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    Factors affecting the accuracy of 18F-FDG PET/CT in detecting additional tumor foci in breast cancer
    (Athens Medical Soc, 2021) Simsek, A.; Kutluturk, K.; Comak, A.; Akatli, A.; Kekilli, E.; Unal, B.
    OBJECTIVE To evaluate the effectiveness of F-18-FDG PET/CT for detecting additional tumor foci in breast cancer. MATERIAL-METHOD The data were reviewed retrospectively of 232 women who underwent F-18-FDG PET/CT examination prior to breast cancer surgery between January 2013 and December 2018. RESULTS Additional tumor foci were suspected in 95 cases on F-18-FDG PET/ CT, which were confirmed by histopathological analysis in 81 cases. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of F-18-FDG PET/CT in detection of additional tumor foci were 77.7%, 79.48%, 66.3%, 87.32%, and 79.23%, respectively. The false negative and false positive rates were 22.22% and 20.51%, respectively. In univariate analysis, only the patient's age was positively associated with accuracy of F-18-FDG PET/CT in detecting additional tumor foci. The accuracy was lower in women aged <= 50 years, with a substantial increase in false positive findings in women in that age group. CONCLUSIONS F-18-FDG PET/CT alone cannot replace conventional diagnostic procedures for evaluating additional tumor foci in breast cancer, as a substantial increase in false positive findings is recorded with this method in women aged <= 50 years old.
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    Factors affecting the accuracy of 18F-FDG PET/CT in evaluating axillary metastases in invasive breast cancer
    (Wolters Kluwer Medknow Publications, 2019) Kutluturk, K.; Simsek, A.; Comak, A.; Gonultas, F.; Unal, B.; Kekilli, E.
    Background and Aim: There are conflicting results of studies on accuracy of positron emission tomography (PET)/computed tomography (CT) for axillary staging. The aim of this study is to determine the factors affecting the efficacy of 18F-fluorodeoxyglucose (F-18-FDG) PET/CT in detecting axillary metastases in invasive breast cancer. Materials and Methods: Data of 232 patients with invasive breast cancer who underwent F-18-FDG PET/CT examination before surgery between January 2013 and September 2017 were reviewed retrospectively. Histopathological examination of axillary lymph nodes (ALNs) was used as a reference to assess the efficacy of F-18-FDG PET/CT in detecting axillary metastases. Results: While 134 (57.8%) patients had axillary metastases as detected in F-18-FDG PET/CT scans, histopathologically axillary metastases were detected in 164 (70.7%) patients. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy of F-18-FDG PET/CT in detection of axillary metastasis were 72.56%, 77.94%, 88.8%, 54%, and 74.1%, respectively. The false-negative and false-positive rates were 27.4% and 22%, respectively. In univariate analysis, patients' age, estrogen receptor positivity, higher ALN SUVmax, greater tumor size, and lymph node size determined by F-18-FDG PET/CT were all significantly associated with accuracy of F-18-FDG PET/CT for axillary metastasis. In multivariate analysis, tumor size determined by F-18-FDG PET/CT and ALN SUVmax were independent variables associated with axillary metastasis. The accuracy of F-18-FDG PET/CT for axillary metastasis was higher in patients with a larger tumor (>= 19.5 mm) and a higher ALN SUVmax (>= 3.2). Conclusion: F-18-FDG PET/CT should not be routinely used for axillary staging, especially in patients with small tumors. It cannot eliminiate the necessity of sentinel lymph node biopsy. When it is used, both visual information and optimal cut-off value of axillary node SUVmax should be taken into consideration.
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    Is FDG-PET/CT used correctly in the combined approach for nodal staging in NSCLC patients?
    (Wolters Kluwer Medknow Publications, 2020) Simsek, F. S.; Comak, A.; Asik, M.; Kuslu, D.; Balci, T. A.; Ulutas, H.; Koroglu, R.
    Background: The most widely accepted approach nowadays in nodal staging of non-small cell lung cancer (NSCLC) is the combined use of 18-Fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) and endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA). However, this approach may not be sufficient, especially for early stages. Aims: Our aim was to assess whether more satisfactory results can be obtained with standardized uptake value maximum lymph node/standardized uptake value mean mediastinal blood pool (SUVmax LN/SUVmean MBP), SUVmax LN/Primary tumor, or a novel cut-off value to SUVmax in this special group. Subjects and Methods: Patients with diagnosed NSCLC and underwent FDG-PET/CT were reviewed retrospectively. 168 LNs of 52 early stage NSCLC patients were evaluated. The LNs identified in surgery/pathology reports were found in the FDG-PET/CT images. Anatomic and metabolic parameters were measured. Statistical analysis was performed by using of MedCalc Statistical Software. Results: Regardless of LNs size; sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of SUVmax >2.5 were 91.5%, 65.9%, 58.2%, and 95.1%, respectively. Optimum cut-off value of SUVmax was >4.0. Sensitivity, specificity, PPV, and NPV were found as 81.0%, 90.0%, 81.0%, and 90.0% respectively. Optimum cut-off value of SUVmax LN/SUVmean MBP was >1.71. Sensitivity, specificity, PPV, and NPV were found as 94.7%, 80.0%, 71.1%, and 96.7%, respectively. Optimum cut-off value of SUVmax LN/Primary tumor was >0.28. Sensitivity, specificity, PPV, and NPV were found as 81.1%, 85.1%, 72.9% and 90.1%, respectively. Conclusion: SUVmax LN/SUVmean MBP >1.71 has higher PPV than currently used, with similar NPV and sensitivity. This can provide increase in the accuracy of combined approach. In this way, faster nodal staging/treatment decisions, cost savings for healthcare system and time saving of medical professionals can be obtained.