Interim PET-driven strategy in de novo diffuse large B-cell lymphoma: Do we trust the driver?

Steven Le Gouill and Rene-Olivier Casasnovas


FDG-PET has become central tool for both accurate initial staging and determination of prognosis after treatment of diffuse Large B Cell Lymphoma (DLBCL). However, the role of PET during treatment (iPET) in daily practice remains a matter of significant debate. This perspective reviews the published studies on iPET in DLBCL including the methods used to analyze iPET, its timing, and studies of iPET-driven therapy to illuminate where daily practice may benefit from the use of iPET. When performed after 2 and/or 4 courses of immunochemotherapy iPET has a very good negative predictive value, utilizing both visual (qualitative) and semi-quantitative methods. The visual method accurately predicts outcome for patients with limited disease. The semi-quantitative method, e.g. the change of delta SUVmax (ΔSUVmax), is for patients with advanced DLBCL, for whom iPET identifies patients with very good outcome with continuation of standard therapy. A low ΔSUVmax also helps identify patients with a risk for relapse averaging 50% and warrants review of their scheduled therapy. To date, no trial has demonstrated the superiority of an iPET-driven strategy in DLBCL. However, the very good negative and good positive predictive value of iPET supports its use in daily practice as a better predictive tool than contrast enhanced CT scan for therapeutic decision making.

  • Submitted May 10, 2016.
  • Accepted April 3, 2017.