Semiquantitative measurements of standardized uptake value in assessment of response and outcomes in patients with lymphoma

Abstract

Abstract Objectives To evaluate the accuracy of semiquantitative measurements of standardized uptake value (ΔSUVmax) in the assessment of response to treatment in patients with lymphoma. Background Positron emission tomography (PET) with 2-[18 F]-fluoro-2-deoxy-D-glucose is an essential tool for accurate staging and early and late therapy response assessments in all 2-[18 F]-fluoro-2-deoxy-D-glucose -avid histologies. Patients and methods The study included 73 patients diagnosed as having diffuse large B-cell lymphoma or Hodgkin’s disease. PET/CT examinations were performed at baseline (PET0), then after 2 cycles of chemotherapy (PET 2), and after 4 cycles of chemotherapy (PET4). PET scans were analyzed according to Deauville five-point scale, and cutoff values for changes in the maximum standardized uptake value (SUVmax). The change in activity (ΔSUV) from initial (SUVmax1) to later scans (SUVmax2) was calculated. Biopsy was also taken when PET4 was visually positive but delta SUVmax was negative or in case of new lesions if other sites have improved. Results In comparison with the results of biopsy, ΔSUV0-2 had 80% sensitivity, 94.1% specificity, and 90.91% accuracy, with significant P value of 0.001. Moreover, ΔSUV0–4 had sensitivity of 80%, specificity of 100%, and accuracy of 95.45%, with high agreement k(P) 0.861 with significant P value less than 0.001. On the contrary, the visual five-point scale analysis specificity was 17.65% and accuracy was 36.36%, with insignificant P value less than 0.321. Neither the Deauville criteria nor ΔSUVmax was significantly associated with time to progression and overall survival. Conclusion ΔSUVmax is comparable to biopsy and significantly more accurate than Deauville criteria in response assessment to chemotherapy.