Serum level of soluble interleukin-2 receptor is positively correlated with metabolic tumor volume on 18 F-FDG PET/CT in newly diagnosed patients with diffuse large B-cell lymphoma

Diffuse large B‐cell lymphoma (DLBCL) is the most frequent subtype of non‐Hodgkin lymphoma. High total metabolic tumor volume (TMTV) calculated using ¹⁸F‐FDG PET/CT images at diagnosis predicts poor prognosis of patients with DLBCL. However, high cost and poor access to the imaging facilities hamper wider use of ¹⁸F‐FDG PET/CT. In order to explore a surrogate marker for TMTV, we evaluated the correlation between the serum levels of soluble interleukin‐2 receptor (sIL‐2R) and TMTV in 64 patients with DLBCL, and the results were verified in an independent validation cohort of 86 patients. Serum levels of sIL‐2R were significantly correlated with TMTV. ROC analysis revealed that the cutoff value of TMTV ≥150 cm³ or sIL‐2R ≥ 1300 U/mL could predict failure to achieve EFS24 with areas under the curve (AUC) 0.706 and 0.758, respectively. Each of TMTV ≥150 cm³ and sIL‐2R ≥1300 U/mL was significantly associated with worse 5‐year overall survival and event‐free survival. Importantly, each of sIL‐2R <1300 U/mL or TMTV <150 cm³ identified patients with favorable prognosis among NCCN‐IPI high‐intermediate and high‐risk group. Serum level of sIL‐2R represents a convenient surrogate marker to estimate metabolic tumor burden measured by ¹⁸F‐FDG PET/CT that can predict treatment outcomes of patients with DLBCL.

Comparison of therapeutic evaluation criteria in FDG-PET/CT in patients with diffuse large-cell B-cell lymphoma: Prognostic impact of tumor/liver ratio

PURPOSE

The study objective was to compare the prognostic value of interim and end-of-treatment FDG PET/CT using five therapeutic evaluation criteria in patients with diffuse large B cell lymphoma (DLBCL).

METHODS

181 patients were retrospectively analysed. All patients underwent FDG-PET at baseline and after four cycles (iPET4) of first-line chemotherapy and 165 at the end-of-treatment (PET-eot). Ratio Deauville score (rDS) (SUVmax-target residual lesion/SUVmax-liver) was measured in iPET4 and PET-eot, and its optimal threshold was determined using receiver operating characteristic (ROC) curve analysis. Deauville score (DS) (iPET4 and PET-eot), ΔSUVmax, ΔSUVmax determined according to Menton 2011 criteria (ΔSUVmax+DS) and ΔSUVmax+rDS were also evaluated (iPET4 only). Median follow-up was 44 months.

RESULTS

ROC analysis revealed the optimal cut-off value was 1.4-fold of SUVmax-liver on iPET4 and PET-eot. On iPET4, positive predictive value (PPV) of rDS was significantly better than DS: 81.58% vs. 67.79%. In univariate analysis, the five interpretation methods were statistically significant (p<0.0001 for progression-free survival [PFS] and overall survival [OS]). In multivariate analysis, only rDS was an independent prognostic factor (p = 0.0002 and p<0.0001 for PFS and OS, respectively). On PET-eot, similarly, the two therapeutic evaluation criteria analysed (rDS and DS) were statistically significant at the univariate level (p<0.0001). rDS was the only significant prognostic factor in multivariate analysis (p<0.0001). PPV and accuracy of rDS were also better than DS.

CONCLUSIONS

rDS with a tumor/liver ratio of 1.4 is a robust prognostic factor in patients with DLBCL on iPET4 and PET-eot.

CT findings predict survival of patients with peripheral T cell lymphoma: a preliminary study

Background Peripheral T-cell lymphoma (PTCL) is an uncommon disease with poor clinical outcomes. Radiological reports on the survival of patients with PTCL are scarce. The purpose of this study is to investigate the prognostic value of CT findings to predict clinical outcomes in fifty-one patients with histologically proven PTCL. Patients and methods The clinical data and CT images of all patients were retrospectively reviewed. CT features including number of involvement sites, lesion size, shape, margin, density, peritumoral invasion, intratumoral necrosis, lymph node involvement, and degree of contrast enhancement were evaluated. Univariate and multiple logistic regression analysis were used to determine the association between the clinical outcome and radiologic factors. Results Multiple site involvement, an ill-defined margin with peritumoral invasion, inhomogeneous density, and intratumoral necrosis were found to be associated with poor outcomes in univariate analysis (P < 0.05). An ill-defined margin with peritumoral invasion, was identified as an independent risk sign by further multivariate logistic regression analysis (P < 0.05). The area under the ROC curve of this CT feature was 0.745 (P < 0.05). Conclusions An ill-defined margin with peritumoral invasion was a valuable prognostic factor to predict the worse clinical outcomes in patients with PTCL.

Prognostic value of baseline metabolic tumor volume and total lesion glycolysis in patients with lymphoma: A meta-analysis

Whether baseline metabolic tumor volume (TMTV) and total lesion glycolysis (TLG) measured by FDG-PET/CT affected prognosis of patients with lymphoma was controversial. We searched PubMed, EMBASE and Cochrane to identify studies assessing the effect of baseline TMTV and TLG on the survival of lymphoma patients. Pooled hazard ratios (HR) for overall survival (OS) and progression-free survival (PFS) were calculated, along with 95% confidence intervals (CI). Twenty-seven eligible studies including 2,729 patients were analysed. Patients with high baseline TMTV showed a worse prognosis with an HR of 3.05 (95% CI 2.55–3.64, p<0.00001) for PFS and an HR of 3.07 (95% CI 2.47–3.82, p<0.00001) for OS. Patients with high baseline TLG also showed a worse prognosis with an HR of 3.44 (95% CI 2.37–5.01, p<0.00001) for PFS and an HR of 3.08 (95% CI 1.84–5.16, p<0.00001) for OS. A high baseline TMTV was significantly associated with worse survival in DLBCL patients treated with R-CHOP (OS, pooled HR = 3.52; PFS, pooled HR = 2.93). A high baseline TLG was significantly associated with worse survival in DLBCL patients treated with R-CHOP (OS, pooled HR = 3.06; PFS, pooled HR = 2.93). The negative effect of high baseline TMTV on PFS was demonstrated in HL (pooled HR = 3.89). A high baseline TMTV was significantly associated with worse survival in ENKL patients (OS, pooled HR = 2.24; PFS, pooled HR = 3.25). A high baseline TLG was significantly associated with worse survival in ENKL patients (OS, pooled HR = 2.58; PFS, pooled HR = 2.99). High baseline TMTV or TLG predict significantly worse PFS and OS in patients with lymphoma. Future studies are warranted to explore whether TMTV or TLG could be integrated into various prognostic models for clinical decision making.

Risk factors and timing of autologous stem cell transplantation for patients with peripheral T-cell lymphoma

High-dose chemotherapy with autologous stem cell transplantation (HDC-ASCT) is an option for patients with peripheral T-cell lymphoma (PTCL); however, neither prospective nor retrospective studies support proceeding with ASCT upfront, and the timing of HDC-ASCT remains controversial. We retrospectively analyzed the risk factors for outcomes of 570 patients with PTCL, including PTCL not otherwise specified (PTCL-NOS) and angioimmunoblastic T-cell lymphoma (AITL), who received ASCT for frontline consolidation (n = 98 and 75, respectively) or alternative therapies after either relapse (n = 112 and 75) or primary induction failure (PIF; n = 127 and 83) between 2000 and 2015. Significant risk factors for overall survival (OS) after upfront ASCT were a ≥ 2 prognostic index for T-cell lymphoma (P < 0.001) and partial response (PR) at ASCT (P = 0.041) in PTCL-NOS patients, and > 60 years of age (P = 0.0028) and PR at ASCT (P = 0.0013) in AITL patients. Performance status of ≥ 2 at ASCT (P < 0.001), receiving ≥ 3 regimens before ASCT (P = 0.018), and PR at ASCT (P = 0.018) in PTCL-NOS patients and > 60 years of age at ASCT (P = 0.0077) in AITL patients were risk factors for OS after ASCT with a chemosensitive PIF status. Strategies that carefully select PTCL patients may allow identification of individuals suitable for ASCT.

Prognostic role of baseline 18F-FDG PET/CT metabolic parameters in Burkitt lymphoma

PURPOSE

Burkitt's lymphoma (BL) is an aggressive lymphoma subtype with high 18F-FDG avidity at 18F-FDG-PET/CT, but no validated criteria for PET/CT in treatment evaluation or prediction of outcome in BL are available. The aim of our study was to investigate whether the metabolic baseline PET/CT parameters can predict treatment response and prognosis in BL.

MATERIALS AND METHODS

We retrospectively enrolled 65 patients who underwent baseline 18F-FDG-PET/CT, interim and end of treatment PET/CT. The PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value body weight (SUVbw), the maximum standardized uptake value lean body mass (SUVlbm), the maximum standardized uptake value body surface area (SUVbsa), lesion to liver SUVmax ratio (L-L SUV R), lesion to blood-pool SUVmax ratio (L-BP SUV R), total metabolic tumor volume (tMTV) and total lesion glycolysis (TLG). Survival curves were plotted according to the Kaplan-Meier method.

RESULTS

At a median follow-up of 40 months, the median PFS and OS were 34 and 39 months. MTV and TLG were significantly higher in patients with partial response compared to complete response group at end of treatment, while no significant differences were found at interim. Other metabolic PET/CT parameters were not related to treatment response. MTV and TLG were demonstrated to be independent prognostic factors for both PFS and OS; instead SUVbw, SUVlbm, SUVbsa, L-L SUV R and L-BP SUV R were not related to outcome survival.

CONCLUSIONS

Metabolic tumour features (MTV and TLG) were significantly correlated with response to treatment and long-term outcome.

FDG-PET/CT in the management of lymphomas: current status and future directions

FDG-PET/CT is the current state-of-the-art imaging in lymphoma and plays a central role in treatment decisions. At diagnosis, accurate staging is crucial for appropriate therapy selection: FDG-PET/CT can identify areas of lymphoma missed by CT alone and avoid under-treatment of patients with advanced disease stage who would have been misclassified as having limited stage disease by CT. Particularly in Hodgkin lymphoma, positive interim FDG-PET/CT scans are adversely prognostic for clinical outcomes and can inform PET-adapted treatment strategies, but such data are less consistent in diffuse large B-cell lymphoma. The use of quantitative FDG-PET/CT metrics using metabolic tumour volume, possibly in combination with other biomarkers, may better define prognostic subgroups and thus facilitate better treatment selection. After chemotherapy, FDG-PET/CT response is predictive of outcome and may identify a subgroup who benefit from consolidative radiotherapy. Novel therapies, in particular immunotherapies, exhibit different response patterns than conventional chemotherapy, which has led to modified response criteria that take into account the risk of transient pseudo-progression. In relapsed lymphoma, FDG-PET/CT after second-line therapy and prior to high-dose therapy is also strongly associated with outcome and may be used to guide intensity of salvage therapy in relapsed Hodgkin lymphoma. Currently, FDG-PET/CT has no role in the routine follow-up after complete metabolic response to therapy, but it remains a powerful tool for excluding relapse if patients develop clinical features suggestive of disease relapse. In conclusion, FDG-PET/CT plays major roles in the various phases of management of lymphoma and constitutes a step towards the pursuit of personalized treatment.

Prognostic value of baseline metabolic tumor volume in early-stage Hodgkin lymphoma in the standard arm of the H10 trial

We tested baseline positron emission tomography (PET)/computed tomography (CT) as a measure of total tumor burden to better identify high-risk patients with early-stage Hodgkin lymphoma (HL). Patients with stage I-II HL enrolled in the standard arm (combined modality treatment) of the H10 trial (NCT00433433) with available baseline PET and interim PET (iPET2) after 2 cycles of doxorubicin, bleomycin, vinblastine, and dacarbazine were included. Total metabolic tumor volume (TMTV) was measured on baseline PET. iPET2 findings were reported negative (DS1-3) or positive (DS4-5) with the Deauville scale (DS). The prognostic value of TMTV was evaluated and compared with baseline characteristics, staging classifications, and iPET2. A total of 258 patients were eligible: 101 favorable and 157 unfavorable. The median follow-up was 55 months, with 27 progression-free survival (PFS) and 12 overall survival (OS) events. TMTV was a prognosticator of PFS (P < .0001) and OS (P = .0001), with 86% and 84% specificity, respectively. Five-year PFS and OS were 71% and 83% in the high-TMTV (>147 cm³) group (n = 46), respectively, vs 92% and 98% in the low-TMTV group (≤147 cm³). In multivariable analysis including iPET2, TMTV was the only baseline prognosticator compared with the current staging systems proposed by the European Organization for Research and Treatment of Cancer/Groupe d'Etude des Lymphomes de l'Adulte, German Hodgkin Study Group, or National Comprehensive Cancer Network. TMTV and iPET2 were independently prognostic and, combined, identified 4 risk groups: low (TMTV≤147+DS1-3; 5-year PFS, 95%), low-intermediate (TMTV>147+DS1-3; 5-year PFS, 81.6%), high-intermediate (TMTV≤147+DS4-5; 5-year PFS, 50%), and high (TMTV>147+DS4-5; 5-year PFS, 25%). TMTV improves baseline risk stratification of patients with early-stage HL compared with current staging systems and the predictive value of early PET response as well.

Combination of baseline FDG PET/CT total metabolic tumour volume and gene expression profile have a robust predictive value in patients with diffuse large B-cell lymphoma

PURPOSE

This study evaluated the predictive significance of total metabolic tumour volume (TMTV) measured on baseline FDG PET/CT and its value in addition to gene expression profiling using a new method of gene analysis (rapid reverse transcriptase multiplex ligation-dependent probe amplification assay, RT-MLPA) in patients with diffuse large B-cell lymphoma treated with R-CHOP or R-CHOP-like chemotherapies.

METHODS

The analysis included 114 patients. TMTV was measured using a 41% SUVmax threshold and tumours were classified into GCB or ABC subtypes according to the RT-MLPA assay.

RESULTS

The median follow-up was 40 months. the 5-year progression-free survival (PFS) was 54% and the 5-year overall survival (OS) was 62%. The optimal TMTV cut-off value was 261 cm³. In 59 patients with a high TMTV the 5-year PFS and OS were 37% and 39%, respectively, in comparison with 72% and 83%, respectively, in 55 patients with a low TMTV (p = 0.0002 for PFS, p < 0.0001 for OS). ABC status was significantly associated with a worse prognosis. TMTV combined with molecular data identified three groups with very different outcomes: (1) patients with a low TMTV whatever their phenotype (n = 55), (2) patients with a high TMTV and GCB phenotype (n = 33), and (3) patients with a high TMTV and ABC phenotype (n = 26). In the three groups, 5-year PFS rates were 72%, 51% and 17% (p < 0.0001), and 5-year OS rates were 83%, 55% and 17% (p < 0.0001), respectively. In multivariate analysis, TMTV, ABC/GCB phenotype and International Prognostic Index were independent predictive factors for both PFS and OS (p < 0.05 for both).

CONCLUSIONS

This integrated risk model could lead to more accurate selection of patients that would allow better individualization of therapy.

Predictive Value of PET Response Combined with Baseline Metabolic Tumor Volume in Peripheral T-Cell Lymphoma Patients

Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of aggressive non-Hodgkin lymphomas with poor outcomes on current therapy. We investigated whether response assessed with PET/CT combined with baseline total metabolic tumor volume (TMTV) could detect early relapse or refractory disease. Methods: From 7 European centers, 140 patients with nodal PTCL who underwent baseline PET/CT were selected. Forty-three had interim PET (iPET) performed after 2 cycles (iPET2), 95 had iPET performed after 3 or 4 cycles (iPET3/4), and 96 had end-of-treatment PET (eotPET). Baseline TMTV was computed with a 41% SUV_max threshold, and PET response was reported using the Deauville 5-point scale. Results: With a median of 43 mo of follow-up, the 2-y progression-free survival (PFS) and overall survival (OS) were 51% and 67%, respectively. iPET2-positive patients (Deauville score ≥ 4) had a significantly worse outcome than iPET2-negative patients (P < 0.0001, hazard ratio of 6.8 for PFS; P < 0.0001, hazard ratio of 6.6 for OS). The value of iPET3/4 was also confirmed for PFS (P < 0.0001) and OS (P < 0.0001). The 2-y PFS and OS for iPET3/4-positive (n = 28) and iPET3/4-negative (n = 67) patients were 16% and 32% versus 75% and 85%, respectively. The eotPET results also reflected patient outcome. A model combining TMTV and iPET3/4 stratified the population into distinct risk groups (TMTV ≤ 230 cm³ and iPET3/4-negative [2-y PFS/OS, 79%/85%]; TMTV > 230 cm³ and iPET3/4-negative [59%/84%]; TMTV ≤ 230 cm³ and iPET3/4-positive [42%/50%]; TMTV > 230 cm³ and iPET3/4-positive [0%/18%]). Conclusion: iPET response is predictive of outcome and allows early detection of high-risk PTCL patients. Combining iPET with TMTV improves risk stratification in individual patients.

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.

Predictive value of 18F-FDG PET/CT in adults with T-cell lymphoblastic lymphoma: post hoc analysis of results from the GRAALL-LYSA LLO3 trial

PURPOSE

We examined whether FDG PET can be used to predict outcome in patients with lymphoblastic lymphoma (LL).

METHODS

This was a retrospective post hoc analysis of data from the GRAAL-LYSA LL03 trial, in which the treatment of LL using an adapted paediatric-like acute lymphoblastic leukaemia protocol was evaluated. PET data acquired at baseline and after induction were analysed. Maximum standardized uptake values (SUV_max), total metabolic tumour volume and total lesion glycolysis were measured at baseline. The relative changes in SUV_max from baseline (ΔSUV_max) and the Deauville score were determined after induction.

RESULTS

The population analysed comprised 36 patients with T-type LL. SUV_max using a cut-off value of ≤8.76 vs. >8.76 was predictive of 3-year event-free survival (31.6% vs. 80.4%; p = 0.013) and overall survival (35.0% vs. 83.7%; p = 0.028). ΔSUV_max using a cut-off value of ≤80% vs. >80% tended also to be predictive of 3-year event-free survival (40.0% vs. 76.0%; p = 0.054) and overall survival (49.2% vs. 85.6%; p = 0.085). Total metabolic tumour volume, baseline total lesion glycolysis and response according to the Deauville score were not predictive of outcome.

CONCLUSIONS

A low initial SUV_max was predictive of worse outcomes in our series of patients with T-type LL. Although relatively few patients were included, the study also suggested that ΔSUV_max may be useful for predicting therapeutic efficacy.

18F-FDG PET/CT in the clinical management of patients with lymphoma

The aim of this work was to review the current recommendations for staging and response assessment of patients with Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) in routine clinical practice after chemotherapy and/or stem cell transplantation. A five-point scale (5-PS) from the First International Workshop on PET in Lymphoma in Deauville, France, in 2009, was recommended as the standard tool to score imaging to assess treatment response in patients with lymphoma using ¹⁸F-Fluorodeoxyglucose (FDG) PET/CT. Following the recommendations of the 11th and 12th International Conferences on Malignant Lymphoma held in Lugano (Switzerland), in 2011 and 2013, respectively, a consensus (the so-called Lugano Classification) was reached regarding the use of PET/CT for staging and response assessment in FDG-avid lymphomas. As a result, ¹⁸F-FDG PET/CT was formally incorporated into standard staging for FDG-avid lymphomas. A bone marrow biopsy is no longer indicated for the routine staging of HL and most diffuse large B-cell lymphomas. PET/CT will be used to assess response in FDG-avid histologies using the 5-point scale. The recent introduction of biological agents with immune mechanisms requires flexibility in interpretations of the Lugano criteria due to tumour flare or a pseudo-progression effect produced by these agents. Provisional criteria have been proposed (Lymphoma Response to Immunomodulatory Therapy Criteria) with the introduction of the term 'Indeterminate Response' in order to identify this phenomenon until confirmed as flare/pseudoprogression or true progression. All these recommendations will improve evaluations of patients with lymphoma, and allow comparison of results from clinical practice and trials.

FDG-PET Scan: a new Paradigm for Follicular Lymphoma Management

In the present review, the reader will be led to the most relevant observations that prompted oncologists and haematologist to consider FDG-PET/CT as a new paradigm for FL management in clinical practice. The role of functional imaging in lymphoma staging, restaging, prognostication, and metabolic tumour volume computing will be reviewed in detail. Moreover, a special focus will be addressed to technical and practical aspects of PET scan reporting, which have been set during the last decade to ensure the reproducibility of the therapeutic results. Finally, the predictive role of PET/CT on long-term treatment outcome will be compared with another well-known prognosticator as minimal residual disease (MRD) detection by Immunoglobulin gene rearrangement assessment.

How I manage peripheral T-cell lymphoma, not otherwise specified and angioimmunoblastic T-cell lymphoma: current practice and a glimpse into the future

Peripheral T-cell lymphoma (PTCL), not otherwise specified (NOS) and angioimmunoblastic T-cell lymphoma (AITL) are the most frequent of more than 20 mature PTCL entities featuring a broad spectrum of morphological, immunophenotypic, molecular and clinical characteristics. Unfortunately, recent progress in understanding the (epi)genetic background of PTCL has not been met with similar advances in treatment. Thus, CHO(E)P [cyclophosphamide, doxorubicin, vincristine, and prednisone (plus etoposide)] remains standard first-line therapy. Patients without comorbidities achieving complete or partial remission proceed to autologous stem cell transplantation. With this approach about 50% of patients survive long-term. Patients relapsing after or progressing during first-line therapy have a dismal prognosis. They receive salvage gemcitabine-therapy followed by allogeneic transplantation whenever possible. After allografting, approximately half of the patients survive long-term; any other treatment is palliative. New drugs investigated in phase II studies achieved response rates between 10% and 30%; long-term remissions are the exception to the rule. While most new drugs are not licensed and not readily available, a plethora of other innovative drugs targeting (epi-)genetic abnormalities are in early development. These, together with combinations of new and old drugs, will hopefully increase response to first-line therapy, bridge more patients to transplantation, and finally improve prognosis for all patients with PTCL.

Baseline Total Metabolic Tumor Volume Measured with Fixed or Different Adaptive Thresholding Methods Equally Predicts Outcome in Peripheral T Cell Lymphoma

The purpose of this study was to compare in a large series of peripheral T cell lymphoma, as a model of diffuse disease, the prognostic value of baseline total metabolic tumor volume (TMTV) measured on ¹⁸F-FDG PET/CT with adaptive thresholding methods with TMTV measured with a fixed 41% SUV_max threshold method.

METHODS

One hundred six patients with peripheral T cell lymphoma, staged with PET/CT, were enrolled from 5 Lymphoma Study Association centers. In this series, TMTV computed with the 41% SUV_max threshold is a strong predictor of outcome. On a dedicated workstation, we measured the TMTV with 4 adaptive thresholding methods based on characteristic image parameters: Daisne (Da) modified, based on signal-to-background ratio; Nestle (Ns), based on tumor and background intensities; Fit, including a 3-dimensional geometric model based on spatial resolution (Fit); and Black (Bl), based on mean SUV_max The TMTV values obtained with each adaptive method were compared with those obtained with the 41% SUV_max method. Their respective prognostic impacts on outcome prediction were compared using receiver-operating-characteristic (ROC) curve analysis and Kaplan-Meier survival curves.

RESULTS

The median value of TMTV_41%, TMTV_Da, TMTV_Ns, TMTV_Fit, and TMTV_Bl were, respectively, 231 cm³ (range, 5-3,824), 175 cm³ (range, 8-3,510), 198 cm³ (range, 3-3,934), 175 cm³ (range, 8-3,512), and 333 cm³ (range, 3-5,113). The intraclass correlation coefficients were excellent, from 0.972 to 0.988, for TMTV_Da, TMTV_Fit, and TMTV_Ns, and less good for TMTV_Bl (0.856). The mean differences obtained from the Bland-Altman plots were 48.5, 47.2, 19.5, and -253.3 cm³, respectively. Except for Black, there was no significant difference within the methods between the ROC curves (P > 0.4) for progression-free survival and overall survival. Survival curves with the ROC optimal cutoff for each method separated the same groups of low-risk (volume ≤ cutoff) from high-risk patients (volume > cutoff), with similar 2-y progression-free survival (range, 66%-72% vs. 26%-29%; hazard ratio, 3.7-4.1) and 2-y overall survival (79%-83% vs. 50%-53%; hazard ratio, 3.0-3.5).

CONCLUSION

The prognostic value of TMTV remained quite similar whatever the methods, adaptive or 41% SUV_max, supporting its use as a strong prognosticator in lymphoma. However, for implementation of TMTV in clinical trials 1 single method easily applicable in a multicentric PET review must be selected and kept all along the trial.

Baseline Metabolic Tumor Volume Predicts Outcome in High-Tumor-Burden Follicular Lymphoma: A Pooled Analysis of Three Multicenter Studies

PURPOSE

Identifying patients at high risk of progression and early death among those with high-tumor-burden follicular lymphoma (FL) is unsatisfactory with current prognostic models. This study aimed to determine the prognostic impact of the total metabolic tumor volume (TMTV) measured at baseline with [¹⁸F]fluorodeoxyglucose/positron emission tomography-computed tomography ([¹⁸F]FDG/PET-CT) scans and its added value to these models.

PATIENTS AND METHODS

A pooled analysis was performed by using patient data and centrally reviewed baseline PET-CT scans for 185 patients with FL who were receiving immunochemotherapy within three prospective trials. TMTV was computed by using the 41% maximum standardized uptake value thresholding method, and the optimal cutoff for survival prediction was determined.

RESULTS

Median age was 55 years, 92% of patients had stage III to IV disease, 37% had a Follicular Lymphoma International Prognostic Index (FLIPI) score of 3 to 5, and 31% had a FLIPI2 score of 3 to 5. With a median follow-up of 64 months, overall 5-year progression-free survival (PFS) was 55% and overall survival (OS) was 92%. Median TMTV was 297 cm³ (quartile 1 through quartile 3, 135 to 567 cm³). The optimal cutoff identified was 510 cm³, with a markedly inferior survival in the 29% of patients with TMTV > 510 cm³. Five-year PFS was 33% versus 65% (hazard ratio [HR], 2.90; P < .001), and 5-year OS was 85% versus 95% (HR, 3.45; P = .010). On multivariable analysis, TMTV (HR, 2.3; P = .002) and FLIPI2 score (HR, 2.2; P = .002) were independent predictors of PFS. In combination, they identify three risk groups: high TMTV and intermediate-to-high FLIPI2 score with 5-year PFS of 20% (HR, 5.0; P < .001), high TMTV or intermediate-to-high FLIPI2 score with 5-year PFS of 46% (HR, 2.1; P = .007), and low TMTV and low FLIP2 with 5-year PFS of 69%.

CONCLUSION

Baseline TMTV is a strong independent predictor of outcome in FL. In combination with FLIPI2 score, it identifies patients at high risk of early progression. It warrants further validation as a biomarker for development of first-line PET-adapted approaches in FL.

Molecular Profile and FDG-PET/CT Total Metabolic Tumor Volume Improve Risk Classification at Diagnosis for Patients with Diffuse Large B-Cell Lymphoma

PURPOSE

The prognostic impact of total metabolic tumor volume (TMTV) measured on pretreatment (18)F-FDG PET/CT and its added value to molecular characteristics was investigated in patients with diffuse large B-cell lymphoma (DLBCL).

EXPERIMENTAL DESIGN

For 81 newly diagnosed patients with DLBCL treated with rituximab and CHOP/CHOP-like regimen, TMTV was computed using the 41% SUVmax thresholding method. According to the gene expression profile, determined using DASL (cDNA-mediated Annealing, Selection, Ligation and extension) technology, a subset of 57 patients was classified in germinal center B (GCB) or activated B-cell (ABC) subtypes and MYC or BCL2 overexpressed.

RESULTS

Median follow-up was 64 months. Five-year progression-free survival (PFS) and overall survival (OS) were 60% and 63% in the whole population. Median pretherapy TMTV was 320 cm(3) (25th-75th percentiles 106-668 cm(3)). With a 300 cm(3) cutoff, patients with high TMTV (n = 43) had a 5-year PFS and OS of 43% and 46% compared with 76% and 78% for patients with a low TMTV (P = 0.0023, P = 0.0047). ABC status, MYC, or BCL2 overexpression and both overexpression ("dual expressor," DE) were significantly associated with a worse PFS and OS. TMTV combined with molecular data allowed a significant better risk substratification of ABC/GCB patients, on PFS and OS. High TMTV individualized in molecular-low-risk patients a group with a poor outcome (MYC, PFS=51%, OS=55% BCL2, PFS=49%, OS=49% or DE PFS=50%, OS=50%) and a group with a good outcome (MYC, PFS=93%, OS=93% BCL2, PFS=86%, OS=86%, or DE PFS=81%, OS=81%).

CONCLUSIONS

The combination of molecular and imaging characteristics at diagnosis could lead to a more accurate selection of patients, to increase tailor therapy. Clin Cancer Res; 22(15); 3801-9. ©2016 AACR.