Risk stratification of diffuse large B-cell lymphoma with interim PET-CT based on different cutoff Deauville scores

Evaluation of therapeutic effect and prognostic value of 18F-FDG PET/CT in different treatment nodes of DLBCL patients

BACKGROUND

In the present study, we aimed to investigate the role of baseline (B), interim (I) and end-of-treatment (Eot) 18F-FDG PET/CT in assessing the prognosis of diffuse large B cell lymphoma (DLBCL), so as to identify patients who need intensive treatment at an early stage.

METHODS

A total of 127 DLBCL patients (62 men; 65 women; median age 62 years) were retrospectively analyzed in this study. Baseline (n = 127), interim (n = 127, after 3-4 cycles) and end-of-treatment (n = 53, after 6-8 cycles) PET/CT images were re-evaluated; semi-quantitative parameters such as maximum standardized uptake value of lesion-to-liver ratio (SUVmax(LLR)) and lesion-to-mediastinum ratio (SUVmax(LMR)), total metabolic tumor volume (TMTV) and total metabolic tumor volume (TLG) were recorded. ΔTLG1 was the change of interim relative to baseline TLG (I to B), ΔTLG2 (Eot to B). ΔSUVmax and ΔTMTV were the same algorithm. The visual Deauville 5-point scale (D-5PS) has been adopted as the major criterion for PET evaluation. Visual analysis (VA) and semi-quantitative parameters were assessed for the ability to predict progression-free survival (PFS) and overall survival (OS) by using Kaplan-Meier method, cox regression and logistic regression analysis. When visual and semi-quantitative analysis are combined, the result is only positive if both are positive.

RESULTS

At a median follow-up of 34 months, the median PFS and OS were 20 and 32 months. The survival curve analysis showed that advanced stage and IPI score with poor prognosis, ΔSUVmax(LLR)1 < 89.2%, ΔTMTV1 < 91.8% and ΔTLG1 < 98.8%, ΔSUVmax(LLR)2 < 86.4% were significantly related to the shortening of PFS in patient (p < 0.05). ΔSUVmax(LLR)1 < 83.2% and ΔTLG1 < 97.6% were significantly correlated with the shortening of OS in patients (p < 0.05). Visual analysis showed that incomplete metabolic remission at I-PET and Eot-PET increased the risk of progress and death. In terms of predicting recurrence by I-PET, the combination of visual and semi-quantitative parameters showed higher positive predictive value (PPV) and specificity than a single index.

CONCLUSION

Three to four cycles of R-CHOP treatment may be a time point for early prediction of early recurrence/refractory (R/R) patients and active preemptive treatment. Combined visual analysis with semi-quantitative parameters of 18F-FDG PET/CT at interim can improve prognostic accuracy and may allow for more precise screening of patients requiring early intensive therapy.

Analysis of Positive Results of 18F-FDG PET/CT Imaging after Hematopoietic Stem Cell Transplantation in Lymphoma

PURPOSE

The purpose of this study was to differentiate between false-positive and true-positive positron emission tomography (PET) results after hematopoietic stem cell transplantation (SCT) for lymphoma involvement by analyzing several clinical variables and specific imaging features.

PATIENTS AND METHODS

Patients with lymphoma who received SCT and underwent post-transplantation ¹⁸F-FDG PET/CT scans between January 2013 and April 2021 at our institution were included. Associations between PET positivity and related clinical information were assessed using t-tests and χ² tests. The significance of variables differentiating benign lesions from malignant FDG-avid lesions was evaluated by logistic regression analysis. Survival probabilities were derived from Kaplan-Meier curves and compared using the log-rank test.

RESULTS

A total of 185 patients (235 post-transplantation PET/CT scans) were enrolled in our present study. Compared with those with true-positive PET results, patients with false-positive PET results exhibited a better prognosis. For the autologous SCT group, false-positive cases were more commonly seen when FDG-avid foci appeared outside the sites of the original disease (p = 0.004), and the integrated CT imaging showed negative results (p = 0.000). In multivariate logistic regression analysis, integrated CT results were the only significant factor. For the allogeneic SCT group, false-positive cases were significantly more commonly seen when DS = 4 (p = 0.046), FDG-avid foci appeared outside the sites of the original disease (p = 0.022), and the integrated CT imaging showed negative results (p = 0.001). In a multivariate logistic regression analysis, whether FDG-avid foci were in the sites of the original disease and integrated CT results were both significant factors.

CONCLUSION

False-positive FDG uptake in post-transplantation PET was not uncommon. Several variables could provide an important reference to differentiate false-positive from true-positive post-SCT PET results for lymphoma involvement.

TRIAL REGISTRATION NUMBER

ChiCTR2300067355.

PET/CT in Non-Hodgkin Lymphoma: An Update

Non-Hodgkin lymphomas represents a heterogeneous group of lymphoproliferative disorders characterized by different clinical courses, varying from indolent to highly aggressive. ¹⁸F-FDG-PET/CT is the current state-of-the-art diagnostic imaging, for the staging, restaging and evaluation of response to treatment in lymphomas with avidity for ¹⁸F-FDG, despite it is not routinely recommended for surveillance. PET-based response criteria (using five-point Deauville Score) are nowadays uniformly applied in FDG-avid lymphomas. In this review, a comprehensive overview of the role of ¹⁸F-FDG-PET in Non-Hodgkin lymphomas is provided, at each relevant point of patient management, particularly focusing on recent advances on diffuse large B-cell lymphoma and follicular lymphoma, with brief updates also on other histotypes (such as marginal zone, mantle cell, primary mediastinal- B cell lymphoma and T cell lymphoma). PET-derived semiquantitative factors useful for patient stratification and prognostication and emerging radiomics research are also presented.

PET-CR as a potential surrogate endpoint in untreated DLBCL: meta-analysis and implications for clinical trial design

This study's focus is the association of end-of-therapy (EOT) PET results with progression-free (PFS) and overall survival (OS) in patients with diffuse large B-cell lymphoma receiving first-line chemoimmunotherapy. We develop a Bayesian hierarchical model for predicting PFS and OS from EOT PET-complete response (PET-CR) using a literature-based meta-analysis of 20 treatment arms and a substudy of 4 treatment arms in 3 clinical trials for which we have patient-level data. The PET-CR rate in our substudy was 72%. The modeled estimates for hazard ratio (PET-CR/non-PET-CR) were 0.13 for PFS (95% CI 0.10, 0.16) and 0.10 for OS (CI 0.07, 0.12). Hazard ratios varied little by patient subtype and were confirmed by the overall meta-analysis. We link these findings to designing future clinical trials and show how our model can be used in adapting the sample size of a trial to accumulating results regarding treatment benefits on PET-CR and a survival endpoint.

Risk Stratification for Diffuse Large B-Cell Lymphoma by Integrating Interim Evaluation and International Prognostic Index: A Multicenter Retrospective Study

The baseline International Prognostic Index (IPI) is not sufficient for the initial risk stratification of patients with diffuse large B-cell lymphoma (DLBCL) treated with R‐CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone). The aims of this study were to evaluate the prognostic relevance of early risk stratification in DLBCL and develop a new stratification system that combines an interim evaluation and IPI. This multicenter retrospective study enrolled 314 newly diagnosed DLBCL patients with baseline and interim evaluations. All patients were treated with R-CHOP or R-CHOP-like regimens as the first-line therapy. Survival differences were evaluated for different risk stratification systems including the IPI, interim evaluation, and the combined system. When stratified by IPI, the high-intermediate and high-risk groups presented overlapping survival curves with no significant differences, and the high-risk group still had >50% of 3-year overall survival (OS). The interim evaluation can also stratify patients into three groups, as 3-year OS and progression-free survival (PFS) rates in patients with stable disease (SD) and progressive disease (PD) were not significantly different. The SD and PD patients had significantly lower 3-year OS and PFS rates than complete remission and partial response patients, but the percentage of these patients was only ~10%. The IPI and interim evaluation combined risk stratification system separated the patients into low-, intermediate-, high-, and very high-risk groups. The 3-year OS rates were 96.4%, 86.7%, 46.4%, and 40%, while the 3-year PFS rates were 87.1%, 71.5%, 42.5%, and 7.2%. The OS comparison between the high-risk group and very high-risk group was marginally significant, and OS and PFS comparisons between any other two groups were significantly different. This combined risk stratification system could be a useful tool for the prognostic prediction of DLBCL patients.

The Role of Interim PET/CT on Survival in Diffuse Large B Cell Lymphoma

BACKGROUND

Diffuse large B cell lymphoma is the most frequent aggressive non-Hodgkin lymphoma. Predicting response and estimating prognosis earlier makes management of this heterogeneous lymphoma more satisfying. Interim PET response is established in Hodgkin Lymphoma to tailor the therapy but results for non-Hodgkin Lymphoma is unconvincing. In the current study evaluation of interim PET and survival outcomes of 103 DLBCL patients is performed.

PATIENTS AND METHODS

About 103 Patients with DLBCL followed up in a single center between 2009 and 2019 were enrolled the study. All patients received R-CHOP chemoimmunotherapy at first line. Interim PET was performed after at least one or more cycles. All PET scans were performed with ¹⁸F-FDG isotope as PET/CT. PET scoring results were evaluated according to the 5-Point Deauville Scoring system defined in the National Comprehensive Cancer Network clinical guidelines for iPET and eotPET. 5-P DS of scores of 1 to 3 were defined as negative scans, and scores of 4 to 5 were considered to be positive scans.

RESULTS

Forty-six (44.7%) Female and 57 (55.3%) male aged between 25 and 83 (median 57) years newly diagnosed DLBCL patients were enrolled in the study. Median PFS was 21 (interquartile range 8.5-53.7) months and median OS was 33.5 (interquartile range 12.5-62.9) months for the total cohort. Positive predictive value of interim PET according to Deauville scoring system was 65.4% and negative predictive value was 77.9%.

CONCLUSION

Our study showed that according to Deauville 5 point scale (D 5PS) scoring system, interim PET-positive patients have shorter both PFS and OS than iPET-negative patients.

Improved prediction of chemoresistance in patients with diffuse large B-cell lymphoma through a new interim positron emission tomography-computed tomography evaluation model

OBJECTIVES

The positron emission tomography (PET) could predict the prognosis of DLBCL patients, but the exact procedure on interim PET (iPET) to determine chemoresistant patients remains elusive.

METHODS

We retrospectively analyzed 593 newly diagnosed DLBCL patients uniformly treated with R-CHOP regimen. Among them, 352 patients diagnosed from August 2010 to December 2016 were included in the test cohort and 241 patients diagnosed from January 2017 to December 2019 were included in the validation cohort. The iPET was evaluated with Deauville criteria and ΔSUVmax method. The reduction of maximal SUV between baseline and after 4 cycles of chemotherapy were defined as ΔSUVmax. The survival functions were depicted using the Kaplan-Meier method and compared with the log-rank test.

RESULTS

Patients with iPET Deauville 4 had heterogeneous outcome and end of treatment complete response rates (eCRR). Combined Deauville with ΔSUVmax method, we proposed a modified-Deauville model: patients with Deauville 4 and ΔSUVmax > 70%, as well as those with Deauville 1-3, were reclassified into the modified-Deauville negative group, while patients with Deauville 4 and ΔSUVmax ≤ 70%, as well as those with Deauville 5, into the modified-Deauville positive group. In the test cohort, 3-year PFS, OS and eCRR of modified-Deauville negative group were 80.2%, 89.9% and 91.8%, significantly higher than those of positive group (12.5%, 27.3% and 29.2%, p ≤ .001). Similar results were found in the validation cohort, that 3-year PFS, OS and eCRR were 87.8%, 95.4%, 96.3% in modified-Deauville negative group, and 27.4%, 32.5%, 13.5% in positive group. Through modified-Deauville model, patients in iPET positive group had very low eCRR and were resistant to conventional chemotherapy.

CONCLUSIONS

The modified-Deauville model could better distinguish DLBCL patients with poor response to chemotherapy. Accordingly, these patients could be recognized early and provided with alternative therapeutic agents, which might improve the clinical outcome of refractory DLBCL 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.

The Clinical Accuracy and Risk Stratification in End of Therapy 18F-FDG PET/CT in Burkitt Lymphoma

Purpose

Burkitt lymphoma (BL) is an invasive lymphoma subtype with FDG avid at ¹⁸F-FDG PET/CT, but there is currently no validated criterion in treatment evaluation and prognosis prediction. The aim of this study was to analyze the clinical accuracy of ¹⁸F-FDG PET/CT in Burkitt lymphoma in end of therapy PET/CT (EOT-PET) to assess the treatment response in BL and conduct a survival analysis with different Deauville 5-point score (DS) cutoff values.

Materials and Methods

A total of 189 patients were retrospectively included: 97 underwent baseline PET/CT and all underwent EOT-PET. Survival curves were plotted according to the Kaplan-Meier method. Different DS cutoff values in EOT-PET were evaluated for risk stratification in Burkitt lymphoma.

Results

The median progression free survival (PFS) and overall survival (OS) were 52 and 53 months, respectively. Applying the conventional DS 4 to 5, there was significant difference in outcome between EOT-PET negative and positive patients. However, the positive predictive value (PPV) (28.3% for PFS and 26.4% for OS) is low despite a high negative predictive value (NPV) (94.1% for OS and 94.9% for OS). When we moved the cutoff point to DS 5, the PPV was improved evidently (88.2% for PFS and 82.3% for OS) with the satisfactory NPV simultaneously (95.3% for PFS and 95.9% for OS).

Conclusions

EOT-PET results using DS significantly related with PFS and OS. DS of 5 may be a better cutoff point at the end of treatment to determine whether patients have a significant risk of recurrence or progress.

Early Interim Chemotherapy Response Evaluation by F-18 FDG PET/CT in Diffuse Large B Cell Lymphoma

Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) after one cycle of standard chemotherapy in patients with diffuse large B cell lymphoma (DLBCL) was assessed. Prospectively enrolled 51 patients had four PET/CT studies using the same protocol and system: at baseline and after one, three, and six cycles of chemotherapy (PET0, PET1, PET3, PET6). The PET1 and PET6 Deauville five-point score (D5PS) agreed in 60.8%, while PET3 and PET6 D5PS agreed in 90.2%. The absolute and percent changes of peak standard uptake value corrected for lean body mass (SULpeak) compared to baseline were significantly different between PET1 and PET3 (p = 0.001, p < 0.001) and PET1 and PET6 (p = 0.002, p = 0.001), but not between PET3 and PET6 (p = 0.276, p = 0.181). The absolute SULpeak from PET1 predicted treatment failure with accuracy of 78.4% (area under the curve 0.73, p = 0.023). D5PS, SULpeak, and metabolic tumor volume (MTV) were not statistically different between responders versus non-responders, or the one year disease-free versus relapse groups. D5PS and PERCIST responses showed 100% agreement at end-of-therapy. In conclusion, the responses after three and six cycles of therapy showed high degree of agreement. D5PS or MTV after one cycle of chemotherapy could not predict response or one-year disease-free status, but the SULpeak from PET1 was associated with response to first line therapy in DLBCL. Deauville and PERCIST criteria show high concordance.

Quantitative Assessment of Interim PET/CT Could Have More Prognostic Relevance than Visual Assessment for Predicting Clinical Outcome of Extranodal Diffuse Large B Cell Lymphoma

BACKGROUND/AIM

The present study retrospectively investigated the predictive accuracy of interim positron emission tomography/computed tomography (iPET/CT) based on the Deauville 5-point scale (5-PS) and a quantitative SUV-based assessment in patients with extranodal (EN) diffuse large B cell lymphoma (DLBCL).

PATIENTS AND METHODS

The Deauville 5-PS and the SUVmax reduction (ΔSUVmax) assessment for interpreting the response to iPET/CT were used.

RESULTS

A total of 163 patients were enrolled in this study. With a median follow-up of 52.5 months, ΔSUVmax successfully predicted the survival outcomes of patients with one extranodal (EN) involvement in terms of overall survival (OS) (p=0.012) and progression-free survival (PFS) (p<0.001). Visual assessment using the Deauville 5-PS did not predict survival outcomes in patients with one or more EN involvements in terms of OS and PFS.

CONCLUSION

The quantitative SUV-based assessment with iPET/CT was a significant prognosticator for long-term survival outcomes, especially in patients with one EN involvement.

RESISTing the Need to Quantify: Putting Qualitative FDG-PET/CT Tumor Response Assessment Criteria into Daily Practice

Tumor response assessments are essential to evaluate cancer treatment efficacy and prognosticate survival in patients with cancer. Response criteria have evolved over multiple decades, including many imaging modalities and measurement schema. Advances in FDG-PET/CT have led to tumor response criteria that harness the power of metabolic imaging. Qualitative PET/CT assessment schema are easy to apply clinically, are reproducible, and yield good prognostic results. We present 3 such criteria, namely, the Lugano classification for lymphoma, the Hopkins criteria, and the Neck Imaging Reporting and Data Systems criteria for head and neck cancers. When comparing baseline PET/CTs with interim or end-of-treatment PET/CTs, radiologists can classify the tumor response as complete metabolic response, partial metabolic response, no metabolic response, or progressive disease, which has important implications in directing further cancer management and long-term patient prognosis. The purpose of this article is to review the progression of tumor response assessments from CT- and PET/CT-based quantitative and semi-quantitative systems to PET/CT-based qualitative systems; introduce the classification schema for these systems; and describe how to use these rapid, powerful, and qualitative PET/CT-based systems in daily practice through illustrative cases.

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.

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.

Prognostic analysis of interim 18F-FDG PET/CT in patients with diffuse large B cell lymphoma after one cycle versus two cycles of chemotherapy

Objectives

¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) is routinely used in diffuse large B cell lymphoma (DLBCL) for staging, assessment of remission and recurrence, and estimation of therapeutic efficacy. In this study, we aimed to assess the role of an early interim PET/computed tomography (CT) in the evaluation of response in DLBCL.

Methods

Sixty primary DLBCL patients (31 females) were analyzed. Baseline and follow-up ¹⁸F-FDG PET/CT was performed in patients after one cycle (n = 30) and two cycles (n = 30) of chemotherapy. The ΔSUVmax% was calculated. Patients were additionally evaluated using the conventional Deauville five-point scale (D-5PS) system. Fluorescence in situ hybridization (FISH) was employed to characterize the MYC gene status. We determined the optimum cutoff value of ΔSUVmax% using receiver operating characteristic (ROC) analysis. Kaplan–Meier analysis was applied to test for the influence of prognostic values.

Results

The optimal cutoff for the prediction of treatment outcome was a ΔSUVmax% of 57% (after one cycle) and 63% (after two cycles); we could not detect a difference in accuracy with respect to a PET scan performed after one cycle and two cycles of chemotherapy (P  > 0.05). The ΔSUVmax% and the D-5PS (score 5) showed the highest prognostic value compared to a score of 3 and/or 4 (both after one cycle and two cycles). No significant difference in sensitivity, specificity, accuracy, or the area of under the curve (AUC) of ΔSUVmax% and D-5PS (score 5) was observed between PETs performed after one cycle or two cycles of therapy (P  > 0.05). ΔSUVmax%, D-5PS (score 5), and MYC gene rearrangement correlated significantly (P  < 0.001).

Conclusion

Interim ¹⁸F-FDG PET/CT after one cycle of chemotherapy is feasible and yields similar predictive results as compared to an interim ¹⁸F-FDG PET/CT after two cycles of chemotherapy in patients suffering from DLBCL. The combination of interim ¹⁸F-FDG PET/CT with the MYC gene diagnosis might provide increased prognostic value for DLBCL.

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.

Radiomics in Oncological PET/CT: Clinical Applications

18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is widely used for staging, evaluating treatment response, and predicting prognosis in malignant diseases. FDG uptake and volumetric PET parameters such as metabolic tumor volume have been used and are still used as conventional PET parameters to assess biological characteristics of tumors. However, in recent years, additional features derived from PET images by computational processing have been found to reflect intratumoral heterogeneity, which is related to biological tumor features, and to provide additional predictive and prognostic information, which leads to the concept of radiomics. In this review, we focus on recent clinical studies of malignant diseases that investigated intratumoral heterogeneity on PET/CT, and we discuss its clinical role in various cancers.