FDG positron emission tomography/computed tomography scan may identify mantle cell lymphoma patients with unusually favorable outcome

[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.

Treatment of Mantle Cell Lymphoma in the Frontline Setting: Are We Ready for a Risk-Adapted Approach?

Mantle cell lymphoma (MCL), a type of B-cell non-Hodgkin lymphoma characterized by the t(11;14)(q13q32) translocation, is a clinically heterogenous disease which can range from indolent to highly aggressive. Numerous prognostic factors have been identified, including blastoid histology, the Mantle Cell Lymphoma International Prognostic Index (MIPI) score, high proliferation index, p53 deletions and/or mutations, complex karyotype, minimal residual disease, and several others. However, using these prognostic factors to guide treatment selection has largely remained elusive. Given the heterogeneous behavior of this disease and varying patient characteristics, we suggest that the time has come for a more risk-adapted approach to this disease. In this article, we review the numerous prognostic factors that have been described for MCL, both at the time of diagnosis and following first-line treatment. We then propose a risk-adapted approach to first-line therapy for MCL, which would reserve intensive therapy for the highest risk patients and spare others excessive toxicity.

Deep Neural Networks and Machine Learning Radiomics Modelling for Prediction of Relapse in Mantle Cell Lymphoma

Simple Summary

Mantle cell lymphoma (MCL) is an aggressive lymphoid tumour with a poor prognosis. There exist no routine biomarkers for the early prediction of relapse. Our study compared the potential of radiomics-based machine learning and 3D deep learning models as non-invasive biomarkers to risk-stratify MCL patients, thus promoting precision imaging in clinical oncology.

Abstract

Mantle cell lymphoma (MCL) is a rare lymphoid malignancy with a poor prognosis characterised by frequent relapse and short durations of treatment response. Most patients present with aggressive disease, but there exist indolent subtypes without the need for immediate intervention. The very heterogeneous behaviour of MCL is genetically characterised by the translocation t(11;14)(q13;q32), leading to Cyclin D1 overexpression with distinct clinical and biological characteristics and outcomes. There is still an unfulfilled need for precise MCL prognostication in real-time. Machine learning and deep learning neural networks are rapidly advancing technologies with promising results in numerous fields of application. This study develops and compares the performance of deep learning (DL) algorithms and radiomics-based machine learning (ML) models to predict MCL relapse on baseline CT scans. Five classification algorithms were used, including three deep learning models (3D SEResNet50, 3D DenseNet, and an optimised 3D CNN) and two machine learning models based on K-nearest Neighbor (KNN) and Random Forest (RF). The best performing method, our optimised 3D CNN, predicted MCL relapse with a 70% accuracy, better than the 3D SEResNet50 (62%) and the 3D DenseNet (59%). The second-best performing method was the KNN-based machine learning model (64%) after principal component analysis for improved accuracy. Our optimised CNN developed by ourselves correctly predicted MCL relapse in 70% of the patients on baseline CT imaging. Once prospectively tested in clinical trials with a larger sample size, our proposed 3D deep learning model could facilitate clinical management by precision imaging in MCL.

Lesion-Based Radiomics Signature in Pretherapy 18F-FDG PET Predicts Treatment Response to Ibrutinib in Lymphoma

PURPOSE

The aim of this study was to develop a pretherapy PET/CT-based prediction model for treatment response to ibrutinib in lymphoma patients.

PATIENTS AND METHODS

One hundred sixty-nine lymphoma patients with 2441 lesions were studied retrospectively. All eligible lymphomas on pretherapy 18F-FDG PET images were contoured and segmented for radiomic analysis. Lesion- and patient-based responsiveness to ibrutinib was determined retrospectively using the Lugano classification. PET radiomic features were extracted. A radiomic model was built to predict ibrutinib response. The prognostic significance of the radiomic model was evaluated independently in a test cohort and compared with conventional PET metrics: SUVmax, metabolic tumor volume, and total lesion glycolysis.

RESULTS

The radiomic model had an area under the receiver operating characteristic curve (ROC AUC) of 0.860 (sensitivity, 92.9%, specificity, 81.4%; P < 0.001) for predicting response to ibrutinib, outperforming the SUVmax (ROC AUC, 0.519; P = 0.823), metabolic tumor volume (ROC AUC, 0.579; P = 0.412), total lesion glycolysis (ROC AUC, 0.576; P = 0.199), and a composite model built using all 3 (ROC AUC, 0.562; P = 0.046). The radiomic model increased the probability of accurately predicting ibrutinib-responsive lesions from 84.8% (pretest) to 96.5% (posttest). At the patient level, the model's performance (ROC AUC = 0.811; P = 0.007) was superior to that of conventional PET metrics. Furthermore, the radiomic model showed robustness when validated in treatment subgroups: first (ROC AUC, 0.916; P < 0.001) versus second or greater (ROC AUC, 0.842; P < 0.001) line of defense and single treatment (ROC AUC, 0.931; P < 0.001) versus multiple treatments (ROC AUC, 0.824; P < 0.001).

CONCLUSIONS

We developed and validated a pretherapy PET-based radiomic model to predict response to treatment with ibrutinib in a diverse cohort of lymphoma patients.

Role of 18F-Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography Imaging in the Prediction of Prognosis in Patients With Indolent Lymphoma: Prospective Study

BACKGROUND

The role of fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) in indolent lymphoma has been minimally studied.

OBJECTIVE

This study aims to assess the value of FDG-PET/CT in predicting the prognosis of indolent lymphoma.

METHODS

We prospectively recruited 42 patients with indolent lymphoma. A total of 2 patients were excluded, and 40 underwent baseline PET/CT and follow-up at various time points. A total of 9 patients were observed only, 7 received 4 doses of rituximab alone, and 24 received chemoimmunotherapy. Metabolic response on follow-up PET/CT was assessed using the maximum standardized uptake value (SUVmax) and Deauville criteria (DC). We aimed to obtain the best SUVmax and DC to predict optimal survival rates, risk stratification, and optimize therapeutic strategies. The mean follow-up from the initial diagnosis was 33.83 months.

RESULTS

SUVmax <4.35 at interim PET/CT provided the best discrimination, with a progression-free survival (PFS) of 100% and a median survival time of 106.67 months compared with SUVmax ≥4.35 (P=.04), which had a PFS of 43.8% and a median survival time of 50.17 months. This cutoff was also valuable in predicting overall survival at baseline, that is, 100% overall survival with baseline SUVmax <4.35, versus 58.4% for SUVmax ≥4.35 (P=.13). The overall survival of patients with a baseline DC score <3.0 was 100%, with a median overall survival of 106.67 months.

CONCLUSIONS

We demonstrated the utility of PET/CT in indolent lymphomas. SUVmax (<4.35 vs ≥4.35) on interim PET/CT performed best in predicting PFS.

A picture is worth a thousand words: a history of diagnostic imaging for lymphoma

The journey from early drawings of Thomas Hodgkin's patients to deep learning with radiomics in lymphoma has taken nearly 200 years, and in many ways, it parallels the journey of medicine. By tracing the history of imaging in clinical lymphoma practice, we can better understand the motivations for current imaging practices. The earliest imaging modalities of the 2D era each had varied, site-dependent sensitivity, and the improved accuracy of imaging studies allowed new diagnostic and therapeutic techniques. First, we review the initial imaging technologies that were applied to understand lymphoma spread and achieve practical guidance for the earliest lymphoma treatments. Next, in the 3D era, we describe how anatomical imaging advances replaced and complemented conventional modalities. Afterward, we discuss how the PET era scans were used to understand response of tumors to treatment and risk stratification. Finally, we discuss the emergence of radiomics as a promising area of research in personalized medicine. We are now able to identify involved lymph nodes and body sites both before and after treatment to offer patients improved treatment outcomes. As imaging methods continue to improve sensitivity, we will be able to use personalized medicine approaches to give targeted and highly focused therapies at even earlier time points, and ideally, we can obtain long-term disease control and cures for lymphomas.

Application of 18F-fluorodeoxyglucose positron emission tomography/computerized tomography in mantle cell lymphoma

OBJECTIVE

The study is to investigate the application of F-fluorodeoxyglucose (F-FDG) PET/computerized tomography (CT) for the evaluation of mantle cell lymphoma (MCL).

METHODS

We retrospectively analyzed 39 patients who were pathologically diagnosed with MCL and underwent F-FDG PET/CT before treatment between August 2007 and August 2018. We compared the clinical information and PET/CT imaging characteristics in different groups based on bone marrow invasion, spleen invasion or International Prognostic Index (IPI) score. We also assessed the efficacy of PET/CT evaluation basing on the follow-up PET CT findings of 21 MCL patients and their biopsies.

RESULTS

Thirty-five patients were stage IV according to the Revised Ann Arbor Staging System. Lymph node involvement was observed in all 39 cases. The maximum diameter of the affected lymph nodes (4.33 ± 3.09 cm) and maximum standardized uptake value (SUVmax) (8.38 ± 4.99) was positively correlated (r = 0.486, P = 0.002). Extranodal invasion was identified in 38 patients with MCL, and the SUVmax of extranodal invasion was 7.34 ± 3.31. Extranodal invasion was most common in the spleen (25/38) and bone marrow (18/38). The group with bone marrow invasion was more prone to nasopharyngeal, lung and renal invasions (all P < 0.05). The groups with bone marrow invasion or spleen invasion were more likely to have decreased hemoglobin (Hgb) and platelets (all P < 0.01). The IPI high-risk group was more prone to lung involvement, elevated LDH and CRP, and decreased Hgb (all P < 0.05). Among the follow-up of 30 MCL patients, the 2-year progression-free survival and overall survival rates were 73.33 and 87.50%, respectively. PET/CT reexaminations of 21 MCL patients after treatment showed that the sensitivity, specificity, negative predictive value, positive predictive value and accuracy of the efficacy evaluation were 80, 90.91, 88.89, 83.33 and 85.71%, respectively.

CONCLUSION

F-FDG PET/CT imaging has important application value in the diagnosis, staging, treatment efficacy assessment and prognosis monitoring of MCL, especially in the systemic assessment of advanced MCL.

18F-FDG PET or PET/CT in Mantle Cell Lymphoma

The aim of this systematic review was to examine published data about the potential role of Fluorine-18-fluorodeoxyglucose positron emission tomography or positron emission tomography/computed tomography (¹⁸F-FDG PET or PET/CT) in patients affected by mantle cell lymphoma (MCL). A comprehensive computer literature search of Scopus, PubMed/MEDLINE, and Embase databases was conducted, including articles indexed up to November, 2019; 25 studies or subsets in studies analyzing the value of ¹⁸F-FDG PET or PET/CT in patients with MCL were eligible for inclusion. From the analyses of the selected studies, the following main findings are described: (1) MCL are ¹⁸F-FDG-avid in most of cases, especially nodal lesions, but bone marrow and gastrointestinal disease localizations have low ¹⁸F-FDG avidity; (2) ¹⁸F-FDG PET/CT seems to be helpful in staging setting, showing a better diagnostic performance than conventional imaging and a positive impact on clinical stage; (3) ¹⁸F-FDG PET/CT is useful in evaluating treatment response, especially after chemotherapy and transplantation; and (4) metabolic response after therapy seems to have a prognostic role. Despite several limitations affecting this analysis, especially related to the heterogeneity of the studies included, MCL is an ¹⁸F-FDG-avid lymphoma in most of the cases, with the exception of bone marrow and gastrointestinal disease. Moreover, ¹⁸F-FDG PET/CT seems to be useful in evaluating treatment response and prognosis.

The Role of 18F-FDG PET/CT in Staging and Prognostication of Mantle Cell Lymphoma: An Italian Multicentric Study

Mantle cell lymphoma (MCL) is an aggressive lymphoma subtype with poor prognosis in which 18F-FDG-PET/CT role in treatment response evaluation and prediction of outcome is still unclear. The aim of this multicentric study was to investigate the role of 18F-FDG-PET/CT in staging MCL and the prognostic role of Deauville criteria (DC) in terms of progression-free survival (PFS) and overall survival (OS). We retrospectively enrolled 229 patients who underwent baseline and end-of-treatment (eot) 18F-FDG-PET/CT after first-line therapy. EotPET/CT scans were visually interpreted according to DC. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT for evaluation of bone marrow (BM) were 27%, 100%, 100%, 48% and 57%, respectively. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of PET/CT for evaluation of the gastrointestinal (GI) tract were 60%, 99%, 93%, 90% and 91%, respectively. At a median follow-up of 40 months, relapse occurred in 104 cases and death in 49. EotPET/CT results using DC significantly correlated with PFS, not with OS. Instead, considering OS, only MIPI score was significantly correlated. In conclusion, we demonstrated that MCL is an FDG-avid lymphoma and 18F-FDG-PET/CT is a useful tool for staging purpose, showing good specificity for BM and GI evaluation, but suboptimal sensitivity. EotPET/CT result was the only independent significant prognostic factor that correlated with PFS.

Prognostic impact of interim positron emission tomography in mantle cell lymphoma patients treated with frontline R-CHOP

Although ¹⁸F‐fluorodeoxyglucose positron emission tomography (¹⁸F‐FDG PET) is commonly used for initial staging and therapeutic response evaluation in aggressive lymphomas, its prognostic utility for mantle cell lymphoma (MCL) is controversial. Therefore, we retrospectively evaluated the correlations of interim PET (iPET) and end‐of‐treatment PET (ePET) response with survival outcomes in 89 consecutive advanced MCL patients treated with frontline R‐CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone). iPET positivity was strongly associated with inferior five‐year overall survival (OS) [hazard ratio (HR) 7·84, P < 0·0001] and poor five‐year progression‐free survival (PFS) (HR 3·34, P < 0·0001). OS and PFS were more favourable in the order early metabolic responder (iPET^neg → ePET^neg), delayed responder (iPET^pos → ePET^neg), loss‐metabolic responder (iPET^neg → ePET^pos), and never‐metabolic responder (iPET^pos → ePET^pos). In the autologous haematopoietic stem cell transplantation (auto‐HSCT)‐fit subgroup, OS was more favourable in the order early metabolic responders, delayed metabolic responders, and non‐metabolic responders, with a marginal trend toward statistical significance (HR 3·41, P = 0·051), and PFS was significantly superior in early metabolic responders (HR 4·43, P = 0·002). In a group that was ineligible for auto‐HSCT, OS and PFS were significantly superior in early metabolic responders. Our results suggested that iPET is of prognostic value and an independent predictor of survival in MCL patients receiving frontline R‐CHOP. Therefore, prospective clinical trials of iPET‐guided treatment strategies for these patients are warranted.

Radiomic features of glucose metabolism enable prediction of outcome in mantle cell lymphoma

PURPOSE

To determine whether [¹⁸F]FDG PET/CT-derived radiomic features alone or in combination with clinical, laboratory and biological parameters are predictive of 2-year progression-free survival (PFS) in patients with mantle cell lymphoma (MCL), and whether they enable outcome prognostication.

METHODS

Included in this retrospective study were 107 treatment-naive MCL patients scheduled to receive CD20 antibody-based immuno(chemo)therapy. Standardized uptake values (SUV), total lesion glycolysis, and 16 co-occurrence matrix radiomic features were extracted from metabolic tumour volumes on pretherapy [¹⁸F]FDG PET/CT scans. A multilayer perceptron neural network in combination with logistic regression analyses for feature selection was used for prediction of 2-year PFS. International prognostic indices for MCL (MIPI and MIPI-b) were calculated and combined with the radiomic data. Kaplan-Meier estimates with log-rank tests were used for PFS prognostication.

RESULTS

SUVmean (OR 1.272, P = 0.013) and Entropy (heterogeneity of glucose metabolism; OR 1.131, P = 0.027) were significantly predictive of 2-year PFS: median areas under the curve were 0.72 based on the two radiomic features alone, and 0.82 with the addition of clinical/laboratory/biological data. Higher SUVmean in combination with higher Entropy (SUVmean >3.55 and entropy >3.5), reflecting high "metabolic risk", was associated with a poorer prognosis (median PFS 20.3 vs. 39.4 months, HR 2.285, P = 0.005). The best PFS prognostication was achieved using the MIPI-bm (MIPI-b and metabolic risk combined): median PFS 43.2, 38.2 and 20.3 months in the low-risk, intermediate-risk and high-risk groups respectively (P = 0.005).

CONCLUSION

In MCL, the [¹⁸F]FDG PET/CT-derived radiomic features SUVmean and Entropy may improve prediction of 2-year PFS and PFS prognostication. The best results may be achieved using a combination of metabolic, clinical, laboratory and biological parameters.

Interest of FDG-PET in the Management of Mantle Cell Lymphoma

FDG-PET changed response assessment and therapy strategy in diffuse large B-cell lymphoma and Hodgkin disease lymphoma. The value of FDG-PET evaluation in MCL has not been extensively studied and a recent expert consensus highlighted the need for more studies addressing this question. Data of the literature show the value of FDG-PET at baseline in patients with MCL, underlining the good sensitivity of this examination for the initial staging of this pathology, but also the potential impact of semi-quantitative analysis in this indication. The determination of SUVmax at diagnosis might indeed provide important prognostic information. Some studies also suggest the potential value of early and end-of-treatment metabolic assessment in MCL, but these results need to be validated in standardized prospective studies. These results also underlie the need to integrate FDG-PET results into MCL treatment strategy to improve disease management in identifying patients who might benefit from more intensive therapy.

Spontaneous regression of mantle cell lymphoma: a report of four cases

Background

Spontaneous regression has been reported in some indolent forms of lymphoma. Mantle cell lymphoma (MCL) is an aggressive lymphoid neoplasm and has a poor prognosis. However, approximately 30% of MCL patients can exhibit indolent clinical behavior. To date, complete spontaneous regression of MCL has not been reported.

Case presentation

We describe four cases of spontaneous regression of MCL. At the time of presentation, these patients were asymptomatic, with lymph node enlargement and mild to moderate fluorodeoxyglucose (FDG) uptake on FDG-positron emission tomography combined with computed tomography. One of the possible mechanisms of spontaneous regression of the tumor could be due to the host immune response through humoral and cellular immunity, which may have a role in the clearance of tumor cells.

Conclusions

In this report, we support the use of a “wait and watch” strategy for MCL patients with no risk factors and indolent behavior. This strategy helps spare patients from further potentially harmful chemotherapy. In addition, we describe the phenomenon of spontaneous regression in MCL patients who are asymptomatic and have low-volume disease.

Mantle cell lymphoma in the era of precision medicine-diagnosis, biomarkers and therapeutic agents

Despite advances in the development of clinical agents for treating Mantle Cell Lymphoma (MCL), treatment of MCL remains a challenge due to complexity and frequent relapse associated with MCL. The incorporation of conventional and novel diagnostic approaches such as genomic sequencing have helped improve understanding of the pathogenesis of MCL, and have led to development of specific agents targeting signaling pathways that have recently been shown to be involved in MCL. In this review, we first provide a general overview of MCL and then discuss about the role of biomarkers in the pathogenesis, diagnosis, prognosis, and treatment for MCL. We attempt to discuss major biomarkers for MCL and highlight published and ongoing clinical trials in an effort to evaluate the dominant signaling pathways as drugable targets for treating MCL so as to determine the potential combination of drugs for both untreated and relapse/refractory cases. Our analysis indicates that incorporation of biomarkers is crucial for patient stratification and improve diagnosis and predictability of disease outcome thus help us in designing future precision therapies. The evidence indicates that a combination of conventional chemotherapeutic agents and novel drugs designed to target specific dysregulated signaling pathways can provide the effective therapeutic options for both untreated and relapse/refractory MCL.

Smoldering mantle cell lymphoma

Background

Mantle cell lymphoma (MCL) is an aggressive disease, with poor prognosis and a limited survival. However, some patients with indolent MCL can survive beyond 7~10 years. These patients remain largely asymptomatic and can be in observation for a long time without any treatment. The process of “wait and watch” leaves these patients with the potential risk of evolution to classic, aggressive MCL. On the other hand, early treatment for these patients may not impact overall survival but rather affects the quality of life. Therefore, it is essential to clearly identify this type of indolent MCL at the time of diagnosis.

Results

Reported findings of indolent presentation of MCL include: lack of B symptoms, normal serum lactic dehydrogenase (LDH) and β2-microglobulin levels (β2M), low MCL-International Prognostic Index (MIPI) score, maximum tumor diameter less than 3 cm, spleen size < 20 cm, positron emission tomography/computerized tomography with the Standard Uptake Value max <6, Ki-67 less than 30%, with some particular immunophenotype, such as CD5 and CD38 negative, markedly increased CD23 positive lymphocytes proportions, high expression of CD200, kappa light chain restriction, without C-myc, TP53 and NOTCH1/2 mutations, non-blastoid/pleomorphic histology, and no tumor growth on reevaluation every 2~3 months (followed for at least 6 months). Imaging evaluation may only be performed in the presence of disease-related symptoms or organ involvement. Meanwhile, if novel nodal or extranodal lesion is found, biopsy is mandatory to exclude lymphoma.

Common clinopathological forms of indolent presentations include monoclonal B lymphocytosis with t (11; 14); “indolent leukemic” presentation of MCL with involvement of peripheral blood, bone marrow involvement, splenomegaly, and minimal lymphadenopathies and in situ lymphoma (often found in lymph nodes removed for other reasons, and in gastrointestinal biopsies).

Conclusions

Considering these distinct indolent clinical presentations with particular features in cytology and gene mutational status, we propose to include these MCL clinical presentations under the umbrella of “Smoldering Mantle Cell Lymphoma”.

Evaluating the Predictive Ability of Initial Staging F-18 FDG PET/CT for the Prognosis of Non-Hodgkin Malignant Lymphoma Patients Who Underwent Stem Cell Transplantation

Objectives

This study aimed to determine the value of clinical prognostic factors and semiquantitative metabolic parameters from initial staging fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (F-18 FDG PET/CT) in non-Hodgkin lymphoma (NHL) patients treated with stem cell transplantation (SCT).

Methods

A total of 39 malignant lymphoma patients who underwent initial staging F-18 FDG PET/CT were enrolled in this study. SUVmax, MTV_wb, and TLG_wb were measured during the initial staging PET/CT. Receiver operating characteristic curve (ROC) analysis was adopted to dichotomize continuous variables. Log-rank test and Cox proportional hazard regression analysis were used to evaluate disease-free survival (DFS) rate.

Results

Among the 39 patients with malignant lymphoma, 17 (43.6%) had a relapse. For several clinical factors such as age, ECOG performance score, AMC/ALC score, stages, and revised International Prognostic Index score, differences between the two dichotomized groups were statistically insignificant. In univariate analysis, DFS estimates were 71.0 ± 7.8 months and 18.0 ± 5.9 months in high-SUVmax and low-SUVmax group, respectively (P < 0.01). For MTV_wb, DFS estimates were 46.6 ± 12.4 months and 69.1 ± 8.5 months in high-MTV_wb and low-MTV_wb group, respectively (P = 0.12). For TLG_wb, DFS estimates were 65.3 ± 7.5 months and 13.7 ± 8.6 months in high-TLG_wb and low-TLG_wb group, respectively (P = 0.02). In Cox proportional hazard regression analysis, only MTV_wb showed statistical significance (HR 3.01, 95% CI 1.04-8.74, P = 0.04).

Conclusion

In NHL patients treated with SCT, the MTV_wb of initial staging F-18 FDG PET/CT was an independent prognostic factor.

SUV navigator enables rapid [18F]-FDG PET/CT image interpretation compared with 2D ROI and 3D VOI evaluations

PURPOSE

Positron emission tomography (PET) and the maximum standardized uptake value (SUV_max) is a useful technique for assessing malignant tumors. Measurements of SUV_max in multiple lesions per patient frequently require many time-consuming procedures. To address this issue, we designed a novel interface named SUV Navigator (SUVnavi), and the purpose of this study was to investigate its utility.

MATERIALS AND METHODS

We measured SUV_max in 661 lesions from 100 patients with malignant tumors. Diagnoses and SUV_max measurements were made with SUVnavi, 2D, and 3D measurements. SUV measurement accuracy in each method were also evaluated.

RESULTS

The average reduction in time with SUVnavi versus 2D was 53.8% and 3D was 37.5%; time required with SUVnavi was significantly shorter than with 2D and 3D (P < 0.001 and P < 0.001, respectively). The time reduction and lesion number had a positive correlation (P < 0.001 and P < 0.001, respectively). SUV_max agreed with precise SUV_max in all lesions measured with SUVnavi and 3D but in only 466 of 661 lesions (70.5%) measured with 2D.

CONCLUSION

SUVnavi may be useful for rapid [¹⁸F]-fluorodeoxyglucose positron emission tomography/computed tomography ([¹⁸F]-FDG PET/CT) image interpretation without reducing the accuracy of SUV_max measurement.

Prognostic value of SUVmax measured by pretreatment 18F-FDG PET/CT in patients with primary gastric lymphoma

PURPOSE

The aim of this retrospective study was to determine whether glucose metabolism assessed by fluorine-18 fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) provides prognostic information independent of established prognostic factors in patients with gastric lymphoma.

PATIENTS AND METHODS

We reviewed the medical records of 86 patients retrospectively (men, 42; women, 44; mean age 58±13 years) with pathologically proven gastric lymphoma (34 mucosa-associated lymphoid tissue and 52 aggressive non-Hodgkin's lymphoma). They underwent F-FDG PET/CT as part of a pretreatment work-up from February 2004 to July 2012. For the analysis, patients were classified by age, sex, Musshoff stage, serum lactate dehydrogenase, International Prognostic Index score, extragastric spread, and visual intensity [visual assessment and maximum standardized uptake value (SUVmax), respectively]. The relationship between F-FDG uptake and survival was analyzed using the Kaplan-Meier method with a log-rank test and Cox's proportional-hazard regression method.

RESULTS

The median survival of all 86 study participants was 1117 days and the median SUV measured by PET/CT was 6.1 (range, 1.9-32.7). Patients with an SUVmax less than or equal to 5.2 survived significantly longer than patients with an SUVmax more than 5.2 (median, 1163 vs. 1004 days; P=0.003). Survival was also found to be significantly related to age (P=0.0005), histological type (P=0.004), extragastric spread (P=0.0004), International Prognostic Index score (P<0.0001), serum lactate dehydrogenase (P=0.02), stage (P<0.0001), and visual intensity (P=0.041). A multivariate analysis showed that patients with a higher SUVmax [P=0.021; 95% confidence interval (CI), 1.52-8.14; hazard ratio (HR)=6.29], older age (P=0.001; 95% CI, 4.64-219.96; HR=18.8), more aggressive histologic type (P=0.006; 95% CI, 2.20-70.63; HR=12.76), and higher stage (P=0.0006; 95% CI, 5.81-206.43; HR=17.48) showed worse survival.

CONCLUSION

A higher SUVmax on pretreatment F-FDG PET/CT can predict poorer survival in patients with gastric lymphoma.

Imaging of non-Hodgkin lymphomas: diagnosis and response-adapted strategies

Optimal lymphoma management requires accurate pretreatment staging and reliable assessment of response, both during and after therapy. Positron emission tomography with computerized tomography (PET/CT) combines functional and anatomical imaging and provides the most sensitive and accurate methods for lymphoma imaging. New guidelines for lymphoma imaging and recently revised criteria for lymphoma staging and response assessment recommend PET/CT staging, treatment monitoring, and response evaluation in all FDG-avid lymphomas, while CT remains the method of choice for non-FDG-avid histologies. Since interim PET imaging has high prognostic value in lymphoma, a number of trials investigate PET-based, response-adapted therapy for non-Hodgkin lymphomas (NHL). PET response is the main determinant of response according to the new response criteria, but PET/CT has little or no role in routine surveillance imaging, the value which is itself questionable. This review presents from a clinical point of view the evidence for the use of imaging and primarily PET/CT in NHL before, during, and after therapy. The reader is given an overview of the current PET-based interventional NHL trials and an insight into possible future developments in the field, including new PET tracers.

Mantle cell lymphoma: observation to transplantation

Mantle cell lymphoma as a rare non-Hodgkin B-cell lymphoma can present in different clinical presentations such as an aggressive form or a more indolent picture. Treatment modality is based on multiple factors including age, presence or absence of symptoms, and comorbidities. Watchful waiting is a reasonable approach for asymptomatic patients especially in elderly. In symptomatic patients, treatment is chemo-immunotherapy followed by maintenance immunotherapy or autologous bone marrow transplant. Allogeneic bone marrow transplant has a potential benefit of cure for relapsed/refractory cases, but it has a high mortality rate. Novel treatment with agents such as ibrutinib, a Bruton tyrosine kinase inhibitor, has shown promising results in relapse/refractory cases. We extensively review the most recent data on diagnostic and therapeutic management of mantle cell lymphoma through presenting two extreme clinical scenarios.

FDG PET/CT imaging as a biomarker in lymphoma

FDG PET/CT has changed the management of FDG-avid lymphoma and is now recommended as the imaging technique of choice for staging and restaging. The need for tailoring therapy to reduce toxicity in patients with a favourable outcome and for improving treatment in those with high-risk factors requires accurate diagnostic methods and a new prognostic algorithm to identify different risk categories. New drugs are used in relapsed/refractory patients. The role of FDG PET/CT as a biomarker in this context is summarized in this review. New trends in FDG metabolic imaging in lymphoma are addressed including metabolic tumour volume measurement at staging and integrative PET which combines PET data with clinical and molecular markers or other imaging techniques. The quantitative approach for response assessment which is under investigation and is used in large ongoing trials is compared with visual criteria. The place of FDG in the era of targeted therapy is discussed.

Positron Emission Tomography (PET) in Oncology

Since its introduction in the early nineties as a promising functional imaging technique in the management of neoplastic disorders, FDG-PET, and subsequently FDG-PET/CT, has become a cornerstone in several oncologic procedures such as tumor staging and restaging, treatment efficacy assessment during or after treatment end and radiotherapy planning. Moreover, the continuous technological progress of image generation and the introduction of sophisticated software to use PET scan as a biomarker paved the way to calculate new prognostic markers such as the metabolic tumor volume (MTV) and the total amount of tumor glycolysis (TLG). FDG-PET/CT proved more sensitive than contrast-enhanced CT scan in staging of several type of lymphoma or in detecting widespread tumor dissemination in several solid cancers, such as breast, lung, colon, ovary and head and neck carcinoma. As a consequence the stage of patients was upgraded, with a change of treatment in 10%-15% of them. One of the most evident advantages of FDG-PET was its ability to detect, very early during treatment, significant changes in glucose metabolism or even complete shutoff of the neoplastic cell metabolism as a surrogate of tumor chemosensitivity assessment. This could enable clinicians to detect much earlier the effectiveness of a given antineoplastic treatment, as compared to the traditional radiological detection of tumor shrinkage, which usually takes time and occurs much later.

Is there a role for therapy response assessment with 2-[fluorine-18] fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography in mantle cell lymphoma?

2-[Fluorine-18] fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) scanning is used for response assessment in mantle cell lymphoma (MCL). However, its ability to predict outcome is debatable. We retrospectively evaluated the prognostic impact of interim and post therapy FDG-PET/CT scan on outcome of 58 consecutive MCL patients. Scans performed at diagnosis, mid-therapy, post-chemotherapy and post-transplant were reviewed and outcome analyzed. Median age was 59; MCL International Prognostic Index (MIPI) was low in 45%, intermediate in 41% and high in 14%. Thirty-four patients (58%) received R-CHOP (rituximab, cyclophosphamide, hydroxydaunorubicin, oncovin, prednisone) or R-CHOP-like chemotherapy, 24 (42%) underwent upfront autologous stem-cell transplant (ASCT). Three-year overall (OS) and progression-free-survival (PFS) were 81% and 45%, respectively. No differences in OS or PFS between PET-positive and PET-negative groups both for interim and post-therapy scans were observed. We conclude that in patients treated with R-CHOP, using the International-Harmonization-Project criteria for FDG-PET/CT interpretation, there is no role for interim or post-therapy PET.

Recent Trends in PET Image Interpretations Using Volumetric and Texture-based Quantification Methods in Nuclear Oncology

Image quantification studies in positron emission tomography/computed tomography (PET/CT) are of immense importance in the diagnosis and follow-up of variety of cancers. In this review we have described the current image quantification methodologies employed in (18)F-fluorodeoxyglucose ((18)F-FDG) PET in major oncological conditions with particular emphasis on tumor heterogeneity studies. We have described various quantitative parameters being used in PET image analysis. The main contemporary methodology is to measure tumor metabolic activity; however, analysis of other image-related parameters is also increasing. Primarily, we have identified the existing role of tumor heterogeneity studies in major cancers using (18)F-FDG PET. We have also described some newer radiopharmaceuticals other than (18)F-FDG being studied/used in the management of these cancers. Tumor heterogeneity studies are being performed in almost all major oncological conditions using (18)F-FDG PET. The role of these studies is very promising in the management of these conditions.

Initial therapy of mantle cell lymphoma

Mantle cell lymphoma is a well-recognized distinct clinicopathologic subtype of B-cell non-Hodgkin lymphoma. The current World Health Organization (WHO) classification subdivides this entity into aggressive and other variants. The disease has a predilection for older males, and patients typically present at an advanced stage with frequent splenomegaly and extranodal involvement including bone marrow, peripheral blood, gastrointestinal, and occasional central nervous system involvement. Early studies of therapy outcomes in this disease revealed that while response rates where high, relapse was expected after a limited period of time. Prolonged survival was uncommon, with initial median survival rates typically in the 3-4-year range. Those with a high proliferative rate, blastoid morphology, and selected clinical features were recognized as having a worse prognosis. Therapeutic approaches have diverged into aggressive therapies with high response rates and promising progression free survival rates, which may be applied to younger healthy patients, and less aggressive approaches. Aggressive therapies include intensive chemotherapy alone or chemotherapy followed by autologous stem cell transplant, which has been shown to be most effective when applied in first remission. Whether these more intense therapies result in improved survival as compared with less aggressive therapies is not well established. Allogeneic transplant has also been investigated, although high treatment-related mortality and the risk of chronic graft versus host disease and the relatively advanced age of this patient population have tempered enthusiasm for this approach. A number of less aggressive therapies have been shown to produce promising results. Consolidation and maintenance strategies are an active area of investigation. A number of newer agents have shown promising activity in relapsed disease, and are being investigated in the front-line setting. Overall survival rates are improving in this disease, with current studies suggesting a median survival of 5 or more years.

Utility of positron emission tomography scans in mantle cell lymphoma

Positron emission tomography (PET) scans are widely used in patients with lymphoma but little is known about their utility in mantle cell lymphoma (MCL). MCL patients were included from two prospective trials and one observational study at our institution. A total of 276 PET scans were performed among 52 patients. After a median follow-up of 37.5 months, the 3-year event-free survival (EFS) and overall survival (OS) were 73% (95% confidence interval [CI]: 61-85%) and 92% (95% CI 85-100%), respectively. There were 34 pretreatment PET scans, 26 interim, 28 end-of-treatment, 162 surveillance, and 26 scans at relapse or beyond. Pretreatment PETs were positive in 94%. A negative interim or end-of-therapy PET scan was not significantly associated with better EFS or OS, but no deaths were observed in patients who had a negative interim or end-of-therapy PET. Surveillance PET scans had a high false positive rate (35%) and low positive predictive value (8%). PET scans contributed to an earlier diagnosis of relapse in only two out of the 18 patients (11%) who relapsed. PET scans did not meaningfully contribute to staging or surveillance of MCL patients in this study. There was a trend toward improved survival in patients who had a negative end-of-therapy PET scan.

Interim positron emission tomography scan associated with international prognostic index and germinal center B cell-like signature as prognostic index in diffuse large B-cell lymphoma

[(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET) imaging is essential to optimize the initial staging and to predict the prognosis of diffuse large B-cell lymphoma (DLBCL). To assess the relationship between the germinal center B cell-like/activated B cell-like (GCB/ABC) classification and PET scan features in DLBCL, 57 cases treated with rituximab and a cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP)/CHOP-like regimen were analyzed. The expression profile of 18 GCB/ABC related genes and five genes coding for glucose transporters (GLUTs) was determined from frozen tissues using DASL (cDNA-mediated Annealing, Selection, Ligation and extension) technology. According to the gene expression profile (GEP), 30 cases of DLBCL were classified as GCB subtype (2-year progression-free survival [PFS] 76%) and 27 cases as ABC subtype (2-year PFS 51%, p = 0.03). Using a semiquantitative assessment of the decrease in standard uptake value (SUV) at interim PET performed after 3-4 cycles of chemotherapy, we defined fast (n = 36) and slow (n = 9) metabolic responders. In multivariate analysis, GCB/ABC subtype, age-adjusted international prognostic index (aaIPI) and slow/fast metabolic response were independent variables that predicted outcome. A score incorporating aaIPI, fast/slow metabolic response and GCB/ABC classification was used to define two groups with highly significantly distinct outcomes. Our study suggests that the combination of GEP, aaIPI and interim PET more accurately predicts DLBCL prognosis and is therefore suitable for tailoring therapeutic strategies.

Expression of glucose transporter-1, hypoxia-inducible factor-1α, phosphatidylinositol 3-kinase and protein kinase B (Akt) in relation to [(18)F]fluorodeoxyglucose uptake in nasopharyngeal diffuse large B-cell lymphoma: a case report and literature review

This report presents a case of nasopharyngeal diffuse large B-cell lymphoma and a literature review concerning the use of [(18)F]fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT). A 37-year old man was admitted to hospital complaining of nasal secretions with minor epistaxis and a 20-year history of snoring. Nasal endoscopy found diffuse swelling in the nasopharynx and a biopsy was performed. Prior to chemotherapy, FDG-PET/CT showed soft tissue diffuse thickening and FDG accumulation in the nasopharynx and bilateral cervical lymph nodes; FDG did not accumulate elsewhere. After four cycles of chemotherapy (rituximab, cyclo phosphamide, doxorubicin, vincristine) and prednisone treatment, FDG-PET/CT showed that FDG still accumulated in the nasopharynx and bilateral cervical lymph nodes, therefore radiotherapy was initiated. At 1 year, FDG-PET/CT showed no FDG accumulation. Immunohistochemical analysis revealed that the tumour was positive for phosphorylated protein kinase B (Akt), suggesting that FDG uptake may be associated with factors activated by the phosphatidylinositol 3-kinase/Akt signalling pathway.

Fluorodeoxyglucose-positron-emission tomography findings in mantle cell lymphoma

OBJECTIVE

Mantle cell lymphoma (MCL) is an aggressive type of non-Hodgkin lymphoma with a propensity for extranodal involvement. The role of fluorodeoxyglucose (FDG)-positron emission tomography (PET) imaging in common types of lymphoma has been well-established. However, there is limited information in the literature about the utility of FDG-PET imaging in patients who have MCL. The aim of this study was to determine the role of FDG-PET imaging in assessment of disease activity in MCL compared with conventional imaging techniques such as computerized tomography/magnetic resonance imaging (CT/MRI).

METHODS

FDG-PET images of 20 patients with MCL who were referred to our center for assessment of extent of disease were reviewed retrospectively. The FDG-PET findings were compared with those of CT/MRI and were correlated with clinical information, histopathology, and outcome.

RESULTS

The diagnostic sensitivity for PET was 90% (17/19), and specificity was 100% (1/1). For CT/MRI, the sensitivity was 87% (14/16) and specificity was 50% (2/4). PET was better than CT/MRI in detecting nodal involvement. With respect to extranodal involvement, PET detected more cases of spleen involvement than CT/MRI. PET was equivalent to conventional imaging in detecting bowel involvement.

CONCLUSIONS

PET imaging has a high sensitivity in detecting both nodal and extranodal involvement in patients who have MCL. Based on the available data in patients who had other subtypes of non-Hodgkin lymphoma, the specificity of PET also appears to be superior to anatomic imaging techniques. FDG-PET imaging may prove to be the single most effective method for detection.

Standardised uptake value of 18F-FDG on staging PET/CT in newly diagnosed patients with different subtypes of non-Hodgkin's lymphoma

OBJECTIVES

Positron emission tomography using 2-[fluorine-18]-fluoro-2-deoxy-D-glucose ((18) F-FDG) is considered to be the most beneficial imaging method for staging patients with non-Hodgkin's lymphoma (NHL). The intensity of (18) F-FDG accumulation may be determined by calculating the so-called standardised uptake value (SUV). The study aimed at assessing the benefit of SUV(max) determination in staging (18) F-FDG PET/CT in untreated patients with NHL.

METHODS

One hundred and forty-nine initial staging (18) F-FDG PET/CT scans performed in patients with NHL between January 2007 and August 2009 were assessed, and the SUV(max) was determined.

RESULTS

The highest mean and median values of SUV(max) were observed in patients with diffuse large B-cell lymphoma (DLBCL), the lowest mean and median values were found in small lymphocytic lymphoma. The overlap in SUV(max) < 10 between DLBCL and the other subgroups of NHL was very significant. Statistically, no correlation was found between the lactate dehydrogenase and SUV(max) values. On the other hand, a correlation of the Ki-67 proliferative index of tumour cells and SUV(max) was revealed (r = 0.409, P < 0.001). The geometric mean of SUV(max) in patients with Ki-67 ≤ 60 and those with Ki-67 > 60 was 8.8 and 14.3, respectively (P < 0.001).

CONCLUSIONS

The results confirm that SUV(max) is not beneficial for making a more precise diagnosis in most patients with NHL. Correlation of SUV(max) with the Ki-67 values suggests that SUV(max) might have a prognostic values in NHL.

Prognostic impact of 18F-fluoro-deoxyglucose positron emission tomography in untreated mantle cell lymphoma: a retrospective study from the GOELAMS group

PURPOSE

(18)F-fluorodeoxyglucose (FDG) PET is a non-invasive imaging technique recommended for the management of both diffuse large B-cell and Hodgkin's lymphomas. This retrospective study investigated the value of FDG PET for initial staging and its prognostic impact on patients with mantle cell lymphoma (MCL).

METHODS

A total of 44 untreated MCL patients assessed by both conventional evaluations (CE) and FDG PET for initial staging were included. The maximum standardized uptake value (SUV(max)) in the most intense pathological area was recorded for each patient. Disease status after chemotherapy completion was assessed according to the International Workshop Criteria (IWC) for non-Hodgkin's lymphoma (NHL) response and IWC+PET.

RESULTS

FDG PET uptakes at diagnosis were abnormal in all cases. Compared to CT scan, nodal and extranodal sites were only detected by FDG PET. Due to insufficient sensibility for bone marrow (BM) and gastrointestinal (GI) involvement, FDG PET did not modify initial staging. Positive and negative predictive values of IWC+PET for relapse at 1 year were 62.5 and 100%. With a median follow-up of 21 months, only the International Prognostic Index (IPI) and IWC+PET modified both event-free survival (EFS) (p = .02 and .0001, respectively) and overall survival (p = .03 and .05, respectively) duration. When combining IPI and SUV(max) at diagnosis, we were able to identify patients with low (29%; no relapse/progression), intermediate (42%; median EFS: 37 months) and high risk (29%, median EFS: 22 months) (p = .004).

CONCLUSION

In MCL, FDG PET at diagnosis is complementary to CE, but BM and GI biopsies remain mandatory. IWC+PET criteria are highly efficient to identify patients with high risk for early relapse. Combining IPI and SUV(max) may predict patient outcome and warrant further prospective investigations towards designing risk-adapted strategies.