Introduction

Thyroid nodules are the most prevalent endocrine disorder, affecting 10–70% of the overall population and holding a 3–9% chance of developing cancer [1]. High-resolution sonography possesses four primary practical significance: detecting thyroid and other cervical masses during and following thyroidectomy, differentiating malignant from benign masses relying on sonographic appearance, facilitating FNA biopsy, guiding minimally invasive treatment of non-functional and hyper-functional noncancerous nodules, and analyzing lymph node metastases from papillary carcinoma. Although FNA is the most accurate diagnostic technique for physically perceptible thyroid nodules [2]. Observations on color and grayscale Doppler ultrasonography only become a highly effective predictor of malignancy when several symptoms appear in a nodule at once [3, 4]. A high level of specificity was attained for the interpretation of thyroid carcinomas in a group of patients where the absence of the halo sign was observed combined with microcalcifications and an intranodular low echogenicity pattern [5]. The inclusion of minimum single cancerous sonographic characteristic (taller-than-wider form, spiculated margins, significant hypo-echogenicity, micro-calcifications, and macrocalcification) showed a sensitivity of 83.5%, specificity of 74.1%, and diagnostic accuracy of 78.1% in large research. Other criteria, such as rim calcification, demonstrated no significant influence on distinguishing between non-cancerous and cancerous nodules [6]. Thyroid Imaging Reporting and Data System [TIRADS] was proposed as a standardized strategy for evaluating and reporting thyroid ultrasonography as well as risk assessment to ease interpretation and consistency across professionals [7, 8].

Preoperative examination of a thyroid nodule can be done using the well-established technique of fine-needle aspiration cytology (FNAC) [9]. It is viewed as the gold standard in diagnostic methods for assessing thyroid nodules. A standardized, categorical diagnostic and reporting method for thyroid fine-needle aspiration (FNA) specimens was established named as the Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) which reports in 6 diagnostic categories; (a) non-diagnostic or un-satisfactory; (b) benign; (c) atypia of undetermined significance (AUS) or follicular lesion of undetermined significance (FLUS); (d) follicular neoplasm or suspicious for a follicular neoplasm; (e) suspicious for malignancy; and (f) malignant [10, 11].

Ultrasonography is an easily available, non-invasive, painless, radiation-free and less expensive diagnostic modality in comparison to other modalities and can easily distinguish and categorize thyroid nodules into benign and malignant. This study provided statistical evidence of the precision of thyroid nodule's sonographic findings in distinguishing between malignant and benign nodules in contrast to the results of Fine Needle Aspirates of Thyroid Nodules under scoring of BETHESDA Classification and was found to be more useful in parameters where FNAC is not easily accessible, so decisions can be derived on a considerable degree on the US TIRADS Classification and early management of the pathology can be attained.

Materials and method

A cross-sectional study design was conducted in the Radiology Department of Chughtai Lab Head Office in Lahore. The total sample size for the study is 154 patients. The sampling technique employed is the consecutive sampling technique. IBM SPSS statistics version 26 was used for the data analysis of this study. The inclusion criteria for this study included patients with a history of thyroid nodule or those who have been previously diagnosed, and those who presented with clinical and physical manifestations of thyroid nodule. The study included patients of both genders and aged between 10 and 85 years. On the other hand, the exclusion criteria comprised patients who had no TIRADS Category, which means a normal thyroid ultrasound, patients who were under treatment, or had undergone thyroidectomy before, and those who had an ongoing thyroid infection. These criteria were necessary to ensure that the study focuses only on patients with thyroid nodules and eliminates any other confounding factors that could affect the study's results. The ultrasound equipment used for the study is the Toshiba Applio 500 model, while the equipment for FNAC included topical anesthesia, 21-gauge 10 CC syringes, glass slides, cellblock, and the Olympus CX23 microscope. Study was conducted after the approval from Research Ethics Committee, The University of Lahore REC # 245.

Results

Out of 154 patients, the mean age was 42.0 ± 13.6 years. Majority were female (89%) while 11% are male. Hyperechoic (29%) and isoechoic (32.9%) were the most common types. Wider than taller (49.4%) is predominant, followed by round (37%). Smooth margins (72.1%) were most frequent, followed by ill-defined (13.6%). Mixed solid cystic (42.9%) and solid (26.6%) were prevalent compositions. Most nodules have none (74.7%), while comet tail artifact (24.3%) was the most common echogenic foci. In TIRADS category (I–V) 15 nodules (9.7%) were classified as category I, 89 nodules (57.8%) as category II, 24 nodules (15.6%) as category III, 8 nodules (24%) as category IV, and 18 nodules (11.7%) as category V and category II (57.8%) has the highest frequency. In TIRADS suspiciousness, 15 nodules (9.7%) were classified as Benign, 18 nodules (11.7%) as highly suspicious, 25 nodules (16.2%) as mildly suspicious and 8 nodules (5.2%) as moderately suspicious and 88 nodules (57.1%) as not suspicious. Bethesda categories among thyroid nodules is as follows: 14 nodules (9.1%) were classified as category I, 104 nodules (67.5%) as category II, 11 nodules (7.1%) as category III, 11 nodules (7.1%) as category IV, 6 nodules (3.9%) as category V, and 8 nodules (5.2%) as category VI. In Bethesda, final diagnoses for thyroid nodules 119 nodules (77.3%) were diagnosed as benign, while 35 nodules (22.7%) were diagnosed as malignant (Table 1). To eliminate interobserver variability, all patients were scored using TIRADS by a single radiologist. In TIRADS category I, 86.7% are classified as Bethesda category I, and 13.3% as category II. TIRADS category II predominantly falls into Bethesda category II, with 97.8%. For TIRADS category III, 62.5% are Bethesda category II, 33.3% are category III, and 4.2% are category IV. In TIRADS category IV, 25.0% are Bethesda category III, and 75.0% are category IV. TIRADS category V includes nodules mainly categorized as Bethesda category IV (22.2%), category V (33.3%), and category VI (44.4%). The P-value of <0.0001 suggests a statistically significant association between TIRADS and Bethesda categories (Table 2). The findings suggested that ultrasonography is a highly reliable and effective method for diagnosis, with a superior degree of sensitivity and specificity in addition to invasive cytology tests. Results from the ROC curve analysis showed an impressive area under the curve of 0.972. These observations indicate that ultrasonography may offer more accurate and definitive diagnoses than other methods currently employed. Therefore, ultrasonography may be a valuable diagnostic tool in the future (Tables 3 and 4) (Fig. 1). The sonographic features show significant associations with TIRADS categories (P-value <0.0001). Ill-defined margins were more prevalent in TIRADS II (52.4%) compared to other categories, while irregular margins were predominant in TIRADS V (77.8%). Lobulated margins were exclusively observed in TIRADS V. Anechoic echogenicity was mainly found in TIRADS I (93.8%), while hyperechoic echogenicity was common in TIRADS II (78.3%). Hypoechoic echogenicity was more frequent in TIRADS V (60.7%). Cystic composition was significantly associated with TIRADS I (93.8%), while solid composition was more common in TIRADS II (46.3%). Round shape was predominant in TIRADS II (56.1%), whereas wider than taller shape was more prevalent in TIRADS V (71.4%). Comet tail artifact echogenic foci were prominent in TIRADS I (86.7%). Microcalcifications were observed in TIRADS V (16.7%), and none was seen in TIRADS II (89.9%) (Table 5). The association between TIRADS suspiciousness and Bethesda diagnosis is statistically significant (P-value <0.0001). Benign nodules were most commonly classified as not suspicious (56.5%), followed by mildly suspicious (9.7%), while malignant nodules were primarily classified as highly suspicious (11.0%). Notably, no malignant nodules were categorized as benign (Table 6) (Fig. 2).

View Full Size

Sensitivity & specificity for TIRADS classification

Citation: Imaging 16, 2; 10.1556/1647.2024.00199

• Download Figure
• Download figure as PowerPoint slide

View Full Size

Comparison of TIRADS suspiciousness with BETHESDA final diagnosis

Citation: Imaging 16, 2; 10.1556/1647.2024.00199

• Download Figure
• Download figure as PowerPoint slide

Discussion

The purpose of the current research was to compare thyroid cytological assessment (TBSRTC) with USG assessment (TIRADS) on thyroid lesions. Cytology using fine needle aspiration is a precise, accurate, and cost-effective method that can delay surgical intervention. Under ideal circumstances, USG evaluation comes after clinical assessment of thyroid nodules with thyroid function tests. Then, lesions with suspected malignancy should undergo FNA. The endorsement of TIRADS Classification by ACR has provided an effective risk stratification method that is comparable to the BIRADS Classification. This technique is designed to tie sonographic characteristics to cytological categorization and provides an estimation of the likelihood that a specific nodule will develop malignancy. According to our findings, the risk of malignancy increased noticeably from TIRADS III to V. This became 0 for TIRADS I & II, as would be anticipated given that TIRADS II is regarded as a generally benign lesion on ultrasound. The TIRADS Category II emerged as the most prevalent, with an aggregate 89 patients out of 154 patients, or 57.8% of all patients. On ultrasound, the majority of nodules 76% of the sample size were diagnosed as TIRADS II–III lesions. With FNAC, it was observed that 85% of the data set fell into Bethesda Classification Categories II, III, and I. The Bethesda IV or V nodules were not found in any of the TI-RADS I & II nodules. Only one Bethesda IV nodule was found out of 24 TI-RADS III nodules. The sensitivity of TIRADS Classification in this study turned out to be 96.0% and Specificity being 98.4%. Some US characteristics, such as significant hypoechogenicity, taller-than-wide form, irregular contours, and the occurrence of calcifications, had previously been recognized as highly suggestive for neoplasia. The risk of cancer increased noticeably from ACR-TIRDAS Category III to V in this study. This was 0 for Category II, which is in line with expectations given that Category II is regarded as an ultrasonographically typical benign tumor. According to Horvath's research, the likelihood of developing cancer was less than 5% for Category III, between 5% and 10% for Category IVa, between 10% and 80% for Category IVb, and greater than 80% for Category V [7]. Our results fall within Horvath's indicated range and are comparable to Russ et al [12]. This is crucial in determining the risk of thyroid nodule cancer. So, if a nodule is correctly identified on ultrasound, the TIRADS category can reasonably be used to extrapolate the likelihood that a given nodule is malignant, allowing for the initiation of therapeutic strategies. Several ultrasound characteristics, such as significant hypo echogenicity, a taller than wider form, erratic contours, and the existence of intranodular calcifications, have previously been reported as being highly suggestive for malignancy [3, 12, 14]. The sensitivities and specificities of our investigation revealed that these characteristics were highly dubious for carcinoma [13]. With an estimated 5% frequency, thyroid carcinoma is a very uncommon disease [13–15]. This value was similar to the percentage of malignant thyroid nodules seen in this investigation. In this investigation, the diagnostic efficacy of US was superior to that achieved by Moon et al [16]. In one investigation, Hong YJ et al. [17] came to the conclusion that the existence of micro-calcifications, noticeable hypo-echogenicity, and a taller than wider structure are the 3 ultrasound markers that are significant findings in the identification of thyroid cancer. The US characteristics of hypo-echogenicity, marked hypo-echogenicity, non-parallel alignment, micro-lobulated or speculated margins, irregular margins, and the presence of micro-calcifications were significant statistically for malignant thyroid nodules in a multicenter Korean retrospective study [18].

The investigation confirms the correlation between TIRADS categories and the final cytology of thyroid nodules. This correlation provides a reliable method for clinicians to assess the malignancy risk of thyroid nodules based on their ultrasonography characteristics. By using the TIRADS classification system, clinicians can make more informed decisions about the need for further diagnostic procedures, such as fine needle aspiration biopsy (FNAB). TIRADS IV & V nodules are considered to have a high malignancy risk, and thus, diagnostic aspiration (FNAB) is recommended. On the other hand, nodules with a TIRADS II or III classification have a very low malignancy risk, ranging from 0 to 2%. Therefore, these nodules can be safely monitored without the need for unnecessary diagnostic procedures, reducing patient anxiety and healthcare costs.

Overall, the TIRADS classification system is a valuable tool for clinicians in evaluating the malignancy risk of thyroid nodules, improving patient care and reducing unnecessary procedures.

Conclusion

Healthcare professionals may consider utilizing TIRADS as first-line imaging method and then BETHESDA if needed to optimize their evaluation of thyroid nodules and provide patients with the most accurate diagnosis and by reducing the number of unnecessary interventions. When it comes to assessing the potential for malignancy in thyroid nodules, both TIRADS and BETHESDA categories tend to align with one another. In fact, this study concluded that, combining these two scoring methods appears to yield the most precise outcomes for identifying and distinguishing benign from malignant nodules, which is critical for arriving at a definitive diagnosis in individuals with thyroid malignancies.

Authors' contributions

WSK: Data Collection and writing; SMYF: Idea, Writing – Review and Data Analysis; SN: Literature review and Editing.

Funding sources

None.

Conflict of interest

None.

Ethical statement

The study was approved by the Research Ethical Committee, The University of Lahore, Dated: 15-09-2022, REC # 245. Following rules and regulations set by the ethical committee of the University of Lahore were followed while conducting the research and the rights of the research participants were respected. Written informed consent (attached) was taken from all the participants. All information and data collection were kept confidential. Participants were anonymous throughout the study.