. E. Jende¹, R. Gnirs¹, F. Kurz², P. Dreger¹, A. Dimitrakopoulou-Strauss¹, H-P. Schlemmer¹; ¹Heidelberg/DE, ²Geneva/CH
Purpose: To evaluate the utility of early whole-body MRI (wbMRI) for the prediction of long-term metabolic response in patients with large B-cell lymphoma (LBCL) following chimeric antigen receptor T-cell therapy (CARTT).
Methods or Background: In this prospective, IRB-approved study, we assessed 9 LBCL patients with target lesions identified on baseline wbMRI according to adapted Response Evaluation Criteria in Lymphoma (RECIL), who were fit to undergo wbMRI within two weeks (mean 11 days) following CARTT in an outpatient setting. Complete remission was defined as the absence of measurable disease and any lesions on diffusion-weighted imaging. Early wbMRI findings were compared with PET-CT results at 3-month follow-up, with metabolic responses classified according to the Lugano criteria.
Results or Findings: At the 3-month PET-CT follow-up 4 patients showed a complete metabolic response (CMR), 2 patients had a partial metabolic response (PMR) and 3 patients demonstrated progressive disease (PD). Of the 4 patients with CMR, 2 had already achieved complete remission on the early wbMRI, while the other 2 patients had a minor and partial response. The 2 patients with PMR exhibited minor responses on early wbMRI and finally of the 3 patients with PD, one had a partial and two had minor responses.
Conclusion: All patients demonstrated some degree of response on early wbMRI within two weeks after CARTT. Early complete remission appeared to be a predictor of long-term metabolic response. However, early wbMRI was inconclusive in patients with initial minor or partial responses, as these patients may still achieve complete metabolic remission or progress over time.
Limitations: The lymphodepleting chemotherapy administered prior to the CAR T-cell infusion complicates the differentiation of the specific effects of chemotherapy versus the CAR T-cell therapy itself.
Funding for this study: No funding was provided for this study.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: The study was approved by the institutional review board (S-950/2021) and written informed consent was obtained from all participants.

Author Block: C. R. G. L. O. M. Talei Franzesi, C. Maino, P. N. Franco, D. Ippolito, R. Corso; Milan/IT
Purpose: To compare the effectiveness and accuracy of whole-body magnetic resonance imaging (WBMRI) short protocols for the overall assessment of bone marrow involvement in patients with multiple myeloma (MM), in comparison with standard whole-body MRI protocol
Methods or Background: Sixty-four patients with biopsy-proven MM, who underwent an WBMRI with full body coverage (from vertex to feet) were retrospectively enrolled. WBMRI images were independently evaluated, by two expert radiologists. After identifying the infiltration pattern (normal, focal, diffuse and combined), the whole skeleton was divided into six anatomic districts: skull, spine, sternum and ribs, upper limbs, pelvis and proximal two-third of femur, remaining parts of lower limbs, and patients were grouped according to number(< 5, 5-20, and > 20) and location of the lesions
Results or Findings: Most of patients showed a focal (59%) and combined (33%) infiltration patterns with lytic lesions predominantly distributed in the spine (82%) and pelvis (67%). Locations less frequently involved by focal bone lesions were skull and lower limbs (12%, respectively). Excluding both the anatomic regions mentioned before from the standard MRI protocol, a short MRI protocol with a shorter execution time (saving about 14 minutes) could be obtained, maintaining a good sensitivity (89.9%), specificity (66.7%) and diagnostic accuracy (AUROC=0.881; 95%CIs: 0.797-0.965)
Conclusion: MRI short protocols could be proposed as an effective and reliable approach to reduce the examination time, preserving a high diagnostic accuracy and can be more focused on the main involved districts
Limitations: None
Funding for this study: None
Has your study been approved by an ethics committee? Not applicable
Ethics committee - additional information: None

Author Block: Y. Dong; Shanghai/CN
Purpose: To explore the diagnostic performance of the super-resolution ultrasound (SRUS) imaging in dual-vessel systems, i.e., the microvascular system and the microlymphatic system, for predicting B cell and T cell subtypes in intranodal NHL.
Methods or Background: Forty-two patients with intranodal NHL were included in this prospective study. All patients underwent dual-vessel system SRUS imaging via intravenous and intra-lymph node routes. SRUS parameters such as vessel density, vessel ratio, vessel complexity level, diameter, distance, tortuosity, and flow velocity were measured for the microvascular and microlymphatic circulations. Principal component analysis (PCA) was utilized to interpret parameters, and a regression model was developed to predict NHL subtypes. The areas under the receiver operating characteristic curve (AUC), sensitivity, and specificity were calculated.
Results or Findings: Among the 42 patients, 35 were diagnosed with B cell NHL and 7 with T cell NHL. Sixty parameters from dual-vessel SRUS image analysis were obtained for each case. PCA extracted six principal components accounting for 93.1% of the total variance. The regression model utilizing these components to distinguish between B-cell and T-cell lymphomas achieved an AUC of 0.927 (95% CI: 0.841-1.000), a sensitivity of 85.7% (95% CI: 42.1%-99.6%), and a specificity of 94.3% (95% CI: 80.8%-99.3%).
Conclusion: Dual-vessel SRUS imaging, in conjunction with quantitative analysis, could effectively differentiate between B-cell and T-cell NHL, offering a non-invasive diagnostic alternative.
Limitations: First, due to the relatively low prevalence of lymphoma in the general population, the sample size is relatively small. Second, the methodology of microlymphatic SRUS imaging is confined primarily to intact lymph nodes. In cases of 'bulky mass' lymphomas, where there is extensive disruption of the lymph node architecture, as well as in NHL presenting within the trunk region, this approach might not be appropriate.
Funding for this study: No.
Has your study been approved by an ethics committee? Yes
Ethics committee - additional information: Ruijin Hospital Clinical Research Center Shanghai Jiaotong University, School of Medicine, Ethic No. 20240116021828990.