Role of F-18 FDG PET/CT in Predicting Response to Neoadjuvant Chemotherapy in Invasive Ductal Breast Cancer.

Original Article Eur J Breast Health 2023; 19(2): 159-165 DOI: 10.4274/ejbh.galenos.2023.2023-1-3 Role of F-18 FDG PET/CT in Predicting Response to Neoadjuvant Chemotherapy in Invasive Ductal Breast Cancer Tarik Sengoz¹, Zehra Kesen5, Yeliz Arman Karakaya2, Aziz Gültekin1, Olga Yaylali¹, Dogangun Yuksel1 Sevda Yilmaz3, Ergun Erdem3, Burcu Yapar Taskoylu4, ¹Department of Nuclear Medicine, Pamukkale University Faculty of Medicine, Denizli, Turkey 2 Department of Pathology, Pamukkale University Faculty of Medicine, Denizli, Turkey 3 Department of General Surgery, Pamukkale University Faculty of Medicine, Denizli, Turkey 4 Department of Medical Oncology, Pamukkale University Faculty of Medicine, Denizli, Turkey 5 Kesen Pathology Laboratory, Denizli, Turkey ABSTRACT Objective: The role of baseline and post-treatment standardized uptake value (SUVmax) values in predicting pathological response in patients with breast cancer after neoadjuvant chemotherapy (NAC). Materials and Methods: Thirty patients with invasive ductal breast cancer were included in this retrospective study. F-18 fluorodeoxyglucose (FDG) positron emission tomography/computerized tomography (PET/CT) examinations were performed before and after NAC. Pretreatment SUVmax (SUVmax I), post-treatment SUVmax (SUVmax II) and ΔSUVmax values of primary breast cancer were obtained. Breast tumor pathology preparations were examined for the evaluation of tumor response according to the Miller and Payne classification. Patients were grouped as responding to treatment (pCR) and unresponsive to treatment (nonpCR). In all analyses, p<0.05 was considered statistically significant. Results: The mean age of the 30 patients included in the study was 51.2±11.98 years. In the study-defined grouping, 13 patients (43.3%) were nonresponders and 17 patients (56.7%) were responders. ΔSUVmax was significantly greater in the responders group compared to the nonresponders group, while SUVmax II was lower (p = 0.001 and p = 0.004, respectively). There was no significant difference between the responders and nonresponders in terms of age, tumor diameter, and SUVmax I values. Multivariate logistic regression analysis showed ΔSUVmax to be the only independent predictive factor for pCR. Conclusion: F-18 FDG PET/CT was an effective method in evaluating the treatment response after NAC in breast cancer, and ΔSUVmax and posttreatment SUVmax can be used to predict the response of the primary tumor to treatment. Keywords: Breast cancer, F-18 FDG, SUVmax, neoadjuvant chemotherapy Cite this article as: Sengoz T, Arman Karakaya Y, Gültekin A, Yilmaz S, Erdem E, Yapar Taskoylu B, Kesen Z, Yaylali O, Yuksel D. Role of F-18 FDG PET/ CT in Predicting Response to Neoadjuvant Chemotherapy in Invasive Ductal Breast Cancer.Eur J Breast Health 2023; 19(2): 159-165 Key Points • F-18 FDG PET/CT is an effective method in evaluating the treatment response after NAC in breast cancer. • ΔSUVmax and post-treatment SUVmax values correlate with pathological evaluation in predicting pCR. • Multivariate logistic regression analysis showed ΔSUVmax to be the only independent predictive factor for pCR. Introduction Breast cancer is the most common type of cancer among women and its incidence has been increasing over the years (1). In the treatment of breast cancer, neoadjuvant chemotherapy (NAC) has recently become more frequently used. NAC is preferred, especially in locally advanced breast cancer, to reduce tumor volume and to allow breast-conserving surgery (2). In addition, it is stated that NAC has advantages, such as Corresponding Author: Tarik Sengoz; early detection of possible resistance to chemotherapy and predicting prognosis (3). Patients with pathological complete response (pCR) after NAC had better disease-free survival and overall survival rates than patients without a complete response (4). Although anatomical imaging methods are primarily used in the evaluation of response after NAC, there are some limitations. Conventional methods may not be able to clearly distinguish between viable tumor tissue and fibrotic scar tissue in patients with residual tissue after treatment. Received: 18.01.2023 Accepted: 19.02.2023 Available Online Date: 01.04.2023 ©Copyright 2023 by the Turkish Federation of Breast Diseases Societies / European Journal of Breast Health published by Galenos Publishing House. 159 Eur J Breast Health 2023; 19(2): 159-165 2-deoxy-2-[18F]-fluoro-D-glucose positron emission tomography/ computed tomography (F-18 FDG PET/CT) is a molecular imaging method frequently used in oncology practice to evaluate response to treatment. Glucose metabolism is increased in cancer tissue and this a decrease in the metabolic activity of the residual tumor tissue after NAC is indicative of the response to treatment. In the literature, there are several studies investigating the accuracy of F-18 FDG PET/CT in evaluating response to treatment after NAC, with the pathological response criteria as reference (5-9). Due to the cytotoxic effect of chemotherapy, a decrease in cellular glycolysis is observed before tumor shrinkage. Therefore, standardized uptake value (SUVmax), which is a semi-quantitative parameter, is used to show the metabolic activity change more accurately. In this study, the role of baseline and post-treatment SUVmax values and SUVmax change in predicting pathological response in patients with breast cancer after NAC was investigated. Materials and Methods Patients Thirty patients with newly diagnosed, non-inflammatory, nonmetastatic, invasive breast cancer were included in this retrospective study. In all patients, the diagnosis of invasive breast cancer was made with tru-cut biopsy and NAC treatment was given. F-18 FDG PET/ CT examinations were performed on the patients before and after NAC. F-18 FDG PET/CT examination after NAC was performed at least 15 days after the end of the treatment. All patients underwent mastectomy/breast-conserving surgery 4-6 weeks after post-treatment F-18 FDG PET/CT. Exclusion criteria of the patients in the study were: patients who were diagnosed with inflammatory breast cancer; whose F-18 FDG PET/CT examination was contraindicated (for example with pregnancy or high blood sugar); who had a chronic disease; and who had previously received surgery or radiotherapy as treatment were excluded from the study. In this study, patients underwent two F-18 FDG PET/CT scans; basal scan for staging before NAC and post-treatment scan for response to treatment after NAC. Both examinations were performed on the patients under the same conditions and the same acquisition parameters. Image Analysis F-18 FDG PET/CT images were evaluated by two nuclear medicine physicians and consensus was reached in all patients. The isocontour method was used to create volume of interest (VOI) around the tumor. A 40% SUVmax threshold was used for the isocontour. SUVmax was defined as the maximum SUV from a single voxel anywhere within (...truncated)