RT Journal Article SR Electronic T1 Role of F18-FDG PET-CT in detection of contralateral second primary breast cancer in patients of known primary breast cancer undergoing F18-FDG PET-CT scan for restaging/follow-up. JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 2986 OP 2986 VO 63 IS supplement 2 A1 Singh, Tejesh A1 Kumar, Rakesh A1 Sharma, Anshul A1 Prakash, Sneha A1 Syeddharvesh, N A1 Roy, Arup A1 Goel, Rashi A1 Shamim, Shamim Ahmed A1 Patel, Chetan YR 2022 UL http://jnm.snmjournals.org/content/63/supplement_2/2986.abstract AB 2986 Introduction: Patients with primary breast cancer are at a 2-to-6-fold increased risk of developing contralateral second primary breast cancer. The reported incidence of bilateral breast cancer ranges from 1.4 to 11.8%. As a direct result of improvement in treatment with patients living longer and advances in diagnostics the incidence of bilateral breast cancer has been increasing. The present study evaluated the role of F18-FDG PET-CT in detecting contralateral second primary breast cancer in patients of known primary breast cancer undergoing F18-FDG PET-CT scan for restaging/follow-up.Methods: Retrospective analysis of data of 2632 breast cancer patients undergoing F18-FDG PET-CT scan for restaging/follow-up in our department in last 5 years.Results: Metachronous and synchronous second primary breast carcinoma in contralateral breast were detected in 65 individuals out of 2632 patients considered for this study. Mean age of these patients were 44.6 years (range of 21-64 years). Synchronous second primary breast carcinoma in contralateral breast were reported in 23/65 (35.3%) patients. Out of these 16 were suspected for second primary based on clinical or mammographic examination before undergoing F18-FDG PET-CT scan. In 7/23 (30.4%) were confirmed to have synchronous second primary breast carcinoma on visualization of abnormal increased uptake in contralateral breast on F18-FDG PET-CT scan. Metachronous second primary breast carcinoma in contralateral breast were reported in 42 out of 65 (64.6%) patients. In 10/42 patients (23%) were suspected for second primary based on clinical or mammographic examination before undergoing F18-FDG PET-CT scan. Abnormal increased FDG uptake was seen in all of these lesions and confirmed by histopathological examination. In rest 32/42 (76.1%) patients’ suspicion for metachronous second primary breast carcinoma was raised after visualization of abnormal increased FDG uptake on F18-FDG PET-CT scan and later confirmed on further evaluation. In this study, F18-FDG PET-CT scan was able to detect unsuspected metachronous and synchronous second primary breast cancer in 39/2632 (~ 1.48%) patients. Of overall 65 patients with second primary breast cancer F18-FDG PET-CT contributed 39/65 (60%) of detections.Conclusions: There is significant contribution of F18-FDG PET-CT in detection of contralateral second primary breast cancer in patients of known primary breast cancer undergoing F18-FDG PET-CT scan for restaging/follow-up.