Quantitative and qualitative analysis of metabolic response at interim positron emission tomography scan combined with International Prognostic Index is highly predictive of outcome in diffuse large B-cell lymphoma

A retrospective head-to-head comparison of the Lugano classification and PERCIST for FDG-PET/CT response assessment in diffuse large B-cell lymphoma

BACKGROUND

Diffuse large B-cell lymphoma (DLBCL) is the most common form of lymphoma. European guidelines recommend FDG-PET/CT for staging and end of treatment (EOT) response assessment, mid-treatment response assessment is optional. We compared the Lugano classification and PET Response Criteria In Solid Tumours (PERCIST) for FDG-PET/CT response assessment in DLBCL head-to-head.

METHODS

We retrospectively included patients with DLBCL who underwent first-line R-CHOP(-like) therapy (2013-2020). Interim and EOT FDG-PET/CT response were reevaluated using the Lugano classification and PERCIST. Response was dichotomized into complete metabolic response (CMR) versus non-CMR (interim and EOT) and responders versus nonresponders (interim only). The cutoff for nonresponse at interim was a Deauville score of 5 (DS5) with the Lugano classification and a partial metabolic response with ≤66% reduction in SULpeak using PERCIST (PERCIST66).

RESULTS

In multivariable Cox regression (N = 170), DS5 at interim, PERCIST66 at interim, non-CMR at EOT with the Lugano classification and non-CMR at EOT with PERCIST were predictive of progression-free survival (PFS). The Lugano classification and PERCIST agreed perfectly at interim and EOT and with 98.4% for the identification of nonresponders at interim. The accuracy for predicting events within 2 years of diagnosis was 84.2% for DS-5 at interim, 87.6% for PERCIST66 at interim, 86% for non-CMR with the Lugano classification at EOT and 83.3% for non-CMR with PERCIST at EOT.

CONCLUSION

The Lugano classification and PERCIST were equally predictive of PFS. Nonresponse at interim and non-CMR at EOT were predictive of poor PFS with comparable accuracy for predicting events within 2 years.

Validation of the ΔSUVmax for Interim PET Interpretation in Diffuse Large B-Cell Lymphoma on the Basis of the GAINED Clinical Trial

The GAINED phase 3 trial (ClinicalTrials.gov identifier: NCT01659099) evaluated a PET-driven consolidative strategy in patients with diffuse large B-cell lymphoma. In this post hoc analysis, we aimed to compare the prognostic value of the per-protocol PET interpretation criteria (Menton 2011 consensus) with the change in the SUVmax (ΔSUVmax) alone. Methods: Real-time central review of 18F-FDG PET/CT was performed in 581 patients after 2 cycles (PET2) and 4 cycles (PET4) of immunochemotherapy using the Menton 2011 criteria, combining the ΔSUVmax (cutoffs of 66% and 70% at PET2 and PET4, respectively) and the Deauville scale. In "special cases," when the baseline SUVmax was less than 10.0 or the interim residual tumor SUVmax was greater than 5.0, the Menton 2011 experts' consensus agreed that the ΔSUVmax may not be reliable and that the Deauville score is preferable. Prognostic values of Menton 2011 and ΔSUVmax were evaluated by Kaplan-Meier analyses in terms of progression-free survival (PFS). Results: Seventeen percent of patients at PET2 (100/581) and 8% at PET4 (49/581) had PET-negative results by ΔSUVmax but were considered to have PET-positive results according to Menton 2011 with residual SUVmax of greater than 5.0. For the population with PET2-positive results, 2-y PFS was 70% (range, 58%-80%) with ΔSUVmax alone, whereas the outcome tended to be better for those who were considered to have PET-positive results by Menton 2011, 81% (range, 72%-87%). Conversely, all 10 patients with baseline SUVmax of less than 10.0 had PET2-positive results by ΔSUVmax but were considered to have PET2-negative results by Menton 2011. These patients had the same 2-y PFS as patients with PET2-negative/PET4-negative results, indicating that the ΔSUVmax yielded false-positive results in this situation. Conclusion: We recommend the use of the ΔSUVmax alone rather than the Menton 2011 criteria for assessing the interim metabolic response in patients with diffuse large B-cell lymphoma, except when the baseline SUVmax is less than 10.0.

Prognostic value of 18F-FDG lesion dissemination features in patients with peripheral T-cell lymphoma (PTCL)

PURPOSE

To explore the prognostic value of the distance between the two lesions that were farthest apart (Dmax) on baseline 18F-FDG PET/CT in peripheral T lymphoma (PTCL) and establish a new prognostic model for predicting the survival outcomes of patients with PTCL.

METHODS

In this study, a retrospective analysis of 95 patients with PTCL who underwent baseline 18F-FDG PET/CT was performed to assess the predictive value of Dmax. The total metabolic tumour volume (TMTV), total lesion glycolysis (TLG), standardized uptake value (SUV), and Dmax were calculated with LIFEx software. Progression-free survival (PFS) and overall survival (OS) were used as endpoints. The prognostic model was developed based on the results of the multivariate analysis. The time-dependent area under the ROC curve (tdAUC), calibration curves, Harrell C-index, and decision curve analysis (DCA) were used to assess the model.

RESULTS

Patients were followed up for a median of 17.0 months. Multivariate analysis showed that bone marrow biopsy (BMB) and Dmax were independent predictors of PFS (HR: 1.889, P = 0.039; HR: 1.965, P = 0.047) and OS (HR: 1.923, P = 0.031; HR: 1.982, P = 0.034). The model consisting of Dmax, TMTV, and BMB had substantial prognostic value for survival outcomes of PTCL and could successfully identify four groups of patients with significantly different prognoses (χ² = 13.731, P = 0.003 for PFS; χ² = 11.841, P = 0.008 for OS). The tdAUC, C-index, calibration curves, and DCA supported that the model was superior to the prognostic index for T-cell lymphoma (PIT) and International Prognostic Index (IPI) scores.

CONCLUSION

BMB and Dmax were independent predictors of PTCL in our study. Moreover, a prognostic model based on the Dmax, TMTV, and BMB could be useful for predicting the survival outcomes of patients with PTCL.

Standardized classification schemes in reporting oncologic PET/CT

The imaging report is essential for the communication between physicians in patient care. The information it contains must be clear, concise with evidence-based conclusions and sufficient to support clinical decision-making. In recent years, several classification schemes and/or reporting guidelines for PET have been introduced. In this manuscript, we will review the classifications most frequently used in oncology for interpreting and reporting 18F-FDG PET imaging in lymphoma, multiple myeloma, melanoma and head and neck cancers, PSMA-ligand PET imaging for prostate cancer, and 68Ga-DOTA-peptide PET in neuroendocrine tumors (NET).

18F-FDG PET Improves Baseline Clinical Predictors of Response in Diffuse Large B-Cell Lymphoma: The HOVON-84 Study

We aimed to determine the added value of baseline metabolic tumor volume (MTV) and interim PET (I-PET) to the age-adjusted international prognostic index (aaIPI) to predict 2-y progression-free survival (PFS) in diffuse large B-cell lymphoma. Secondary objectives were to investigate optimal I-PET response criteria (using Deauville score [DS] or quantitative change in SUV_max [ΔSUV_max] between baseline and I-PET4 [observational I-PET scans after 4 cycles of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone administered in 2-wk intervals with intensified rituximab in the first 4 cycles [R(R)-CHOP14]). Methods: I-PET4 scans in the HOVON-84 (Hemato-Oncologie voor Volwassenen Nederland [Haemato Oncology Foundation for Adults in the Netherlands]) randomized clinical trial (EudraCT 2006-005174-42) were centrally reviewed using DS (cutoff, 4-5). Additionally, ΔSUV_max (prespecified cutoff, 70%) and baseline MTV were measured. Multivariable hazard ratio (HR), positive predictive value (PPV), and negative predictive value (NPV) were obtained for 2-y PFS. Results: In total, 513 I-PET4 scans were reviewed according to DS, and ΔSUV_max and baseline MTV were available for 367 and 296 patients. The NPV of I-PET ranged between 82% and 86% for all PET response criteria. Univariate HR and PPV were better for ΔSUV_max (4.8% and 53%, respectively) than for DS (3.1% and 38%, respectively). aaIPI and ΔSUV_max independently predicted 2-y PFS (HR, 3.2 and 5.0, respectively); adding MTV brought about a slight improvement. Low or low-intermediate aaIPI combined with a ΔSUV_max of more than 70% (37% of patients) yielded an NPV of 93%, and the combination of high-intermediate or high aaIPI and a ΔSUV_max of 70% or less yielded a PPV of 65%. Conclusion: In this study on diffuse large B-cell lymphoma, I-PET after 4 cycles of R(R)-CHOP14 added predictive value to aaIPI for 2-y PFS, and both were independent response biomarkers in a multivariable Cox model. We externally validated that ΔSUV_max outperformed DS in 2-y PFS prediction.

Prognostic value of interim FDG PET-CT in patients older than 60 years with diffuse large B-cell lymphoma treated by PMitCEBO plus rituximab. Comparison between Deauville 5-point scale and International Harmonization Project criteria

BACKGROUND

Advanced age is an independent poor prognostic factor of diffuse large B-cell lymphoma (DLBCL). PMitCEBO (mitoxantrone, cyclophosphamide, etoposide, vincristine, bleomycin, and prednisolone) is an alternative to the cyclophosphamide, doxorubicin, vincristine, and prednisolone regimen to decrease side effects in elderly patients. Many studies have shown prognostic value of an interim FDG PET-CT to predict survival. A recent consensus (ICML, Lugano 2013) has suggested using the 5-point scale Deauville criteria instead of those of the International Harmonization Project (IHP) to visually assess the response on interim PET. The objective of this study was to evaluate the prognostic value of an interim FDG PET-CT in patients older than 60 with treated DLBCL and to compare IHP and 5-PS Deauville visual interpretation to predict survival.

METHODS

Forty-eight patients (mean age 73.2±5.2 years) treated by R-PMitCEBO for DLBCL undergoing FDG PET-CT before and after 3 cycles of treatment were retrospectively included. Event-free survival and overall survival were determined by Kaplan-Meier method and compared with interim PET-CT results using IHP and 5-PS Deauville criteria.

RESULTS

Interim PET results using 5-PS Deauville criteria were significantly correlated with EFS (P<0.0001) and OS (P=0.001) whereas they were moderately correlated with EFS (P=0.046) and not with OS (P=0.106) using IHP criteria. Two-year EFS and OS rates were 86.5% and 89.2%, respectively, for patients in 1-3 score group, and 27.3% and 36.4%, respectively, for patients in ≥4 score group using the Deauville criteria.

CONCLUSIONS

Our results confirmed the prognostic value of an interim PET-CT in elderly patients with DLBCL and the better performance of the 5-PS Deauville criteria.

Diffuse large B-cell lymphoma: A consensus practice statement from the Australasian Lymphoma Alliance

Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoma subtype, accounting for 30-40% of lymphoma diagnoses. Though aggressive, cure is achievable in approximately 60% of cases with primary chemo-immunotherapy, and in a further substantial minority by salvage therapy and autologous stem cell transplantation. Despite promising activity in early phase clinical trials, no intensified or novel treatment regimen has improved outcomes over R-CHOP21 in randomised studies. However, there remain several areas of controversy including the most appropriate prognostic markers, CNS prophylaxis and the optimal treatment for patients with high-risk disease. This position statement presents an evidence-based synthesis of the literature for application in Australasian practice. This article is protected by copyright. All rights reserved.

Positron emission tomography/computed tomography in the management of Hodgkin and B-cell non-Hodgkin lymphoma: An update

¹⁸ F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is now an integral part of lymphoma staging and management. Because of its greater accuracy compared with CT alone, PET/CT is currently routinely performed for staging and for response assessment at the end of treatment in the vast majority of FDG-avid lymphomas and is the cornerstone of response classification for these lymphomas according to the Lugano classification. Interim PET/CT, typically performed after 2 to 4 of 6 to 8 chemotherapy/chemoimmunotherapy cycles with or without radiation, is commonly performed for prognostication and potential treatment escalation or de-escalation early in the course of therapy, a concept known as response-adapted or risk-adapted treatment. Quantitative PET is an area of growing interest. Metrics, such as the standardized uptake value, changes (Δ) in the standardized uptake value, metabolic tumor volume, and total lesion glycolysis, are being investigated as more reproducible and potentially more accurate predictors of response and prognosis. Despite the progress made in standardizing the use of PET/CT in lymphoma, challenges remain, particularly with respect to its limited positive predictive value, emphasizing the need for more specific molecular probes. This review highlights the most relevant applications of PET/CT in Hodgkin and B-cell non-Hodgkin lymphoma, its strengths and limitations, as well as recent efforts at implementing PET/CT-based metrics as promising tools for precision medicine.

Predicting primary treatment failure using interim FDG-PET scanning in diffuse large B-cell lymphoma

Interim FDG-PET (iPET) in diffuse large B-cell lymphoma (DLBCL) is increasingly practised and used in clinical trials to adapt further therapy. However, the optimum timing and methodology of iPET remains controversial. We retrospectively analysed the iPET results and outcomes of 200 DLBCL patients where FDG-PET was routinely performed at baseline, after 2 cycles (iPET2) and at completion of chemoimmunotherapy. iPET was also performed after 4 cycles (iPET4) where at iPET2, Deauville score (DS) was ≥4. Scans were assessed by blinded expert lymphoma PET physicians for DS, maximum standard uptake value (SUVmax), total metabolic tumour volume (TMTV) and total lesion glycolysis (TLG). Treatment failure was defined as death, progression or refractory disease. 95.5% of patients received R-CHOP. No baseline PET parameter was predicted for EFS or OS independent of the NCCN-IPI. The multivariable analysis at iPET2 showed DS5 (19.5% of cases) predicted treatment failure (HR 6.29, 95% CI 3.01-13.17, P < .001), but DS4 was equivalent to DS1-3. At iPET4, ΔSUVmax < 66% predicted treatment failure (HR 5.49, 95% CI 3.03-9.99, P < .001). By multivariable analysis of all time points, high NCCN-IPI and DS5 at iPET2 were negative predictors of survival. These findings were independent of novel prognostic markers.

Correlation of 18-fluorodeoxyglucose PET/computed tomography parameters and clinical features to predict outcome for diffuse large B-cell lymphoma

PURPOSE

To determine if the correlation between different metabolic parameters along with clinical features can create an improved model of prognostication for diffuse large B-cell lymphoma (DLBCL) patients.

METHODS

We retrospectively evaluated 89 patients with DLBCL. All patients had a baseline and an interim 18F-FDG PET/CT. Seventy-nine also had an end-of-treatment PET/CT (EOT-PET). For each scan, we collected standardized uptake value (SUVmax, SUVmean, SUVpeak), metabolic tumor volume (MTV), total lesion glycolysis (TLG), SUVmaxsum, SUVmeansum, MTVsum, and TLGsum. These metabolic parameters were combined with clinical features in order to identify a new prognostic model. The predictive value of interim PET and EOT-PET using Deauville score was also determined.

RESULTS

Baseline SUVmaxsum and SUVmeansum were significantly correlated to overall survival (OS) (P value = 0.012 and 0.011, respectively). The percentage change of MTV and TLG sum from baseline to EOT was predictive of progression-free survival (PFS) (P value = 0.003 and 0.022, respectively). The combination of either Deauville score at the EOT and SUVmaxsum at baseline significantly predicted OS (P value <0.001); Eastern Cooperative Oncology Group performance status, presence of extranodal disease and percentage change of MTVsum from baseline to EOT were significant predictors of PFS (P value = 0.001).

CONCLUSIONS

SUVmaxsum and SUVmeansum at baseline and percentage change in MTV and TLG sum from baseline to EOT are predictors of outcome in DLBCL patients. These metabolic parameters combined to Deauville score and some clinical features could be used together to stratify patients.

Prognostic Role of Interim 18-Fluorodeoxyglucose-PET in Diffuse Large B Cell Lymphoma: Experience from a Tertiary Care Centre in North India

This study was done to investigate the role of Interim 18-FDG-PET/CT (i-PET) in predicting the outcome of Diffuse Large B Cell Lymphoma (DLBCL) patients. The Lymphoma registry data base of the Department of Haematology was reviewed for all newly diagnosed DLBCL patients treated with R-CHOP-21 (n = 63). The PET-CT data of these patients at pre-defined time points (baseline, interim and end of treatment) was systematically collected. The predictive accuracy of i-PET-CT (done after 4 cycles R-CHOP-21 chemotherapy) was analysed to define their prognostic importance. 47 patients were eligible for final analysis in this study. According to Deauville's criteria 15 patients (31%) were positive on i-PET. The positive predictive value (PPV) of i-PET by DS was 73.3%. At a median follow up of 21 months, DS based i-PET negative and positive cases showed significant differences in 2-year OS (81.2% vs 46.7%, p = 0.007) and PFS (75% vs 26.7%, p = 0.005). Combined analysis of i-PET (by DS) and IPI showed negative predictive value (NPV) of 92.3% in Low IPI while PPV of 76.9% in high IPI subgroup of DLBCL. On a multivariate analysis of all prognostic variables, i-PET was found to be independent prognostic marker predicting outcome in DLBCL patients. i-PET is an independent prognostic marker for outcome in DLBCL patients. Combined analysis of Interim PET along with IPI score at diagnosis improves the predictive accuracy of i-PET (both PPV & NPV) and may guide tailoring of therapy in these patients.

PET Molecular Imaging: A Holistic Review of Current Practice and Emerging Perspectives for Diagnosis, Therapeutic Evaluation and Prognosis in Clinical Oncology

PET/CT molecular imaging has been imposed in clinical oncological practice over the past 20 years, driven by its two well-grounded foundations: quantification and radiolabeled molecular probe vectorization. From basic visual interpretation to more sophisticated full kinetic modeling, PET technology provides a unique opportunity to characterize various biological processes with different levels of analysis. In clinical practice, many efforts have been made during the last two decades to standardize image analyses at the international level, but advanced metrics are still under use in practice. In parallel, the integration of PET imaging with radionuclide therapy, also known as radiolabeled theranostics, has paved the way towards highly sensitive radionuclide-based precision medicine, with major breakthroughs emerging in neuroendocrine tumors and prostate cancer. PET imaging of tumor immunity and beyond is also emerging, emphasizing the unique capabilities of PET molecular imaging to constantly adapt to emerging oncological challenges. However, these new horizons face the growing complexity of multidimensional data. In the era of precision medicine, statistical and computer sciences are currently revolutionizing image-based decision making, paving the way for more holistic cancer molecular imaging analyses at the whole-body level.

Radiologists and Clinical Trials: Part 1 The Truth About Reader Disagreements

The debate over human visual perception and how medical images should be interpreted have persisted since X-rays were the only imaging technique available. Concerns over rates of disagreement between expert image readers are associated with much of the clinical research and at times driven by the belief that any image endpoint variability is problematic. The deeper understanding of the reasons, value, and risk of disagreement are somewhat siloed, leading, at times, to costly and risky approaches, especially in clinical trials. Although artificial intelligence promises some relief from mistakes, its routine application for assessing tumors within cancer trials is still an aspiration. Our consortium of international experts in medical imaging for drug development research, the Pharma Imaging Network for Therapeutics and Diagnostics (PINTAD), tapped the collective knowledge of its members to ground expectations, summarize common reasons for reader discordance, identify what factors can be controlled and which actions are likely to be effective in reducing discordance. Reinforced by an exhaustive literature review, our work defines the forces that shape reader variability. This review article aims to produce a singular authoritative resource outlining reader performance's practical realities within cancer trials, whether they occur within a clinical or an independent central review.

Statistical Challenges in Development of Prognostic Models in Diffuse Large B-Cell Lymphoma: Comparison Between Existing Models - A Systematic Review

Background and Aim

Based on advances in the diagnosis, classification, and management of diffuse large B-cell lymphoma (DLBCL), a number of new prognostic models have been proposed. The aim of this study was to review and compare different prognostic models of DLBCL based on the statistical methods used to evaluate the performance of each model, as well as to analyze the possible limitations of the methods.

Methods and Results

A literature search identified 46 articles that proposed 55 different prognostic models for DLBCL by combining different clinical, laboratory, and other parameters of prognostic significance. In addition, six studies used nomograms, which avoid risk categorization, to create prognostic models. Only a minority of studies assessed discrimination and/or calibration to compare existing models built upon different statistical methods in the process of development of a new prognostic model. All models based on nomograms reported the c-index as a measure of discrimination. There was no uniform evaluation of the performance in other prognostic models. We compared these models of DLBCL by calculating differences and ratios of 3-year overall survival probabilities between the high- and the low-risk groups. We found that the highest and lowest ratio between low- and high-risk groups was 6 and 1.31, respectively, while the difference between these groups was 18.9% and 100%, respectively. However, these studies had limited duration of follow-up and the number of patients ranged from 71 to 335.

Conclusion

There is no universal statistical instrument that could facilitate a comparison of prognostic models in DLBCL. However, when developing a prognostic model, it is recommended to report its discrimination and calibration in order to facilitate comparisons between different models. Furthermore, prognostic models based on nomograms are becoming more appealing owing to individualized disease-related risk estimations. However, they have not been validated yet in other study populations.

Prognostic value of post-treatment ¹⁸F-fluorodeoxyglucose positron emission tomography in uterine cervical cancer patients treated with radiotherapy: a systematic review and meta-analysis

Objectives

To perform a systematic review and meta-analysis of the prognostic value of post-treatment ¹⁸F-fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET) in uterine cervical cancer patients treated with radiotherapy (RT) with or without chemotherapy.

Methods

PubMed and Embase databases were searched up to July 22, 2018, for studies which evaluated the response outcomes of ¹⁸F-FDG PET following RT, and their prognostic significance in uterine cervical cancer was assessed with overall survival (OS) or progression-free survival (PFS) as endpoints. Hazard ratios (HRs) were meta-analytically pooled using the random-effects model.

Results

Eleven studies with 12 patient cohorts including 1,104 patients were included. For a quantitative synthesis of OS, 7 cohorts were included. Two cohorts which reported disease-specific survival instead of OS were also included with flexibility. Pooled HR of complete metabolic response (CMR) compared to partial metabolic response (PMR) was 0.19 (95% confidence interval [CI]=0.11–0.31). Pooled HR of CMR compared to progressive metabolic disease (PMD) was more evident at 0.07 (95% CI=0.04–0.12), and that of CMR compared to both PMR and PMD was 0.20 (95% CI=0.12–0.34). Quantitative synthesis for PFS was performed with a total of 8 cohorts. Pooled HR of CMR was 0.17 (95% CI=0.10–0.29) compared to PMR, 0.02 (95% CI=0.01–0.06) compared to PMD and 0.12 (95% CI=0.07–0.19) compared to both PMR and PMD.

Conclusion

Response results of post-RT ¹⁸F-FDG PET were significant prognostic factors in patients with uterine cervical cancer, and ¹⁸F-FDG PET could be a reasonable follow-up imaging modality.

Early risk stratification for diffuse large B-cell lymphoma integrating interim Deauville score and International Prognostic Index

The aim of this study was to evaluate the prognostic relevance of early risk stratification in diffuse large B-cell lymphoma (DLBCL) using interim Deauville score on positron emission tomography-computed tomography (PET-CT) scan and baseline International Prognostic Index (IPI). This retrospective study included 220 patients (median age, 64 years; men, 60%) diagnosed with DLBCL between 2007 and 2016 at our institution, treated with rituximab-based chemotherapy. Interim PET-CT was performed after three cycles of immuno-chemotherapy. Interim Deauville score was assessed as 4 or 5 in 49 patients (22.3%), and 94 patients (42.7%) had high-intermediate or high-risk IPI scores. In multivariate analysis, interim Deauville score (1-3 and 4-5) and baseline IPI (low/low-intermediate and high-intermediate/high) were independently associated with progression-free survival (for Deauville score, hazard ratio [HR], 1.00 vs. 2.96 [95% confidence interval (CI), 1.83-4.78], P < 0.001; for IPI, HR, 1.00 vs. 4.84 [95% CI, 2.84-8.24], P < 0.001). We stratified patients into three groups: low-risk (interim Deauville scores 1-3 and low/low-intermediate IPI), intermediate-risk (Deauville scores 1-3 with high-intermediate/high IPI or Deauville scores 4-5 with low/low-intermediate IPI), and high-risk (Deauville scores 4-5 and high-intermediate/high IPI). This early risk stratification showed a strong association with progression-free survival (HR, 1.00 vs. 3.98 [95% CI 2.10-7.54] vs. 13.97 [95% CI 7.02-27.83], P < 0.001). Early risk stratification using interim Deauville score and baseline IPI predicts the risk of disease progression or death in patients with DLBCL. Our results provide guidance with interim PET-driven treatment intensification strategies.

Risk Stratification Of Diffuse Large B-Cell Lymphoma With Interim PET/CT By Combining Deauville Scores And International Prognostic Index

Purpose

Prognostic evaluation using interim positron emission tomography/computed tomography (interim PET/CT; I-PET) remains controversial. For any predictor, the prognosis of patients around its cutoff value is most uncertain. If the patients around the cutoff value could be subdivided by another factor, like the international prognostic index (IPI), it may improve the predictive power of I-PET. The combination of I-PET and IPI for risk stratification of patients was explored in this study.

Patients and methods

One hundred and eleven diffuse large B-cell lymphoma (DLBCL) patients treated with R-CHOP therapy were included retrospectively, 59 of whom underwent PET/CT after three or four cycles of treatment (I-PET). Fifty-two patients underwent PET/CT after five or six cycles of treatment (end of treatment; E-PET).

Results

When Deauville 5-point scale (5-DS) scores of 4–5 were classified as a positive scan (denoted by DS [score 4]), there was no significant difference in progression-free survival (PFS) between I-PET positive and negative patients (P=0.151). Further, patients with 5-DS score 3 and high IPI were stratified into I-PET positive-, whereas those with 5-DS score 3 and low IPI were classified into I-PET negative scan groups. Under this stratification, there was a significant difference in PFS between I-PET positive and negative patients (P=0.001). The sensitivity, positive predictive value, and negative predictive value for 2-year PFS for the combination score were higher than DS (score 4) alone (66.7% vs 33.3%, 50.0%vs 37.5%, 93.6% vs 88.2%) whereas specificity was almost the same (90.0% vs 88.0%).

Conclusion

Subdivision of patients with 5-DS score 3 by IPI improved prognostic prediction accuracy. The IPI adds strength to 5-DS in I-PET to detect patients with good or poor prognosis. Compared with other combinations of I-PET and IPI, dividing the patients around the cutoff value of 5-DS by IPI was easily accepted by clinicians and allowed them to decide on further treatment practically.

Prognostic Value of Pre-Autologous Stem Cell Transplantation PET/CT in Diffuse Large B-Cell Lymphoma: The Deauville Score Is Prognostically Superior to ΔSUVmax

OBJECTIVE

The predictive value of pre-autologous stem cell transplantation (pre-ASCT) positron emission tomography/computed tomography (PET/CT) scans according to different criteria remains elusive in patients with diffuse large B-cell lymphoma (DLBCL).

METHODS

A total of 46 DLBCL patients treated with pre-ASCT were enrolled in the present study, and two methods, Deauville score and maximal standardized uptake value reduction (ΔSUVmax), were used to evaluate the PET/CT scans before transplantation.

RESULTS

In patients with Deauville 1-3 and ≥4, the 2-year progression-free survival (PFS) rates were 82.8 and 11.8% (p < 0.001), respectively, while the 2-year overall survival (OS) rates were 89.7 and 41.2%, respectively (p < 0.001). When using the ΔSUVmax cut-off of 66% criterion, in patients with a ΔSUVmax of >66 and ≤66%, the 2-year PFS rates were 78.1 and 7.1%, respectively (p < 0.001), while the 2-year OS rates were 87.5 and 35.7%, respectively (p < 0.001). In the univariate analysis, the ΔSUVmax, Deauville score, NCCN-IPI and serum lactate dehydrogenase levels were significantly correlated with the 2-year PFS/OS. Furthermore, the multivariate analysis revealed that the Deauville score was an independent prognostic factor for 2-year PFS.

CONCLUSION

The present results indicate that PET/CT scans at pre-ASCT can predict the survival of DLBCL patients, and the Deauville score is better than ΔSUVmax in prognostic prediction.

Dynamic Risk Profiling Using Serial Tumor Biomarkers for Personalized Outcome Prediction

Accurate prediction of long-term outcomes remains a challenge in the care of cancer patients. Due to the difficulty of serial tumor sampling, previous prediction tools have focused on pretreatment factors. However, emerging non-invasive diagnostics have increased opportunities for serial tumor assessments. We describe the Continuous Individualized Risk Index (CIRI), a method to dynamically determine outcome probabilities for individual patients utilizing risk predictors acquired over time. Similar to "win probability" models in other fields, CIRI provides a real-time probability by integrating risk assessments throughout a patient's course. Applying CIRI to patients with diffuse large B cell lymphoma, we demonstrate improved outcome prediction compared to conventional risk models. We demonstrate CIRI's broader utility in analogous models of chronic lymphocytic leukemia and breast adenocarcinoma and perform a proof-of-concept analysis demonstrating how CIRI could be used to develop predictive biomarkers for therapy selection. We envision that dynamic risk assessment will facilitate personalized medicine and enable innovative therapeutic paradigms.

Interim PET/CT in diffuse large B-cell lymphoma may facilitate identification of good-prognosis patients among IPI-stratified patients

Treating patients with DLBCL remains a challenge, as the response to first-line immunochemotherapy is somewhat unpredictable. The International Prognostic Index (IPI) is one of the most widely used methods for assessing prognosis. Interim PET/CT (iPET/CT) can play an important role in the early identification of 'non-responder' patients before the end of treatment examination. In this study, we retrospectively analyzed 104 newly diagnosed DLBCL patients treated with R-CHOP-like regimens who underwent iPET/CT imaging during therapy. There was a significant difference in 2-year OS between patients with negative iPET/CT and those with positive iPET/CT. Patients who had positive iPET/CT showed inferior 2-year PFS compared to those with negative iPET/CT. According to IPI, there was a statistically significant difference in 2-year OS and PFS between patients in the lower and higher risk groups. However, these patients can be further subdivided according to iPET/CT. The iPET/CT results in the present study clearly separate good- and poor-prognosis patients according to differences in 2-year OS, both in the lower and higher IPI risk groups. These results are in agreement with those of previous studies that demonstrated that iPET/CT has high negative predictive value, clearly identifying good-prognosis patients even within the poor-prognosis IPI group.

Evolving Role of PET-Based Novel Quantitative Techniques in the Management of Hematological Malignancies

"The role of ¹⁸F-fluorodeoxyglucose PET/computed tomography in hematological malignancies continues to expand in disease diagnosis, staging, and management. A key advantage of PET over other imaging modalities is its ability to quantify tracer uptake, which can be used to determine degree of disease activity. Although tracer uptake with PET is conventionally measured in focal lesions, novel quantitative techniques are being investigated that set objective protocols and produce robust parameters that represent total disease activity portrayed by PET. This article discusses recent advances in PET quantification that can improve reliability and accuracy of characterizing hematological malignancies."

Time to Prepare for Risk Adaptation in Lymphoma by Standardizing Measurement of Metabolic Tumor Burden

Increased tumor burden is associated with inferior outcomes in many lymphoma subtypes. Surrogates of tumor burden that are easy to measure, such as the maximum tumor dimension of the bulkiest lesion on CT, have been used as prognostic indices for many years. Recently, total metabolic tumor volume (MTV) and tumor lesion glycolysis have emerged as promising and robust biomarkers of outcome in various lymphomas. The median MTV and the optimal cutoffs to separate patients into risk groups in a study population are, however, highly dependent on the population characteristics and the delineation method used to outline tumor on the PET image. This issue has precluded the use of MTV for risk stratification in trials and clinical practice. Standardization of the methodology is timely to allow the potential for risk adaptation to be explored in addition to response adaptation using PET. Meetings between representatives from research groups active in the field were held under the auspices of the PET International Lymphoma and Myeloma Workshop. A summary of those discussions, which included a review of the literature and a practical assessment of methods used for outlining, including various software options, is presented. Finally, a proposal is made to perform a technical validation of MTV measurement enabling benchmark reference ranges to be derived for published delineation approaches used for outlining with various software. This process would require collation of representative imaging data sets of the most common lymphoma subtypes; agreement on pragmatic criteria for the selection of lesions; generation of a range of MTVs, with consensus to be reached on final contours in a training set; and development of automated software solutions with a set of minimum functionalities to reduce measurement variability. Methods developed in the above training exercise could then be applied to another data set, with a final set of contours and values generated. This final data set would provide a benchmark against which end-users could test their ability to measure MTVs that are consistent with expected values. The data set and automated software solutions could be shared with manufacturers with the aim of including these in standard workflows to allow standardization of MTV measurement across the world.

[Prognostic significance of (18)F-fluorodeoxyglucose positron emission tomography in patients with diffuse large B cell lymphoma undergoing autologous stem cell transplantation]

Objective: To evaluate the prognostic value of (18)F-fluorodeoxyglucose positron emission tomography (PET)/computed tomography (CT) in patients with diffuse large B cell lymphoma (DLBCL) undergoing autologous hematopoietic stem cell transplantation (auto-HSCT). Methods: Forty-eight patients with DLBCL treated at Peking University Cancer Hospital between November 2010 and December 2014 were assessed. All patients underwent PET/CT scanning prior to or after auto-HSCT. Correlation analysis was done based upon patients characteristics, PET/CT scan results and survival. Results: ①Among 48 patients, 27 was male, 21 female, median age was 43 (17-59) years old. ② Patients with negative pre-auto-HSCT PET/CT assessment demonstrated significantly better 3-year progression free survival (PFS) (87.1% vs 53.3%, χ(2)=7.02, P=0.019) and overall survival (OS) (90.3% vs 60.0%, χ(2)=6.51,P=0.022) than patients with positive pre-auto-HSCT PET/CT assessment. Three-year PFS (94.1% vs 30.0%, χ(2)=22.75, P=0.001) and OS (97.1% vs 40.0%, χ(2)=21.09, P=0.002) were also significantly different between patients with negative and positive post-auto-HSCT PET/CT assessment. ③ Multivariate analysis indicated a significant association of PFS (HR=13.176, P=0.005) and OS (HR=20.221, P=0.007) with post-auto-HSCT PET/CT assessment. Number of prior treatment regimens was associated with PFS (HR=10.039, P=0.040). ④ Harrell's C index revealed that the value of combined use of number of prior treatment regimens and post-auto-HSCT PET/CT assessment was superior to either one used alone in PFS (Harrell's C values were 0.976, 0.869 and 0.927 in combined use, number of prior treatment regimens and post-auto-HSCT PET/CT assessment, respectively), and the combined use of ECOG performance status and post-auto-HSCT PET/CT assessment significantly increased the Harrell's C index in OS (Harrell's C values were 0.973, 0.711 and 0.919 in combined use, ECOG performance status and post-auto-HSCT PET/CT assessment, respectively). Conclusions: Post-auto-HSCT PET/CT assessment is the main predictor of outcomes in DLBCL patients receiving auto-HSCT. Combined use of post-auto-HSCT PET/CT assessment and number of prior treatment regimens and ECOG performance status is a better prognostic tool in patients with DLBCL undergoing transplantation.

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.

Prognostic value of 18F-fluorodeoxyglucose positron emission tomography using Deauville criteria in diffuse large B cell lymphoma treated with autologous hematopoietic stem cell transplantation

Objective

High-dose chemotherapy (HDC) followed by autologous hematopoietic stem cell transplantation (auto-HSCT) plays an important role in improving outcomes of diffuse large B cell lymphoma (DLBCL) patients. ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET)/computed tomography (CT) has been widely accepted in response assessment and prediction of prognosis in DLBCL. Here, we report the value of ¹⁸F-FDG PET/CT pre- and post-HSCT in predicting outcomes of patients with DLBCL.

Methods

DLBCL patients who had PET/CT scan before and after HSCT were included. PET results were interpreted based upon Deauville criteria. The prognostic value of ¹⁸F-FDG PET/CT in auto-HSCT was evaluated.

Results

Eighty-four patients were enrolled. In univariate analysis, pre- and post-HSCT PET findings were correlated with 3-year progression-free survival (PFS) [hazard ratio (HR)=4.391, P=0.001; HR=7.607, P<0.001] and overall survival (OS) (HR=4.792, P=0.008; HR=26.138, P<0.001). Patients receiving upfront auto-HSCT after first-line treatment had better outcomes than relapsed/refractory DLBCL patients (3-year PFS, P<0.001; 3-year OS, P<0.001). In the relapsed/refractory patients, pre- and post-HSCT PET findings were also associated with 3-year PFS (P=0.003vs. P<0.001) and OS (P=0.027vs. P<0.001). A significant correlation was observed between clinical response to chemotherapy before auto-HSCT and outcomes of patients in the entire cohort (3-year PFS, P<0.001; 3-year OS, P<0.001) and in the subgroup of 21 patients with positive pre-HSCT PET (3-year PFS, P=0.084; 3-year OS, P=0.240). A significant association between survival and post-HSCT PET findings was observed in multivariate analysis (HR=5.168, P<0.001).

Conclusions

PET results before and after HSCT are useful prognostic factors for DLBCL patients receiving HSCT. Patients who responded to chemotherapy, even those with positive pre-HSCT PET, are appropriate candidates for auto-HSCT.

Available prognostic models for risk stratification of diffuse large B cell lymphoma patients: a systematic review

The International Prognostic Index (IPI) has been used for risk stratification for a long time in diffuse large B cell lymphoma (DLBCL). Based on new clinical and biological prognostic markers, many new prognostic models have been described. This review aims to present the progress in development and validation of these prognostic models. A comprehensive literature review was performed to identify studies that proposed a new prognostic model in DLBCL. A total of 38 studies met the inclusion criteria. The IPI, revised IPI (R-IPI), and National Comprehensive Cancer Network (NCCN)-IPI were the most studied prognostic indexes, externally validated and commonly used to compare to other models. Despite an increasing number of prognostic models have been proposed lately, most of them lack external validation. Further studies, that combine biological and clinical markers with prognostic significance, are needed to determine the optimal prognostic tool for more personalized treatment approach to DLBCL patients.

Predictive value of interim positron emission tomography in diffuse large B-cell lymphoma: a systematic review and meta-analysis

Purpose

Diffuse large B-cell lymphoma (DLBCL) represents the most common subtype of non-Hodgkin lymphoma. Most relapses occur in the first 2 years after diagnosis. Early response assessment with ¹⁸F-fluoro-2-deoxy-D-glucose (¹⁸F-FDG) positron emission tomography (PET) may facilitate early change of treatment, thereby preventing ineffective treatment and unnecessary side effects. We aimed to assess the predictive value of visually-assessed interim ¹⁸F-FDG PET on progression-free survival (PFS) or event-free survival (EFS) in DLBCL patients treated with first-line immuno-chemotherapy regimens.

Methods

For this systematic review and meta-analysis Pubmed, Embase, and the Cochrane Library were searched until July 11, 2017. Prospective and retrospective studies investigating qualitative interim PET response assessment without treatment adaptation based on the interim PET result were eligible. The primary outcome was two-year PFS or EFS. Prognostic and diagnostic measures were extracted and analysed with pooled hazard ratios and Hierarchical Summary Receiver Operator Characteristic Curves, respectively. Meta-regression was used to study covariate effects.

Results

The pooled hazard ratio for 18 studies comprising 2,255 patients was 3.13 (95%CI 2.52–3.89) with a 95% prediction interval of 1.68–5.83. In 19 studies with 2,366 patients, the negative predictive value for progression generally exceeded 80% (64–95), but sensitivity (33–87), specificity (49–94), and positive predictive values (20–74) ranged widely.

Conclusions

These findings showed that interim ¹⁸F-FDG PET has predictive value in DLBCL patients. However, (subgroup) analyses were limited by lack of information and small sample sizes. Some diagnostic test characteristics were not satisfactory, especially the positive predictive value should be improved, before a successful risk stratified treatment approach can be implemented in clinical practice.

Electronic supplementary material

The online version of this article (10.1007/s00259-018-4103-3) contains supplementary material, which is available to authorized users.

Metabolic Tumor Volume Metrics in Lymphoma

Although visual assessment using the Deauville criteria is strongly recommended by guidelines for treatment response monitoring in all FDG-avid lymphoma histologies, the high rate of false-positives and concerns about interobserver variability have motivated the development of quantitative tools to facilitate objective measurement of tumor response in both routine and clinical trial settings. Imaging studies using functional quantitative measures play a significant role in profiling oncologic processes. These quantitative metrics allow for objective end points in multicenter clinical trials. However, the standardization of imaging procedures including image acquisition parameters, reconstruction and analytic measures, and validation of these methods are essential to enable an individualized treatment approach. A robust quality control program associated with the inclusion of proper scanner calibration, cross-calibration with dose calibrators and across other scanners is required for accurate quantitative measurements. In this section, we will review the technical and methodological considerations related to PET-derived quantitative metrics and the relevant published data to emphasize the potential value of these metrics in the prediction of patient prognosis in lymphoma.

Comparison Between Different PET and CT-Based Imaging Interpretation Criteria at Interim Imaging in Patients With Diffuse Large B-Cell Lymphoma

OBJECTIVE

To evaluate the predictive value of interim PET (iPET) in diffuse large B-cell lymphoma (DLBCL) using 5 different imaging interpretation criteria: Deauville 5-point scale criteria, International Harmonization Project (IHP) criteria, Response Evaluation Criteria In Solid Tumors (RECIST) 1.1, European Organization for Research and Treatment of Cancer, and PET Response Criteria in Solid Tumors (PERCIST) 1.0.

METHODS

We retrospectively reviewed records from 38 patients with DLBCL who underwent baseline and iPET at our institution. Imaging was interpreted according to the previously mentioned criteria. Results were correlated with end-of-treatment response, based on reports at the end of treatment radiological examinations, overall survival (OS), and progression-free survival (PFS) to assess and compare the predictive value of iPET according to each criterion. We also evaluated the concordance between different criteria.

RESULTS

The Deauville and PERCIST criteria were the most reliable for predicting end-of-treatment response, reporting an accuracy of 81.6%. They also correlated with OS and PFS (P = 0.0004 and P = 0.0001, and P = 0.0007 and P = 0.0002, for Deauville and PERCIST, respectively). Interim PET according to European Organization for Research and Treatment of Cancer also predicted the end-of-treatment response with an accuracy of 73.7% and had a significant correlation with OS (P = 0.007) and PFS (P = 0.007). In contrast, the IHP criteria and RECIST did not predict outcomes: the accuracy for end-of-treatment response was 34.2% and 36.8%, respectively, with no significant correlation with OS or PFS (P = 0.182 and P = 0.357, and P = 0.341 and P = 0.215, for OS and PFS, respectively).

CONCLUSIONS

The predictive value of iPET in DLBCL patients is most reliable using the Deauville and PERCIST criteria. Criteria that rely on anatomical characteristics, namely, RECIST and IHP criteria, are less accurate in predicting patient outcomes in DLBCL.

Prognostic value of pre- and post-transplantation 18F-fluorodeoxyglucose positron emission tomography results in non-Hodgkin lymphoma patients receiving autologous stem cell transplantation

Objective

High-dose chemotherapy (HDC) followed by autologous stem cell transplantation (ASCT) is the standard of care in the upfront or relapsed/refractory setting in some patients with non-Hodgkin lymphoma (NHL). However, a proportion of patients do not respond to ASCT. ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) has been widely used for staging, response evaluation, and prognosis prediction. Here, we investigated the prognostic role of PET/CT in NHL patients before and after ASCT.

Methods

A retrospective study was conducted at Peking University Cancer Hospital. All NHL patients who underwent ASCT between March 2010 and July 2016 were identified. Patients who had PET/CT scan before and after ASCT were included. Deauville criteria (5-point scale) were used to interpret PET scans. Univariate and multivariate survival analyses were performed using Cox regression. The predictive value of PET scanning was estimated by comparing the area under the receiver operating characteristic (ROC) curve.

Results

In total, 79 patients were enrolled in this study. In univariate analysis, pre- and post-ASCT PET result was identified as prognostic factors for 3-year progression-free survival (PFS) and overall survival (OS). Patients with negative pre-ASCT PET result demonstrated significantly better PFS (84.2% vs. 54.2%) and OS (89.2% vs. 63.6%) than patients with positive pre-ASCT PET result. PFS (91.6% vs. 25.3%) and OS (96.5% vs. 36.8%) were also significantly different between patients with negative and positive post-ASCT PET result. Multivariate analysis also showed a significant association between survival and post-ASCT PET result. ROC analysis revealed that the predictive value of post-ASCT PET result was superior to that of pre-ASCT PET result alone. Combined pre- and post-ASCT PET result is better for predicting outcomes in patients with NHL receiving transplantation. Deauville criteria score >3 was identified as the best cutoff value for post-ASCT PET.

Conclusions

Post-ASCT PET result was more important than pre-ASCT PET result in predicting outcomes for NHL patients who underwent ASCT. The prognostic significance can be improved when combining pre-ASCT PET result with post-ASCT PET result. Deauville criteria can be used for interpreting PET scans in this scenario.

Predictive value of interim PET/CT visual interpretation in the prognosis of patients with aggressive non-Hodgkin's lymphoma

Objective

The objective of the study was to evaluate the prognostic value of positron emission tomography (PET)/computed tomography (CT) visual interpretation in patients with aggressive non-Hodgkin’s lymphoma (NHL) using a meta-analysis and systematic review.

Methods

Using the PubMed, Embase, and Web of Science databases, we performed a systematic review of the use of visual evaluation mid-chemotherapy to evaluate the prognosis of aggressive NHL in studies published up to May 2017. Prospective and retrospective studies assessing progression-free survival (PFS) and overall survival (OS) were included. We used hazard ratio (HR) to determine the value of Deauville criteria and International Harmonization Project (IHP) criteria for measuring survival. Subgroup analysis was performed based on the number of chemotherapy cycles before the mid-term evaluation as well as the visual evaluation method.

Results

A total of 11 studies were included. PFS (HR =2.93, 95% confidence interval [CI]: 2.93–3.90, p<0.0001) and OS (HR =2.55, 95% CI: 1.76–3.68, p<0.0001) of PET/CT-positive patients were significantly lower when determined by the visual method. In subgroup analysis, IHP, Deauville criteria, and having no standard interpretation groups were factors able to predict PFS; IHP and having no standard interpretation group were able to predict OS. With PET/CT, IHP, and Deauville 5-point criteria, the PFS of patients receiving 2–4 cycles of chemotherapy before PET/CT was significantly lower than that of PET/CT-negative patients. No significant difference in OS was observed when patients received 3 or fewer cycles of chemotherapy before PET/CT, though OS was significantly lower in patients receiving more than 3 chemotherapy cycles.

Conclusion

IHP and Deauville criteria are commonly used for PET/CT visual evaluation at present. Interim PET/CT analysis after 3–4 chemotherapy cycles is capable of predicting disease prognosis. Large-scale prospective clinical trials are needed to confirm whether PET/CT analysis can be used as an indication for changing a treatment strategy.

Interim 18F-FDG PET/CT improves the prognostic value of S-IPI, R-IPI and NCCN-IPI in patients with diffuse large B-cell lymphoma

The current study aimed to explore whether the efficiency of the standard International Prognostic Index (S-IPI), revised-IPI (R-IPI) and enhanced-IPI (NCCN-IPI) in evaluating the prognosis of patients with diffuse large B-cell lymphoma (DLBCL) may be improved by interim ¹⁸F-FDG PET/CT. A total of 185 patients with newly diagnosed DLBCL were enrolled in the current study. All patients underwent interim PET/CT following the 4th cycle of chemotherapy. Patients were divided into different risk groups using S-IPI, R-IPI and NCCN-IPI and further subdivided into risk groups using interim PET/CT. Interpretations were evaluated for 2-year progression-free survival (PFS) and overall survival (OS). With a median follow-up time of 44 months, the 2-year PFS and OS were 60% [95% confidence interval (CI) 53–67%] and 81% (95% CI 74–86%), respectively. Analysis of S-IPI and NCCN-IPI identified no significant difference in PFS and OS between high intermediate and high risk groups. However, there were significant differences in the PFS and OS between the low and low intermediate risk groups (P<0.01). Interim PET/CT was used to redistribute patients in the higher risk group into PET negative and positive groups (P<0.01) and arallel results were observed in the lower risk group. In R-IPI, interim PET/CT identified a significant difference between PFS and OS in the good and poor risk groups but not in the very good risk group. Therefore, the results of the current study indicate that S-IPI, R-IPI and NCCN-IPI are three clinically useful prognostic indexes for patients with DLBCL. Interim PET/CT may improve the prognostic value of S-IPI, R-IPI and NCCN-IPI in predicting 2-year PFS and OS, particularly in patients with a high IPI score.

Prognostic value of pre-transplant PET/CT in patients with diffuse large B-cell lymphoma undergoing autologous stem cell transplantation

Pre-transplant PET/CT may be prognostic in diffuse large B-cell lymphoma (DLBCL) patients undergoing autologous stem cell transplantation (ASCT). We reviewed relapsed and pre-transplant PET/CT scans of 32 patients with DLBCL treated with ASCT to determine the Deauville score and the maximum standardized uptake value (SUV_max). Patients with a Deauville score of 4 had a significantly inferior prognosis. The 3-year progression-free survival (PFS) for patients with Deauville 1-3 score was 64%, compared to 0% for Deauville 4, while the 3-year overall survival (OS) was 84% and 25%, respectively (p < .001, p = .002). The change in the SUV_max (>66 versus ≤66%) was not predictive of PFS or OS, but a high pre-transplant SUV_max (>6) demonstrated a trend towards an inferior PFS. Pre-transplant PET/CT is a tool for identifying DLBCL patients at high risk for treatment failure with ASCT and could be used to risk-stratify patients in prospective clinical trials of novel transplant strategies.

FDG PET for therapy monitoring in Hodgkin and non-Hodgkin lymphomas

PET using 18F-FDG for treatment monitoring in patients with lymphoma is one of the most well-developed clinical applications. PET/CT is nowadays used during treatment to assess chemosensitivity, with response-adapted therapy given according to 'interim' PET in clinical practice to adults and children with Hodgkin lymphoma. PET is also used to assess remission from disease and to predict prognosis in the pretransplant setting. Mature data have been reported for the common subtypes of aggressive B-cell lymphomas, with more recent data also supporting the use of PET for response assessment in T-cell lymphomas. The Deauville five-point scale incorporating the Deauville criteria (DC) is recommended for response assessment in international guidelines. FDG uptake is graded in relation to the reference regions of normal mediastinum and liver. The DC have been validated in most lymphoma subtypes. The DC permit the threshold for adequate or inadequate response to be adapted according to the clinical context or research question. It is important for PET readers to understand how the DC have been applied in response-adapted trials for correct interpretation and discussion with the multidisciplinary team. Quantitative methods to perform PET in standardized ways have also been developed which may further improve response assessment including a quantitative extension to the DC (qPET). This may have advantages in providing a continuous scale to refine the threshold for adequate/inadequate response in specific clinical situations or treatment optimization in trials. qPET is also less observer-dependent and limits the problem of optical misinterpretation due to the influence of background activity.

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.

Optimisation of metabolic criteria in the prognostic assessment in patients with lymphoma. A multicentre study

OBJECTIVE

To compare sensitivity, specificity and predictive value of Deauville score (DS) vs. ΔSUVmax in interim-treatment PET (iPET) and end-treatment PET (ePET), in patients with diffuse large B cell lymphoma (DLBCL), Hodgkin lymphoma (HL), and follicular lymphoma (FL).

METHOD

Retrospective longitudinal multicentre study including 138 patients (46 DLBCL, 46 HL, 46 FL), on whom 3 ¹⁸F-FDG PET/CT were performed: baseline, iPET, and ePET. Visual (DS) and semi-quantitative (ΔSUVmax) parameters were determined for iPET and ePET. Predictive value was determined in relation to disease-free interval.

RESULTS

Statistical analysis. iPET for DLBCL, HL, and FL: 1) sensitivity of DS: 76.92/83.33/61.53%; specificity: 78.78/85/81.81%; 2) sensitivity of ΔSUVmax: 53.84/83.33/61.53%; specificity: 87.87/87.50/78.78%. ePET for DLBCL, HL and FL: 1) sensitivity of DS: 61.53/83.33/69.23%; specificity: 90.90/85/87.87%; 2) sensitivity of ΔSUVmax: 69.23/83.33/69.23%; specificity: 90.90/87.50/84.84%. Predictive assessment. iPET study: in DLBCL, DS resulted in 10.3% recurrence of negative iPET, and 17.1% in ΔSUVmax at disease-free interval; in HL, both parameters showed a 2.8% recurrence of negative iPET; in FL, DS resulted in 15.6% recurrence of negative iPET, and 16.1% in ΔSUVmax, with no statistical significance. ePET study: in DLBCL, DS resulted in 14.3% recurrence of negative ePET, and 11.8% in ΔSUVmax at disease-free interval; in HL and FL, both methods showed 2.8 and 12.5% recurrence in negative ePET, respectively.

CONCLUSION

DS and ΔSUVmax did not show significant differences in DLBCL, HL and FL. Their predictive value also did not show significant differences in HL and FL. In DLBCL, DS was higher in iPET, and ΔSUVmax in ePET.

Interim PET-driven strategy in de novo diffuse large B-cell lymphoma: do we trust the driver?

¹⁸F-Fluorodeoxyglucose-positron emission tomography (FDG-PET) has become a central tool for both accurate initial staging and determination of prognosis after treatment of diffuse large B-cell lymphoma (DLBCL). However, the role of PET during treatment (iPET) in daily practice remains a matter of significant debate. This perspective reviews the published studies on iPET in DLBCL, including the methods used to analyze iPET, its timing, and studies of iPET-driven therapy to illuminate where daily practice may benefit from the use of iPET. When performed after 2 and/or 4 courses of immunochemotherapy, iPET has a very good negative predictive value, utilizing both visual (qualitative) and semiquantitative methods. The visual method accurately predicts outcome for patients with limited disease. The semiquantitative method, eg, the change of the difference of maximum standardized uptake value (ΔSUVmax), is for patients with advanced DLBCL, for whom iPET identifies patients with very good outcome with continuation of standard therapy. A low ΔSUVmax also helps identify patients with a risk for relapse averaging 50% and warrants review of their scheduled therapy. To date, no trial has demonstrated the superiority of an iPET-driven strategy in DLBCL. However, the very good negative and good positive predictive values of iPET support its use in daily practice as a better predictive tool than contrast-enhanced computed tomographic scan for therapeutic decision making.

Interim fluorine-18 fluorodeoxyglucose PET-computed tomography and cell of origin by immunohistochemistry predicts progression-free and overall survival in diffuse large B-cell lymphoma patients in the rituximab era

Supplemental Digital Content is available in the text.

Objective

The aim of this study was to analyze the prognostic value of the interim PET (iPET)-computed tomography (CT) (iPET-CT) after two cycles of immunochemotherapy with the R-CHOP protocol in patients with diffuse large B-cell non-Hodgkin lymphoma (DLBCL) treated with a curative intent in combination with the neoplastic cell origin defined by Hans’s immunohistochemstry algorithm followed in a reference center for cancer treatment in Brazil.

Materials and methods

We prospectively evaluated 147 DLBCL patients treated with R-CHOP-21 to assess the value of the International Prognostic Index, iPET-CT, and cell of origin by immunohistochemistry as prognostic markers in the rituximab era. Fluorine-18 fluorodeoxyglucose PET-CT was performed after two cycles (iPET-CT) and at the end of treatment in 111 patients. Lymphoma cases were categorized into germinal center (GC) and nongerminal center subtypes by immunohistochemistry according to Hans’s algorithm.

Results

The median age of GC-DLBCL patients (52.7 years) was lower than that of nongerminal center-DLBCL patients (59.4 years) (P=0.021); in addition, it was lower in patients with negative iPET-CT findings (52.7 years) versus positive findings (59.4 years) (P=0.031). The overall survival at 48 months was 100% for iPET-CT-negative GC-DLBCL patients and 61.2% for iPET-CT-positive GC-DLBCL patients (P=0.002). Progression-free survival at 30 months was 100% for iPET-CT-negative GC-DLBCL patients and 60.3% for iPET-CT-positive GC-DLBCL patients (P=0.001).

Conclusion

We conclude that iPET-CT associated with cell origin identified a very good prognostic group in DLBCL patients treated with R-CHOP. Video Abstract: http://links.lww.com/NMC/A59

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.

Diffuse large B-cell lymphoma: R-CHOP failure-what to do?

Although rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) is the standard treatment for patients with diffuse large B-cell lymphoma (DLBCL), ∼30% to 50% of patients are not cured by this treatment, depending on disease stage or prognostic index. Among patients for whom R-CHOP therapy fails, 20% suffer from primary refractory disease (progress during or right after treatment) whereas 30% relapse after achieving complete remission (CR). Currently, there is no good definition enabling us to identify these 2 groups upon diagnosis. Most of the refractory patients exhibit double-hit lymphoma (MYC-BCL2 rearrangement) or double-protein-expression lymphoma (MYC-BCL2 hyperexpression) which have a more aggressive clinical picture. New strategies are currently being explored to obtain better CR rates and fewer relapses. Although young relapsing patients are treated with high-dose therapy followed by autologous transplant, there is an unmet need for better salvage regimens in this setting. To prevent relapse, maintenance therapy with immunomodulatory agents such as lenalidomide is currently undergoing investigation. New drugs will most likely be introduced over the next few years and will probably be different for relapsing and refractory patients.

Early treatment intensification with R-ICE and 90Y-ibritumomab tiuxetan (Zevalin)-BEAM stem cell transplantation in patients with high-risk diffuse large B-cell lymphoma patients and positive interim PET after 4 cycles of R-CHOP-14

In the treatment of diffuse large B-cell lymphoma, a persistently positive [¹⁸F]fluorodeoxyglucose positron emission tomography (PET) scan typically carries a poor prognosis. In this prospective multi-center phase II study, we sought to establish whether treatment intensification with R-ICE (rituximab, ifosfamide, carboplatin, and etoposide) chemotherapy followed by 90Y-ibritumomab tiuxetan-BEAM (BCNU, etoposide, cytarabine, and melphalan) for high-risk diffuse large B-cell lymphoma patients who are positive on interim PET scan after 4 cycles of R-CHOP-14 (rituximab, cyclophosphamide, doxorubicin, and prednisone) can improve 2-year progression-free survival from a historically unfavorable rate of 40% to a rate of 65%. Patients received 4 cycles of R-CHOP-14, followed by a centrally-reviewed PET performed at day 17-20 of cycle 4 and assessed according to International Harmonisation Project criteria. Median age of the 151 evaluable patients was 57 years, with 79% stages 3-4, 54% bulk, and 54% International Prognostic Index 3-5. Among the 143 patients undergoing interim PET, 101 (71%) were PET-negative (96 of whom completed R-CHOP), 42 (29%) were PET-positive (32 of whom completed R-ICE and 90Y-ibritumomab tiuxetan-BEAM). At a median follow up of 35 months, the 2-year progression-free survival for PET-positive patients was 67%, a rate similar to that for PET-negative patients treated with R-CHOP-14 (74%, P=0.11); overall survival was 78% and 88% (P=0.11), respectively. In an exploratory analysis, progression-free and overall survival were markedly superior for PET-positive Deauville score 4 versus score 5 (P=0.0002 and P=0.001, respectively). Therefore, diffuse large B-cell lymphoma patients who are PET-positive after 4 cycles of R-CHOP-14 and who switched to R-ICE and 90Y-ibritumomab tiuxetan-BEAM achieved favorable survival outcomes similar to those for PET-negative R-CHOP-14-treated patients. Further studies are warranted to confirm these promising results. (Registered at: ACTRN12609001077257).

Interim PET Scans in Diffuse Large B-Cell Lymphoma: Is It Ready for Prime Time?

Prognostication of patients with diffuse large B-cell lymphoma (DLBCL) has improved in the past decade with a variety of clinical, morphologic, molecular, and radiographic methods. Comparable to data on the value of interim positron emission tomography (I-PET) in Hodgkin lymphoma, several retrospective and prospective studies are attempting to assess the value of I-PET scanning in DLBCL patients. In this review, we briefly describe and analyze the various prognostic methods in DLBCL with specific focus on the value of I-PET scanning in this disease. This is a timely analysis, as tailoring therapies based on prognosis at diagnosis are becoming of increased investigational interest.

Prognostic value of interim FDG-PET in R-CHOP-treated diffuse large B-cell lymphoma: Systematic review and meta-analysis

This study aimed to systematically review and meta-analyze the prognostic value of interim (18)F-fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) in diffuse large B-cell lymphoma (DLBCL) patients treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP). MEDLINE and EMBASE were systematically searched for suitable studies. Included studies were methodologically appraised, and results were summarized both descriptively and meta-analytically. Nine studies, comprising a total of 996 R-CHOP-treated DLBCL patients, were included. Overall, studies were of moderate methodological quality. The area under the summary receiver operating curve (AUC) of interim FDG-PET in predicting treatment failure and death were 0.651 and 0.817, respectively. There was no heterogeneity in diagnostic odds ratios across available studies (I(2)=0.0%). At multivariable analysis, 2 studies reported interim FDG-PET to have independent prognostic value in addition to the International Prognostic Index (IPI) in predicting treatment failure, whereas 3 studies reported that this was not the case. One study reported interim FDG-PET to have independent prognostic value in addition to the IPI in predicting death, whereas 2 studies reported that this was not the case. In conclusion, interim FDG-PET in R-CHOP-treated DLBCL has some correlation with outcome, but its prognostic value is homogeneously suboptimal across studies and it has not consistently proven to surpass the prognostic potential of the IPI. Moreover, there is a lack of studies that compared interim FDG-PET to the recently developed and superior National Comprehensive Cancer Network-IPI. Therefore, at present there is no scientific base to support the clinical use of interim FDG-PET in R-CHOP-treated DLBCL.

FDG-PET imaging in hematological malignancies

The majority of aggressive lymphomas is characterized by an up regulated glycolytic activity, which enables the visualization by F-18 FDG-PET/CT. One-stop hybrid FDG-PET/CT combines the functional and morphologic information, outperforming both, CT and FDG-PET as separate imaging modalities. This has resulted in several recommendations using FDG-PET/CT for staging, restaging, monitoring during therapy, and assessment of treatment response as well as identification of malignant transformation. FDG-PET/CT may obviate the need for a bone marrow biopsy in patients with Hodgkin's lymphoma and diffuse large B cell lymphoma. FDG-PET/CT response assessment is recommended for FDG-avid lymphomas, whereas CT-based response evaluation remains important in lymphomas with low or variable FDG avidity. The treatment induced change in metabolic activity allows for assessment of response after completion of therapy as well as prediction of outcome early during therapy. The five-point scale Deauville Criteria allows the assessment of treatment response based on visual FDG-PET analysis. Although the use of FDG-PET/CT for prediction of therapeutic response is promising it should only be conducted in the context of clinical trials. Surveillance FDG-PET/CT after complete remission is discouraged due to the relative high number of false-positive findings, which in turn may result in further unnecessary investigations. Future directions include the use of new PET tracers such as F-18 fluorothymidine (FLT), a surrogate biomarker of cellular proliferation and Ga-68 CXCR4, a chemokine receptor imaging biomarker as well as innovative digital PET/CT and PET/MRI techniques.

PET Scans for Staging and Restaging in Diffuse Large B-Cell and Follicular Lymphomas

Positron emission tomography (PET)-CT was recommended in updated international guidelines for staging/restaging of diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL). In FL, PET was previously regarded as a research application only. This review concentrates on new publications related to PET in these diseases. In DLBCL, PET appears appropriate for staging using prognostic indices established with CT and baseline PET parameters, e.g. metabolic tumour volume, are prognostic of outcome. Early complete metabolic response (CMR) predicts end-of-treatment CMR with excellent prognosis. Patients without CMR at interim should not have treatment altered, but have a worse prognosis, and patients with other high risk features may need closer monitoring. The end-of-treatment scan is confirmed as the standard for remission assessment using Deauville criteria, which are also predictive for patients undergoing ASCT. In FL, PET is more sensitive for staging than CT but misses bone marrow involvement. PET-CT identifies patients at risk of progression after induction chemotherapy better than CT.