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