Use of the ultrasound-based total malignancy score in the management of thyroid nodules

Article information

Ultrasonography. 2019;38(2):188-189

Publication date (electronic) : 2019 January 3

doi : https://doi.org/10.14366/usg.18068

Juan Sebastian Gomez, Luis Fernando Serrano

Department of Radiology, Santafe Foundation University Hospital, Bogota, Colombia

Correspondence to: Juan Sebastian Gomez, MD, Department of Radiology, Santafe Foundation University Hospital, Carrera 7 No 117-15, Bogotá 11001000, Colombia Tel. +57-16030303 Fax. +57-16575714 E-mail: juan.sebastian.77gomez@gmail.com

Received 2018 November 20; Accepted 2019 January 3.

We read with great interest the article by Dr. Pompili et al. [1], "Use of the ultrasound-based total malignancy score in the management of thyroid nodules." First, we would like to congratulate and thank the authors for providing a novel resource in the form of the ultrasound-based total malignancy score for the management of thyroid nodules, because this is a brand-new scoring system that can guide radiologists in the diagnostic and clinical setting of managing thyroid nodules that are suspicious for malignancy. From our perspective, we concur that it is always important to review ultrasound descriptors and features for benign and malignant thyroid lesions in order to understand the likelihood of a certain thyroid nodule developing into cancer. Additionally, observing how the mechanisms for diagnosing this entity have changed over time and have ultimately evolved into the current cutting-edge method using imaging has proven to be endlessly fascinating.

We would like to highlight several vital factors regarding the methods, results, and discussion of the aforementioned study based on our literature review of PubMed, MEDLINE, and the Cochrane Library. The sample size (231 thyroid nodules) of the aforementioned study is smaller than that of other publications, such as a study regarding the Thyroid Imaging Reporting and Data System that evaluated 1,959 thyroid nodules [2] or the study written by Rosario et al. [3] that studied the diagnostic value of Doppler ultrasound in 1,502 thyroid nodules. Having a small size may lessen the internal or external validity of the study [4], as well as decreasing its statistical power. As physicians and researchers, we believe that it is crucial to have a sufficient number of patients because sample size is an extremely important parameter for interpreting the findings of a study.

Another important factor to discuss is the small number of ultrasound features that comprise the new score. In the publication, the reader is unable to find information on the background parenchyma; the presence of abnormal lymph nodes; calcification subtypes such as rim, speckled, and coarse; or margin-related characteristics, such as smooth, irregular, and poorly defined margins or the presence of extrathyroid extension [2,5].

The ultrasound-based total malignancy score includes Doppler features such as the vascularity pattern in order to classify a thyroid nodule as negative or non-negative. However, this method is debatable because several publications have concluded that Doppler ultrasound is not a useful modality for distinguishing malignant from benign thyroid nodules [3].

Therefore, based on our literature review, we conclude that the small sample size of the study may have affected its validity and power, that the pattern of vascularity does not provide additional value for differentiating between benign and malignant thyroid nodules, and that additional ultrasound features of thyroid nodules, such as microcalcification subtypes or margin-related characteristics, may provide vital information for the final classification of thyroid nodules.