Radiomics analysis improves 18FDG PET/CT-based risk stratification of cytologically indeterminate thyroid nodules

Abstract

Purpose As ~25% of cytologically indeterminate thyroid nodules harbour malignancy, diagnostic lobectomy is still performed in many cases. 18FDG PET/CT rules out malignancy in visually negative nodules; however, none of the currently available interpretation criteria differentiates malignant from benign 18FDG-avid nodules. We evaluated the ability of PET metrics and radiomics features (RFs) to predict final diagnosis of 18FDG-avid cytologically indeterminate thyroid nodules. Methods Seventy-eight patients were retrospectively included. After volumetric segmentation of each thyroid lesion, 4 PET metrics and 107 RFs were extracted. A logistic regression was performed including thyroid stimulating hormone, PET metrics, and RFs to assess their predictive performance. A linear combination of the resulting parameters generated a radiomics score (RS) that was matched with cytology classes (Bethesda III and IV) and compared with final diagnosis. Results Two RFs (shape_Sphericity and glcm_Autocorrelation) differentiated malignant from benign lesions. A predictive model integrating RS and cytology classes effectively stratified the risk of malignancy. The prevalence of thyroid cancer increased from 5 to 37% and 79% in accordance with the number (score 0, 1 or 2, respectively) of positive biomarkers. Conclusions Our multiparametric model may be useful for reducing the number of diagnostic lobectomies with advantages in terms of costs and quality of life for patients.

[18F]FDG-PET/CT to prevent futile surgery in indeterminate thyroid nodules: a blinded, randomised controlled multicentre trial

“…Nodules with Hürthle cell cytology should be excluded from visual analysis with [ 18 F]FDG-PET/CT. Any benefits of quantitative [ 18 F]FDG-PET/CT assessment methods, such as SUV-derived analysis, texture analysis, and radiomics, have shown potential in indeterminate thyroid nodules and [ 18 F]FDG-positive thyroid incidentaloma, although the current evidence is limited and further studies are required [22][23][24]. Other diagnostics, such as molecular analysis for specific driver mutations, mitochondrial DNA mutations, and copy number variations, should be considered for Hürthle cell nodules [25][26][27].…”

Radiomics Analysis of [18F]FDG PET/CT Thyroid Incidentalomas: How Can It Improve Patients’ Clinical Management? A Systematic Review from the Literature

“…Aksu et al [ 28 ] investigated six conventional parameters in their study, excluding MTV, but chose to include only SUV max values in their predictive model. Giovanella et al [ 29 ] estimated the values of SUV max , SUV mean , MTV, and TLG, but only SUV max and TLG retained statistical significance as malignancy predictors. However, these studies did not focus on the usage of volumetric parameters as predictors for malignancy in FDG-avid thyroid incidentalomas, but on their integration in further predictive models, alongside histogram-based or texture radiomics features.…”

Quantitative classification and radiomics of [18F]FDG-PET/CT in indeterminate thyroid nodules

“…To the best of our knowledge, our study is the second to report PET/CT radiomics in indeterminate thyroid nodules. Giovanella et al recently published the first study in 78 Bethesda III/IV patients, demonstrating a 96% NPV and 58% PPV for a multiparametric model including the cytological classification and two radiomic features [19]. PPV improved to 79% if 13 patients with a histopathological Hürthle cell adenoma were excluded (cytology not reported).…”

“…When incorporated in the proposed multiparametric model, however, clinical application of radiomics seems feasible. Future studies are required to validate their results [19].…”

“…In radiomics, large amounts of quantitative features are extracted from medical images, aiming to find stable and clinically relevant image-derived biomarkers that may provide new insights in tumour biology and guide patient management [18]. After a number of studies suggested that radiomic analysis could contribute to the differentiation of [ 18 F]FDG-positive thyroid incidentalomas, one study recently also indicated its potential in the diagnosis of indeterminate nodules [19][20][21][22][23][24].…”