Geographic disparities in thyroid cancer staging at presentation: Insights from an Australian context.

BACKGROUND: Thyroid cancer diagnoses have increased over recent decades at a rate much higher than that of any other cancer in Australia. Rural patients are known to have reduced access to healthcare and may have different thyroid cancer presentation rates. This study examined the relationship between thyroid cancer diagnosis and patient rurality. METHODS: Data from the Australia and New Zealand Thyroid Cancer Registry from 2017 to 2022 were analyzed, stratifying patient postcodes into rurality groups using the Australian Statistical Geography Standard. The American Thyroid Association (ATA) guidelines were used to stratify risk categories and management to compare treatment adequacy between the groups. Statistical analysis assessed demographic, clinical, and management differences. RESULTS: Among 1766 patients, 70.6% were metropolitan (metro) and 29.4% were non-metropolitan (non-metro). Non-metro patients were older at diagnosis (median 56 vs. 50 years, p < 0.001), presented more frequently with T stage greater than 1 (stage 2-4, 41.9% vs. 34.8%, and p = 0.005), AJCC stage greater than 1 (stage 2-4, 18.5% vs. 14.6%, and p = 0.019), and cancers larger than 4 cm (14.3% vs. 9.9%, p = 0.005). No significant differences in treatment adequacy were observed between the groups for ATA low-risk cancers. CONCLUSIONS: Non-metropolitan patients in the registry present with more advanced thyroid cancer, possibly due to differences in healthcare access. Further research should assess long-term survival outcomes and influencing factors. Understanding the impact on patient outcomes and addressing healthcare access barriers can optimize thyroid cancer care across geographic regions in Australia.

Artificial Intelligence for Pre-operative Diagnosis of Malignant Thyroid Nodules Based on Sonographic Features and Cytology Category.

BACKGROUND: Current diagnosis and classification of thyroid nodules are susceptible to subjective factors. Despite widespread use of ultrasonography (USG) and fine needle aspiration cytology (FNAC) to assess thyroid nodules, the interpretation of results is nuanced and requires specialist endocrine surgery input. Using readily available pre-operative data, the aims of this study were to develop artificial intelligence (AI) models to classify nodules into likely benign or malignant and to compare the diagnostic performance of the models. METHODS: Patients undergoing surgery for thyroid nodules between 2010 and 2020 were recruited from our institution's database into training and testing groups. Demographics, serum TSH level, cytology, ultrasonography features and histopathology data were extracted. The training group USG images were re-reviewed by a study radiologist experienced in thyroid USG, who reported the relevant features and supplemented with data extracted from existing reports to reduce sampling bias. Testing group USG features were extracted solely from existing reports to reflect real-life practice of a non-thyroid specialist. We developed four AI models based on classification algorithms (k-Nearest Neighbour, Support Vector Machine, Decision Tree, Naïve Bayes) and evaluated their diagnostic performance of thyroid malignancy. RESULTS: In the training group (n = 857), 75% were female and 27% of cases were malignant. The testing group (n = 198) consisted of 77% females and 17% malignant cases. Mean age was 54.7 ± 16.2 years for the training group and 50.1 ± 17.4 years for the testing group. Following validation with the testing group, support vector machine classifier was found to perform best in predicting final histopathology with an accuracy of 89%, sensitivity 89%, specificity 83%, F-score 94% and AUROC 0.86. CONCLUSION: We have developed a first of its kind, pilot AI model that can accurately predict malignancy in thyroid nodules using USG features, FNAC, demographics and serum TSH. There is potential for a model like this to be used as a decision support tool in under-resourced areas as well as by non-thyroid specialists.

Preoperative serum calcitonin may improve initial surgery for medullary thyroid cancer in patients with indeterminate cytology.

BACKGROUND: Medullary thyroid cancer (MTC) is rare, with poorer outcomes than differentiated thyroid cancer. We aimed to identify areas for improvement in the pre-operative evaluation of patients with possible MTC in a high-volume endocrine surgery unit in accordance with current practice guidelines. We hypothesised that the selective use of serum calcitonin (sCT) as a biomarker for possible MTC could guide the extent of initial surgical management. METHODS: We recruited MTC patients between 2000 and 2020 from the Monash University Endocrine Surgery Unit database. Demographics, tumour characteristics, pre-operative evaluation, operative management, and outcomes were analysed. RESULTS: Of 1454 thyroid cancer patients, 43 (3%) had MTC. Pre-operatively, 36 (84%) patients with MTC confirmed on cytology (28, 65%), elevated sCT (6, 14%) or RET mutation (2, 4%). Of these 36 patients, 31 (86%) had optimal extent of thyroidectomy and lymph node dissection (LND). Five (14%) had less than total thyroidectomy due to nerve injury. Thirty-four patients had compartmental LND. In the 12 (27%) patients with indeterminate or non-diagnostic cytology, 5 had elevated sCT and were managed as above. None of the remaining seven had LND, thus potentially suboptimal surgery. CONCLUSION: Our findings reflect the rarity of MTC, and the challenges of pre-operative diagnosis. The addition of sCT may improve surgical planning in patients with indeterminate cytology.

Patient Reported Experience on Consenting for Surgery - Elective Versus Emergency Patients.

INTRODUCTION: Informed consent for surgery is a medical and legal requirement, but completing these does not necessarily translate to high patient satisfaction. This patient-reported experience study aimed to examine the surgical consent process, comparing the patients' experience in elective and emergency settings. METHODS: Over a 6-mo period, postoperative patients at The Alfred Hospital Breast and Endocrine Surgical Unit were invited to participate in a survey on the surgical consent process - including perceived priorities, information provided and overall experience. Standard statistical techniques were used, with a significant P-value of < 0.05. RESULTS: A total of 412 patients were invited, with 130 (32%) responses. More patients underwent elective surgery (N= 90, 69%) than emergency surgery (N = 40, 31%). Emergency patients were more likely to sign the consent form regardless of its contents (93% versus 39%, P < 0.001) and more likely to be influenced by external pressures (63% versus 1%, P < 0.001). Elective patients were more likely to want to discuss their surgery with a senior surgeon (74% versus 23%, P < 0.001) and more likely to seek advice from external sources (83% versus 10%, P < 0.001). Both groups highly valued the opportunity to ask questions (67% versus 63%, P = 0.65). CONCLUSION: This study shows patients have a range of different priorities in preparation for surgery. Therefore, each consent process should be patient-specific, and focus on providing the patient with quality resources that inform decision-making.

Investigation of recurrent laryngeal palsy rates for potential associations during thyroidectomy.

BACKGROUND: There are many clinical associations and potential mechanisms of injury resulting in recurrent laryngeal nerve palsy (RLNP) after thyroidectomy. One possible cause of RLNP is focal intralaryngeal compression of the recurrent laryngeal nerve (RLN), which may be associated with the tracheal tube (TT). Therefore, we examined current RLNP rates to investigate potential associations, including intralaryngeal, airway, anaesthetic and anthropometric factors. METHODS: We analysed 1003 patients undergoing thyroid surgery at The Alfred from 2010 to 2017, who had anatomically intact RLNs at the conclusion of thyroidectomy. All included patients underwent pre- and post-operative flexible nasendoscopy. The primary outcome was RLNP rate. We analysed potential associated factors including age, sex, operative time, surgical indication, pathology, American Society of Anaesthesiologists Physical Status, Mallampati scores, body mass index, intubation grade, TT size and specimen weight. The independent risk factors were identified by logistic regression analysis. RESULTS: Overall, RLNP occurred in 83 patients (8.3%) of which one was permanent (0.1%). On univariate analysis, RLNP was associated with male sex (P = 0.02), and duration of surgery (P = 0.002). On multivariate analysis, both male sex (P = 0.047) and duration of surgery (P = 0.04) remained significant. Further, factors postulated to cause intralaryngeal compression of the RLN, including TT size, body mass index, intubation grade and Mallampati score, were not significantly associated with RLNP. CONCLUSION: Our study showed a RLNP rate of 8.3%, and associations with longer operative duration, and male sex. Potential intralaryngeal factors were not identified.

Anti-Thyroid Antibodies and TSH as Potential Markers of Thyroid Carcinoma and Aggressive Behavior in Patients with Indeterminate Fine-Needle Aspiration Cytology.

BACKGROUND: Indeterminate fine-needle aspiration cytology (FNAC) imposes challenges in the management of thyroid nodules. This study aimed to examine whether preoperative anti-thyroid antibodies (Abs) and TSH are indicators of thyroid malignancy and aggressive behavior in patients with indeterminate FNAC. METHODS: This was a retrospective study of thyroidectomy patients from 2008 to 2016. We analyzed Abs and TSH levels, FNAC, and histopathology. Serum antibody levels were categorized as 'Undetectable', 'In-range' if detectable but within normal range, and 'Elevated' if above upper limit of normal. 'Detectable' levels referred to 'In-range' and 'Elevated' combined. RESULTS: There were 531 patients included. Of 402 patients with preoperative FNAC, 104 (25.9%) had indeterminate cytology (Bethesda III-V). Of these, 39 (37.5%) were malignant and 65 (62.5%) benign on histopathology. In the setting of indeterminate FNAC, an increased risk of malignancy was associated with 'Elevated' thyroglobulin antibodies (TgAb) (OR 7.25, 95% CI 1.13-77.15, P = 0.01) and 'Elevated' thyroid peroxidase antibodies (TPOAb) (OR 6.79, 95% CI 1.23-45.88, P = 0.008). Similarly, while still 'In-range', TSH ≥ 1 mIU/L was associated with an increased risk of malignancy (OR 3.23, 95% CI 1.14-9.33, P = 0.01). In all patients with malignancy, the mean tumor size was 8 mm larger in those with TSH ≥ 1 mIU/L (P = 0.03); furthermore, in PTC patients, 'Detectable' TgAb conferred a 4 × risk of lymph node metastasis (95% CI 1.03-13.77, P = 0.02). CONCLUSION: In this cohort, in indeterminate FNAC patients, Abs and TSH were associated with an increased risk of malignancy. Additionally, TgAb and TSH were potential markers of aggressive biology. As such, they may be diagnostic and prognostic adjuncts.

Routine Preoperative Laryngoscopy for Thyroid Surgery Is Not Necessary Without Risk Factors.

Background: Routine preoperative vocal cord (VC) assessment with laryngoscopy in patients undergoing thyroidectomy allows clear documentation of baseline VC function, aids in surgical planning in patients with palsies, and facilitates interpretation of intraoperative neuromonitoring (IONM) findings. We aimed to determine the incidence of preoperative vocal cord palsy (VCP); to evaluate the associated risk factors for preoperative VCP; and to calculate the cost-savings potential of implementing a selective approach. Methods: Patients with a pre-thyroidectomy VC assessment by fiberoptic laryngoscopy were retrospectively recruited from the Monash University Endocrine Surgery Unit database from 2000 to 2018. Cases with preoperative VCP were reviewed for potential contributing factors and compared with a non-palsy cohort. Results: Of the 5987 patients who had preoperative laryngoscopy, VCP was documented in 41 (0.68%) patients. Four clinical parameters were found to be potential indicators of VCP, including: age (p < 0.001), nodule ≥3.5 cm recorded on ultrasound imaging (p = 0.01), presence of voice symptoms (p < 0.001), and previous neck surgery (p < 0.001). Malignant cytology (p = 0.5) and exposure to head and neck irradiation were not different between the groups. Utilizing these risk factors, 2354 (39%) patients had at least one feature that may raise suspicion for preoperative VCP. By performing preoperative laryngoscopy only on this subset of patients, the potential cost savings exceeds 400 Australian Dollars per patient. Conclusions: Using this large dataset, we have established that a VCP is rare in the absence of a large nodule, hoarseness, or previous neck surgery. Therefore, in the era of IONM, we support a selective approach to preoperative laryngoscopy by using the aforementioned criteria.

Thyroidectomy Then and Now: A 50-Year Australian Perspective.

BACKGROUND: Since the mid-1800s, thyroidectomy has transformed from a procedure associated with high to near-zero mortality. Nonetheless, surgeons must continue to strive to improve patient care. Using historical records and contemporary data, this study compares the practice and outcomes of thyroid surgery at a tertiary institution during two periods, 50 years apart. METHODS: 'The Alfred Hospital Clinical Reports' recorded all cases of surgically managed thyroid disease from 1946 to 1959. These historical cases were compared to contemporary thyroidectomy cases at the Alfred Hospital from 2007 to 2016. Cases were compared for surgical indication and post-operative outcomes. RESULTS: There were 746 patients in the historical group (mean age 53 years; 87% female) and 787 patients in the contemporary group (mean age 52 years; 80% female). The most common indication for thyroidectomy in both groups was non-toxic nodular goitre. A greater proportion of the contemporary group were diagnosed with thyroid malignancy (27% vs. 8%; p < 0.001). The contemporary group recorded significantly fewer cases of thyrotoxic crisis (2.1% vs. 0%; p = 0.001), permanent nerve palsy (4.6% vs. 0.4%; p < 0.001) and bilateral nerve palsy (1.2% vs. 0%; p = 0.01). There were no mortalities in the contemporary group, while the historical data recorded three deaths (0.44%). CONCLUSIONS: This study compared thyroid surgery in two cohorts separated by a 50-year period. While it is not surprising that outcomes of thyroidectomy have improved, this study uniquely demonstrates trends of thyroid surgery over time and areas in which further improvements may be made.

Adrenal incidentaloma follow-up is influenced by patient, radiologic, and medical provider factors: A review of 804 cases.

BACKGROUND: The majority of adrenal incidentalomas are benign, although some are large, functional, or malignant and may require surgery. Therefore all require follow-up. This study aimed to determine the pattern of adrenal incidentaloma follow-up in a level 1 trauma center, focusing on the factors that influence whether follow-up is facilitated. METHODS: Patients with computed tomography-detected adrenal incidentalomas between January 2010 and September 2015 were included. A keyword search identified case files, which were reviewed for demographic characteristics, managing unit, computed tomography indication and findings, and follow-up arrangements. Statistical analysis was performed using Stata SE Version 14. RESULTS: A total of 38,848 chest and abdominal computed tomographic scans were performed in the study period, revealing 804 patients with adrenal incidentalomas who met inclusion criteria (mean age 65, 58% male). The mean size of adrenal incidentaloma was 23 mm. Follow-up was organized in 30% of cases and was more likely to occur in younger patients (mean age 62 vs 66, P < .001); in larger lesions (mean size 26 mm vs 21 mm, P < .001); if the computed tomographic scan suggested follow-up (P < .001); or if the computed tomography report suggested a diagnosis (P < .001). Follow-up arrangements were most likely to be made by the trauma unit (39%, P = .01). CONCLUSION: This study highlights that adrenal incidentalomas follow-up is often overlooked, and that follow-up is influenced by patient, radiologic, and medical provider factors. An adrenal lesion follow-up protocol may improve follow-up rates but requires further analysis.

Body weight change is unpredictable after total thyroidectomy.

BACKGROUND: There is a common perception that total thyroidectomy causes weight gain beyond expected age-related changes, even when thyroid replacement therapy induces a euthyroid state. The aim of this study was to determine whether patients who underwent total thyroidectomy for a wide spectrum of conditions experienced weight gain following surgery. METHODS: We retrospectively studied 107 consecutive total thyroidectomy patients treated between January 2013 and June 2014. Medical records were reviewed to determine underlying pathology, thyroid status, use of antithyroid drugs and preoperative weight. Follow-up data were obtained from 79 patients at least 10 months post-operatively to determine current weight, the type of clinician managing thyroid replacement therapy and patient satisfaction with post-thyroidectomy management. RESULTS: The cohort was 73% female, with a mean age of 55.8 ± 15.7 years and a mean preoperative weight of 78.8 ± 17.5 kg. Commonest pathologies were multinodular goitre, Graves' disease, thyroid cancer and Hashimoto's thyroiditis. Preoperatively, 63.2% of patients were hyperthyroid. Mean weight change at follow-up was a non-significant increase of 0.06 ± 6.9 kg (P = 0.094). Weight change was not significant regardless of preoperative thyroid function status. This study did not demonstrate any significant differences in clinical characteristics (including post-operative thyroid-stimulating hormone) between the group with >2% weight gain and those who did not. CONCLUSIONS: This study did not reveal significant weight gain following thyroidectomy for a wide spectrum of pathologies. Specifically, preoperative hyperthyroidism, female gender and use of antithyroid medications do not predict weight gain after thyroid surgery.

Stressing the recurrent laryngeal nerve during thyroidectomy.

BACKGROUND: In thyroidectomy, little has been reported on the differential recurrent laryngeal nerve (RLN) palsy rates between the left and right sides. Even less is known about the potential differences causing these differential rates. This study reports the left versus right RLN palsy rates of total thyroidectomy cases in a single institution, relating them to the comparative stiffness of the left and right porcine RLNs. Computed stress modelling was also used to estimate the differential levels of tension within each RLN. METHODS: For the comparison of the left and right RLN palsy rates, 1926 cases of total thyroidectomy (between 2007 and 2013) from the Monash University Endocrine Surgery Unit were included. Stiffness of porcine RLNs was experimentally determined by measuring nerve extension against incremental increase in load. Additionally, the tension of intraoperatively stretched RLNs was estimated by computer modelling. RESULTS: The left RLN had a palsy rate of 0.9% (18/1926), which was significantly lower (P = 0.025) than the right RLN palsy rate of 1.8% (34/1926). The left porcine RLN was 22% stiffer than the right RLN (P = 0.004). The stress modelling estimated that at the apex of the artificial RLN genu during anteromedial rotation of the thyroid lobe, the right RLN experiences twice the tension experienced by the left RLN. CONCLUSION: The stiffer left RLN and the higher tension generated in the right RLN during thyroidectomy may jointly contribute to the higher right RLN palsy rate.

Anti-thyroid antibodies as a predictor of thyroid cancer.

BACKGROUND: Recent literature has suggested an association between autoimmune thyroiditis and papillary thyroid cancer. The aims of this study were to evaluate if positive thyroid antibodies are associated with thyroid carcinoma and to examine the role of thyroid antibodies in the management of thyroid nodules. METHODS: This is a database study of all patients undergoing thyroidectomy with recorded preoperative thyroid antibodies (autoantibodies to thyroglobulin and/or thyroid peroxidase) levels from 2010 to 2012. We analysed preoperative thyroid antibody levels, fine needle aspiration cytology (FNAC) results, type of thyroid surgery and final histopathology. RESULTS: There were 960 patients who underwent thyroidectomy with recorded preoperative thyroid antibodies. Of 960 patients, 784 had preoperative FNAC of thyroid nodules. Final histopathology showed 758 benign and 202 malignant cases. As expected, there was a strong association between raised thyroid antibodies and lymphocytic thyroiditis on histology (P = 0.0001) (two-sided probability). Overall, positive thyroid antibodies were not found to be a predictor of thyroid carcinoma (P = 0.161) (two-sided probability). However, in patients with benign FNAC, positive thyroid antibodies increased the risk of thyroid malignancy (odds ratio 2.16; 95% confidence interval 1.11 to 4.21, P = 0.027) (two-sided probability). CONCLUSION: Patients with positive thyroid antibodies have a greater risk of malignancy in those with benign FNAC. We recommend routine thyroid antibody assessment in addition to FNAC as part of the assessment of thyroid nodules.

Differential recurrent laryngeal nerve palsy rates after thyroidectomy.

INTRODUCTION: Recurrent laryngeal nerve (RLN) palsy is a devastating complication of thyroidectomy. Although neurapraxia is thought to be the most common cause, the underlying mechanisms are poorly understood. The objectives of this study were to examine the differential palsy rates between the left and right RLNs, and the role of intraoperative nerve swelling as a risk factor of postoperative palsy. METHODS: Thyroidectomy data were collected, including demographics, change in RLN diameter, and RLN electromyographic (EMG) reading. Left and right RLNs, as well as bilateral and unilateral subgroup analyses were performed. RESULTS: A total of 5,334 RLNs were at risk in 3,408 thyroidectomies in this study. The overall RLN palsy rate was 1.5%, greater on the right side than the left for bilateral cases (P = .025), and greater on the left side than the right for unilateral cases (P = .007). In a subgroup of 519 RLNs, the diameter and EMG amplitude were measured. The RLN diameter increased by approximately 1.5-fold (P < .001), and corresponded to increased EMG amplitude (P = .01) during the procedure. The diameter of the right RLN was larger than the left RLN, both at the beginning and end of the dissection (P = .001). CONCLUSION: The right-left differential rates of post-thyroidectomy RLN palsy seemed to be due in part to differential RLN diameters, with stretch having a more deleterious effect on RLNs with a smaller diameter; also, edema as a result of stretch might be an underlying mechanism for postoperative neurapraxia and palsy. Thyroid surgeons should be aware of the different vulnerabilities of each RLN and develop practices to avoid iatrogenic injury.