Utility of PET/CT for therapy response assessment in non-Hodgkin's lymphoma

Abstract

PET is an integral part of monitoring therapy in lymphomas. PET is used to assess remission from disease but more recently has become an important tool to guide response-adapted treatment in non-Hodgkin lymphoma, enabling de-escalation in some patients with reduced toxicity and escalation in others to improve outcomes. PET/CT is used to determine to plan treatment. The Deauville Criteria have evolved as a standardized method for monitoring disease response, with quantitative approaches in development to further improve the quality and reproducibility of PET response assessment. The interim PET/CT has a high prognostic value. A precise early prediction of the response to therapy might be able to separate patients who could be cured with conventional therapy from patients for whom an early switch to alternative, more aggressive treatment strategies is needed. Response assessment after end of treatment: masses often do not regress completely after adequate (curative) treatment because of fibrosis and necrotic debris. It has been demonstrated that 18F-FDG PET/CT is extremely useful for therapy response assessment due to its capacity to help distinguish between residual metabolically active tumor and areas of necrosis and fibrosis, thus identifying which of these patients have achieved satisfactory functional remission and which that needs further treatment.