Relationship between ¹⁸F-FDG PET/CT Semi-Quantitative Parameters and International Association for the Study of Lung Cancer, American Thoracic Society/European Respiratory Society Classification in Lung Adenocarcinomas

Abstract

Objective To investigate the relationship between 18 F-FDG PET/CT semi-quantitative parameters and the International Association for the Study of Lung Cancer, American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) histopathologic classification, including histological subtypes, proliferation activity, and somatic mutations. Materials and Methods This retrospective study included 419 patients (150 males, 269 females; median age, 59.0 years; age range, 23.0–84.0 years) who had undergone surgical removal of stage IA–IIIA lung adenocarcinoma and had preoperative PET/CT data of lung tumors. The maximum standardized uptake values (SUVmax), background-subtracted volume (BSV), and background-subtracted lesion activity (BSL) derived from PET/CT were measured. The IASLC/ATS/ERS subtypes, Ki67 score, and epidermal growth factor/anaplastic lymphoma kinase (EGFR/ALK) mutation status were evaluated. The PET/CT semi-quantitative parameters were compared between the tumor subtypes using the Mann–Whitney U test or the Kruskal–Wallis test. The optimum cutoff values of the PET/CT semi-quantitative parameters for distinguishing the IASLC/ATS/ERS subtypes were calculated using receiver operating characteristic curve analysis. The correlation between the PET/CT semi-quantitative parameters and pathological parameters was analyzed using Spearman’s correlation. Statistical significance was set at p < 0.05. Results SUVmax, BSV, and BSL values were significantly higher in invasive adenocarcinoma (IA) than in minimally IA (MIA), and the values were higher in MIA than in adenocarcinoma in situ (AIS) (all p < 0.05). Remarkably, an SUVmax of 0.90 and a BSL of 3.62 were shown to be the optimal cutoff values for differentiating MIA from AIS, manifesting as pure ground-glass nodules with 100% sensitivity and specificity. Metabolic-volumetric parameters (BSV and BSL) were better potential independent factors than metabolic parameters (SUVmax) in differentiating growth patterns. SUVmax and BSL, rather than BSV, were strongly or moderately correlated with Ki67 in most subtypes, except for the micropapillary and solid predominant groups. PET/CT parameters were not correlated with EGFR/ALK mutation status. Conclusion As noninvasive surrogates, preoperative PET/CT semi-quantitative parameters could imply IASLC/ATS/ERS subtypes and Ki67 index and thus may contribute to improved management of precise surgery and postoperative adjuvant therapy.

18F-FDG PET/CT characteristics of IASLC grade 3 invasive adenocarcinoma and the value of 18F-FDG PET/CT for preoperative prediction: a new prognostication model

“…The different biological characteristics of different grade tumors can explain the usefulness of the above two parameters for prediction. A large number of studies have proven that higher grade tumor often have a higher glucose metabolism [30,31], which can not only provide more carbon sources to synthesize more organelles to support the proliferation of high-grade tumor, but also to meet the energy demand for high activity and invasion of these tumors [32]. On the contrary, it is well known that lung adenocarcinoma originates from alveoli and bronchioles and they often make regional bronchioles and alveoli to dilate during the growth process.…”

18F-FDG PET/CT characteristics of IASLC grade 3 invasive adenocarcinoma and the value of18F-FDG PET/CT for preoperative prediction

“…A large number of studies have proven that higher grade tumor often have a higher glucose metabolism, 30,31 which can not only provide more carbon sources to synthesize more organelles to support the proliferation of high grade tumor, but also to meet the energy demand for high activity and invasion of these tumors. 32 On the contrary, it is well known that lung adenocarcinoma originates from alveoli and bronchioles and they often make regional bronchioles and alveoli to dilate during the growth process. The attenuation of IASLC grade 1 or 2 tumor is usually low and the dilated bronchioles and alveoli can be easily found on CT. 33 However, IASLC grade 3 tumors often grow rapidly, which compress the dilated bronchus to make it narrow or collapse.…”

The Role and Potential of 18F-FDG PET/CT in Malignant Melanoma: Prognostication, Monitoring Response to Targeted and Immunotherapy, and Radiomics

“…Aside from qualitative image interpretation, it is well known that PET technology allows for the calculation of several quantitative parameters, including maximum and mean standardized uptake value (SUVmax and SUVmean) and the more recently introduced volumetric ones, such as metabolic tumor volume (MTV) and total lesion glycolysis (TLG); this last result was the product of MTV and SUVmean. Of note, both MTV and TLG were found to be strictly correlated with tumor aggressiveness and biological behavior and was impactful on patients' prognosis [30][31][32].…”