Radiology reports for incidental thyroid nodules on CT and MRI: high variability across subspecialties

Incidental Findings in Lung Cancer Screening

While low-dose computed tomography (LDCT) for lung cancer screening (LCS) has been recognized for its effectiveness in reducing lung cancer mortality, it often simultaneously leads to the detection of incidental findings (IFs) unrelated to the primary screening indication. These IFs present diagnostic and management challenges, potentially causing unnecessary anxiety and further invasive diagnostic procedures for patients. This review article provides an overview of IFs encountered in LDCT, emphasizing their clinical significance and recommended management strategies. We categorize IFs based on their anatomical locations (intrathoracic-intrapulmonary, intrathoracic-extrapulmonary, and extrathoracic) and discuss the most common findings. We highlight the importance of utilizing guidelines and standardized reporting systems by the American College of Radiology (ACR) to guide appropriate follow-ups. For each category, we present specific IF examples, their radiologic features, and the suggested management approach. This review aims to provide radiologists and clinicians with a comprehensive understanding of IFs in LCS for accurate assessment and management, ultimately enhancing patient care. Finally, we outline a few key aspects for future research and development in managing IFs.

Thyroid abnormalities identified on CT screening for lung cancer

PURPOSE

Because incidental thyroid nodules (ITNs) are common extrapulmonary findings in low-dose computed tomography (LDCT) scans for lung cancer screening, we aimed to investigate the frequency of ITNs on LDCT scans separately on baseline and annual repeat scans, the frequency of malignancy among the ITNs, and any association with demographic, clinical, CT characteristics.

METHODS

Retrospective case series of all 2309 participants having baseline and annual repeat screening in an Early Lung and Cardiac Action Program (MS-ELCAP) LDCT lung screening program from January 2010 to December 2016 was performed. Frequency of ITNs in baseline and annual repeat rounds were determined. Multivariable regression analysis was performed to identify significant predictors.

RESULTS

Dominant ITNs were seen in 2.5 % of 2309 participants on baseline and in 0.15 % of participants among 4792 annual repeat LDCTs. The low incidence of new ITNs suggests slow growth as it would take approximately an average of 16.8 years for a new ITN to be detected on annual rounds of screening. Newly detected ITNs on annual repeat LDCT were all smaller than 15 mm. Regression analysis showed that the increasing of age, coronary artery calcifications score and breast density grade were significant predictors for females having an ITN. No significant predictors were found for ITNs in males.

CONCLUSION

ITNs are detected at LDCT however, no malignancy was found. Certain predictors for ITNs in females have been identified including breast density, which may point towards a common causal pathway.

Thyroid Nodules Detected on CT: A Retrospective Audit Study and Analysis of Differences in Reporting Practices Across Radiology Subspecialties

Thyroid nodules (TNs) are common incidental findings  on imaging and TN reporting practices are variable among radiologists, leading to unnecessary or inadequate investigations. We aimed to document current literature adherence for TN reporting practices on thoracic CTs and assess the variability in TN reporting across radiology subspecialties. This is a 2-parts retrospective study. First part was an audit study including all adult patients with thoracic CTs in January 2020. Patients with prior thyroidectomy and/or lack of TN were excluded. A local committee was created for literature review and elaboration of a local TN management algorithm. The algorithm was shared with the thoracic radiology team. Imaging and medical records were reviewed and adequate adherence was assessed in the pre- and post-intervention cohorts. Second part included all adult patients who underwent neck or cervical spine CT imaging in the same timeframe and with same inclusion/exclusion criteria as the pre-intervention thoracic cohort. In the pre-intervention cohort 802 participants were screened and 137 patients included. TNs were reported in "body" and "conclusion" of the report in 51% and 7% of the time respectively. Thyroid US was recommended in 10% of the patients and inadequately recommended 3% of the time. Overall adequate adherence was 86%. In the post-intervention cohort 962 participants were screened and 167 patients included. Thyroid US was recommended in 7% of the patients and no inadequate US recommendation was made. Overall adequate adherence in the post-intervention cohort was 93%, increased by 7% (P= 0.039). The musculoskeletal and neuroradiology cohorts reported more TNs in "conclusion" (P= 0.013 and P< 0.0001) and recommended more thyroid US (P = 0.033 and P= 0.0018) compared to the preintervention thoracic cohort. No significant difference in overall adequate adherence between subspecialties (P= 0.48 and P= 0.51). Improvement in adequate TN reporting on thoracic CT by 7% while reducing inadequate thyroid US recommendations from 3% to none. Significant reporting trends were also noted across radiology subspecialties.

Incidentalomas in the head & neck

Incidental findings (IFs) in the head & neck are a frequent challenge to the reporting radiologist. A combination of complex anatomy, widely varied imaging techniques and the high prevalence of benign pathology, makes safe and appropriate management of head & neck IFs problematic. The non-head & neck radiologist is unlikely to have prior personal experience of the relevant specialties or current involvement with the pertinent multidisciplinary teams, creating unfamiliarity with both the clinical aspects of head & neck disease and the value of examination techniques. This triumvirate of complex anatomy, pathology and imaging creates the perfect environment for excessive investigation and overdiagnosis. In this article, the most frequently encountered and clinically relevant head & neck IFs are summarised. To reflect daily clinical practice, we will firstly consider anatomic abnormalities identified on cross-sectional imaging and ultrasound, followed by a review of PET-CT incidental findings.

Evaluation of Guideline Adherence and Subsequent Follow-Up Outcomes for Incidental Thyroid Nodules Detected in Hybrid Academic-Community Practice

OBJECTIVE

Incidental thyroid nodules (ITNs) are common, and variability regarding follow-up and recommendation practices exist. The study purpose was to determine adherence to the American College of Radiology (ACR) ITN criteria and analyze recommendation outcomes.

METHODS

ITNs listed in the impression section on computed tomography, magnetic resonance imaging, and positron emission tomography studies over a 6-month period were included. Report recommendations were compared with ACR white paper criteria for adherence (concordant recommendation) or nonadherence (discordant recommendation). Reader characteristics, further ITN workup, and pathology were recorded. A P value less than 0.05 was used for significance.

RESULTS

Three hundred fifty patients (mean age, 64.6 years) were included with a median ITN size of 18-mm. Most nodules (289/350) were reported on computed tomography and were identified for follow-up due to size (235/350). Only 39 of 350 reports (11.1%) did not follow ACR recommendations. Patient age was significantly related to recommendation adherence (P < 0.05) as opposed to radiologist practice type (ie, community-based or academic) which was not. Nonadherence most often involved recommending ultrasound follow-up for nonactionable small ITNs. The rate of fine-needle aspiration biopsy from concordant ITNs was significantly higher than discordant ITNs (P < 0.05). Six patients, all with concordant recommendations, had malignant final pathology results.

CONCLUSION

Recommendation adherence to the ACR ITN criteria was high, approaching 90%. Nonadherence was mostly due to recommending thyroid ultrasound when not indicated and was correlated with a younger patient age. The rate of fine-needle aspiration biopsy stemming from nonindicated ultrasounds was significantly lower and did not result in the diagnosis of any malignancies.

Contrast-Enhanced CT-Based Radiomics for the Differentiation of Nodular Goiter from Papillary Thyroid Carcinoma in Thyroid Nodules

Background

Papillary thyroid carcinoma (PTC) and nodular goiter (NG) represent the most commonly malignant and benign diseases of thyroid nodules and are often confused in diagnosis. CT examination has a certain diagnostic value for the diagnosis of suspected malignant thyroid nodules. The application of machine learning to radiomics features provides a new diagnostic approach, which has been widely used in ultrasound examination of the thyroid, but there are few literatures on CT examination.

Purpose

To explore the efficacy of a diagnostic model aided by machine learning for preoperative differentiation of nodular goiter and papillary thyroid carcinoma thyroid nodules on the basis of 3D arterial-phase contrast-enhanced computed tomography (CECT) features.

Materials and Methods

We collected the data of 193 NG and 214 PTC thyroid nodules from 407 patients in CT examinations. Together with the pathologist findings and radiology diagnosis, we built a radiomics model using the 1218 features extracted from the arterial phase of CECT images. By comparing the diagnostic performance of the radiomics model with that of the clinical diagnosis, we assessed the performance of the radiomics model.

Results

The radiomics model was developed based on multivariable logistic regression with the optimal 12 radiomics features after feature dimension reduction. The radiomics model performed well on the classification accuracy of the PTC and NG thyroid nodules in the training group and validation group.

Conclusion

The radiomics model based on the 3D arterial phase of CECT features performed better than the group of experienced radiologists in differentiating NG and PTC thyroid nodules.

The Role of the ACR TI-RADS Scoring System to Evaluate Solid and Cystic Thyroid Nodules Compared With Those Solid Nodules With or Without Echogenic Foci and Their Cytology Results

Objective:

The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS) is a reporting system for thyroid nodules detected with sonography and proposed by the ACR. The scoring of punctate echogenic foci (PEF) increases the TI-RADS score and leads to a biopsy of many thyroid nodules, otherwise found clinically. The aim of this study was to assess the risk of malignancy for mixed and solid nodules, with and without PEF, and cytologic correlation.

Materials and Methods:

Thyroid sonograms and ultrasound-guided thyroid biopsies were performed, at a University of Iowa Hospitals & Clinics for 105 patients, during July 2019 to June 2020. All these retrospective clinical studies were reviewed against the cytologic examinations.

Results:

Based on the 189 thyroid nodule biopsies reviewed, 82.5% were benign compared with 17.5% malignant lesions. A solid nodule composition was noted in 35.2%, and had a higher risk for malignancy, compared with 7.7% of the mixed nodules. There was a 33.3% incidence of malignancy for solid nodules with PEF, compared with 35.8% of lesions lacking PEF. For mixed nodules, 6.2% nodules demonstrated PEF and 7.7% of nodules, without PEF, were malignant.

Conclusion:

In this cohort, solid nodules had a higher risk of malignancy than mixed nodules. PEF did not increase the risk of malignancy in either solid or mixed thyroid nodules, in these patients. These findings would suggest that existing guidelines may overestimate the value of PEF in scoring, as well as determining which thyroid nodules require biopsy.

Pituitary neuroendocrine tumors: a model for neuroendocrine tumor classification

The classification of adenohypophysial neoplasms as "pituitary neuroendocrine tumors" (PitNETs) was proposed in 2017 to reflect their characteristics as epithelial neuroendocrine neoplasms with a spectrum of clinical behaviors ranging from small indolent lesions to large, locally invasive, unresectable tumors. Tumor growth and hormone hypersecretion cause significant morbidity and mortality in a subset of patients. The proposal was endorsed by a WHO working group that sought to provide a unified approach to neuroendocrine neoplasia in all body sites. We review the features that are characteristic of neuroendocrine cells, the epidemiology and prognosis of these tumors, as well as further refinements in terms used for other pituitary tumors to ensure consistency with the WHO framework. The intense study of PitNETs has provided information about the importance of cellular differentiation in tumor prognosis as a model for neuroendocrine tumors in different locations.

Verbal Notification of Radiology Results: Are radiologists meeting expectations?

BACKGROUND

Delayed communication of radiographic findings is associated with poor patient outcomes and significant medicolegal risk. Radiologists verbally contact referring practitioners with urgent findings, though practitioner's expectations regarding notification has rarely been examined.

AIM

To assess differences in preferred practice between radiologists and referring practitioners in the verbal communication of urgent radiology findings.

METHODS

For 33 clinical stems, respondents were asked if they would issue (radiologists) or expect to receive (referring practitioners) verbal notification of results or routine written communication only. Surveys were emailed to radiologists and referring practitioners of varying experience at a tertiary referral hospital in Melbourne, Victoria.

RESULTS

A total of 97 survey responses were received. 80 responses were from referring practitioners and 17 from radiologists. Referring practitioners were seen to slightly prefer verbal notification more often than issued by radiologists overall (61%; 95CI 57-66% verbal notification expected versus 58%; 95CI 52-64% issued). More senior referring practitioners with greater than 10 years' experience expected verbal notification more often (67%; 95CI 59-75%), and more senior radiologists issued verbal reports less often (54%; 95CI 39-69%). More junior referring practitioners, for example registrars or fellows, expected notification less often overall (59%; 95CI 43-76%). Subgroup analysis demonstrated statistically significant differences in notification preferences for certain clinical scenarios.

CONCLUSIONS

Overall results show fair correlation between referrer's expectations of verbal notification and the provision of verbal notification by radiologists. However, there were discrepancies in the practice and preferences of more junior and senior practitioners, in addition to in certain clinical scenarios. This article is protected by copyright. All rights reserved.

Automatic Detection of Thyroid and Adrenal Incidentals Using Radiology Reports and Deep Learning

BACKGROUND

Computed tomography (CT) is commonly performed when evaluating trauma patients with up to 55% showing incidental findings. Current workflows to identify and inform patients are time-consuming and prone to error. Our objective was to automatically identify thyroid and adrenal lesions in radiology reports using deep learning.

MATERIALS AND METHODS

All trauma patients who presented to an accredited Level 1 Trauma Center between January 2008 and January 2019 were included. Radiology reports of CT scans that included either a thyroid or adrenal gland were obtained. Preprocessing included word tokenization, removal of stop words, removal of punctuation, and replacement of misspellings. A word2vec model was trained using 1.4 million radiology reports. Both training and testing reports were selected at random, manually reviewed, and were considered the gold standard. True positive cases were defined as any lesions in the thyroid or adrenal gland, respectively. Training data was used to create models that would identify reports that contained either thyroid or adrenal lesions. Our primary outcomes were sensitivity and specificity of the models using predetermined thresholds on a separate testing dataset.

RESULTS

A total of 51,771 reports were identified on 35,859 trauma patients. A total of 1,789 reports were annotated for training and 500 for testing. The thyroid model predictions resulted in a 90.0% sensitivity and 95.3% specificity. The adrenal model predictions resulted in a 92.3% sensitivity and a 91.1% specificity. A total of 240 reports were confirmed to have thyroid incidentals (mean age 69.1 yrs ± 18.9, 35% M) and 214 reports with adrenal incidentals (mean age 68.7 yrs ± 16.9, 50.5% M).

CONCLUSIONS

Both the thyroid and adrenal models have excellent performance with sensitivities and specificities in the 90s. Our deep learning model has the potential to reduce administrative costs and improve the process of informing patients.

The undiagnosed potential clinically significant incidental findings of neck CTA: A large retrospective single-center study

To assess the prevalence and missed reporting rate of potential clinically-significant incidental findings (IFs) in the neck CTA scans.All consecutive patients undergoing neck CTA imaging, from January 1, 2017 to December 31, 2018, were retrospectively evaluated by a radiologist for the presence of incidental findings in the upper chest, lower head and neck regions. These incidental findings were subsequently classified into 3 categories in terms of clinical significance: Type I, highly significant, Type II, moderately significant; and Type III, mildly or not significant. Type I and Type II IFs were determined as potential clinically significant ones and were retrospectively analyzed by another 2 radiologists in consensus. The undiagnosed findings were designated as those that were not reported by the initial radiologists. The differences in the rate of unreported potential clinically significant IFs were compared between the chest group and head or neck group.A total of 376 potential clinically significant IFs were detected in 1,698 (91.19%) patients, of which 175 IFs were classified as highly significant findings (Type I), and 201 (53.46%) as moderately significant findings (Type II). The most common potential clinically significant findings included thyroid nodules (n = 88, 23.40%), pulmonary nodules (n = 56, 14.89%), sinus disease (n = 39, 10.37%), intracranial or cervical artery aneurysms (n = 30, 7.98%), enlarged lymph nodes (n = 24, 6.38%), and pulmonary embolism (n = 19, 5.05%). In addition, 184 (48.94%) of them were not mentioned in the initial report. The highest incidence of missed potential clinical findings were pulmonary embolism and pathologic fractures and erosions (100% for both). The unreported rate of the chest group was significantly higher than that of the head or neck one, regardless of Type I, Type II or all potential clinically significant IFs (χ = 32.151, χ = 31.211, χ = 65.286, respectively; P < .001 for all).Important clinically significant incidental findings are commonly found in a proportion of patients undergoing neck CTA, in which nearly half of these patients have had potential clinically significant IFs not diagnosed in the initial report. Therefore, radiologists should beware of the importance of and the necessity to identify incidental findings in neck CTA scans.

Thyroid Incidentalomas: Practice Considerations for Radiologists in the Age of Incidental Findings

Radiologists very frequently encounter incidental findings related to the thyroid gland. Given increases in imaging use over the past several decades, thyroid incidentalomas are increasingly encountered in clinical practice, and it is important for radiologists to be aware of recent developments with respect to workup and diagnosis of incidental thyroid abnormalities. Recent reporting and management guidelines, such as those from the American College of Radiology and American Thyroid Association, are reviewed along with applicable evidence in the literature. Trending topics, such as artificial intelligence approaches to guide thyroid incidentaloma workup, are also discussed.

Incidentally Discovered Thyroid Nodules by Routine Magnetic Resonance Imaging of the Cervical Spine: Incidence and Clinical Significance

OBJECTIVE

The aim of our study was to present the prevalence of thyroid nodules we incidentally discovered by routine Magnetic Resonance Imaging (MRI) of the cervical spine, to evaluate their clinical significance, and to discuss the current clinical approach to incidental thyroid nodules.

METHODS

We retrospectively evaluated the cervical spinal MRI studies of 512 patients. Thyroid glands were evaluated for morphologic and signal characteristics and examined for the presence of nodule(s). The nodules with a maximum diameter of 5 mm or more were taken into analysis.

RESULTS

Of 512 MRI studies, 254 revealed incidental thyroid nodule(s) (49.6%). The mean maximum nodule diameter was 7.48±2.92 mm. Thirty-eight of 254 incidental thyroid nodules were radiologically reported, 35 reported nodules were evaluated by US, and 22 were further analyzed by fine needle aspiration cytology. The final diagnosis of 11 aspirated nodules was an adenomatous nodule, whereas 3 were papillary thyroid carcinoma. One of the patients with papillary thyroid carcinoma was a 32-year-old man with a nodule with a maximum diameter of 7 mm.

CONCLUSION

Incidental thyroid nodule is a frequent non-spinal lesion detected by routine cervical spinal MRI. The 3-tiered system which is recommended in the clinical approach to incidental thyroid nodules may miss some clinically significant thyroid nodules. We suggest the criteria of this system to be re-evaluated and modified if necessary. In addition, we would like to emphasize the need for a guideline for radiologists for reporting incidental thyroid nodules on MRI on the basis of a standard clinical approach.

Diagnostic Performance of Different Thyroid Imaging Reporting and Data Systems (Kwak-TIRADS, EU-TIRADS and ACR TI-RADS) for Risk Stratification of Small Thyroid Nodules (≤10 mm)

Due to the widespread use of ultrasound, small thyroid nodules (TNs) ≤ 10 mm are common findings. Standardized approaches for the risk stratification of TNs with Thyroid Imaging Reporting and Data Systems (TIRADS) were evaluated for the clinical routine. With TIRADS, the risk of malignancy in TNs is calculated by scoring the number or combination of suspicious ultrasound features, leading to recommendations for further diagnostic steps. However, there are only scarce data on the performance of TIRADS for small TNs. The aim was to compare three different TIRADS for risk stratification of small TNs in routine clinical practice. We conducted a retrospective cohort analysis of TNs ≤ 10 mm and their available histology. Nodules were classified according to three different TIRADS. In the study, 140 patients (n = 113 female) with 145 thyroid nodules (n = 76 malignant) were included. Most of the malignant nodules were papillary carcinoma (97%), and the remaining 3% were medullary carcinoma. For all tested TIRADS, the prevalence of malignancy rose with increasing category levels. The highest negative predictive value was found for ACR TI-RADS and the highest positive predictive value for Kwak-TIRADS. All tested variants of TIRADS showed comparable diagnostic performance for the risk stratification of small TNs. TIRADS seems to be a promising tool to reliably assess the risk of malignancy of small TNs.

Evolving Understanding of the Epidemiology of Thyroid Cancer

The incidence of thyroid cancer worldwide has increased significantly over the past 3 decades, due predominantly to an increase in papillary thyroid cancer. Although most of these cancers are small and localized, population-based studies have documented a significant increase in thyroid cancers of all sizes and stages, in addition to incidence-based mortality for papillary thyroid cancer. This suggests that the increasing incidence of thyroid cancer is due in large part to increasing surveillance and overdiagnosis, but that there also appears to be a true increase in new cases of thyroid cancer.

Incidental Non-cardiac Findings in Cardiovascular Imaging

Improvements in imaging techniques have led to an expansion in the number of cross-sectional cardiac studies being performed. This means that incidental non-cardiac findings (INCF) identified on cardiac imaging have become an important clinical concern. The majority of INCF are not clinically significant. However, some INCF will require follow-up or changes in management. Differentiating clinically significant from non-significant INCF can be challenging, particularly given the breadth of potential findings and the range of organ systems involved. Following up INCF also has economic implications. Recent changes to the lung nodule follow-up guidelines will reduce the cost of following up incidental lung nodules. In this manuscript, we discuss the common and important INCF which may be identified in cardiovascular imaging and explore potential implications of these findings.

Incidental Thyroid Nodules in the National Lung Screening Trial: Estimation of Prevalence, Malignancy Rate, and Strategy for Workup

RATIONALE AND OBJECTIVES

There is limited research on the prevalence of incidental thyroid nodules (ITNs) in the United States screening population and on the appropriate evaluation of computed tomography (CT)-detected ITNs. The purpose of this study is to determine the prevalence of ITNs in the National Lung Screening Trial (NLST) and develop a workup strategy for ITNs.

MATERIALS AND METHODS

CT images were obtained for subjects with documented thyroid abnormalities in the CT screening arm of the NLST, subjects diagnosed with thyroid malignancies, and control subjects. Several size thresholds were compared to determine how many nodules would be further evaluated and how many thyroid malignancies would be missed had each threshold been applied at the time of workup.

RESULTS

Thyroid nodules were reported in 0.7% (117 of 17,309 subjects). In 663 control subjects without reported thyroid nodules, thyroid nodules were identified in 78 (11.8%). Reported nodules were larger than unreported nodules (21.3 vs 16.9 mm, P = .03). Thyroid malignancies were diagnosed in 0.1% (22 of 17,309). If a 20-mm rather than a 10-mm cutoff were used to determine which nodules should be further evaluated, all malignancies would be detected, but 24 rather than 62 patients would require workup, for a workup reduction rate of 48.7% (38 of 78).

CONCLUSIONS

Less than 1% of subjects in the NLST had reported ITNs. The true prevalence of ITNs was estimated to be 11.8%, which provides a better approximation of the number of patients who could potentially receive workup. A 20-mm rather than a 10-mm cutoff would reduce the workup rate by almost 50% while still capturing all malignancies.

Impact of clinical history on choice of abdominal/pelvic CT protocol in the Emergency Department

INTRODUCTION

Radiologists and other specialty consultants play a role in diagnosing patients with acute abdominal conditions. Numerous Computed Tomography (CT) protocols are available and radiologists' choices are influenced by the clinical history provided. We hypothesize that the quality of the initial communication between referring physicians and radiologists greatly affects the utilization of health resources and subsequent patient care. The purpose of this pilot study was to employ a grading system to quantitatively evaluate a provided history. We also sought to evaluate inter-rater reliability by having radiologists evaluate sample histories and finally, to assess whether the quality of history has an impact on the number of CT protocols radiologists choose as potentially appropriate, with less potential protocols being seen as a positive outcome.

METHODS

Four reviewers, (2 attendings and 2 residents) evaluated 350 consecutive clinical histories provided for patients presenting to a tertiary care Emergency Department (ED) between September-October, 2012. Reviewers graded histories on a 5-point scale using 4 categories of criteria. This includes a) presenting complaint, b) relevant past medical history or symptom evolution, c) objective laboratory or prior examination results and d) differential diagnosis.

RESULTS

There was substantial agreement among all four reviewers when evaluating the quality of history, ICC 0.61, (95% CI 0.48-0.71). In particular, agreement amongst attending radiologists was substantial, with ICC 0.69 (0.48-0.80). Significant negative correlation was observed between history grade and number of potentially appropriate protocols in 3 of 4 reviewers (Spearman's rho: -0.394, -0.639, -0.864, p <0.0001 for these reviewers). This correlation was significantly stronger for attending radiologists (Spearman's rho: -0.763, 95% CI -0.7933 to -0.731; p<0.0001). Agreement was poor among reviewers when asked exactly how many protocols could potentially be used to answer the clinical question based on provided history, ICC 0.08, (95% -0.03-0.13).

CONCLUSION

Although there is still variability in radiologists' approach to protocoling urgent studies, a more comprehensive requisition history narrowed the number of protocols considered.

The effect of routine radiological reporting of thyroid incidentalomas on rates of thyroid needle biopsy, thyroid surgery and detection of thyroid malignancy

OBJECTIVE

This study looked at the effect of a changing radiology reporting policy to routinely review the thyroid gland where visible and report on any thyroid lesion, recommending further investigation as appropriate.

CONTEXT

Incidentaloma is a term used to describe a lesion found on imaging unrelated to the clinical issue under investigation. There is variability in the radiological reporting of thyroid incidentalomas and conflicting recommendations as to how these lesions should be managed.

DESIGN

Data were collected retrospectively during a two-year period, including 12 months before and 12 months after the change in reporting policy and categorized according to whether the lesion under investigation was a thyroid incidentaloma or a symptomatic thyroid lesion.

PATIENTS

All patients undergoing ultrasound-guided fine-needle aspiration cytology or core biopsy were included.

MEASUREMENTS

The effects of the change in policy were analysed including rates of needle biopsy, rates of malignancy and subsequent surgical intervention.

RESULTS

There was a 122% increase in thyroid incidentalomas undergoing needle biopsy, the majority of these were detected on computed tomography. The number of malignancies increased from 1 to 4 from year 1 to year 2. All patients were >35 years old. One patient had a positron emission tomography (PET)-detected cancer, two of four of the non-PET-detected malignancies were <1.5 cm.

CONCLUSION

This study posits that routine radiological reporting of thyroid incidentalomas, with further investigation when clinically appropriate, is warranted. The results suggest that lesion size and CT characteristics are not reliable criteria to triage patients for investigation/biopsy.

Incidental Findings on FDG PET/CT in Head and Neck Cancer

Objective

18F-fluoro-deoxy-glucose positron emission tomography/computed tomography (FDG PET/CT) imaging is common in head and neck cancer and often identifies incidental findings that necessitate additional patient evaluations. Our goal was to assess the frequency and nature of these incidental imaging findings on FDG-PET/CT.

Study Design

Retrospective cohort study.

Setting

Tertiary medical center.

Subjects and Methods

All patients with head and neck cancer who had undergone FDG-PET/CT imaging between January 2014 and June 2015 at our institution were evaluated for incidental findings.

Results

A total of 293 patients met criteria; more than one-third (n = 103) had at least 1 finding unrelated to their head and neck cancer, for a total of 134 incidental findings. Incidental findings within the head and neck (33.5% of all) excluding the thyroid were most common: 35% incidental findings were concerning for malignancy; of these, 25.5% were malignant with further workup. Recommendations were given by the head and neck radiologist on 72 (53.7%) findings: 74.5% of potentially malignant findings and 42.5% of benign findings had recommendations for follow-up. Significantly more patients with findings described as malignant were given recommendations for follow-up ( P = .0004).

Conclusion

Incidental findings on FDG-PET/CT are present in more than one-third of patients with head and neck cancer. More than one-third of incidental findings were concerning for malignancy. This study illustrates how the incidental findings discovered on FDG PET/CT frequently necessitate additional evaluations unrelated to the index head and neck cancer. The impact of these additional assessments on the cost and quality of health care warrants future evaluation.

Integrated Pathology Informatics Enables High-Quality Personalized and Precision Medicine: Digital Pathology and Beyond

CONTEXT

- The critical role of pathology in diagnosis, prognosis, and prediction demands high-quality subspecialty diagnostics that integrates information from multiple laboratories.

OBJECTIVE

- To identify key requirements and to establish a systematic approach to providing high-quality pathology in a health care system that is responsible for services across a large geographic area.

DESIGN

- This report focuses on the development of a multisite pathology informatics platform to support high-quality surgical pathology and hematopathology using a sophisticated laboratory information system and whole slide imaging for histology and immunohistochemistry, integrated with ancillary tools, including electron microscopy, flow cytometry, cytogenetics, and molecular diagnostics.

RESULTS

- These tools enable patients in numerous geographic locations access to a model of subspecialty pathology that allows reporting of every specimen by the right pathologist at the right time. The use of whole slide imaging for multidisciplinary case conferences enables better communication among members of patient care teams. The system encourages data collection using a discrete data synoptic reporting module, has implemented documentation of quality assurance activities, and allows workload measurement, providing examples of additional benefits that can be gained by this electronic approach to pathology.

CONCLUSION

- This approach builds the foundation for accurate big data collection and high-quality personalized and precision medicine.

Incidental thyroid nodules on thoracic contrast-enhanced computed tomography in clinical practice during a 10-year period: Characteristics, clinical outcomes, and factors contributing to further evaluation

The purposes of this study were to assess the prevalence, malignancy rate, and characteristics of incidental thyroid nodules (ITNs), and to identify factors that contribute the additional workup by ultrasound.The medical records and imaging features of ITNs reported via thoracic computed tomography (CT) were retrospectively reviewed to determine the size, multiplicity, attenuation, shape, and presence of calcification. To identify the factors associated with additional workup, we compared the workup and non-workup groups in terms of nodule characteristics, indications, and CT slices. We identified factors that could distinguish malignant ITNs from non-malignant nodules.A total of 60,921 thoracic CT scans met the inclusion criteria, and ITNs were reported using formal radiology in 2733 patients (4.5%). Among all patients with reported ITNs, 546 (20.0%) underwent further workup. Of these patients, 62 (2.3%, 62/2773) were diagnosed with malignant nodules. Multivariable analysis identified multiple factors associated with additional workup, including female sex, younger age, larger nodule size, calcification, anteroposterior to transverse dimension ratio >1, heterogeneous attenuation in the nodule, and scanning indications such as infection or screening. However, only calcification was associated with malignant nodules (odds ratio [OR] = 2.313; 95% confidence interval [CI], 1.301-4.113).We observed discordance between the numbers of reported ITNs and case with additional workup and identified multiple factors associated with additional workup. We have, therefore, demonstrated a need for reliable subsequent evaluation guidelines and note that the appearance of calcification in an ITN on imaging may be a factor indicating the need for additional workup.

Overdiagnosis of thyroid cancer: answers to five key questions

Thyroid cancer fulfills the criteria for overdiagnosis by having a reservoir of indolent cancers and practice patterns leading to the diagnosis of incidental cancers from the reservoir. The occurrence of overdiagnosis is also supported by population-based data showing an alarming rise in thyroid cancer incidence without change in mortality. Because one of the activities leading to overdiagnosis is the workup of incidental thyroid nodules detected on imaging, it is critical that radiologists understand the issue of overdiagnosis and their role in the problem and solution. This article addresses 1) essential thyroid cancer facts, 2) the evidence supporting overdiagnosis, 3) the role of radiology in overdiagnosis, 4) harms of overdiagnosis, and 5) steps radiologists can take to minimize the problem.