Predictive Value of PET Response Combined with Baseline Metabolic Tumor Volume in Peripheral T-Cell Lymphoma Patients

Abstract

Peripheral T-cell lymphoma (PTCL) is a heterogeneous group of aggressive non-Hodgkin lymphomas with poor outcomes on current therapy. We investigated whether response assessed with PET/CT combined with baseline total metabolic tumor volume (TMTV) could detect early relapse or refractory disease. From 7 European centers, 140 patients with nodal PTCL who underwent baseline PET/CT were selected. Forty-three had interim PET (iPET) performed after 2 cycles (iPET2), 95 had iPET performed after 3 or 4 cycles (iPET3/4), and 96 had end-of-treatment PET (eotPET). Baseline TMTV was computed with a 41% SUV threshold, and PET response was reported using the Deauville 5-point scale. With a median of 43 mo of follow-up, the 2-y progression-free survival (PFS) and overall survival (OS) were 51% and 67%, respectively. iPET2-positive patients (Deauville score ≥ 4) had a significantly worse outcome than iPET2-negative patients ( < 0.0001, hazard ratio of 6.8 for PFS; < 0.0001, hazard ratio of 6.6 for OS). The value of iPET3/4 was also confirmed for PFS ( < 0.0001) and OS ( < 0.0001). The 2-y PFS and OS for iPET3/4-positive ( = 28) and iPET3/4-negative ( = 67) patients were 16% and 32% versus 75% and 85%, respectively. The eotPET results also reflected patient outcome. A model combining TMTV and iPET3/4 stratified the population into distinct risk groups (TMTV ≤ 230 cm and iPET3/4-negative [2-y PFS/OS, 79%/85%]; TMTV > 230 cm and iPET3/4-negative [59%/84%]; TMTV ≤ 230 cm and iPET3/4-positive [42%/50%]; TMTV > 230 cm and iPET3/4-positive [0%/18%]). iPET response is predictive of outcome and allows early detection of high-risk PTCL patients. Combining iPET with TMTV improves risk stratification in individual patients.

Does PET Reconstruction Method Affect Deauville Score in Lymphoma Patients?

“…Additionally, the use of SUV metrics as prognostic factors when pooling data from several PET systems would be affected by reconstruction inconsistencies. Finally, the delineation of metabolically active tumor volume, which is increasingly being used as a prognosticator in lymphoma patients (19,20), is strongly affected by the use of advanced reconstruction algorithms (21). For these reasons, it seems preferable to pursue ongoing harmonization efforts with programs such as EARL or QIBA.…”

Hybridbildgebung bei Lymphom

“…Eine zunehmende Anzahl von Studien berichtet von der prognostischen Aussagekraft prätherapeutischer oder (seltener) Interim-Response (semi)quantitativer [18F]FDG-PET-Parameter, welche neben SUV-Werten auch metabolisches Tumorvolumen (MTV) und totale Glykolyse im Lymphomgewebe (TLG, Produkt aus MTV und mittlerem SUV) umfassen. Die bisherigen Ergebnisse lassen auf eine Anwendbarkeit über ein breites Spektrum verschiedener Lymphomsubtypen schließen, welches u. a. Hodgkin-Lymphome, DLBCL, follikuläre Lymphome, MALT-Lymphome und T-Zell-Lymphome umfasst [32][33][34][35][36][37]. Diese prognostische Aussagekraft, welche in den meisten Fällen auf die Vorhersage des progressionsfreien Überlebens (PFS, "progression-free survival") oder Gesamtüberlebens (OS, "overall survival") abzielt, ließ sich für Patienten unter verschiedenen Therapien nachweisen.…”

MRI and PET/MRI in hematologic malignancies

“…Notably, many previous studies have also shown that pretherapeutic SUVs, metabolic tumor volumes (MTV), and total lesion glycolysis (TLG) extracted from [ 18 F]FDG‐PET enable outcome prognostication in a variety of histological subtypes, including HL, DLBCL, FL, and also T‐cell lymphomas . In addition, [ 18 F]FDG‐PET has also been evaluated as a tool for risk stratification in clinical trials, and several studies to investigate this topic are still ongoing.…”