FDG-PET scan in assessing lymphomas and the application of Deauville Criteria

Objective: To evaluate the role of Fluorine-18-fluorodexoyglucose Positron Emission Tomography (FDG-PET) scan in staging and its implications on the treatment of lymphoma, and to study the concordance between visual assessment and Deauville criteria for the interpretation of interim scans. Methods: The prospective single-arm experimental study was conducted at the Shaukat Khanum Memorial Cancer Hospital, Lahore, from May 2011 to October 2011. It comprised 53 newly diagnosed lymphoma patients who agreed to participate in the study. All patients underwent scans with contrast-enhanced computerised tomography at baseline. Treatment plan was formulated based on the final stage. Interim scans were acquired after 2 cycles of chemotherapy and were reported using visual criteria and compared with the 5-point Deauville criteria. Score of 1- 3 was taken as disease-negative, while 4-5 was taken as disease-positive. SPSS 19 was used for statistical analysis. Results: Of the 53 patients, 35 (66%) had Hodgkin's Lymphoma, while 18 (34%) had Non-Hodgkin's Lymphoma. Scans resulted in disease upstaging in 4 (7.5%) patients, and detecting increased disease burden in 12 (23%). On interim scans, complete remission was achieved in 38 (71%) patients (Deauville score 1-3); 12 (23%) showed partial response (Deauville score 4-5); and 3 (6%) had progression. Kappa test was statistically significant (kappa 0.856; p <0.001). Conclusion: The positron emission tomography helped to upstage lymphoma and reflected increased disease burden. The Deauville criteria correlated very well with visual assessment criteria and can be applied in the patient population.