Interim PET

Purpose

In lymphoma, [18]FDG-PET is well established for staging and end-of-therapy response assessment. A promising more recent application is ‘early response assessment’, meaning that response to treatment is predicted using interim PET (i-PET), i.e. PET during treatment. Timely assessment of forthcoming therapy failure in individual patients would have a profound impact on patient care by avoiding unnecessary toxicity and timely switching to potentially curative alternatives. Several observational studies have indicated that i-PET may be effective in early response prediction, but inconsistencies prevail, especially in non-Hodgkin’s lymphoma (NHL) including diffuse large B-cell lymphoma (DLBCL). It is unclear to which extent these are due to differences in the timing of PET during therapy, different PET positivity criteria, different therapies and/or different subtypes of lymphoma. There is an urgent need to address these issues but this requires an integral approach using the results of various studies.

Objectives

  • To build a PETRA database consisting of individual patient data (including PET scans) of the major international clinical studies on the value of i-PET in lymphomas

  • To determine the optimal timing of i-PET during first-line therapy with R-CHOP of DLBCL

  • To determine which i-PET response criteria perform best in predicting end-of-therapy response rate and progression-free survival at 2 years follow-up in patients with DLBCL

  • To assess whether and how chemo-immunotherapy affects the performance of i-PET

  • To assess whether and how type of NHL affects the performance of interim [18]FDG-PET

  • To determine the cost-effectiveness of i-PET in DLBCL

Overall aim

To validate [18]FDG-PET as a biomarker of response in first-line BLBCL therapy using meta-analysis of individual patient data, and to determine its cost-effectiveness.

This research was originally published in Blood Advances. Eertink J.J. Optimal timing and criteria of interim PET in DLBCL: a comparative study of 1692 patients. Blood Adv (2021) 5 (9): 2375–2384. © the American Society of Hematology.

https://ashpublications.org/bloodadvances/article/5/9/2375/475850/Optimal-timing-and-criteria-of-interim-PET-in