ORIGINAL ARTICLE Journal of the College of Physicians and Surgeons Pakistan 2020, Vol. 30(09): 946-950 946 PET-CT and MR Imaging in the Management of Axillary Nodes in Early Stage Breast Cancer Mehmet Tarık Baran 1 , Hasan Gundogdu 2 , Gokhan Demiral 1 , Osman Kupik 3 , Medeni Arpa 4 and Ahmet Pergel 1 1 Department of General Surgery, Recep Tayyip Erdogan University, Rize, Turkey 2 Department of Radiology, Recep Tayyip Erdogan University, Rize, Turkey 3 Department of Nuclear Medicine, Recep Tayyip Erdogan University, Rize, Turkey 4 Department of Biochemistry, Recep Tayyip Erdogan University, Rize, Turkey ABSTRACT Objective: To discriminate between malignant or benign axillary lymph nodes in breast cancer using MRI, PET-CT, and sentinel lymph node biopsy. Study Design: Observational study. Place and Duration of Study: Department of General Surgery, Recep Tayyip Erdogan University School of Medicine, from January 2014 to March 2019. Methodology: Sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (ALND) was carried out on 102 patients, who had locally advanced cases and had not previously received neoadjuvant therapy. Axillary lymph nodes pathology results were eval- uated and compared with PET-CT and MRI findings. Results: PET-CT specificity was 93.18%, MRI specificity was 93.75%, and combined PET-CT and MRI specificity was 97.67%. PET-CT sensitivity was 81.03%, MRI sensitivity was 68.57%, and combined PET-CT and MRI sensitivity was 83.05%. For detecting the pres- ence of axillary lymph node metastasis, there was a good correlation between histopathological results and the combined evalua- tion with PET-CT and MRI (kappa: 0.785, p <0.001). In combined PET-CT and MRI, short diamater mean values of lymph nodes in 10 patients, which could not detect lymph node metastases, were determined to be 5.2 ±0.9 mm. Conclusion: Combining PET-CT and MRI is superior to PET-CT or MRI imaging alone in distinguishing benign and malignant axillary lymph node; and contributes to deciding the approach to axillary lymph node surgery. Lymph node size is also important for this imaging method to determine benign and malignant nodes correctly. Key Words: Breast cancer, PET-CT, MRI, Sentinel lymph node biopsy, Axilla. How to cite this article: Baran MT, Gundogdu H, Demiral G, Kupik O, Arpa M, Pergel A. PET-CT and MR Imaging in the Management of Axillary Nodes in Early Stage Breast Cancer. J Coll Physicians Surg Pak 2020; 30(09):946-950 . INTRODUCTION Breast cancer is the second most frequently diagnosed malig- nancy in the world after lung cancer; and more than two million new cases are seen each year. 1 It is the leading cause of death in women around the world. 2 The most important factors determining the prognosis are: tumour size, histological grade, hormonal receptor status, human epidermal growth factor receptor 2 (HER-2) status, axil- lary lymph node involvement, and metastasis. Axillary lymph node involvement is very important in terms of prognosis,staging,andtreatmentplanningtobeselectedforthe management of the disease. Correspondence to: Dr. Mehmet Tarık Baran, Department of General Surgery, Recep Tayyip Erdogan University, Rize, Turkey E-mail: mehmettarik.baran@erdogan.edu.tr ..................................................... Received: June 12, 2020; Revised: September 18, 2020; Accepted: September 18, 2020 DOI: https://doi.org/10.29271/jcpsp.2020.09.946 The examination to be performed after staging, the treatment modalities to be applied, and the management of the patients were determined in detail by National Comprehensive Cancer Network (NCCN). 3 Surgeries are performed specifically for the mass in the breast and for the axilla, depending on the condition of the axillary lymphnodes.Axillarylymphnodedissection(ALND)orsentinel lymph node biopsy (SLNB) is performed according to the condi- tion of the axilla. In patients undergoing sentinel lymph node sampling during surgery, it is to be determined whether or not there will be an intervention to the axilla. 4 Serious morbid complications,suchaslymphedemaofthearm,mayoccurafter surgery or local radiotherapy to the axilla. 5 In order to establish a good preoperative decision, the objective of this study was to discriminatebetweenmalignantorbenignaxillarylymphnodes in breast cancer using MRI, PET-CT, and sentinel lymph node biopsy. METHODOLOGY A total of 102 patients, diagnosed with locally advanced breast cancer between March 2014 and January 2019 at General