Assessment of Fluorodeoxyglucose F18–Labeled Positron Emission Tomography for Diagnosis of High-Risk Lung Nodules

Abstract

IMPORTANCE Clinicians rely heavily on fluorodeoxyglucose F18–labeled positron emission tomography (FDG-PET) imaging to evaluate lung nodules suspicious for cancer. We evaluated the performance of FDG-PET for the diagnosis of malignancy in differing populations with varying cancer prevalence. OBJECTIVE To determine the performance of FDG-PET/computed tomography (CT) in diagnosing lung malignancy across different populations with varying cancer prevalence. DESIGN, SETTING, AND PARTICIPANTS Multicenter retrospective cohort study at 6 academic medical centers and 1 Veterans Affairs facility that comprised a total of 1188 patients with known or suspected lung cancer from 7 different cohorts from 2005 to 2015. EXPOSURES 18F fluorodeoxyglucose PET/CT imaging. MAIN OUTCOME AND MEASURES Final diagnosis of cancer or benign disease was determined by pathological tissue diagnosis or at least 18 months of stable radiographic follow-up. RESULTS Most patients were male smokers older than 60 years. Overall cancer prevalence was 81% (range by cohort, 50%–95%). The median nodule size was 22 mm (interquartile range, 15–33 mm). Positron emission tomography/CT sensitivity and specificity were 90.1% (95%CI, 88.1%–91.9%) and 39.8% (95%CI, 33.4%–46.5%), respectively. False-positive PET scans occurred in 136 of 1188 patients. Positive predictive value and negative predictive value were 86.4% (95%CI, 84.2%–88.5%) and 48.7% (95%CI, 41.3%–56.1%), respectively. On logistic regression, larger nodule size and higher population cancer prevalence were both significantly associated with PET accuracy (odds ratio, 1.027; 95%CI, 1.015–1.040 and odds ratio, 1.030; 95%CI, 1.021–1.040, respectively). As the Mayo Clinic model–predicted probability of cancer increased, the sensitivity and positive predictive value of PET/CT imaging increased, whereas the specificity and negative predictive value dropped. CONCLUSIONS AND RELEVANCE High false-positive rates were observed across a range of cancer prevalence. Normal PET/CT scans were not found to be reliable indicators of the absence of disease in patients with a high probability of lung cancer. In this population, aggressive tissue acquisition should be prioritized using a comprehensive lung nodule program that emphasizes advanced tissue acquisition techniques such as CT-guided fine-needle aspiration, navigational bronchoscopy, and endobronchial ultrasonography.

Comparison of [68Ga]Ga-DOTA-FAPI-04 PET/CT with [18F]FDG PET/CT for Nodule Characterization and Staging in NSCLC Patients

“…[ 18 F]FDG PET/CT has been demonstrated as a useful, yet incomplete, tool for lung nodules diagnosis. One of the main limitations is that many benign lesions also present high FDG uptake which can easily lead to falsepositive results [27,28] . SCC and solid nodules of AC showed high uptake of both [ 18 F]FDG and [ 68 Ga]Ga-DOTA-FAPI-04 because the solid components consist of densely packed tumor cells and peri-tumoral stroma, while GGO showed low uptake for lacking tumor cells and peri-tumoral stroma.…”

Does aggressive management of solitary pulmonary nodules pay off?

“…PET-CT is a noninvasive and highly precise procedure to characterise SPNs with a reported sensitivity of up to 96–97% and a specificity of 85–88% [15]. PET-CT plays a crucial role in differentiating nodules >1 cm but, for those <1 cm, in single metastases in some types of malignancies or in benign diseases with increased FDG uptake, it is not conclusive [18, 24]. For nodules >8 mm, radiological imaging (CT and PET-CT) is usually accompanied by FNAB and even nodule resection.…”

“…However, in a study by N omori et al [18], 90% of GGNs, finally diagnosed as well-differentiated adenocarcinomas, had a low metabolic uptake. Similarly, inflammatory nodules commonly present as ground-glass or subsolid attenuation, are often metabolically active, and lead to false-positive results [24].…”

Management of screen-detected lung nodules: A Canadian partnership against cancer guidance document

“…107 A multicenter study including 7 centers in North America concluded that PET/ CT has limited value to diagnose IPNs suspicious for lung cancer across a variety of clinical contexts, geographic regions and nodule sizes. 108 The overall sensitivity and specificity of FDG-PET to diagnose lung cancer was found to be 90.1% (95% CI, 88.1%-91.9%) and 39.8% (33.4%-46.5%), respectively. In the COSMOS screening study in 351 participants with 383 nodules, the overall sensitivity, specificity and accuracy of visually evaluated PET-CT in distinguishing malignant from benign nodules were 64% (95% CI 56-70%), 89% (83-93%) and 76% (71-80%), respectively.…”