The value of negative F-18-FDG-PET in patients with Hodgkin’s disease and residual mass after therapy

THE VALUE OF NEGATIVE F-18-FDG-PET IN PATIENTS WITH HODGKIN'S DISEASE AND A RESIDUAL MASS AFTER THERAPY Dražen Huic, Andrea Mutvar, Sandra Kinda-Basic, Igor Aurer, Martina Ciglar, Darko Grosev, Ivo Radman, Boris Labar, Damir Dodig Department of Nuclear Medicine and Radiation Protection, Department of Internal Medicine, Division of Hematology, Zagreb University Hospital Centre, Zagreb, Croatia Aim: To asses the negative predictive value (NPV) of FDG-PET performed with triple-head coincidence gamma camera after first-line therapy or salvage therapy in patients with Hodgkin’s disease (HD) compared by long-term follow-up as a reference standard. Design and Setting: This single centre retrospective diagnostic test study was done in University Hospital Centre between June 2001 and February 2008. Participants: The charts of 131 consecutive patients with Hodgkin’s disease were reviewed. Seventy-three consecutive PET-negative patients (median age 28 years ; range 12-80 years) with primary or recurrent biopsy confirmed lymphoma after first-line therapy or salvage therapy were followed-up at least 12 months (median 23 months ; range 12-69 months). All already performed 18F-FDG PET scans (using hybrid PET camera with triple head coincidence imaging capability within a few months after completion of therapy) were again visually interpreted by two board-certified nuclear medicine physicians who were blinded to any clinical or CT data. Main outcome measure: The negative predictive value of FDG-PET performed with triple-head coincidence gamma camera (Index test) was compared with long-term follow-up as a reference standard. Results: Out of 131 patients 73 turned-out to be PET-negative. Of those 73 PET-negative patients 61 patients have been scanned after first-line chemotherapy/radiotherapy, and only 3 (4.9%) of them relapsed in a follow-up (negative predictive value 95%). Twelve patients with resistant disease have been scanned after repeated therapy, and 4 (25%) of them relapsed in a follow-up period (negative predictive value 66%). Conclusions: This methodology with triple-head coincidence gamma camera has high negative predictive value in patients with Hodgkin's disease.