18FDG-PET following treatment as valid predictor for disease-free survival in Hodgkin's lymphoma

Purpose: The value of (18)FDG-PET to predict the outcome after therapy in Hodgkin's lymphoma was compared to morphologic staging and ESR. Patients and methods: A total of 50 concurrent (18)FDG-PET and CT studies were performed in 37 patients with Hodgkin's lymphoma. ESR was evaluated 32 times after treatment was completed. Results: Out of 39 residual masses found by CT 8 relapses could be proven. Out of 11 CT exams with CR 3 relapses occurred. CT turned out to show a sensitivity, specificity, PPV, NPV, and accuracy of 72%, 21%, 21%, 73%, and 32%, with respect to predict disease-free survival (DFS). (18)FDG-PET was positive in 22 examinations with 10 recurrences in this group. Out of 28 negative (18)FDG-PET 1 relapse developed 3 years later. (18)FDG-PET turned out to show promising sensitivity, specificity, PPV, NPV, and accuracy of 91%, 69%, 46%, 96%, 74%, with respect to predict DFS. ESR was elevated in 12 studies of which 5 relapses could be proven, while out of 20 normal ESR-studies 3 relapses occurred. Thus, ESR turned out to show sensitivity, specificity, PPV, NPV, and accuracy of 63%, 71%, 42%, 85%, and 75%, with respect to predict DFS. In summary, only (18)FDG-PET was able to predict DFS statistically significant. Conclusion: (18)FDG-PET can be very useful in patients with residual masses after treatment.