Prognostic Significance of PET/CT in Patients with Chronic Lymphocytic Leukemia (CLL) Treated with Frontline Chemoimmunotherapy

Abstract

<jats:p>The role of positron emission tomography/computed tomography (PET/CT) in identifying Richter Syndrome (RS) is well established, while its impact on the survival of patients with chronic lymphocytic leukemia (CLL) has been less explored. The clinical characteristics and PET/CT data of 40 patients with a biopsy-proven CLL who required frontline chemoimmunotherapy, FCR (fludarabine, cyclophosphamide, rituximab) in 20 patients, BR (bendamustine, rituximab) in 20, were retrospectively analyzed. Standardized uptake volume (SUVmax) values ≥ 5 were observed more frequently in patients with deletion 11q (p = 0.006) and biopsies characterized by a rate of Ki67 positive cells ≥ 30% (p = 0.02). In the multivariate analysis, the presence of large and confluent PCs emerged as the only factor with a negative impact on progression-free survival (PFS), and overall survival (OS). Deletion 11q also revealed a significant and independent effect on PFS. SUVmax values ≥ 5 showed no statistical impact on PFS while in multivariate analysis, they revealed a significant adverse impact on OS (median survival probability not reached vs. 56 months; p = 0.002). Moreover, patients with higher SUVmax values more frequently developed Richter Syndrome (p = 0.015). Our results show that higher SUVmax values identify CLL patients with a pronounced rate of proliferating cells in the lymph-node compartment, inferior survival, and an increased risk of developing RS.</jats:p>

The Role of 2-[18F]-FDG PET/CT in Detecting Richter Transformation in Chronic Lymphocytic Leukemia: A Systematic Review

“…After the revision of the titles and abstracts, 90 records were eliminated because they were not within the field of interest of the research of this review and 44 records were eliminated because they were editorials, comments, case reports, small case series, reviews or conference proceedings. Finally, 13 studies (for a total of 1336 patients affected by CLL who performed 2-[ 18 F]-FDG PET or PET/CT) were screened in their full-text version and included in this systematic review [14][15][16][17][18][19][20][21][22][23][24][25][26] (Figure 1). No additional manuscripts were discovered while checking the references of the selected articles.…”

“…Tables 1-3 contain the main characteristics and results of the studies included. Of the 13 studies, 10 were of retrospective nature [14][15][16][19][20][21][23][24][25][26] and only 3 were prospective [17,18,22]. In two papers the scanner utilized was PET only [15,24], while in the other 10 cases the scanner used was hybrid PET/CT [14,[16][17][18][20][21][22][23]25,26]; only in one manuscript both techniques were considered [19].…”

“…Of the 13 studies, 10 were of retrospective nature [14][15][16][19][20][21][23][24][25][26] and only 3 were prospective [17,18,22]. In two papers the scanner utilized was PET only [15,24], while in the other 10 cases the scanner used was hybrid PET/CT [14,[16][17][18][20][21][22][23]25,26]; only in one manuscript both techniques were considered [19]. In all the included studies, PET or PET/CT images were analyzed visually and semi-quantitatively.…”

“…In three studies [15][16][17], only visual analysis of PET was used to detect RT and SUVmax was not applied. In the other 6 studies [18][19][20]22,24,25], an SUVmax of 5 was used to detect RT with an average overall sensitivity of 87% (range 71-96%), an average overall specificity of 49% (range 4-80%), an average overall PPV of 41% (range 16-53%) and an average overall NPV of 84% (range 33-97%). Albano et al [26] and Michallet et al [21] proposed a different SUVmax threshold as the best predictor for RT: an SUVmax of 9 and of 10, respectively, with a sensitivity, specificity, PPV and NPV of 67%, 90%, 67% and 90%, respectively, in the first case [26], and 91%, 95%, 29% and 99%, respectively, in the second one [21].…”

Chronic Lymphocytic Leukemia

“…In this issue, some aspects of these three main features of CLL are both reported and discussed as novel findings and reviewed to make an update of the available data. Porrazzo and colleagues present an original article where they describe the prognostic significance of PET/CT applied to CLL to identify patients characterized by a more pronounced rate of proliferating cells in lymph nodes, an inferior outcome, and at higher risk of developing Richter's syndrome [26]. In a large, retrospective multicenter study, Autore and colleagues report serum lactate dehydrogenase levels as a statistically significant prognostic marker that can predict progression-free survival, treatment-free survival, and overall survival in CLL patients that harbor trisomy 12 [27].…”