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Date publication

septembre 2013

Auteurs

Membres identifiés du Cancéropôle Est :
Dr CASASNOVAS Olivier


Tous les auteurs :
Itti E, Meignan M, Berriolo-Riedinger A, Biggi A, Cashen AF, Vera P, Tilly H, Siegel BA, Gallamini A, Casasnovas RO, Haioun C

Résumé

PURPOSE: The role of interim PET/CT in guiding therapeutic strategies in diffuse large B-cell lymphoma (DLBCL) is debated, mainly because interpretation rules vary among centres. This study aimed to explore the reproducibility and confirm the prognostic value of early PET/CT using the Deauville criteria and DeltaSUVmax. METHODS: This international confirmatory study retrospectively evaluated 114 patients with newly diagnosed DLBCL treated with a rituximab-containing regimen. All patients underwent (1)(8)F-FDG PET/CT at baseline (PET0) and after two cycles (PET2), with no therapy change based on the latter. Scans were interpreted by three observers using the Deauville five-point scale and DeltaSUVmax between PET0 and PET2 was calculated. Interpretations were evaluated for interobserver agreement and for progression-free survival (PFS) prediction. RESULTS: Median follow-up was 39 months. Early PET/CT was predictive of outcome when interpreted with the Deauville criteria and DeltaSUVmax. Using the five-point scale, the overall kappa value was 0.66 with the reference background set in the liver (score >/=4) and interobserver agreement was even better using a 66% DeltaSUVmax cut-off (kappa = 0.83). Moreover, the prognostic value of interim PET was slightly inferior when using a Deauville score >/=4 than when using a 66% DeltaSUVmax cut-off: for the Deauville score the 3-year PFS estimate was 59% (45-73%) in PET2-positive patients vs. 81% (71-91%) in PET2-negative patients (P = 0.003); for the 66% DeltaSUVmax cut-off the 3-year PFS estimate was 44% (23-65%) in PET2-positive patients vs. 79% (70-88%) in PET2-negative patients (P = 0.0002). CONCLUSION: Although the Deauville criteria are valid for assessing the prognostic value of early PET/CT in DLBCL, computation of the DeltaSUVmax leads to better performance and interobserver reproducibility, and should be preferred when a baseline scan is available.

Référence

Eur J Nucl Med Mol Imaging. 2013 Sep;40(9):1312-20