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

Abstract

PurposeThe 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).Methods181 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.ResultsROC 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.ConclusionsrDS with a tumor/liver ratio of 1.4 is a robust prognostic factor in patients with DLBCL on iPET4 and PET-eot.

Interim PET Evaluation in Diffuse Large B-Cell Lymphoma Using Published Recommendations: Comparison of the Deauville 5-Point Scale and the ΔSUVmax Method

“…Despite the good local discrimination performance of the ΔSUV max approach, much is still unknown about its properties. Although several authors (3,(8)(9)(10) confirmed the 66% SUV max reduction cut-off originally proposed by Lin et al (7), available data on inter-rater reliability and reproducibility of the ΔSUV max approach is scarce. In our investigation, the Deauville score assessment is a pre-dominantly centralized post-hoc analysis and, consequently, different nuclear medicine specialists were involved in Deauville score and ΔSUV max assessments, respectively.…”

“…This approach compares SUV max at baseline and interim PET staging. An unfavorable iPET result is defined as relative SUV max reduction of less than or equal to 66% -a cut-off that has been confirmed in several studies (3,(8)(9)(10). Advantages of the Deauville score are that it is easy to apply and only requires the iPET scan.…”

“…Despite their competing nature, little work on a direct comparison of the two methods is available in the literature (9,10,12). The Positron Emission Tomography-guided Therapy of Aggressive non-Hodgkin Lymphomas (PETAL) trial has recently shown that iPET response predicts outcome when assessed using the ΔSUV max approach.…”

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

“…68 To determine the optimal cut-off point for continuous measurements for predicting OS, 11 of 46 studies used the ROC curve, which maximizes the likelihood ratio. 15,35,37,[40][41][42][43][44][45][46][47] The ROC curve analysis has earned a place in biomedical studies when interpreting the results of diagnostic accuracy of a continuous marker. The performance of a marker is evaluated by the area under the ROC curve (AUC), an indicator of overall "accuracy", in which a higher AUC value indicates a better performance.…”

“…15,35,37,[40][41][42][43][44][45][46][47] One study each used ROC curves to select the best cut-off of beta-2 microglobulin (B2M), 40 C-reactive protein (CRP), 44 lymphocyte to monocyte ratio, 44 platelet to lymphocyte ratio (PLR), 45 tumor-infiltrating T-lymphocyteproportion and ratio between CD4-positive and CD8-positive T-lymphocytes, 48 age, 35 maximum standardized uptake value, 47 and ratio Deauville score. 46 In two studies, ROC was used to assess the albumin level, 35,44 and in two the absolute monocyte count and absolute lymphocyte count. 42,43 One study used X-tile software to calculate the optimal cut-off value for the albumin to globulin ratio.…”