Maximum standard uptake value of 18F-fluorodeoxyglucose positron emission tomography is a prognostic factor for progression-free survival of newly diagnosed patients with diffuse large B cell lymphoma

Radioimmunotherapy with 131 I-rituximab for patients with relapsed or refractory follicular or mantle cell lymphoma

AIM

This study aimed to evaluate the safety and efficacy of 131 I-rituximab in patients with relapsed or refractory follicular or mantle cell lymphoma.

METHODS

Twenty-four patients with relapsed or refractory follicular or mantle cell lymphoma were administered unlabeled rituximab (70 mg) immediately before receiving a therapeutic dose of 131 I-rituximab. Contrast-enhanced 18F-fluorodeoxyglucose positron emission tomography/computed tomography was used a month later to assess tumor response.

RESULTS

This study enrolled 24 patients between June 2012 and 2022. Depending on how they responded to radioimmunotherapy (RIT), 131 I-rituximab was administered one to five times. Of the 24 patients, 9 achieved complete response after RIT and 8 achieved partial response. The median progression-free and overall survival was 5.9 and 37.9 months, respectively. During the follow-up period of 64.2 months, three patients were diagnosed with a secondary malignancy. Among treatment-related adverse events, hematologic toxicities were common, and grade 3-4 thrombocytopenia and neutropenia were reported in 66.6% of cases.

CONCLUSION

131 I-rituximab has an effective and favorable safety profile in patients with relapsed or refractory follicular lymphoma and mantle cell lymphoma. This suggests that RIT may also be considered a treatment option for patients with relapsed or refractory follicular lymphoma and mantle cell lymphoma.

Prognostic importance of SUVmax values evaluated by 18F-FDG-PET/CT before nivolumab treatment in patients with metastatic renal cell carcinoma

BACKGROUND

Nivolumab is a monoclonal antibody that binds to the programmed death-1 (PD-1) receptor and blocks its interaction with PD-L1 and PD-L2. High response rates have been achieved with its use in the treatment of metastatic renal cell carcinoma (mRCC). We aimed to determine a relationship between 18-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography/Computed Tomography (18F-FDG-PET/CT) performed before nivolumab treatment and treatment-related survival.

METHODS

Between 2014 and 2021, 32 patients who received nivolumab and had pre-treatment 18F-FDG-PET/CT evaluation were included in this retrospective study. The total SUVmax (sum of SUVmax) of all tumoral foci and the lesion with the highest SUVmax value were recorded. The relationship of these values with progression-free survival (PFS) and overall survival (OS) was evaluated.

RESULTS

The median highest SUVmax and sum of SUVmax values were found as 14.4 and 41.4, respectively. PFS and OS were longer in the group with a sum of SUVmax value below 41.4 compared to the group with a higher group (OS, median 9.52 vs. 4.2 months [P=0.018]; PFS, median 9.6 vs. 3 months [P=0.003], respectively). In the group with the highest SUVmax value below 14.4, PFS was evaluated as statistically significant compared to the higher group (PFS, median 16.74 vs. 3.3 months [P=0.004]), while OS was not found to be statistically significant (OS, median 25.45 vs. 16.74 months (P=0.110)).

CONCLUSIONS

Our study showed that there might be a relationship between SUVmax values and PFS and OS. The SUVmax values before nivolumab treatment can be used to predict prognosis and survival in mRCC patients.

Iterated cross validation method for prediction of survival in diffuse large B-cell lymphoma for small size dataset

Efforts have been made to improve the risk stratification model for patients with diffuse large B-cell lymphoma (DLBCL). This study aimed to evaluate the disease prognosis using machine learning models with iterated cross validation (CV) method. A total of 122 patients with pathologically confirmed DLBCL and receiving rituximab-containing chemotherapy were enrolled. Contributions of clinical, laboratory, and metabolic imaging parameters from fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scans to the prognosis were evaluated using five regression models, namely logistic regression, random forest, support vector classifier (SVC), deep neural network (DNN), and fuzzy neural network models. Binary classification predictions for 3-year progression free survival (PFS) and 3-year overall survival (OS) were conducted. The 10-iterated fivefold CV with shuffling process was conducted to predict the capability of learning machines. The median PFS and OS were 41.0 and 43.6 months, respectively. Two indicators were found to be independent predictors for prognosis: international prognostic index and total metabolic tumor volume (MTVsum) from FDG PET/CT. For PFS, SVC and DNN (both with accuracy 71%) have the best predictive results, of which outperformed other algorithms. For OS, the DNN has the best predictive result (accuracy 76%). Using clinical and metabolic parameters as input variables, the machine learning methods with iterated CV method add the predictive values for PFS and OS evaluation in DLBCL patients.

Comparing lesion and feature selections to predict progression in newly diagnosed DLBCL patients with FDG PET/CT radiomics features

PURPOSE

Biomarkers that can accurately predict outcome in DLBCL patients are urgently needed. Radiomics features extracted from baseline [¹⁸F]-FDG PET/CT scans have shown promising results. This study aims to investigate which lesion- and feature-selection approaches/methods resulted in the best prediction of progression after 2 years.

METHODS

A total of 296 patients were included. 485 radiomics features (n = 5 conventional PET, n = 22 morphology, n = 50 intensity, n = 408 texture) were extracted for all individual lesions and at patient level, where all lesions were aggregated into one VOI. 18 features quantifying dissemination were extracted at patient level. Several lesion selection approaches were tested (largest or hottest lesion, patient level [all with/without dissemination], maximum or median of all lesions) and compared to the predictive value of our previously published model. Several data reduction methods were applied (principal component analysis, recursive feature elimination (RFE), factor analysis, and univariate selection). The predictive value of all models was tested using a fivefold cross-validation approach with 50 repeats with and without oversampling, yielding the mean cross-validated AUC (CV-AUC). Additionally, the relative importance of individual radiomics features was determined.

RESULTS

Models with conventional PET and dissemination features showed the highest predictive value (CV-AUC: 0.72-0.75). Dissemination features had the highest relative importance in these models. No lesion selection approach showed significantly higher predictive value compared to our previous model. Oversampling combined with RFE resulted in highest CV-AUCs.

CONCLUSION

Regardless of the applied lesion selection or feature selection approach and feature reduction methods, patient level conventional PET features and dissemination features have the highest predictive value. Trial registration number and date: EudraCT: 2006-005174-42, 01-08-2008.

Optimal PET-based radiomic signature construction based on the cross-combination method for predicting the survival of patients with diffuse large B-cell lymphoma

PURPOSE

To develop and externally validate models incorporating a PET radiomics signature (R-signature) obtained by the cross-combination method for predicting the survival of patients with diffuse large B-cell lymphoma (DLBCL).

METHODS

A total of 383 patients with DLBCL from two medical centres between 2011 and 2019 were included. The cross-combination method was used on three types of PET radiomics features from the training cohort to generate 49 feature selection-classification candidates based on 7 different machine learning models. The R-signature was then built by selecting the optimal candidates based on their progression-free survival (PFS) and overall survival (OS). Cox regression analysis was used to develop the survival prediction models. The calibration, discrimination, and clinical utility of the models were assessed and externally validated.

RESULTS

The R-signatures determined by 12 and 31 radiomics features were significantly associated with PFS and OS, respectively (P<0.05). The combined models that incorporated R-signatures, metabolic metrics, and clinical risk factors exhibited significant prognostic superiority over the clinical models, PET-based models, and the National Comprehensive Cancer Network International Prognostic Index in terms of both PFS (C-index: 0.801 vs. 0.732 vs. 0.785 vs. 0.720, respectively) and OS (C-index: 0.807 vs. 0.740 vs. 0.773 vs. 0.726, respectively). For external validation, the C-indices were 0.758 vs. 0.621 vs. 0.732 vs. 0.673 and 0.794 vs. 0.696 vs. 0.781 vs. 0.708 in the PFS and OS analyses, respectively. The calibration curves showed good consistency, and the decision curve analysis supported the clinical utility of the combined model.

CONCLUSION

The R-signature could be used as a survival predictor for DLBCL, and its combination with clinical factors may allow for accurate risk stratification.

Prognostic significance of pretreatment 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) in patients with primary T cell lymphomas

OBJECTIVE

T cell lymphomas are associated with an aggressive worse prognosis. This study is designed to assess T cell lymphomas using 18F-FDG PET/CT.

METHODS

Sixty-four patients with newly diagnosed T cell lymphomas underwent PET/computed tomography (PET/CT) scans, 47 cases who were fully followed up were retrospectively reviewed and analyzed. Overall survival (OS) and progression-free survival (PFS) were recorded for prognosis. We measured the maximum standardized uptake value (SUVmax) in all cases, analyzed the correlation between SUVmax and survival and other clinicopathologic parameters. Kaplan-Meier log-rank tests were then used to compare the survival of high and low PET/CT parameter groups, and multivariate Cox proportional hazards regression analysis was carried out to identify predictors of OS and PFS.

RESULTS

With a median follow-up of 26.5 (range 0.7-117.5) months, the 1-, 2- and 3-year OS were 75.6, 61.7 and 49.2%, and PFS were 49.3, 39.9 and 29.9%, respectively in 47 patients. Among them, 33 cases progressed with a median time of 9.5 (0.7-115.0) months, and 26 patients died with a median survival time of 26.5 (0.7-117.5) months. Multivariate analysis showed the following independent prognostic factors for OS: age >60 years (P = 0.002), SUVmax >9.7 (P = 0.009) and extranodal involvement of more than one site (P = 0.018). In addition, lactate dehydrogenase level (P = 0.003) and B symptoms (P = 0.018) were independent risk factors for PFS.

CONCLUSION

Pretherapy SUVmax may serve as an independent predictor of outcome in patients with newly diagnosed T cell lymphomas.

Baseline 18F-FDG PET textural features as predictors of response to chemotherapy in diffuse large B-cell lymphoma

PURPOSE

We sought to investigate the performance of radiomics analysis on baseline 18F-FDG PET/CT for predicting response to first-line chemotherapy in diffuse large B-cell lymphoma (DLBCL).

MATERIAL AND METHODS

Forty-five patients who received first-line rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) chemotherapy for DLBCL were included in the study. Radiomics features and standard uptake value (SUV)-based measurements were extracted from baseline PET images for a total of 147 lesions. The selection of the most relevant features was made using the recursive feature elimination algorithm. A machine-learning model was trained using the logistic regression classifier with cross-validation to predict treatment response. The independent predictors of incomplete response were evaluated with multivariable regression analysis.

RESULTS

A total of 14 textural features were selected by the recursive elimination algorithm, achieving a feature-to-lesion ratio of 1:10. The accuracy and area under the receiver operating characteristic curve of the model for predicting incomplete response were 0.87 and 0.81, respectively. Multivariable analysis revealed that SUVmax and gray level co-occurrence matrix dissimilarity were independent predictors of lesions with incomplete response to first-line R-CHOP chemotherapy.

CONCLUSION

Increased textural heterogeneity in baseline PET images was found to be associated with incomplete response in DLBCL.

Clinical Impact of Extranodal Metabolic Tumor Volume in 240 Diffuse Large B cell Lymphoma Patients with Extranodal Involvement

The present study is to investigate whether extranodal (EN) metabolic tumor volume (MTV) would have a specific clinical meaning for survival in EN diffuse large B cell lymphoma (DLBCL) patients. Two hundred forty DLBCL patients with EN involvement received 18F-fluorodeoxygenase (FDG) positron emission tomography/computed tomography (PET/CT) were enrolled. Survival analysis revealed that low EN MTV (PFS [progression-free survival], HR = 0.278, 95% CI = 0.127-0.807, p = 0.001; OS [overall survival], HR = 0.320, 95% CI = 0.145-0.703, p = 0.003), low total MTV (PFS, HR = 0.194, 95% CI = 0.085-0.445, p < 0.001; OS, HR = 0.213, 95% CI = 0.092-0.491, p < 0.007), and high National Cancer Center Network-International Prognostic Index score (PFS, HR = 3.152, 95% CI = 1.732-5.734, p < 0.001; OS, HR = 2.457, 95% CI = 1.363-4.430, p = 0.003) were independently associated with survivals in the patients. Our data showed that EN MTV is a useful and novel prognostic parameter for predicting survival in DLBCL patients with EN involvement.

Baseline PET/CT imaging parameters for prediction of treatment outcome in Hodgkin and diffuse large B cell lymphoma: a systematic review

Purpose

To systematically review the literature evaluating clinical utility of imaging metrics derived from baseline fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) for prediction of progression-free (PFS) and overall survival (OS) in patients with classical Hodgkin lymphoma (HL) and diffuse large B cell lymphoma (DLBCL).

Methods

A search of MEDLINE/PubMed, Web of Science, Cochrane, Scopus and clinicaltrials.gov databases was undertaken for articles evaluating PET/CT imaging metrics as outcome predictors in HL and DLBCL. PRISMA guidelines were followed. Risk of bias was assessed using the Quality in Prognosis Studies (QUIPS) tool.

Results

Forty-one articles were included (31 DLBCL, 10 HL). Significant predictive ability was reported in 5/20 DLBCL studies assessing SUVmax (PFS: HR 0.13–7.35, OS: HR 0.83–11.23), 17/19 assessing metabolic tumour volume (MTV) (PFS: HR 2.09–11.20, OS: HR 2.40–10.32) and 10/13 assessing total lesion glycolysis (TLG) (PFS: HR 1.078–11.21, OS: HR 2.40–4.82). Significant predictive ability was reported in 1/4 HL studies assessing SUVmax (HR not reported), 6/8 assessing MTV (PFS: HR 1.2–10.71, OS: HR 1.00–13.20) and 2/3 assessing TLG (HR not reported). There are 7/41 studies assessing the use of radiomics (4 DLBCL, 2 HL); 5/41 studies had internal validation and 2/41 included external validation. All studies had overall moderate or high risk of bias.

Conclusion

Most studies are retrospective, underpowered, heterogenous in their methodology and lack external validation of described models. Further work in protocol harmonisation, automated segmentation techniques and optimum performance cut-off is required to develop robust methodologies amenable for clinical utility.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00259-021-05233-2.

Prognostic value of the baseline 18F-FDG PET/CT metabolic tumour volume (MTV) and further stratification in low-intermediate (L-I) and high-intermediate (H-I) risk NCCNIPI subgroup by MTV in DLBCL MTV predict prognosis in DLBCL

INTRODUCTION

In the era of rituximab, the NCCNIPI is widely used in clinical practice as a tool for the prognosis and risk stratification of diffuse large B-cell lymphoma (DLBCL). In recent years, FDG PET/CT has also shown unique prognostic value. We try to further confirm the prognostic role of metabolic parameters in the overall and subgroups patients.

METHODS

We retrospectively analysed 87 DLBCL patients who underwent baseline FDG PET/CT and followed the R-CHOP or R-CHOP-like strategy. The clinical parameters and PET-related metabolic parameters were evaluated.

RESULTS

For all patients, the 2-year PFS rate was 65.5% and the 2-year OS rate was 66.7%. According to Cox multivariate analysis, a high NCCNIPI score (4-8 points) and an MTV greater than 64.1 cm3 (defined by ROC) were independent prognostic factors for PFS and OS. The patients were divided into low, low-intermediate, high-intermediate and high-risk groups by NCCNIPI score. The 2-year PFS rates in each group were 90.9%, 71.3%, 33.2% and 16.7%, and the 2-year OS rates were 100%, 81.6%, 48.4% and 16.7%. In the subsequent subgroup analysis by MTV, it could further stratified low-intermediate and high-intermediate NCCNIPI groups, the P value was 0.068 and 0.069 for PFS, 0.078 and 0.036 for OS.

CONCLUSIONS

MTV, as a tumor metabolic volume parameter, and the NCCNIPI score were independent predictors of prognosis in general DLBCL patients. In the low-intermediate and high-intermediate NCCNIPI subgroup, we further confirm the risk stratification abilities of MTV, which could add the prognostic value of NCCNIPI.

Baseline 18F-FDG PET radiomic features as predictors of 2-year event-free survival in diffuse large B cell lymphomas treated with immunochemotherapy

OBJECTIVES

To explore the prognostic value of positron emission tomography (PET) radiomic features in the field of diffuse large B cell lymphoma (DLBCL) treated with a first-line immunochemotherapy.

METHODS

One-hundred thirty-two patients newly diagnosed with DLBCL were retrospectively included. PET studies were reconstructed using an ordered subset expectation maximisation algorithm with point spread function modelling. The total metabolic tumour volume (MTV) was recorded for each patient, and the volume of interest structure of the largest target lesion was used to compute ¹⁸F-FDG textural parameters. Data was randomly split into training and validation datasets. Optimal cutoff values were determined by means of 2-year event-free survival (EFS) ROC analyses. Two-year EFS analyses were performed using Kaplan-Meier survival analyses and univariable and multivariable Cox regression models.

RESULTS

The median follow-up was 27 months, and the 2-year event-free survival (2y-EFS) was 77.3% in the entire population. ROC analyses for the 2y-EFS reached statistical significance for total MTV as well as four second-order metrics (homogeneity, contrast, correlation, dissimilarity) and five third-order metrics (LZE (Long-Zone Emphasis), LZLGE (Long-Zone Low-Grey Level Emphasis), LZHGE (Long-Zone High-Grey Level Emphasis), GLNU (Grey-Level Non-Uniformity) and ZP (Zone Percentage)). LZHGE displayed the highest ROC analysis accuracy (acc. = 0.76) and the best discriminant value on univariable Kaplan-Meier analysis (p < 0.0001, HR = 4.54). On multivariable analysis, including IPIaa, total MTV and LZHGE, LZHGE was the only independent predictor of 2y-EFS. These results were confirmed on the validation dataset.

CONCLUSIONS

Baseline ¹⁸F-FDG PET heterogeneity of the largest lymphoma lesion is a promising predictor of 2y-EFS in newly diagnosed DLBCL treated with immunochemotherapy.

KEY POINTS

•¹⁸F-FDG metabolic heterogeneity emerges as a new tool for survival prognostication of patients and has been explored in many solid tumours with promising results. • Baseline¹⁸F-FDG PET heterogeneity of the largest lymphoma lesion is an independent predictor of 2y-EFS in newly diagnosed DLBCL treated with immunochemotherapy. • DLBCL patients presenting with a heterogeneous tumour displayed a worse prognosis.

Prediction of Overall Survival and Progression-Free Survival by the 18F-FDG PET/CT Radiomic Features in Patients with Primary Gastric Diffuse Large B-Cell Lymphoma

Purpose. To determine whether the radiomic features of ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) contribute to prognosis prediction in primary gastric diffuse large B-cell lymphoma (PG-DLBCL) patients. Methods. This retrospective study included 35 PG-DLBCL patients who underwent PET/CT scans at West China Hospital before curative treatment. The volume of interest (VOI) was drawn around the tumor, and radiomic analysis of the PET and CT images, within the same VOI, was conducted. The metabolic and textural features of PET and CT images were evaluated. Correlations of the extracted features with the overall survival (OS) and progression-free survival (PFS) were evaluated. Univariate and multivariate analyses were conducted to assess the prognostic value of the radiomic parameters. Results. In the univariate model, many of the textural features, including kurtosis and volume, extracted from the PET and CT datasets were significantly associated with survival (5 for OS and 7 for PFS (PET); 7 for OS and 14 for PFS (CT)). Multivariate analysis identified kurtosis (hazard ratio (HR): 28.685, 95% confidence interval (CI): 2.067–398.152, p=0.012), metabolic tumor volume (MTV) (HR: 26.152, 95% CI: 2.089–327.392, p=0.011), and gray-level nonuniformity (GLNU) (HR: 14.642, 95% CI: 2.661–80.549, p=0.002) in PET and sphericity (HR: 11.390, 95% CI: 1.360–95.371, p=0.025) and kurtosis (HR: 11.791, 95% CI: 1.583–87.808, p=0.016), gray-level nonuniformity (GLNU) (HR: 6.934, 95% CI: 1.069–44.981, p=0.042), and high gray-level zone emphasis (HGZE) (HR: 9.805, 95% CI: 1.359–70.747, p=0.024) in CT as independent prognostic factors. Conclusion. ¹⁸F-FDG PET/CT radiomic features are potentially useful for survival prediction in PG-DLBCL patients. However, studies with larger cohorts are needed to confirm the clinical prognostication of these parameters.

Tumour necrosis as assessed with 18F-FDG PET is a potential prognostic marker in diffuse large B cell lymphoma independent of MYC rearrangements

Objectives

MYC gene rearrangements in diffuse large B cell lymphomas (DLBCLs) result in high proliferation rates and are associated with a poor prognosis. Strong proliferation is associated with high metabolic demand and tumour necrosis. The aim of this study was to investigate differences in the presence of necrosis and semiquantitative ¹⁸F-FDG PET metrics between DLBCL cases with or without a MYC rearrangement. The prognostic impact of necrosis and semiquantitative ¹⁸F-FDG PET parameters was investigated in an explorative survival analysis.

Methods

Fluorescence in situ hybridisation analysis for MYC rearrangements, visual assesment, semiquantitative analysis of ¹⁸F-FDG PET scans and patient survival analysis were performed in 61 DLBCL patients, treated at a single referral hospital between 2008 and 2015.

Results

Of 61 tumours, 21 (34%) had a MYC rearrangement (MYC⁺). MYC status was neither associated with the presence of necrosis on ¹⁸F-FDG PET scans (necrosis^PET; p = 1.0) nor associated with the investigated semiquantitative parameters maximum standard uptake value (SUV_max; p = 0.43), single highest SUV_max (p = 0.49), metabolic active tumour volume (MATV; p = 0.68) or total lesion glycolysis (TLG; p = 0.62). A multivariate patient survival analysis of the entire cohort showed necrosis^PET as an independent prognostic marker for disease-specific survival (DSS) (HR = 13.9; 95% CI 3.0–65; p = 0.001).

Conclusions

MYC rearrangements in DLBCL have no influence on the visual parameter necrosis^PET or the semi-quantiative parameters SUV_max, MATV and TLG. Irrespective of MYC rearrangements, necrosis^PET is an independent, adverse prognostic factor for DSS.

Key Points

• Retrospective analysis indicates that MYC rearrangement is not associated with necrosis on¹⁸F-FDG PET (necrosis^PET) scans or semiquantitative¹⁸F-FDG PET parameters.

• Necrosis^PETis a potential independent adverse prognostic factor for disease-specific survival in patients with DLBCL and is not influenced by the presence of MYC rearrangements.

Electronic supplementary material

The online version of this article (10.1007/s00330-019-06178-9) contains supplementary material, which is available to authorized users.

Prognostic value of interim fluorodeoxyglucose and fluorothymidine PET/CT in diffuse large B-cell lymphoma

OBJECTIVE:

To examine the prognostic value of fluorodeoxyglucose (FDG) and fluorothymidine (FLT) interim positron emission tomography/CT (PET/CT) for diffuse large B-cell lymphoma (DLBCL).

METHODS:

44 patients with newly diagnosed DLBCL underwent both fluorine 18 FDG (¹⁸F-FDG) and ¹⁸F-FLT PET/CT scans at baseline and after two cycles of a rituximab-containing chemotherapy regimen. Maximum standard uptake values (SUV_max) and changes in SUV (ΔSUV) were calculated for both tracers for the predominant lesion of each patient, for prediction of progression-free survival (PFS) and overall survival (OS).

RESULTS:

The median follow-up period was 71 months. Receiver operating characteristic (ROC) analysis indicated that the best ΔSUV cut-off values for FDG (ΔSUV_FDG) and FLT (ΔSUV_FLT) were 79 and 76%, respectively. A ΔSUV_FLT cut-off of 76% had the highest significance for prediction of PFS (p = 0.003) and OS (p = 0009), with sensitivity, specificity, and accuracy of 80.0, 85.7, and 81.8% respectively in response assessment.

CONCLUSION:

Interim FLT PET/CT had higher specificity and accuracy than standard FDG PET/CT-based interpretation.

ADVANCES IN KNOWLEDGE:

This study demonstrated that interim FLT PET/CT had higher accuracy than standardized FDG-based interpretation for therapeutic response assessment in DLBCL. FLT had the advantage of potentially reducing false positive of interim FDG PET/CT.

Primary cauda equina lymphoma diagnosed by nerve biopsy: A case report and literature review

Primary cauda equina lymphoma (CEL) is a rare malignant tumor among various neoplasms that affects the cauda equina nerve roots. The present case report described the case of a 65-year-old man who presented with cauda equina syndrome with progressive motor palsy in the legs and gait disturbance over the last 5 months. Magnetic resonance (MR) images showed enlargement of the cauda equina occupying the dural sac from the L1-S1 level with isointensity to the spinal cord signal on both T1- and T2-weighted imaging. Enhancement of the cauda equina was seen on contrast MR images. On F-18 2-fluoro-2-deoxy-glucose positron emission tomography examination, diffuse accumulation of 2-fluoro-2-deoxy-glucose was observed in the cauda equina with a maximum standardized uptake value of 4.9. Based on elevation of soluble interleukin 2 receptor in cerebrospinal fluid and a biopsy of the enlarging cauda equina, a diagnosis of CEL of the diffuse large B-cell type was made. The present case report provided a detailed case discussion and a review of the available literature on this rare entity, focusing on clinical characteristics and imaging of primary CEL.

Tumor and bone marrow uptakes on [18F]fluorodeoxyglucose positron emission tomography/computed tomography predict prognosis in patients with diffuse large B-cell lymphoma receiving rituximab-containing chemotherapy

The purpose of this study was to determine the relevance of standardized uptake value (SUV) on [F]fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT), focusing on tumor and bone marrow, to disease outcomes based on progression-free survival (PFS) and overall survival (OS) in patients with diffuse large B-cell lymphoma (DLBCL) receiving rituximab-containing chemotherapy.We reviewed the records of patients with DLBCL who were diagnosed between September 2009 and January 2013 and underwent pretreatment whole-body FDG PET/CT scans. All patients received rituximab-containing chemotherapy. The maximal SUV of tumor (SUVt) and maximal SUV of sternum (SUVst) were measured. Univariate and multivariate analyses were used to assess the prognostic significance of SUVt, SUVst, gender, age, clinical stage, international prognostic index (IPI), and laboratory tests.There were total 70 patients enrolled in this study. The median follow-up time was 36 months. An SUVt cut-off value of ≥19 had the best discriminative yield for PFS (P = .04). An SUVst cut-off value of ≥1.6 had the best discriminative yield for OS. The 3-year OS rates for patients with maximal SUVst < 1.6 and for those with maximal SUVst ≥1.6 were 74.8% and 57.1%, respectively (P = .04). Further forward, multivariate Cox proportional hazards model revealed that maximal SUVst (hazard ratio: 2.62; 95% confidence interval: 1.10-6.28; P = .03) and IPI were significant factors affecting OS.In patients with DLBCL receiving rituximab-containing chemotherapy, elevated maximal SUVt ≥19 was an independent predictor for shorter PFS, and maximal SUVst ≥1.6 was an independent predictor for shorter OS. It adds the value of pretreatment FDG PET/CT scans.

Prognostic significance of total metabolic tumor volume on 18F-fluorodeoxyglucose positron emission tomography/ computed tomography in patients with diffuse large B-cell lymphoma receiving rituximab-containing chemotherapy

Purpose

The purpose of this study was to determine the prognostic significance of metabolic parameters on pre-treatment ¹⁸F-fluorodeoxyglucose positron emission tomography/ computed tomography (FDG PET/CT), in patients with diffuse large B-cell lymphoma (DLBCL) receiving rituximab-containing therapy.

Materials and Methods

From September 2009 to December 2014, DLBCL patients who had received FDG PET/CT scans for staging were enrolled. The maximal standardized uptake value of tumor (SUVt) was recorded. The metabolic tumor volume (MTV) was the volume of lesion with an elevated SUV greater than 2.5. The total lesion glycolysis (TLG) was the sum of the products of MTV and mean SUV in all measured lesions. Univariate and multivariate analyses were used to assess the prognostic significance of maximal SUVt, total MTV, TLG and other clinical parameters.

Results

There were 118 patients enrolled in this study. The median follow-up time was 28.7 months. The 5-year progression-free survival (PFS) for patients with higher and lower total MTV was 32.3% and 66.0% respectively (p = 0.0001). The 5-year overall survival (OS) for patients with higher and lower total MTV was 34.3% and 69.9% respectively (p < 0.0001). Multivariate analysis revealed, besides IPI, that total MTV was independently predictive for PFS (HR: 2.31, 95% CI: 1.16 - 4.60, p = 0.0180) and OS (HR: 2.38, 95% CI: 1.12 - 5.04, p = 0.024). TLG and maximal SUV of tumor were not independent prognostic factors.

Conclusions

An elevated total MTV was a predictor for shorter PFS and OS in patients with DLBCL receiving rituximab-containing therapy, independent of IPI.

Correlation of pretreatment 18F-FDG uptake with clinicopathological factors and prognosis in patients with newly diagnosed diffuse large B-cell lymphoma

Supplemental Digital Content is available in the text.

Objectives

The aim of this study is to determine the correlation of pretreatment fluorine-18 fluorodeoxyglucose uptake with clinicopathological factors and its prognostic value in patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL).

Patients and methods

A cohort of 162 patients with newly diagnosed DLBCL who had undergone pretreatment PET/computed tomography was retrospectively reviewed. The relationship of pretreatment maximum standard uptake value (SUV_max) with clinical factors, molecular markers, and efficacy was evaluated. The value of SUV_max in predicting progression-free survival (PFS) and overall survival was analyzed.

Results

In all, 72.9% of the patients received R-CHOP treatment; the rest received CHOP chemotherapy. The median follow-up duration was 30 months (range, 4–124 months). The median SUV_max was 12.2 (range, 1.7–42.7). SUV_max between groups differed significantly with respect to each of International Prognostic Index (IPI) factors, except for age and performance status. High SUV_max was associated with high Ki-67 and Glut-3 protein expression, but not with Glut-1. Complete remission rate differed significantly between the low (SUV_max≤9.0) and the high SUV_max (SUV_max>9.0) groups (91.7 vs. 61.1%, P=0.000). Patients with low SUV_max showed favorable survival (3-year PFS: 92.2 vs. 63.6%, P=0.000; 3-year overall survival: 95.5 vs. 78.3%, P=0.003). On multivariate analyses, SUV_max predicted PFS independent of revised-IPI (SUV_max: P=0.011, hazard ratio 4.784; revised-IPI: P=0.004, hazard ratio 2.551).

Conclusion

Pretreatment SUV_max was associated with clinicopathological factors, efficacy, and survival outcome. A novel prognostic model on the basis of IPI score/pretreatment SUV_max might be useful for risk stratification of patients with newly diagnosed DLBCL Video abstract: http://links.lww.com/NMC/A55.

Predictors of local recurrence after rituximab-based chemotherapy alone in stage III and IV diffuse large B-cell lymphoma: guiding decisions for consolidative radiation

PURPOSE

The role of consolidative radiation therapy (RT) for stage III and IV diffuse large B-cell lymphoma (DLBCL) in the era of rituximab is not well defined. There is evidence that some patients with bulky disease may benefit, but patient selection criteria are not well established. We sought to identify a subset of patients who experienced a high local failure rate after receiving rituximab-based chemotherapy alone and hence may benefit from the addition of consolidative RT.

METHODS AND MATERIALS

Two hundred eleven patients with stage III and IV DLBCL treated between August 1999 and January 2012 were reviewed. Of these, 89 had a complete response to systemic therapy including rituximab and received no initial RT. Kaplan-Meier analysis and Cox proportional hazards regression were performed, with local recurrence (LR) as the primary outcome.

RESULTS

The median follow-up time was 43.9 months. Fifty percent of patients experienced LR at 5 years. In multivariate analysis, tumor ≥ 5 cm and stage III disease were associated with increased risk of LR. The 5-year LR-free survival was 47.4% for patients with ≥ 5-cm lesions versus 74.7% for patients with <5-cm lesions (P=.01). In patients with <5-cm tumors, the maximum standardized uptake value (SUVmax) was ≥ 15 in all patients with LR. The 5-year LR-free survival was 100% in SUV<15 versus 68.8% in SUV ≥ 15 (P=.10).

CONCLUSIONS

Advanced-stage DLBCL patients with stage III disease or with disease ≥ 5 cm appear to be at an increased risk for LR. Patients with <5-cm disease and SUVmax ≥ 15 may be at higher risk for LR. These patients may benefit from consolidative RT after chemoimmunotherapy.

Extranodal lymphoma originating in the gluteal muscle with adjacent bone involvement and mimicking a soft tissue sarcoma

Introduction

Extranodal lymphoma (ENL) in the muscles is a rare manifestation of non-Hodgkin lymphoma (NHL). The aim of this case report is to describe and evaluate the clinical presentation and important radiologic features of ENL affecting the musculoskeletal system.

Presentation of case

We present a 52-year-old female with a 3-week history of left gluteal pain. Computed tomography (CT) showed a non-uniformly early enhancing mass in the left gluteal muscle, the tumor demonstrating central necrosis and adjacent bone involvement. Fluorine-18 fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET)/CT showed areas of increased ¹⁸F-FDG uptake in the left gluteal musculature, pelvic bones, para-aortic and mediastinal lymph nodes and both lungs. Histopathological examination showed a diffuse large B cell lymphoma (DLBCL). After 8 cycles of R-CHOP chemotherapy, the mass in the left gluteal muscle has completely disappeared

Discussion

Although destructive tumor originating in the gluteal muscle with adjacent bone involvement is more common in soft tissue sarcoma, lymphoma should be regularly included in the differential diagnosis. While CT is a useful modality for assessing soft tissue masses, disruption and injury of the surrounding tissues, PET/CT fusion is superior for the detection of unexpected extranodal sites of disease, or for exclusion of disease in the presence of nonspecific extranodal CT findings.

Conclusion

A rapid growth pattern and destructive masses that invade adjacent structures on CT are key findings of DLBCL, and ¹⁸F-FDG PET/CT is a useful imaging modality to accurately determine the disease stage and disease aggressiveness of NHL.

Relationship between pretreatment FDG-PET and diffusion-weighted MRI biomarkers in diffuse large B-cell lymphoma

The purpose of this study was to determine the correlation between the (18)F-fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) standardized uptake value (SUV) and the diffusion-weighted magnetic resonance imaging (MRI) apparent diffusion coefficient (ADC) in newly diagnosed diffuse large B-cell lymphoma (DLBCL). Pretreatment FDG-PET and diffusion-weighted MRI of 21 patients with histologically proven DLBCL were prospectively analyzed. In each patient, maximum, mean and peak standardized uptake value (SUV) was measured in the lesion with visually highest FDG uptake and in the largest lesion. Mean ADC (ADCmean, calculated with b-values of 0 and 1000 s/mm(2)) was measured in the same lesions. Correlations between FDG-PET metrics (SUVmax, SUVmean, SUVpeak) and ADCmean were assessed using Pearson's correlation coefficients. In the lesions with visually highest FDG uptake, no significant correlations were found between the SUVmax, SUVmean, SUVpeak and the ADCmean (P=0.498, P=0.609 and P=0.595, respectively). In the largest lesions, there were no significant correlations either between the SUVmax, SUVmean, SUVpeak and the ADCmean (P=0.992, P=0.843 and P=0.894, respectively). The results of this study indicate that the glycolytic rate as measured by FDG-PET and changes in water compartmentalization and water diffusion as measured by the ADC are independent biological phenomena in newly diagnosed DLBCL. Further studies are warranted to assess the complementary roles of these different imaging biomarkers in the evaluation and follow-up of DLBCL.

The rate of reduction in the maximum standardized uptake value from the initial to the post-R-CHOP therapy in positron emission tomography scan predicts disease progression in diffuse large B cell lymphoma patients

[18F]fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) is useful for primary staging and evaluation of treatment outcome in diffuse large B cell lymphoma (DLBCL) patients. The reduction in the maximum standardized uptake value (ΔSUVmax) from the initial to the interim 18F-FDG PET scan has been reported to predict survival in DLBCL patients. We retrospectively evaluated ΔSUVmax obtained by PET or PET-computed tomography before and after initial therapy in 31 newly diagnosed DLBCL patients who were treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone) therapy. Receiver observation characteristic curve analysis was used to evaluate the optimal cutoff value for the ΔSUVmax for disease progression. The 3-year progression-free survival rate of patients with ΔSUVmax≥83 and <83% was found to be 91 and 25%, respectively (P<0.001). The 4-year overall survival rate of patients with ΔSUVmax≥83 and <83% was found to be 100 and 83%, respectively (P=0.046). The ΔSUVmax observed before and after R-CHOP therapy could be useful in the prediction of disease progression and survival in newly diagnosed DLBCL patients.

Improving survival and preventing recurrence of diffuse large B-cell lymphoma in younger patients: current strategies and future directions

Prognosis of diffuse large B-cell lymphoma (DLBCL) has considerably improved during the last decade, mainly due to the addition of rituximab to chemotherapy. However, a significant proportion of patients still experience primary refractory disease or short-term relapses, conferring poor survival. Thus, achieving first-line complete remission is of major importance, especially in young and fit patients. Current strategies are based on the age-adapted International Prognostic Index, which separates patients into three prognostic subgroups (low-risk, intermediate-risk, and high-risk). However, it is based only on clinical variables, and we have learned from daily practice that there remains a marked heterogeneity within each subgroup. Recently, biological prognostic factors have emerged, and should now be part of initial evaluation to guide treatment. Among those, so-called double-hit DLBCL with deregulation of both MYC and BCL2 genes usually follows a particularly aggressive course and should be treated more intensively. But for many other patients, the indication of high-dose therapy rather than immunochemotherapy alone remains controversial. In these cases, the interest of an early ¹⁸F fluoro-2-deoxy-d-glucose positron emission tomography evaluation-based strategy is now being assessed in ongoing clinical trials. Moreover, other strategies to improve response and survival consist in adding novel agents to standard chemotherapy. In this field, newly developed anti-CD20 monoclonal antibodies and immunomodulatory drugs could be of particular interest during induction therapy to optimize the quality of response, but also in maintenance treatment, in order to decrease the risk of relapse. Only well-conducted clinical trials will be able to resolve all these issues. Therefore, physicians should be encouraged, as far as possible, to propose them to their patients.