Performance of baseline FDG-PET/CT radiomics for prediction of bone marrow minimal residual disease status in the LyMa-101 trial.

The prognostic value of 18F-Fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) at baseline or the predictive value of minimal residual disease (MRD) detection appear as potential tools to improve mantle cell lymphoma (MCL) patients' management. The LyMa-101, a phase 2 trial of the LYSA group (ClinicalTrials.gov:NCT02896582) reported induction therapy with obinutuzumab, a CD20 monoclonal antibody. Herein, we investigated the added prognostic value of radiomic features (RF) derived from FDG-PET/CT at diagnosis for MRD value prediction. FDG-PET/CT of 59 MCL patients included in the LyMa-101 trial have been independently, blindly and centrally reviewed. RF were extracted from the disease area with the highest uptake and from the total metabolic tumor volume (TMTV). Two models of machine learning were used to compare several combinations for prediction of MRD before autologous stem cell transplant consolidation (ASCT). Each algorithm was generated with or without constrained feature selections for clinical and laboratory parameters. Both algorithms showed better discrimination performances for negative vs positive MRD in the lesion with the highest uptake than in the TMTV. The constrained use of clinical and biological features showed a clear loss in sensitivity for the prediction of MRD status before ASCT, regardless of the machine learning model. These data plead for the importance of FDG-PET/CT RF compared to clinical and laboratory parameters and also reinforced the previously made hypothesis that the prognosis of the disease in MCL patients is linked to the most aggressive contingent, within the lesion with the highest uptake.

A collision tumor of nasopharyngeal carcinoma and primary mantle cell lymphoma in the nasopharynx: a case report and review of the literature.

BACKGROUND: Nasopharyngeal carcinoma (NPC) is more common in men aged 40 to 59, and radiotherapy is an effective treatment. Nasopharyngeal lymphoma (NPL) is rare, and the coexistence of nasopharyngeal mantle cell lymphoma (MCL) and NPC is even rarer. A collision tumor is a rare type of tumor that refers to two or more different tumors occurring in the same organ. No reports to date have described a collision tumor of NPC and MCL occurring within the same nasopharyngeal mass. We herein report the successful treatment of a unique case of synchronous coexistence of NPC and MCL occurring in the nasopharynx of a Chinese man. CASE PRESENTATION: A 58-year-old man presented with a 5-month history of swallowing discomfort. Biopsy was performed under nasopharyngeal endoscopy, and histopathology revealed NPC. Magnetic resonance imaging revealed lesions in the nasopharynx, oropharynx, and tonsils, as well as enlarged lymph nodes in the parotid gland, posterior ear, and neck. This may be a synchronous dual primary tumor coexisting with NPC and NPL. Pathology consultation confirmed that the biopsy specimen of the nasopharynx was a collision tumor of NPC and MCL. Positron emission tomography computed tomography (PET-CT) revealed thickening of the posterior wall of the nasopharynx, which was considered NPC with lymphoma. The enlargement of the pharyngeal lymph ring and multiple hypermetabolic lymph nodes were evaluated as lymphoma infiltration. The patient received two courses of R-CHOP chemotherapy (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) followed by head and neck radiotherapy. At the time of this writing, he had remained alive without recurrence for 61 months since the initial treatment and was still undergoing follow-up. CONCLUSIONS: It is very important to correctly recognize collision tumors. Magnetic resonance imaging helps identify different components of collision tumors. Pathological examination helps to confirm the diagnosis. Histological examination reveals different components, and PET-CT can help determine the extent of the lesion. Dose-adjusted chemotherapy combined with radiotherapy may have promising herapeutic effects, but additional case studies are needed to confirm.

68Ga-Pentixafor PET/MRI for Treatment Response Assessment in Mantle Cell Lymphoma: Comparison Between Changes in Lesion CXCR4 Expression on PET and Lesion Size and Diffusivity on MRI.

PURPOSE: The aim of this study was to compare CXCR4 imaging with 68Ga-pentixafor PET to MRI for treatment response assessment in patients with mantle cell lymphoma (MCL). PATIENTS AND METHODS: Twenty-two posttreatment 68Ga-pentixafor PET/MRI scans of 16 patients (7 women and 9 men; mean age, 69.9 ± 7.9) with a total of 67 target lesions on baseline PET/MRI were analyzed. Rates of complete remission per lesion and per scan, according to MRI (based on lesion size) and 68Ga-pentixafor PET (based on SUV decrease to lower than liver and blood pool uptake), were compared using McNemar tests. The t tests and Pearson correlation coefficients (r) were used to compare rates of change in lesion diameter products (DPs) on MRI, and standardized uptake values (SUVmax, SUVmean) on PET, relative to baseline. RESULTS: At interim PET/MRI, 18/32 (56.3%) target lesions met CR criteria on 68Ga-pentixafor PET, and 16/32 (50.0%) lesions met size-based MRI criteria for CR (P = 0.63). At end-of-treatment PET/MRI, 40/57 (70.2%) target lesions met 68Ga-pentixafor PET criteria for CR, and 27/57 (47.4%) lesions met size-based MRI criteria for CR (P = 0.021). Complete remission after treatment was observed more frequently on 68Ga-pentixafor PET (11/22 scans, 54.5%) than on MRI (6/22 scans, 27.3%) (P = 0.031). Rates of change did not differ significantly between lesion DP (-69.20% ± 34.62%) and SUVmax (-64.59% ± 50.78%, P = 0.22), or DP and SUVmean (-60.15 ± 64.58, P = 0.064). Correlations were strong between DP and SUVmax (r = 0.71, P < 0.001) and DP and SUVmean (r = 0.73, P < 0.001). CONCLUSIONS: In MCL patients, 68Ga-pentixafor PET may be superior for assessment of complete remission status than anatomic MRI using lesion size criteria, especially at the end of treatment.

Long-term follow-up after R-High CHOP/CHASER/LEED with Auto-PBSCT in untreated mantle cell lymphoma-Final analysis of JCOG0406.

Progression-free survival after R-High CHOP/CHASER/LEED with auto-PBSCT in untreated mantle cell lymphoma in JCOG0406 study. A continuous pattern of relapse was observed.

Multiple lymphomatous polyposis: rectal prolapse as an atypical presentation of the disease.

Multiple lymphomatous polyposis is a rare entity that can involve different types of both B-cell and T-cell lymphomas, including mantle cell lymphoma. A 57-year-old male patient is presented with prolapse of the rectal canal associated with data of lower digestive tract bleeding. A colonoscopy and subsequent upper endoscopy were performed with findings compatible with lymphomatous polyposis. After a biopsy study, mantle cell lymphoma was diagnosed and chemotherapy treatment was started. The endoscopic finding of multiple lymphomatous polypoposis associated with an adequate histopathological diagnosis improves the treatment success rate in patients with different types of gastrointestinal lymphomas.

[18F]FDG-PET/CT volumetric parameters can predict outcome in untreated mantle cell lymphoma.

Several studies have shown a strong predictive value for pretreatment [18F]FDG-PET/CT metabolic parameters in different lymphoma subtypes. However, few publications exist concerning the role of metabolic parameters in mantle cell lymphoma (MCL). We retrospectively investigated the prognostic value of baseline metabolic tumor volume (MTV) and lesion dissemination in untreated MCL. We compared it to currently used prognostic factors such as stage, mantle cell lymphoma international prognostic index (MIPI) and KI-67. We report that a higher baseline MTV is a risk factor for worse overall survival (OS), progression-free survival (PFS), and disease-specific survival (DSS) in univariate analysis. In multivariate analysis, MTV was significantly associated with DSS, but not with OS and PFS. We found no correlation between lesion dissemination and outcome. The MIPI score remains the strongest predictor of outcome. These results show that MTV is an important prognostic tool and can improve patient risk stratification at staging of untreated MCL.

Mantle cell lymphoma with aseptic meningitis mimicking hydrocephalus on brain imaging.

An 83-year-old man underwent head computed tomography (CT) to investigate cognitive decline and gait disturbance and was admitted to undergo a cerebrospinal fluid (CSF) tap test for suspected idiopathic normal-pressure hydrocephalus. He had a history of chemotherapy for mantle cell lymphoma (MCL), but CT on admission showed no evidence of recurrence. After admission, his level of consciousness rapidly deteriorated and CSF examination suggested infiltration of MCL into the central nervous system (CNS). Although CNS involvement in MCL is rare, this case demonstrates that even if recurrence of MCL is not suspected based on CT findings.

"Hood Sign" in Nuclear Medicine: An Unusual Presentation of Mantle Cell Lymphoma as Detected on FDG PET/CT.

ABSTRACT: Mantle cell lymphoma is a rare and aggressive non-Hodgkin lymphoma with a high propensity for extranodal involvement, typically seen in the liver, marrow, and gastrointestinal system. Being an FDG-avid disease and a sensitive modality for detecting both nodal and extranodal disease, FDG PET/CT is recommended in the workup of mantle cell lymphoma. We present a rare pattern of cutaneous involvement of the head-neck region in a patient with mantle cell lymphoma, which can be described on FDG PET/CT as a "hood sign."

Imaging of C-X-C Motif Chemokine Receptor 4 Expression in 690 Patients with Solid or Hematologic Neoplasms Using 68Ga-Pentixafor PET.

In recent years, molecular imaging addressing the C-X-C motif chemokine receptor 4 (CXCR4) has increasingly been used in various clinical settings. Here, we aimed to assess radiopharmaceutical uptake and image contrast to determine the most relevant clinical applications for CXCR4-directed imaging. We also investigated the impact of specific activity on scan contrast. Methods: Patients (n = 690) with a variety of neoplasms underwent a total of 777 PET/CT scans with 68Ga-Pentixafor, serving as the CXCR4-specific radioligand. A semiquantitative target lesion analysis was conducted (providing SUVmax and target-to-blood pool ratio [TBR], defined as SUVmax [from target lesion] divided by SUVmean [from blood pool]). The applied specific activity (in MBq/µg) was compared with semiquantitative assessments. Results: Of the 777 scans, 242 did not show discernible uptake in disease sites, leaving 535 PET scans (68.9%) for further analysis. Very high tracer uptake (SUVmax > 12) was found in multiple myeloma (n = 113), followed by adrenocortical carcinoma (n = 30), mantle cell lymphoma (n = 20), adrenocortical adenoma (n = 6), and small cell lung cancer (n = 12). Providing information on image contrast, comparable results for TBR were recorded, with TBR (>8) in multiple myeloma, mantle cell lymphoma, and acute lymphoblastoid leukemia (n = 6). When comparing specific activity with semiquantitative parameters, no significant correlation was found for SUVmax or TBR (P ≥ 0.612). Conclusion: In this large cohort, 68Ga-Pentixafor demonstrated high image contrast in a variety of neoplasms, particularly for hematologic malignancies, small cell lung cancer, and adrenocortical neoplasms. The present analysis may provide a roadmap for detecting patients who may benefit from CXCR4-targeted therapies.

Targeting Refractory Mantle Cell Lymphoma for Imaging and Therapy Using C-X-C Chemokine Receptor Type 4 Radioligands.

PURPOSE: Mantle cell lymphoma (MCL) is associated with poor survival. The purpose of this study was to assess whether the C-X-C chemokine receptor type 4 (CXCR4) is a useful target for imaging and radioligand therapy of MCL, using a novel pair of radioligands, [68Ga]Ga and [177Lu]Lu-BL02. EXPERIMENTAL DESIGN: We performed a retrospective analysis of 146 patients with MCL to evaluate CXCR4 expression and its correlation with outcomes. Guided by in silico methods, we designed BL02, a new radioligand labelled with 68Ga or 177Lu for PET imaging and therapy, respectively. We performed imaging and biodistribution studies in xenograft models with varying CXCR4 expression. We evaluated [177Lu]Lu-BL02 in MCL models, and evaluated its potential for therapy in Z138 MCL xenografts. RESULTS: Phosphorylated and nonphosphorylated CXCR4 expression were correlated with poor survival in patients with MCL and characterized by unique underlying molecular signatures. [68Ga]Ga-BL02 uptake correlated with CXCR4 expression, and localized lesions in a metastatic xenograft model. [177Lu]Lu-BL02 showed high uptake in MCL xenografts. Therapy studies with a single dose in the Z138 model showed tumor regression and improved survival compared with a control group. Upon regrowth, the treated mice experienced concurrent metastasis alongside localized xenograft regrowth, and recurrent lesions showed enhanced CXCR4 signaling. CONCLUSIONS: CXCR4 is an independent factor of poor prognosis for MCL and a promising target for imaging and radioligand therapy. [68Ga]Ga-BL02 showed high contrast to visualize CXCR4-expressing xenografts for PET imaging and [177Lu]Lu-BL02 induced rapid tumor regression in a preclinical model of MCL.

The value of complete remission according to positron emission tomography prior to autologous stem cell transplantation in lymphoma: a population-based study showing improved outcome.

BACKGROUND: Chimeric antigen-receptor T-cell and bispecific antibody therapies will likely necessitate a reconsideration of the role of autologous stem-cell transplantation (ASCT) in lymphoma. Patients who are likely to profit from ASCT need to be better identified. METHODS: Here, we investigated the value of positron emission tomography/computerized tomography (PET/CT) before ASCT. All 521 patients transplanted for lymphoma 1994-2019 at Karolinska (497 conditioned with BEAM) were included. RESULTS: Outcome improved over three calendar periods 1994-2004, 2005-2014, 2015-2019 (2-year overall survival [OS]: 66, 73, 83%; P = 0.018). Non-relapse mortality (NRM) at 100 days over the three periods were 9.8, 3.9, 2.9%, respectively. The OS improvement between 1994 and 2004 and 2005-2014 was due to lower NRM (P = 0.027), but the large OS advance from 2015 was not accompanied by a significant reduction in NRM (P = 0.6). The fraction of PET/CT as pre-ASCT assessment also increased over time: 1994-2004, 2%; 2005-2014, 24%; 2015-2019, 60% (P < 0.00005). Complete responses (PET/CT-CR) were observed in 77% and metabolically active partial responses (PET/CT-PR) in 23%. PET/CT-CR was a predictor for survival in the entire population (P = 0.0003), also in the subpopulations of aggressive B-cell (P = 0.004) and peripheral T-cell (P = 0.024) lymphomas. Two-year OS and progression-free survival (OS/PFS) for patients in PET/CT-CR were in relapsed/refractory aggressive B-cell lymphoma 87%/75% and peripheral T-cell lymphoma 91%/78%. The corresponding figures in PET/CT-PR were 43%/44 and 33%/33%. Patients with solitary PET/CT-positive lesions showed acceptable outcome with ASCT followed by local irradiation (2-year OS/PFS 80%/60%). CT was less discriminative: 2-year OS/PFS: CT-CR, 76%/66%; CT-PR, 62%/51%. Outcome was inferior after BEAC compared with BEAM conditioning. CONCLUSIONS: We conclude that the improved outcome reflects better, PET/CT-informed, identification of patients who should proceed to ASCT. The excellent survival of patients in PET/CT-CR indicates that ASCT should remain part of standard therapy for lymphoma.

Longitudinal single-cell profiling reveals molecular heterogeneity and tumor-immune evolution in refractory mantle cell lymphoma.

The mechanisms driving therapeutic resistance and poor outcomes of mantle cell lymphoma (MCL) are incompletely understood. We characterize the cellular and molecular heterogeneity within and across patients and delineate the dynamic evolution of tumor and immune cell compartments at single cell resolution in longitudinal specimens from ibrutinib-sensitive patients and non-responders. Temporal activation of multiple cancer hallmark pathways and acquisition of 17q are observed in a refractory MCL. Multi-platform validation is performed at genomic and cellular levels in PDX models and larger patient cohorts. We demonstrate that due to 17q gain, BIRC5/survivin expression is upregulated in resistant MCL tumor cells and targeting BIRC5 results in marked tumor inhibition in preclinical models. In addition, we discover notable differences in the tumor microenvironment including progressive dampening of CD8+ T cells and aberrant cell-to-cell communication networks in refractory MCLs. This study reveals diverse and dynamic tumor and immune programs underlying therapy resistance in MCL.

Quantitative In Vivo Monitoring of Hypoxia and Vascularization of Patient-Derived Murine Xenografts of Mantle Cell Lymphoma Using Photoacoustic and Ultrasound Imaging.

Tumor oxygenation and vascularization are important parameters that determine the aggressiveness of the tumor and its resistance to cancer therapies. We introduce dual-modality ultrasound and photoacoustic imaging (US-PAI) for the direct, non-invasive real-time in vivo evaluation of oxygenation and vascularization of patient-derived xenografts (PDXs) of B-cell mantle cell lymphomas. The different optical properties of oxyhemoglobin and deoxyhemoglobin make it possible to determine oxygen saturation (sO2) in tissues using PAI. High-frequency color Doppler imaging enables the visualization of blood flow with high resolution. Tumor oxygenation and vascularization were studied in vivo during the growth of three different subcutaneously implanted patient-derived xenograft (PDX) lymphomas (VFN-M1, VFN-M2 and VFN-M5 R1). Similar values of sO2 (sO2 Vital), determined from US-PAI volumetric analysis, were obtained in small and large VFN-M1 tumors ranging from 37.9 ± 2.2 to 40.5 ± 6.0 sO2 Vital (%) and 37.5 ± 4.0 to 35.7 ± 4.6 sO2 Vital (%) for small and large VFN-M2 PDXs. In contrast, the higher sO2 Vital values ranging from 57.1 ± 4.8 to 40.8 ± 5.7 sO2 Vital (%) (small to large) of VFN-M5 R1 tumors corresponds with the higher aggressiveness of that PDX model. The different tumor percentage vascularization (assessed as micro-vessel areas) of VFN-M1, VFN-M2 and VFN-M5 R1 obtained by color Doppler (2.8 ± 0.1%, 3.8 ± 0.8% and 10.3 ± 2.7%) in large-stage tumors clearly corresponds with their diverse growth and aggressiveness. The data obtained by color Doppler were validated by histology. In conclusion, US-PAI rapidly and accurately provided relevant and reproducible information on tissue oxygenation in PDX tumors in real time without the need for a contrast agent.

CXCR4 PET imaging of mantle cell lymphoma using [68Ga]Pentixafor: comparison with [18F]FDG-PET.

For PET imaging of mantle cell lymphoma (MCL), [18F]FDG (2-deoxy-2-[18F]fluoro-D-glucose) is the currently recommended radiotracer, although uptake is variable and bone marrow evaluation is limited. In this prospective study, we evaluated the novel CXCR4 (G-protein-coupled C-X-C chemokine receptor type 4) tracer [68Ga]Pentixafor in MCL patients, and compared it to [18F]FDG. Methods: MCL patients underwent [68Ga]Pentixafor-PET/MRI, and, if required for routine purposes, also [18F]FDG-PET/MRI, before treatment. PET was evaluated separately for 23 anatomic regions (12 lymph node stations and 11 organs/tissues), using MRI as the main reference standard. Standardized uptake values (SUVmax and SUVmean) and tumor-to-background ratios (TBRblood and TBRliver) were calculated. General Estimation Equations (GEE) were used to compare [68Ga]Pentixafor-PET and [18F]FDG-PET sensitivities and positive predictive values (PPV). For bone marrow involvement, where biopsy served as the main reference standard, and splenic involvement, receiver operating characteristic curves were used to determine the optimal SUV and TBR cut-off values, and areas under the curve (AUC) were calculated. Results: Twenty-two MCL patients were included. [68Ga]Pentixafor-PET sensitivity (100%) was significantly higher than for [18F]FDG-PET (75.2%) (P<0.001), and PPV was slightly, but not significantly lower (94.0%.vs. 96.5%; P=0.21). SUVs and TBRs were significantly higher for [68Ga]Pentixafor-PET than for [18F]FDG-PET (P<0.001 in all cases); the greatest difference was observed for mean TBRblood, with 4.9 for [68Ga]Pentixafor-PET and 2.0 for [18F]FDG-PET. For bone marrow involvement, [68Ga]Pentixafor-PET SUVmean showed an AUC of 0.92; and for splenic involvement, TBRblood showed an AUC of 0.81. Conclusion: [68Ga]Pentixafor-PET may become an alternative to [18F]FDG-PET in MCL patients, showing clearly higher detection rates and better tumor-to-background contrast.

Central Nervous System Involvement in Mantle Cell Lymphoma Presenting Magnetic Resonance Imaging Features of Mild Encephalitis/Encephalopathy with a Reversible Splenial Lesion.

Mild encephalitis/encephalopathy with reversible splenial lesion (MERS) has not been described in lymphoma patients. A 65-year-old man with refractory mantle cell lymphoma (MCL) presented typical MRI features of MERS. The patient's cerebrospinal fluid contained an increased number of reactive T-cells; a small number of MCL cells were detected by immunoglobulin heavy chain-polymerase chain reaction (IGH-PCR). His symptoms and the splenial lesion resolved in response to ibrutinib treatment, although the patient eventually died of progressive MCL with overt leptomeningeal disease. We suggest that central nervous system involvement in MCL can present clinicoradiological features of MERS and that ibrutinib could be a choice of treatment.