New Approaches in Characterization of Lesions Dissemination in DLBCL Patients on Baseline PET/CT

Abstract

Dissemination, expressed recently by the largest Euclidian distance between lymphoma sites (SDmax), appeared a promising risk factor in DLBCL patients. We investigated alternative distance metrics to characterize the robustness of the dissemination information. In 290 patients from the REMARC trial (NCT01122472), the Euclidean (Euc), Manhattan (Man), and Tchebychev (Tch) distances between the furthest lesions, firstly based on the centroid of each lesion and then directly from the two most distant tumor voxels and the Travelling Salesman Problem distance (TSP) were calculated. For PFS, the areas under the ROC curves were between 0.63 and 0.64, and between 0.62 and 0.65 for OS. Patients with high SDmax whatever the method of calculation or high SD_TSP had a significantly poorer outcome than patients with low SDmax or SD_TSP (p < 0.001 for both PFS and OS), with significance maintained in Ann Arbor advanced-stage patients. In multivariate analysis with total metabolic tumor volume and ECOG, each distance feature had an independent prognostic value for PFS. For OS, only SDmax_Tch, SDmax_Euc _Vox, and SDmax_Man _Vox reached significance. The spread of DLBCL lesions measured by the largest distance between lymphoma sites is a strong independent prognostic factor and could be measured directly from tumor voxels, allowing its development in the area of the deep learning segmentation methods.

Advances in positron emission tomography and radiomics

“…20 Disease dissemination markers appear to be more promising biomarkers that are independent from tMTV and provide information beyond that afforded by imaging stage (Figure 1). This was first reported in patients with DLBCL by Cottereau et al 21,22,55 The simplest of the measurements reported was the largest distance between the center of two lesions in the body (Dmax) adjusted for body surface area (SDmax) but others such as the distance between the bulkiest lesion and the lesion furthest away (Dmaxbulk) as well as measurements of lesional spread, whereby distance between lesions are summed were also prognostic 21 (Figure 1). In HL, Dmax was reported to be an independent predictor of PFS from baseline tMTV and clinical risk factors, adjusted for radiotherapy and treatment intensification 53 including the subgroup who achieved early complete metabolic response (CMR).…”

18F-FDG PET Maximum-Intensity Projections and Artificial Intelligence: A Win-Win Combination to Easily Measure Prognostic Biomarkers in DLBCL Patients

“…Interestingly, the cut-off values to characterize the lesion dissemination (Dmax and sDmax) in DLBCL patients on baseline PET images were almost identical on the independent cohorts. Dmax and sDmax were defined empirically, yet a recent study has shown that the distance between lesions calculated using different distance measurement methods (namely Euclidean, Manhattan, and Chebyshev) in 3D yielded similar results in predictions of the outcome (21).…”

18F-FDG PET/CT Maximum Tumor Dissemination (Dmax) in Lymphoma: A New Prognostic Factor?

“…Based on the inclusion and exclusion criteria mentioned above, 312 records were excluded (96 as not in the field of interest; 48 as reviews, editorials, or letters; 141 as case reports or case series; and 27 as conference abstracts). Eighteen remaining records were eligible for inclusion in the systematic review (qualitative synthesis) after a full-text assessment [10,[14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. No additional records were assessed as suitable for inclusion after screening the references of these articles.…”

“…assessment [10,[14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. No additional records were assessed as suitable for inclusion after screening the references of these articles.…”