Ability of 18-fludeoxyglucose positron emission tomography/CT to detect incidental cancer

Abstract

Objective: To determine the prevalence and clinical features of pathologically proven incidental cancer (IC) detected by whole-body fluorine-18 fludeoxyglucose ( 18 F-FDG) positron emission tomography (PET)/CT, as well as the incidence of false-positive and false-negative results. Methods: We retrospectively reviewed reports derived from 18 F-FDG PET/CT images of 3079 consecutive patients with known or suspected malignancies for 3 years. Discrete focal uptake indicating IC was identified from reports as well as pathological or clinical diagnoses, and the clinical courses were investigated. The false-positive result was defined as uptake indicating IC but not pathologically confirmed as malignant during follow-up. The false-negative result was defined as pathologically proven IC detected by another modality at initial clinical work-up or diagnosed during the follow-up period. Results: We found 18 F-FDG uptake indicating IC in 6.7% of all patients, and IC was pathologically proven in 2.2% of all patients. The most common sites were the colon, lung and stomach. The median survival duration of patients with IC was 42 months. The results were false positive in 4.5% of all patients, and the results were false negative in 2.3% of all patients. Conclusion:18 F-FDG PET/CT is a valuable tool for detecting IC. The rates of false-positive and false-negative results are within acceptable range. Advances in knowledge: This is the first report to describe the survival of patients with IC, and the detailed features of false-negative results at actual clinical settings.

Parotid incidentalomas: a systematic review

“…The overall incidentaloma detection rate on FDG-PET/CT imaging in the literature is reported as 6.7-12 per cent. 51,52 The low mean parotid incidentaloma incidence reported in this review corresponds with the lower incidence of neoplastic and non-neoplastic disease in these glands. Whilst only a small proportion of incidentaloma aetiology was non-neoplastic (6.3 per cent), this review alerts both clinicians and radiologists to this possibility and particularly systemic disease in cases of bilateral involvement.…”

Positron Emission Tomography With Fluorodeoxyglucose Incidental Detection of Colon Cancer in a Patient’s Follow-Up for Nasopharyngeal Carcinoma During the COVID-19 Pandemic: A Case Report

“…False-positive results were acceptable, reaching 4.5% for all patients. Inflammatory markers, such as neutrophils, lymphocytes, and macrophages, increase FDG uptake, leading to highly false-positive results in patients with infection or inflammation in that organ [ 11 - 12 ]. In Pakistan, a study was conducted to detect the primary site of cancer of patients diagnosed with carcinoma of unknown primary (CUP).…”

Incidentalomas of the prostate detected by 18-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography

“…1 18-Fluoro-2-Deoxy-D-Glucose Positron Emission Tomography/Computed Tomography (FDG PET) detects this increase in glycolysis and, as such, is routinely used in the diagnosis and surveillance of many cancers, including melanoma, lung cancer, squamous cell carcinoma of the head and neck, and lymphoma. 1,2 Prostate cancer (CaP), however, does not routinely experience the Warburg effect and FDG PET is not part of the routine staging of CaP. [3][4][5][6][7] An investigation of FDG PET in localized CaP revealed 51.9% sensitivity and 75.7% specificity in the context of an elevated prostate specific antigen (PSA).…”

“…Incidentalomas are commonly observed, occurring in approximately 10-14% of FDG PET scans. 1,2 Some of these incidentalomas are located within the prostate in the absence of known CaP. The rate of prostate incidentaloma on FDG PET has been reported in two series as 0.086% 9 and 1.4%.…”