Surgical Case Volume has an Impact on Outcomes for Patients with Lateral Neck Disease in Thyroid Cancer.

BACKGROUND: This study aimed to assess whether surgical case volume for lateral neck dissection has an impact on the survival of patients who have well-differentiated thyroid cancer (WDTC) with lateral cervical node metastases. The authors used a population-based cohort study design. METHODS: The study cohort consisted of WDTC patients in Ontario Canada who underwent thyroidectomy and lateral neck dissection. These patients were identified using both hospital- and surgeon-level administrative data between 1993 and 2017 (n = 1832). Surgeon and hospital volumes were calculated based on the number of cases managed in the year before the procedure by the physician and at the institution managing each case, respectively, and divided into tertiles. Multilevel Cox regression models were used to estimate the effect of volume on disease-free survival (DFS). RESULTS: A crude model without patient or treatment characteristics demonstrated that DFS was associated with both higher surgeon volume tertiles (p < 0.01) and higher hospital volume tertiles (p < 0.01). After control for clustering, patient/treatment covariates, and hospital volume, the lowest surgeon volume tertile (range, 0-20/year; mean, 6.5/year) remained an independent statistically significant negative predictor of DFS (hazard ratio, 1.71; 95 % confidence interval, 1.22-2.4; p < 0.01). CONCLUSION: Surgeon lateral neck dissection case volume is a predictor of better DFS for thyroid cancer patients, with the lowest surgeon volume tertile (<20 neck dissections per year) demonstrating poorer DFS.

ENDOCRINE COMPLICATIONS IN PATIENTS WITH GVHD.

Objective: Graft-versus-host disease (GVHD) is an immune phenomenon that occurs in 30 to 70% of patients after allogeneic hematopoietic stem cell transplantation (HST). Chronic GVHD is a state of immune dysregulation wherein, depending on the severity and organ involved, patients may require prolonged treatment with additional or higher corticosteroids and other immunosuppressive agents. The objective of this study was to review the endocrine manifestations following HST that can arise as a consequence of the primary disease or its treatment, including chemotherapeutic agents, corticosteroids, radiation, or GVHD. Methods: We performed a narrative review of GVHD after HST. An English-language search for relevant studies was conducted on PubMed from inception to August 1, 2018, using the following search terms: "endocrine complications," "bone marrow transplantation," "graft-versus-host disease," and "GVHD." The reference lists of relevant studies were also reviewed. Results: Chronic GVHD may be associated with considerable pediatric growth impairment and may also contribute to thyroid gland dysfunction and thyroid cancer. These patients may also be at increased risk for low bone mineral density, reduced fertility, metabolic syndrome, and suppression of the pituitary-adrenal axis with adrenal insufficiency. Conclusion: This review indicates the importance of monitoring, diagnosing, and properly treating the endocrine complications in this population. More studies are needed to investigate the independent impact of GVHD on the endocrine system and treatment for complications. Abbreviations: BMD = bone mineral density; GH = growth hormone; GVHD = graft-versus-host disease; HST = hematopoietic stem cell transplantation; IGF-1 = insulin-like growth factor 1.

A systematic review of primary active surveillance management of low-risk papillary carcinoma.

PURPOSE OF REVIEW: Active surveillance is close follow-up of neoplasms, with predetermined intervention triggers. We systematically reviewed the published English language literature on primary active surveillance of low-risk papillary thyroid cancer (PTC). RECENT FINDINGS: We searched seven electronic databases (1980-2015), supplemented with a hand search. Two reviewers independently screened 1715 citations and reviewed 32 full-text papers, ultimately including two papers. Data were independently abstracted. There were two Japanese single-center, single-arm studies reporting on 1235 and 322 patients with PTC microcarcinoma (primary ≤1 cm in diameter) confined to the thyroid. Mean study follow-up was of 5.0 and 6.5 years, respectively. Disease triggers for thyroidectomy included progression of the primary tumor or incident metastatic disease. The rates of thyroidectomy were 15.5% (191/1235) and 8.7% (28/322) in respective studies. The incidence of primary tumor enlargement ≥3 mm in maximal diameter was 4.6% (58/1235) and 5.0% (16/322). The incidence of nodal metastases was 1.5% (19/1235) and 0.9% (3/322). There were neither reports of PTC-related death nor development of distant metastatic disease. Quality of life, psychosocial health, and economic outcomes were not reported. SUMMARY: In two Japanese single-arm studies, active surveillance of PTC microcarcinoma was relatively well tolerated; however, more long-term outcome research is needed.

Thyroid cancer survivors' perceptions of survivorship care follow-up options: a cross-sectional, mixed-methods survey.

PURPOSE: This study investigated thyroid cancer (TC) survivors' perceived satisfaction with and perceptions of survivorship care follow-up options. METHODS: Well-differentiated TC (WDTC) patients receiving follow-up care at an academic cancer centre completed a questionnaire assessing perceived satisfaction with follow-up care involving different clinicians and mediated by the Internet (email or videoconference) and their perceptions of these follow-up options. We examined associations between patient characteristics and perceived satisfaction with follow-up care options. Qualitative responses were analysed using conventional content analysis. RESULTS: Two hundred and two respondents completed the questionnaire (80 % response rate). The majority strongly agreed or agreed that they would be satisfied with specialist (surgeon, oncologist, or endocrinologist) follow-up (90.6 %) or a shared-care model that integrates specialists with primary care (67.5 %). One third (32 %) would be satisfied with video-based and 26 % with email-based specialist follow-up, 15 % with primary care alone. Longer time since diagnosis and health-related Internet use were associated with higher perceived satisfaction with Internet-based follow-up. Younger age was associated with higher perceived satisfaction with primary care follow-up. Qualitative responses (n = 145) revealed that survivors need reassurance they are receiving adequate care, regardless of the model or medium. Enablers to primary care and Internet-based follow-up are discussed. CONCLUSIONS: WDTC survivors want specialists involved in their follow-up. A specialist/primary care shared-care approach appears to be a suitable alternative to specialist-led follow-up for TC survivors. Internet-based visits could address some aspects of follow-up care for some WDTC survivors. Future work should examine patient and provider requirements for shared, multi-modal survivorship care.

A detailed spatial analysis on contrasting cancer incidence patterns in thyroid and lung cancer in Toronto women.

BACKGROUND: Thyroid cancer has been rapidly rising in incidence in Canada; however, in contrast, lung cancer appears to be decreasing in incidence in Canadian men and stable in women. Moreover, disease-related mortality risk is generally very low in TC but high in LC. We performed a geographic spatial analysis in metropolitan Toronto, Canada to determine if there is regional variability of respective risks of thyroid cancer (TC) and lung cancer (LC), among women. Women were of particular interest for this study, given their known predilection for thyroid cancer. METHODS: The postal codes of all females with TC or LC, residing in metropolitan Toronto from 2004 to 2008, were geocoded to point locations according to 2006 Canadian Census data. The data were analysed using a log-Gaussian Cox Process, where the intensity of age-adjusted cancer cases was modelled as a log-linear combination of the population at risk, explanatory variables (race, immigration, and median household income), and a residual spatially varying random effect. For each respective malignancy, statistical models were fit to make quantify the relationship between cancer incidence and explanatory variables. RESULTS: We included 2230 women with TC and 2412 with LC. The distribution of TC and LC cases contrasted inversely among Toronto neighbourhoods with the highest TC incidence in the Northeast and the highest LC incidence in the Southeast. A higher proportion of Asian ethnicity was associated with higher regional risk of TC and lower risk of LC. A higher proportion of recent immigrants was associated with increased LC and lower TC risk, whereas median household income and proportions of African ethnicity were not significantly associated with risk of either cancer, after adjustment for other socio-demographic variables. CONCLUSIONS: We observed contrasting regional distributions of female TC and LC cases in Toronto. The differences were partly attributed to ethnic composition variability and the proportion of recent immigrants, but substantial unexplained residual variation of incidence patterns of these malignancies exists, suggesting that more individual-level research is needed to explain the regional variability of incidence of these malignancies.

Thyroid cancer patient perceptions of radioactive iodine treatment choice: Follow-up from a decision-aid randomized trial.

BACKGROUND: Patient decision aids (P-DAs) inform medical decision making, but longer term effects are unknown. This article describes extended follow-up from a thyroid cancer treatment P-DA trial. METHODS: In this single-center, parallel-design randomized controlled trial conducted at a Canadian tertiary/quaternary care center, early-stage thyroid cancer patients from a P-DA trial were contacted 15 to 23 months after randomization/radioactive iodine (RAI) decision making to evaluate longer term outcomes. It was previously reported that the use of the computerized P-DA in thyroid cancer patients considering postsurgical RAI treatment significantly improved medical knowledge in comparison with usual care alone. The P-DA and control groups were compared for the following outcomes: feeling informed about the RAI treatment choice, decision satisfaction, decision regret, cancer-related worry, and physician trust. In a subgroup of 20 participants, in-depth interviews were conducted for a qualitative analysis. RESULTS: Ninety-five percent (70 of 74) of the original population enrolled in follow-up at a mean of 17.1 months after randomization. P-DA users perceived themselves to be significantly more 1) informed about the treatment choice (P = .008), 2) aware of options (P = .009), 3) knowledgeable about treatment benefits (P = .020), and 4) knowledgeable about treatment risks/side effects (P = .001) in comparison with controls. There were no significant group differences in decision satisfaction (P = .142), decision regret (P = .199), cancer-related worry (P = .645), mood (P = .211), or physician trust (P = .764). In the qualitative analysis, the P-DA was perceived to have increased patient knowledge and confidence in decision making. CONCLUSIONS: The P-DA improved cancer survivors' actual and long-term perceived medical knowledge with no adverse effects. More research on the long-term outcomes of P-DA use is needed.

Exploring the relationship between patients' information preference style and knowledge acquisition process in a computerized patient decision aid randomized controlled trial.

BACKGROUND: We have shown in a randomized controlled trial that a computerized patient decision aid (P-DA) improves medical knowledge and reduces decisional conflict, in early stage papillary thyroid cancer patients considering adjuvant radioactive iodine treatment. Our objectives were to examine the relationship between participants' baseline information preference style and the following: 1) quantity of detailed information obtained within the P-DA, and 2) medical knowledge. METHODS: We randomized participants to exposure to a one-time viewing of a computerized P-DA (with usual care) or usual care alone. In pre-planned secondary analyses, we examined the relationship between information preference style (Miller Behavioural Style Scale, including respective monitoring [information seeking preference] and blunting [information avoidance preference] subscale scores) and the following: 1) the quantity of detailed information obtained from the P-DA (number of supplemental information clicks), and 2) medical knowledge. Spearman correlation values were calculated to quantify relationships, in the entire study population and respective study arms. RESULTS: In the 37 P-DA users, high monitoring information preference was moderately positively correlated with higher frequency of detailed information acquisition in the P-DA (r = 0.414, p = 0.011). The monitoring subscale score weakly correlated with increased medical knowledge in the entire study population (r = 0.268, p = 0.021, N = 74), but not in the respective study arms. There were no significant associations with the blunting subscale score. CONCLUSIONS: Individual variability in information preferences may affect the process of information acquisition from computerized P-DA's. More research is needed to understand how individual information preferences may impact medical knowledge acquisition and decision-making.

Controversies in primary treatment of low-risk papillary thyroid cancer.

In many parts of the world, incidence of papillary thyroid cancer is increasing faster than any other malignancy. Most papillary thyroid cancers that are diagnosed are small and are generally regarded as being low risk, with little or no effect on mortality. Papillary thyroid cancer is a clinical challenge because it is difficult to prove benefit from the traditional therapeutic triad for this disorder (ie, total thyroidectomy with or without prophylactic central neck dissection, radioiodine remnant ablation, and suppression of serum thyroid-stimulating hormone with levothyroxine). However, risk of disease recurrence might be reduced by these therapies in a subset of patients with more aggressive disease. In the past decade, professional societies and other groups have established evidence-based clinical practice guidelines for management of papillary thyroid cancer, but these efforts have been made difficult by a paucity of randomised controlled trials. In this review, we summarise epidemiological data for disease incidence, discuss some controversies in disease management, and outline a therapeutic framework founded in the best available medical evidence and existing recommendations from clinical practice guidelines.

Decision Regret Following the Choice of Surgery or Active Surveillance for Small, Low-Risk Papillary Thyroid Cancer: A Prospective Cohort Study.

Background: It is important to understand cancer survivors' perceptions about their treatment decisions and quality of life. Methods: We performed a prospective observational cohort study of Canadian patients with small (<2 cm) low-risk papillary thyroid cancer (PTC) who were offered the choice of active surveillance (AS) or surgery (Clinicaltrials.gov NCT03271892). Participants completed a questionnaire one year after their treatment decision. The primary intention-to-treat analysis compared the mean decision regret scale total score between patients who chose AS or surgery. A secondary analysis examined one-year decision regret score according to treatment status. Secondary outcomes included quality of life, mood, fear of disease progression, and body image perception. We adjusted for age, sex, and follow-up duration in linear regression analyses. Results: The overall questionnaire response rate was 95.5% (191/200). The initial treatment choices of respondents were AS 79.1% (151/191) and surgery 20.9% (40/191). The mean age was 53 years (standard deviation [SD] 15 years) and 77% (147/191) were females. In the AS group, 7.3% (11/151) of patients crossed over to definitive treatment (two for disease progression) before the time of questionnaire completion. The mean level of decision regret did not differ significantly between patients who chose AS (mean 22.4, SD 13.9) or surgery (mean 20.9, SD 12.2) in crude (p = 0.730) or adjusted (p = 0.29) analyses. However, the adjusted level of decision regret was significantly higher in patients who initially chose AS and crossed over to surgery (beta coefficient 10.1 [confidence interval; CI 1.3-18.9], p = 0.02), compared with those remaining under AS. In secondary adjusted analyses, respondents who chose surgery reported that symptoms related to their cancer or its treatment interfered with life to a greater extent than those who chose AS (p = 0.02), but there were no significant group differences in the levels of depression, anxiety, fear of disease progression, or overall body image perception. Conclusions: In this study of patients with small, low-risk PTC, the mean level of decision regret pertaining to the initial disease management choice was relatively low after one year and it did not differ significantly for respondents who chose AS or surgery.

Patients' experiences following local-regional recurrence of thyroid cancer: a qualitative study.

BACKGROUND AND OBJECTIVE: The psychosocial impact of local-regional thyroid cancer recurrence is not known. The aim of this study was to explore thyroid cancer patients' experiences relating to diagnosis and treatment of local-regional disease recurrence. METHODS: We conducted 15 semi-structured interviews with survivors of differentiated thyroid cancer who underwent neck reoperation for recurrent disease. Participants were recruited from the clinical practices of thyroid surgeons and endocrinologists at University Health Network and Mount Sinai Hospitals in Toronto, Ontario. Participant interviews were audio-recorded, transcribed verbatim, and analyzed using qualitative methods. Saturation of themes was achieved. RESULTS: Local-regional recurrence of thyroid cancer was associated with significant psychological distress. Confidence in healthcare providers as well as psychosocial support from family or social relations, were helpful in coping with disease recurrence. After recovery from treatment, post-traumatic growth was reported. However, questions and worry about the risk for future recurrence lingered at follow-up. CONCLUSIONS: Local-regional recurrence of thyroid cancer has a significant psychosocial impact on patients, and support needs are heightened throughout the experience. Healthcare providers should strive to ensure that medical information and psychosocial needs of such patients are met, throughout the treatment experience, as well as at follow-up.

Risk of Adverse Cardiovascular Outcomes in Differentiated Thyroid Cancer Survivors: A Systematic Review and Meta-Analysis.

Introduction: Long-term cardiovascular (CV) risk is a concern for differentiated thyroid cancer (DTC) survivors. Methods: We performed a systematic review and meta-analysis evaluating the risks of CV mortality and morbidity in DTC survivors compared with the general population. Respective meta-analyses were conducted for data that were adjusted for relevant confounders and crude data. We searched five electronic databases from inception to October 2021, supplemented with a hand search. Two reviewers independently screened citations, reviewed full text articles, extracted data, and critically appraised the studies, with discrepancies resolved by a third reviewer. The primary outcome was CV mortality. Secondary outcomes included atrial fibrillation, ischemic heart disease, stroke, and heart failure. We estimated the relative risk (RR) and confidence intervals [CI] of outcomes using random-effects models (adjusted for age and gender), compared with the general population. Results: We reviewed 3409 unique citations, 65 full text articles, and included 7 studies. CV mortality risk was significantly increased in DTC survivors in one study adjusted for confounders-adjusted RR (aRR) 3.35 ([CI 1.66-6.67]; 524 DTC, 1572 controls). The risk of CV morbidity in DTC survivors, adjusted for risk factors, was estimated as follows: atrial fibrillation-aRR 1.66 [CI 1.22-2.27] (3 studies, 4428 DTC, I2 = 75%), ischemic heart disease-aRR 0.97 [CI 0.84-1.13] (2 studies, 3910 DTC, I2 = 0%), stroke-aRR 1.14 [CI 0.84-1.55] (2 studies, 3910 DTC, I2 = 69%), and heart failure-aRR 0.98 [CI 0.60-1.59] (2 studies, 3910 DTC, I2 = 79%). In meta-analyses of unadjusted data, the risks of CV mortality were not significantly increased but the CV morbidity risks were similar to adjusted data. Conclusions: There is limited evidence suggesting that DTC survivors may be at an increased risk of CV death and atrial fibrillation (after adjustment for confounders). We did not observe a significantly increased risk of ischemic heart disease, stroke, or heart failure. Most analyses were subject to significant heterogeneity and further research, with careful attention to CV risk factors, is needed to clarify CV risk in DTC survivors. Registration: PROSPERO CRD42021244743.

Gender Differences in Fears Related to Low-Risk Papillary Thyroid Cancer and Its Treatment.

Importance: Fear is commonly experienced by individuals newly diagnosed with papillary thyroid cancer (PTC). Objective: To explore the association between gender and fears of low-risk PTC disease progression, as well as its potential surgical treatment. Design, Setting, and Participants: This single-center prospective cohort study was conducted at a tertiary care referral hospital in Toronto, Canada, and enrolled patients with untreated small low risk PTC (<2 cm in maximal diameter) that was confined to the thyroid. All patients had a surgical consultation. Study participants were enrolled between May 2016 and February 2021. Data analysis was performed from December 16, 2022, to May 8, 2023. Exposures: Gender was self-reported by patients with low-risk PTC who were offered the choice of thyroidectomy or active surveillance. Baseline data were collected prior to the patient deciding on disease management. Main Outcomes and Measures: Baseline patient questionnaires included the Fear of Progression-Short Form and Surgical Fear (referring to thyroidectomy) questionnaires. The fears of women and men were compared after adjustment for age. Decision-related variables, including Decision Self-Efficacy, and the ultimate treatment decisions were also compared between genders. Results: The study included 153 women (mean [SD] age, 50.7 [15.0] years) and 47 men (mean [SD] age, 56.3 [13.8] years). There were no significant differences in primary tumor size, marital status, education, parental status, or employment status between the women and men. After adjustment for age, there was no significant difference observed in the level of fear of disease progression between men and women. However, women reported greater surgical fear compared with men. There was no meaningful difference observed between women and men with respect to decision self-efficacy or the ultimate treatment choice. Conclusions and Relevance: In this cohort study of patients with low-risk PTC, women reported a higher level of surgical fear but not fear of the disease compared with men (after adjustment for age). Women and men were similarly confident and satisfied with their disease management choice. Furthermore, the decisions of women and men were generally not significantly different. The context of gender may contribute to the emotional experience of being diagnosed with thyroid cancer and its treatment perception.

Women and thyroid cancer incidence: overdiagnosis versus biological risk.

PURPOSE OF THE REVIEW: Our aim is to discuss the concepts of sex and gender in the context of thyroid cancer epidemiology. RECENT FINDINGS: It has been long-established in global epidemiologic data that thyroid cancer incidence rates are higher in women than men. However, what has been less well understood is whether this reflects sex disparities in cancer susceptibility, gender disparities in detection, or a combination. A recent meta-analysis of autopsy data from individuals who were not known to have thyroid cancer in their lifetime demonstrated no difference in the prevalence of thyroid cancer in women and men, suggesting that gender differences may be the reason for gender-based differences in thyroid cancer detection. This finding, and sex differences in auto immunity and other factors that may affect cancer susceptibility are explored. SUMMARY: Additional research to explore gender- and sex-specific data on thyroid cancer would inform our understanding of the differences and similarities between men and women in susceptibility and detection of thyroid cancer and help to optimize disease management for all genders and both sexes.

Ultrasonography and Fine-Needle Aspiration in Indeterminate Thyroid Nodules: A Systematic Review of Diagnostic Test Accuracy.

OBJECTIVES/HYPOTHESIS: Sonographic risk criteria may assist in further prognostication of indeterminate thyroid nodules (ITNs). Our aim was to determine whether sonographic criteria could further delineate the post-test probability of malignancy in ITNs. STUDY DESIGN: Meta-analysis of diagnostic test accuracy. METHODS: A systematic review of Web of Science, MEDLINE, EMBASE, and CINAHL was performed from inception to April 15, 2021. Eligible studies included those which reported ultrasonographic evaluations with the American Thyroid Association (ATA) or the Thyroid Imaging Reporting and Data System (TIRADS) in adult patients with ITNs. ATA or TIRADS were scored as low (negative) or high (positive) malignancy risk using a previously validated binary classification. Primary outcomes included pooled sensitivity, specificity, likelihood ratios, and diagnostic odds ratio for all sonographic criteria. Studies were appraised using Quality Assessment of Diagnostic Accuracy Studies and the data were pooled using bivariate random-effects models. RESULTS: Seventeen studies were included in the analysis. For Bethesda III, ATA had a specificity (0.90, 95% confidence interval (CI): 0.74-0.94), but a sensitivity of 0.52 (95% CI: 0.25-0.77). Conversely, K-TIRADS had the highest sensitivity (0.78, 95% CI: 0.62-0.89) with a specificity of 0.53 (95% CI: 0.31-0.74). Furthermore, American College of Radiology and EU TIRADS had specificities of 0.60 (95% CI: 0.36-0.80) and 0.81 (95% CI: 0.73-0.87) with sensitivities of 0.70 (95% CI: 0.37-0.90) and 0.38 (95% CI: 0.20-0.60), respectively. There were few studies with Bethesda IV nodules. CONCLUSIONS: Though dependent on malignancy rates, Bethesda III nodules with low-suspicion TIRADS features may benefit from clinical observation, whereas nodules with high-suspicion ATA features may require molecular testing and/or surgery. LEVEL OF EVIDENCE: NA Laryngoscope, 132:242-251, 2022.

A Quantitative Analysis Examining Patients' Choice of Active Surveillance or Surgery for Managing Low-Risk Papillary Thyroid Cancer.

Background: It is important to understand patient preferences on managing low-risk papillary thyroid cancer (PTC). Methods: We prospectively followed patients with low-risk PTC <2 cm in maximal diameter, who were offered the choice of thyroidectomy or active surveillance (AS) at the University Health Network (UHN), in Toronto, Canada. The primary outcome was the frequency of AS choice (percentage with confidence interval [CI]). Univariate and multivariable analyses were performed to identify predictors of the choice of AS. Results: We enrolled 200 patients of median age 51 years (interquartile range 42-62). The primary tumor measured >1 cm in 55.5% (111/200) of participants. The AS was chosen by 77.5% [71.2-82.7%, 155/200] of participants. In a backwards conditional regression model, the clinical and demographic factors independently associated with choosing AS included: older age (compared with referent group <40 years)-age 40-64 years-odds ratio (OR) 2.78 [CI, 1.23-6.30, p = 0.014], age ≥65 years-OR 8.43 [2.13-33.37, p = 0.002], and education level of high school or lower-OR 4.41 [1.25-15.53, p = 0.021]; AS was inversely associated with the patient's surgeon of record being affiliated with the study hospital-OR 0.29 [0.11-0.76, p = 0.012]. In a separate backwards conditional logistic regression model examining associations with psychological characteristics, AS choice was independently associated with a fear of needing to take thyroid hormones after thyroidectomy-OR 1.24 [1.11-1.39, p < 0.001], but inversely associated with fear of PTC progression-OR 0.94 [0.90-0.98, p = 0.006] and an active coping mechanism ("doing something")-OR 0.43 [0.28-0.66, p < 0.001]. Conclusions: Approximately three-quarters of our participants chose AS over surgery. The factors associated with choosing AS included older age, lower education level, and having a surgeon outside the study institution. Patients' fears about either their PTC progressing or taking thyroid hormone replacement as well as the level of active coping style were associated with the decision. Our results inform the understanding of patients' decisions on managing low-risk PTC. Registration: Clinicaltrials.gov NCT03271892.

Ultrasound in active surveillance for low-risk papillary thyroid cancer: imaging considerations in case selection and disease surveillance.

Active surveillance (AS) of small, low-risk papillary thyroid cancers (PTCs) is increasingly studied in prospective observational studies. Ultrasound is the primary imaging modality for case selection. While researchers have put forward selection criteria for PTCs based on size, absence of suspicious lymph nodes and tumor location, there are limited reported data highlighting inherent ultrasound limitations and guidelines for case selection and follow-up. We report our experience including imaging limitations encountered in the ongoing AS prospective observational study for PTCs measuring < 2 cm at our institute. We define disease progression as an increase in size of > 3 mm in the largest dimension of nodule or evidence of metastatic disease or extrathyroidal extension. Accurate, consistent and reproducible measurements of PTCs are essential in risk stratifying patients for the option of AS or disease progression. Interobserver discrepancy, shadowing from coarse calcification and background parenchyma heterogeneity or thyroiditis can limit accurate PTC size assessment and therefore hinder patient eligibility evaluation or AS follow-up. Following the ACR Thyroid Imaging, Reporting and Data System (TI-RADS) protocol of three-axes technique to measure a thyroid nodule enables reproducibility of measurements. In patients with multi-nodular goiter, accurate identification and labeling of the PTC is important to avoid mistaking with adjacent benign nodules at follow-up. Ultrasound assessment for extrathyroid extension of PTC, and relationship of PTC to trachea and the anatomic course of the recurrent laryngeal nerve are important considerations in evaluation for AS eligibility.