Early Restaging Positron Emmision Tomography (PET) with 18F-Fluorodeoxyglucose (18FDG)Predicts Outcome in Patients with Aggressive Non-Hodgkin's Lymphoma (NHL)

Reviewer: William Levin, MD
The University of Pennsylvania
Last Modified: December 10, 2001

Presenter: Karoline Spaepen
Affiliation: Leuven, Belgium

Positron Emission Tomography (PET) with FDG (a radiolabeled sugar molecule) is a nuclear medicine study that is able to detect areas of active cancer by showing areas of increased sugar metabolism.

Materials and Methods
NHL, treated on a doxorubicin chemotherapy regimen underwent PET scan at midtreatment.

  • All patients had an abnormal PET scan prior to treatment.
  • Each scan was reviewed by a group of nuclear medicine physicians.
  • Scans were graded as showing evidence of abnormal uptake or absence of abnormal FDG uptake.


  • After 3-4 cycles of chemotherapy, 33 patients showed persistent abnormal uptake of FDG on PET, whereas 37 pts had a negative scan.
  • 31 of the 37 pts with negative midtreatment scans remained in CR, with a median follow-up of 1107 days.
  • When pts with negative midtreatment PETs were compared to those who had abnormal scans, those who achieved a midtreatment CR had a significantly better progression free survival and overall survival (p<0.00001)
  • PET was also better at predicting survival (OS, PFS) than the International Prognostic Index.

Author's Conclusions
Early PET-FDG restaging at midtreatment may allow for the tailoring of chemotherapy in patients with aggressive NHL.

Clinical/Scientific Implications

  • PET appears to be useful in the evaluation of cancer patients. But one must remeber that the accuracy of these studies is highly dependent on the person interpreting them.
  • Because PET is neither 100% sensitive or specific, results must be used in conjunction with other clinical information.