Clinical Outcomes in Patients With DLBCL Treated With R-CHOP According to Radiotherapy and Interim PET Response

Background/Aim

Interim positron emission tomography/computed tomography (PET/CT) scan is a valuable tool for assessing the early metabolic response to chemotherapy in diffuse large B-cell lymphoma (DLBCL). Although radiotherapy is an effective treatment for lymphoma, especially for local tumor control, the role of consolidative radiotherapy in diffuse large B-cell lymphoma (DLBCL) remains controversial. This study analyzed the clinical outcomes of patients with DLBCL treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP), stratified by interim PET response and the administration of radiotherapy.

Patients and Methods

We conducted a retrospective review of 107 patients with DLBCL treated with R-CHOP chemotherapy between January 2012 and December 2016. Overall survival (OS), recurrence-free survival (RFS), and freedom from disease progression (FFDP) were calculated using the Kaplan-Meier method and compared using the log-rank test.

Results

Forty-six patients were included in this analysis, with a median follow-up time of 65.9 months (range=4.7-125.3 months). The metabolic CR (mCR) group exhibited superior OS, RFS, and FFDP compared with the metabolic PR (mPR) group (p=0.003, p=0.001, and p=0.008, respectively). The 1-, 2-, and 5-year FFDP were 92.97%, 89.3%, and 85.6%, respectively, in the mCR group and 78.6%, 61.9%, and 44.2%, respectively, in the mPR group. In subgroup analysis, the FFDP of the mPR group without radiotherapy was significantly lower than that of the other groups (mCR with/without radiotherapy and mPR with radiotherapy, p=0.001).

Conclusion

Consolidative radiation therapy using interim PET can benefit patients who do not achieve mCR. Further well-controlled prospective randomized trials are required.

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.

Prognosis and risk stratification of peripheral T-cell lymphomas

Peripheral T-cell lymphomas represent a rare heterogeneous group of non-Hodgkin lymphomas with generally worse outcomes with standard chemotherapy compared to B-cell lymphomas. Clinical risk prediction tools at baseline have been shown to be prognostic but generally do not impact clinical decision making. However, improving understanding of the prognostic implications of histology and its molecular underpinnings as well as strategies surrounding the use of CD30 as a predictive biomarker for brentuximab vedotin have led to better understanding of how to risk stratify patients. Baseline, interim, and end of treatment PET/CT as evaluated by the Lugano criteria as well as by baseline metabolic tumor volume have also been shown to be prognostic. The role of minimal residual disease tools such as cell free DNA and T-cell gene receptor sequencing remain active areas of investigation in hopes to develop predictive biomarkers in these rare diseases. This review focuses on strategies used to prognosticate in more common forms of peripheral T-cell lymphoma as well as in extranodal NK/T-cell lymphoma.

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.

Interim PET/CT based on visual and semiquantitative analysis predicts survival in patients with diffuse large B-cell lymphoma

Purpose

The role of interim ¹⁸F‐FDG PET/CT (iPET/CT) in diffuse large B‐cell lymphoma (DLBCL) remains controversial. The purpose of this study was to assess the prognostic value of iPET/CT in patients with newly diagnosed DLBCL according to visual and semiquantitative interpretation methods.

Methods

A total of 129 newly diagnosed DLBCL patients with baseline PET/CT data were retrospectively screened. The iPET/CT findings were evaluated by the Deauville 5‐point scale (DS) and ΔSUVmax. Furthermore, the reduction in SUVmax incorporated with tumor size (ΔSUVmax*ΔSLD) was calculated. The optimal cutoff values of ΔSUVmax and ΔSUVmax*ΔSLD were determined by receiver operating characteristic (ROC) analysis. Kaplan‐Meier analysis was applied to test for the influence of prognostic values. Univariate and multivariate analyses were conducted to examine the potential independent impacts of iPET/CT.

Results

Seventy‐seven patients with PET/CT images acquired both at baseline and after four cycles of chemotherapy were finally enrolled. The optimal cutoff values for ΔSUVmax and ΔSUVmax*ΔSLD were 74% and 30%, respectively. After a median follow‐up of 23 months, iPET/CT findings were significant predictors of PFS and OS whenever iPET/CT was interpreted by DS, ΔSUVmax, or ΔSUVmax*ΔSLD methods. ΔSUVmax‐based methods were more accurate than those based on DS. The IPI, DS, ΔSUVmax, and ΔSUVmax*ΔSLD were predictive in univariate analyses. However, in the multivariate analysis, only IPI and ΔSUVmax remained independent predictors of PFS and OS.

Conclusions

Interim PET/CT may help to identify DLBCL patients with different prognoses. ΔSUVmax analysis shows the best accuracy and the strongest predictive value among these three methods. ΔSUVmax*ΔSLD may be a promising parameter to interpret iPET/CT images, reflecting both the changes in tumor size and metabolic activity.