Standardized uptake value on FDG-PET as a marker for disease activity in patients with non-Hodgkin’s lymphoma: comparison with serum soluble interleukin-2 receptor values

Background We compared standardized uptake values (SUVs) on positron emission tomography with a glucose analog, 2-[F-18] fluoro-2-deoxy-D-glucose (FDG-PET) and serum soluble interleukin-2 receptor (sIL-2R) values in patients with non-Hodgkin’s lymphoma (NHL) in the pre-, mid- (after three or four cycles), and post-treatment periods of chemotherapy (pre, mid, and post, respectively), and we examined whether the SUV was a useful tumor marker for NHL. Methods The SUVs on PET and sIL-2R values were retrospectively evaluated based on all the clinical information available in 40 patients (31 in pre, 24 in mid, and 24 in the post periods). Patients in complete remission status were classified as group A and those with active residual disease in the mid and post periods were classified as group B. Results In pre, the SUV and sIL-2R values exhibited sensitivity of 100% and 84%, respectively. In mid, the SUV was lower in group A than in group B, while sIL-2R was not different. The SUV yielded better specificity than sIL-2R (88 % vs 25 %, respectively), though the difference was not significant. In mid, the SUV in patients later assigned to group A in post was lower than than the SUV in group B, whereas sIL-2R was not different. In post, the specificity and accuracy of SUV were better than those of sIL-2R (95 vs 47 %, and 96 vs 58 %, respectively). Both the SUV and sIL-2R were lower in group A than in group B. Conclusion The SUV on PET was better than the serum sIL-2R as a marker to evaluate the disease status of NHL, and was considered to be a useful tumor marker for NHL.