Abstract
Early identification of chemotherapy-refractory lymphoma patients provides a basis for alternative treatment strategies. Metabolic imaging with 18F-FDG PET offers functional tissue characterization that is useful for assessing response to therapy. Our objective was to determine the predictive value of 18F-FDG PET early during chemotherapy (after 1 cycle) and at the completion of chemotherapy for subsequent progression-free survival (PFS) in patients with aggressive non-Hodgkin’s lymphoma (NHL) or Hodgkin’s disease (HD). Methods: 18F-FDG PET (dual-head coincidence camera with attenuation correction) was performed before and after 1 cycle of chemotherapy on 30 patients (17 NHL, 13 HD; mean age, 52.3 ± 16.0 y). For 23 of the 30 patients, 18F-FDG PET data were also obtained after the completion of chemotherapy. The patients had a median follow-up of 19 mo (range, 18–24 mo). Follow-up of PFS was compared between patients with positive and negative 18F-FDG PET results obtained after the first cycle of chemotherapy and at the completion of chemotherapy. Results: Positive 18F-FDG PET results obtained both after the first cycle and at the completion of therapy were associated with a shorter PFS (median, 5 and 0 mo, respectively) than were negative 18F-FDG PET results (PFS medians not reached). A statistically significant difference in PFS between positive and negative 18F-FDG PET results was obtained both after the first cycle and at the completion of chemotherapy (P ≤ 0.001). The PFS and 18F-FDG PET results obtained after the first cycle correlated better than those obtained after the completion of chemotherapy (r2 = 0.45 vs. 0.17). 18F-FDG PET had more false-negative results after the last cycle (6/17 cases, or 35%) than after the first cycle (2/13 cases, or 15%). Thus, 18F-FDG PET had greater sensitivity and positive predictive values after the first cycle (82% vs. 45.5% and 90% vs. 83%, respectively) than after the last cycle. Conclusion: 18F-FDG PET after 1 cycle of chemotherapy is predictive of 18-mo outcome in patients with aggressive NHL and HD and may earlier identify patients who would benefit from more intensive treatment programs.
Footnotes
Received Sep. 19, 2001; revision accepted Jan. 3, 2002.
For correspondence or reprints contact: Lale Kostakoglu, MD, New York Presbyterian Hospital, Weill Cornell Medical Center, 525 E. 68th St., Starr: 221, New York, NY 10021.
E-mail: lak2005{at}mail.med.cornell.edu