Summary of meta-analyses of studies considering lesion size cut-off thresholds for
the assessment of eligibility for FNAB and sonoelastography and inter- and
intra-observer agreement in estimating the malignant potential of focal lesions of the
thyroid gland
Authors:   Department of Radiology II, Maria
            Skłodowska-Curie National Research Institute of Oncology, Warsaw, Poland, Dobruch-Sobczak Katarzyna , Adamczewski Zbigniew ,   Department of Nuclear
            Medicine, Medical University of Lodz, Lodz, Poland, Dedecjus Marek ,   Department of Oncological
            Endocrinology and Nuclear Medicine, Maria Skłodowska-Curie National Research Institute
            of Oncology, Warsaw, Poland, Lewiński Andrzej ,   Department of Endocrinology
            and Metabolic Diseases, Polish Mother’s Memorial Hospital – Research Institute, Lodz,
            Poland,   Department of Endocrinology
            and Metabolic Diseases, Medical University of Lodz, Lodz, Poland, Migda Bartosz ,   Ultrasound Diagnostics
            Laboratory, Department of Paediatric Radiology, Faculty of Medicine, Medical University
            of Warsaw, Warsaw, Poland, Ruchała Marek ,   Department of Endocrinology,
            Metabolism and Internal Diseases, Poznan University of Medical Sciences, Poznan,
            Poland, Skowrońska-Szcześniak Anna ,   Department of Internal
            Medicine and Endocrinology, Medical University of Warsaw, Warsaw, Poland, Szczepanek-Parulska Ewelina ,   Department of Endocrinology,
            Metabolism and Internal Diseases, Poznan University of Medical Sciences, Poznan,
            Poland, Zajkowska Klaudia ,   Department of Oncological
            Endocrinology and Nuclear Medicine, Maria Skłodowska-Curie National Research Institute
            of Oncology, Warsaw, Poland, Żyłka Agnieszka ,   Department of Oncological
            Endocrinology and Nuclear Medicine, Maria Skłodowska-Curie National Research Institute
            of Oncology, Warsaw, Poland
Published: May 2022

Thyroid cancer is a tumour with a steadily increasing incidence. It accounts for
7% to 15% of focal lesions detected by ultrasound, depending on age, gender and other
factors affecting its occurrence. Fine-needle aspiration biopsy is an essential method
to establish the diagnosis but, in view of its limitations, sonoelastography is seen as
a non-invasive technique useful in differentiating the nature of lesions and monitoring
them after fine-needle aspiration biopsy. This paper presents a literature review on the
role of both sonoelastographic techniques (relative strain sonoelastography, shear wave
sonoelastography) to assess the deformability of focal thyroid lesions. Ultrasound
examination is a relatively subjective method of thyroid imaging, depending on the
skills of the examiner, the experience of the centre, and the quality of equipment used.
As a consequence, there are inconsistencies between the results obtained by different
examiners (inter-observer variability) and by the same examiner (intra-observer
variability). In this paper, the authors present a review of the literature on
inter-observer and intra-observer variability in the assessment of individual features
of ultrasound imaging of focal lesions in the thyroid. In addition, the authors report
on an analysis of cut-off thresholds for the size of lesions constituting the basis for
fine-needle aspiration biopsy eligibility assessment. The need to diagnose carcinomas up
to 10 mm in diameter is highlighted, however a more liberal approach is recommended in
terms of indications for biopsy in lesions associated with a low risk of malignancy,
where, based on consultations with patients, active ultrasound surveillance might even
be considered.