Effectiveness of 18F-FDG PET/CT in detection of loco-regional recurrence of breast cancer in comparison to CT alone

Abstract

Introduction Breast cancer affects more than 1 million women worldwide. It is the most common type of cancer and the second leading cause of cancer related death among women . The estimated incidence in 2018 was 2.088 million of new cases in the world . Breast cancer was the most common cancer among women and the third leading cause of cancer related death in Egypt . In 2012; 18,660 new cases were estimated in Egypt and out of them the mortality rates was estimated at 7,161 . Recurrence of breast cancer is a major clinical manifestation and represents the principal cause of breast cancerrelated deaths .Loco-regional recurrence (LRR, ipsilateral breast or axillary lymph nodes)may occur in 527% of patients . Early detection and treatment of isolated LRR before symptomatic onset may have a beneficial effect on the prognosis, by improving local treatment feasibility rate and by avoiding the situation of uncontrollable loco-regional disease . Conventional imaging methods which reflect mainly the morphological changes are often inconclusive in differentiating local pathology from post therapeutic changes. Early detection of LRR may necessitate further invasive procedures . Positron emission tomography (PET) with fluorine 18 (F) fluoro deoxyglucose (FDG) has an important role in oncology. Its role in the management of breast cancer patientsis evolving. Combined PET and computed tomography (CT) (PET/CT) systems have replaced PET alone in most nuclear medicine departments . FDG PET/CT is an imaging method that has a strong point as it enables anatomic localization of the PET signal via CT . PET/CT is particularly useful in patients who are suspected to have or who are exhibiting a recurrence on physical examination or conventional imaging methods . Sensitivity of PET/CT for detecting LRR or metastasis among patients with breast cancer is approximately 97%, with a diagnostic accuracy of 95% in one study, supporting the efficacy of PET/CT for patients diagnosed or suspected of having recurrent breast cancer . However, there is a lack of evidence demonstrating the efficacy and cost effectiveness of this modality, along with the hazards of radiation exposure and the absence of specific clinical indications . This study was designed to evaluate the effectiveness of F-FDG PET/CT imaging in diagnosis of LRR of breast cancer in correlation to CT alone. Patients and Methods: This prospective study was approved by Ethical and Research committees at Faculty of Medicine, Sohag University. An informed written