Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Part III. Management of Advanced Differentiated Thyroid Cancers - Chapter 1-2. Locally Recurred/Persistent Thyroid Cancer Management Strategies 2024

These guidelines aim to establish the standard practice for diagnosing and treating patients with differentiated thyroid cancer (DTC). Based on the Korean Thyroid Association (KTA) Guidelines on DTC management, the “Treatment of Advanced DTC” section was revised in 2024 and has been provided through this chapter. Especially, this chapter covers surgical and nonsurgical treatments for the local (previous surgery site) or regional (cervical lymph node metastasis) recurrences. After drafting the guidelines, it was finalized by collecting opinions from KTA members and related societies. Surgical resection is the preferred treatment for local or regional recurrence of advanced DTC. If surgical resection is not possible, nonsurgical resection treatment under ultrasonography guidance may be considered as an alternative treatment for local or regional recurrence of DTC. Furthermore, if residual lesions are suspected even after surgical resection or respiratory-digestive organ invasion, additional radioactive iodine and external radiation treatments are considered.

Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Part I. Initial Management of Differentiated Thyroid Cancers - Chapter 3. Perioperative Assessment of Surgical Complications 2024

Thyroid surgery complications include voice change, vocal fold paralysis, and hypoparathyroidism. The voice status should be evaluated pre- and post-surgery. In patients with voice change, laryngeal visualization is needed.Intraoperative neuromonitoring helps reduce recurrent laryngeal nerve injury. The measurement of serum calcium, parathyroid hormone, and 25-hydroxyvitamin D levels is recommended to evaluate perioperative parathyroid function and prescribe supplementation preoperatively if necessary. For postoperative hypoparathyroidism, vitamin D and oral calcium supplementation are indicated based on serum parathyroid hormone and calcium levels and the severity of symptoms or signs of hypocalcemia. If long-term treatment is required, the appropriateness of treatment should be evaluated based on the disease itself and the consideration of potential benefits and harms from long-term replacement.

Korean Thyroid Association Management Guidelines for Patients with Thyroid Nodules 2024

Thyroid nodules represent a prevalent condition that is detectable via palpation or ultrasound. In recent years, there has been a paradigm shift toward enhanced diagnostic precision and less aggressive therapeutic approaches, highlighting the growing necessity for tailored clinical recommendations to optimize patient outcomes. The Korean Thyroid Association (KTA) has developed guidelines for managing patients with thyroid nodules, following a comprehensive review by task force members of the relevant literature identified via electronic database searches. The recommendations are provided with a level of recommendation for each section. The guidelines encompass thyroid cancer screening in high-risk groups, appropriate diagnostic methods for thyroid nodules, role of pathologic and molecular marker testing in making a diagnosis, long-term follow-up and treatment of benign thyroid nodules, and special considerations for pregnant women. The major revisions that were made in the 2023 guidelines were the definition of high-risk groups for thyroid cancer screening, application of the revised Korean Thyroid Imaging Reporting and Data System (K-TIRADS), addition of the role of core needle biopsy and molecular marker tests, application of active surveillance in patients with low-risk papillary thyroid microcarcinoma, and updated indications for nonsurgical treatment of benign thyroid nodules. In the 2024 revision of the KTA guidelines for thyroid cancer, the evidence for some recommendations has been updated to address the tumor size in the context of active surveillance in patients with low-risk thyroid cancer and the surgical size cutoff. These evidence-based recommendations serve to inform clinical decision-making in the management of thyroid nodules, thereby facilitating the delivery of optimal and efficacious treatments to patients.

Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Part V. Pediatric Differentiated Thyroid Cancer 2024

Pediatric differentiated thyroid cancers (DTCs), mostly papillary thyroid cancer (PTC, 80-90%), are diagnosed at more advanced stages with larger tumor sizes and higher rates of locoregional and/or lung metastasis. Despite the higher recurrence rates of pediatric cancers than of adult thyroid cancers, pediatric patients demonstrate a lower mortality rate and more favorable prognosis. Considering the more advanced stage at diagnosis in pediatric patients, preoperative evaluation is crucial to determine the extent of surgery required. Furthermore, if hereditary tumor syndrome is suspected, genetic testing is required. Recommendations for pediatric DTCs focus on the surgical principles, radioiodine therapy according to the postoperative risk level, treatment and follow-up of recurrent or persistent diseases, and treatment of patients with radioiodine-refractory PTCs on the basis of genetic drivers that are unique to pediatric patients.

Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Overview and Summary 2024

Differentiated thyroid cancer demonstrates a wide range of clinical presentations, from very indolent cases to those with an aggressive prognosis. Therefore, diagnosing and treating each cancer appropriately based on its risk status is important. The Korean Thyroid Association (KTA) has provided and amended the clinical guidelines for thyroid cancer management since 2007. The main changes in this revised 2024 guideline include 1) individualization of surgical extent according to pathological tests and clinical findings, 2) application of active surveillance in low-risk papillary thyroid microcarcinoma, 3) indications for minimally invasive surgery, 4) adoption of World Health Organization pathological diagnostic criteria and definition of terminology in Korean, 5) update on literature evidence of recurrence risk for initial risk stratification, 6) addition of the role of molecular testing, 7) addition of definition of initial risk stratification and targeting thyroid stimulating hormone (TSH) concentrations according to ongoing risk stratification (ORS), 8) addition of treatment of perioperative hypoparathyroidism, 9) update on systemic chemotherapy, and 10) addition of treatment for pediatric patients with thyroid cancer.

Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Part I. Initial Management of Differentiated Thyroid Cancers - Chapter 2. Surgical Management of Thyroid Cancer 2024

The primary objective of initial treatment for thyroid cancer is minimizing treatment-related side effects and unnecessary interventions while improving patients’ overall and disease-specific survival rates, reducing the risk of disease persistence or recurrence, and conducting accurate staging and recurrence risk analysis. Appropriate surgical treatment is the most important requirement for this purpose, and additional treatments including radioactive iodine therapy and thyroid-stimulating hormone suppression therapy are performed depending on the patients’ staging and recurrence risk. Diagnostic surgery may be considered when repeated pathologic tests yield nondiagnostic results (Bethesda category 1) or atypia of unknown significance (Bethesda category 3), depending on clinical risk factors, nodule size, ultrasound findings, and patient preference. If a follicular neoplasm (Bethesda category 4) is diagnosed pathologically, surgery is the preferred option. For suspicious papillary carcinoma (suspicious for malignancy, Bethesda category 5), surgery is considered similar to a diagnosis of malignancy (Bethesda category 6). As for the extent of surgery, if the cancer is ≤1 cm in size and clinically free of extrathyroidal extension (ETE) (cT1a), without evidence of cervical lymph node (LN) metastasis (cN0), and without obvious reason to resect the contralateral lobe, a lobectomy can be performed. If the cancer is 1-2 cm in size, clinically free of ETE (cT1b), and without evidence of cervical LN metastasis (cN0), lobectomy is the preferred option. For patients with clinically evident ETE to major organs (cT4) or with cervical LN metastasis (cN1) or distant metastasis (M1), regardless of the cancer size, total thyroidectomy and complete cancer removal should be performed at the time of initial surgery. Active surveillance may be considered for adult patients diagnosed with low-risk thyroid papillary microcarcinoma. Endoscopic and robotic thyroidectomy may be performed for low-risk differentiated thyroid cancer when indicated, based on patient preference.

2023 Korean Thyroid Association Management Guidelines for Patients with Thyroid Nodules

Thyroid nodules are a prevalent condition that can be detected through palpation or ultrasound. However, a small fraction of these nodules can be cancerous, and even benign nodules can cause symptoms if they grow and compress surrounding tissue. As such, it is important to monitor thyroid nodules and determine appropriate treatment options. In recent years, there has been a shift towards enhancing diagnostic accuracy and less aggressive treatment options. As a result, there is a growing need for the development of appropriate recommendations for their clinical application to ensure optimal patient outcomes. The present clinical practice guideline was developed by extracting the nodule section from the prior version of guidelines and updating it to fit the Korean circumstances. Task force members reviewed relevant studies selected after electronic database searching, and the recommendations are provided with a level of recommendation for each section. The revised guideline includes recommendations for thyroid cancer screening in high-risk groups, appropriate diagnostic methods for thyroid nodules, the role of pathological and molecular marker tests in diagnosis, long-term follow-up and treatment of benign thyroid nodules, and special considerations for pregnant women. The major changes in this revision are the definition of high-risk groups for thyroid cancer screening, the application of the revised Korean Thyroid Imaging Reporting and Data System (K-TIRADS), the addition of the role of core needle biopsy and molecular marker tests, the application of active surveillance in low-risk papillary thyroid microcarcinoma, and updated indications for non-surgical treatment of benign thyroid nodules. These evidence-based recommendations are expected to assist in clinical decision-making for thyroid nodule management, ensuring that patients receive the most appropriate and effective treatment options.

Significance of Lymphovascular Invasion as a Prognostic Factor in Patients with Papillary Thyroid Cancer: a Systematic Review and Meta-Analysis

Conflicting research results have been reported regarding the influence of lymphovascular invasion as a prognostic factor for recurrence of papillary thyroid cancer, and thus, it is continuously discussed. This systematic review and meta-analysis identified an association between recurrence rate and histological lymphatic or vascular invasion in patients with papillary thyroid carcinoma. Clinical data and outcomes were collected from MEDLINE, Embase, the Cochrane Database of Systematic Reviews and KoreaMed. Selection criteria included studies reporting local or distant recurrence rates according to histological lymphatic or vascular invasion in patients with papillary thyroid carcinoma. Twelve observational studies were included in this study. When vascular invasion was confirmed histologically in patients with papillary thyroid cancer, the local recurrence rate was odds ratio 2.544 (95% confidence interval [CI], 1.469-4.407) compared to the patient group without vascular invasion, and the distant recurrence rate was 5.126 (95% CI, 2.853-9.212). The correlation between lymphatic invasion and recurrence rate could not be analyzed. As a result, this systematic review and meta-analysis confirmed that histological vascular invasion affects the rate of local or distant recurrence in patients with papillary thyroid cancer. Therefore, the presence of histological vascular invasion must be evaluated in patients with papillary thyroid cancer.

The Role of De novo Serine Biosynthesis from Glucose in Papillary Thyroid Cancer

Background and Objectives@#The de novo serine biosynthetic pathway from glucose has emerged as one of cancer metabolism; however, it is not explored the interplay between papillary thyroid cancer and metabolic flux of de novo serine synthesis. In this study, we explored the interplay between glucose utilization via GLUT1 expression and phosphoglycerate dehydrogenase (PHGDH). @*Materials and Methods@#The Cancer Genome Atlas (TCGA) database was used to determine the association between glucose importation and the serine metabolic pathway. The effects of glucose on serine biosynthesis and the role of PHGDH were investigated in papillary thyroid cancer cell lines. PHGDH and GLUT1 expression in 230 patients with papillary thyroid cancer (PTC) was explored using immunohistochemistry to explore the impact of the de novo serine biosynthetic pathway from glucose. @*Results@#Glucose importation was significantly correlated with the serine biosynthetic and L-serine metabolic processes. Glucose uptake and serine synthesis were significantly increased and mitochondrial complex expression was upregulated in PTC cell lines grown in high-glucose media. Knockdown and inhibition of PHGDH decreased cell migration associated with glucose utilization. High PHGDH expression is significantly related with tumor aggressiveness and GLUT1 expression in patients with PTC. @*Conclusion@#In this study, we demonstrated that de novo serine biosynthesis from glucose is highly expressed in papillary thyroid cancer and associated with cancer cell metastasis through glucose utility. Our findings suggest the link between glucose utilization PHGDH to regulate tumor aggressiveness in PTC.

Association between DIO2 Thr92Ala polymorphism and hypertension in patients with hypothyroidism: Korean Genome and Epidemiology Study

Background/Aims@#Recent evidence has identified the significance of type 2 iodothyronine deiodinase (DIO2) in various diseases. However, the role of DIO2 polymorphism in metabolic parameters in patients with hypothyroidism is not fully understood. @*Methods@#We assessed the polymorphism of the DIO2 gene and various clinical parameters in 118 patients who were diagnosed with hypothyroidism from the Ansan-Anseong cohort of the Korean Genome and Epidemiology Study. Furthermore, we systematically analyzed Genotype-Tissue Expression (GTEx) data. @*Results@#A total of 118 participants with hypothyroidism were recruited; 32 (27.1%) were homozygous for the Thr allele, 86 (73.9%) were homozygous for the Ala allele or heterozygous. Patients with hypothyroidism with DIO2 polymorphism without hypertension at baseline had higher incidence of hypertension compared to patients without DIO2 polymorphism. Analysis of the GTEx database revealed that elevation of DIO2 expression is associated with enhancement of genes involved in blood vessel regulation and angiogenesis. @*Conclusions@#Commonly inherited variation in the DIO2 gene is associated with high blood pressure and prevalence of hypertension in patients with hypothyroidism. Our results suggest that genetic variation in the hypothalamic-pituitary-thyroid pathway in influencing susceptibility to hypertension.

Hyalinizing Clear Cell Carcinoma of the Base of Tongue Mistaken for Benign Lesion: A Case Report / 대한이비인후과학회지

Hyalinizing clear cell carcinoma (HCCC) is a rare, low-grade malignant tumor of the salivary gland. It usually originates from the minor salivary gland, with the most common site being the palate, followed by the lips and the buccal mucosa. The occurrence of HCCC at the base of the tongue (BOT) is extremely uncommon, thus it must be differentiated from other malignant clear cell tumors. Immunohistochemistry is a useful tool to make an appropriate diagnosis. To obtain the best prognosis for HCCC, complete surgical resection is necessary. Here we report a case of a 47-year-old male with a benign-looking neoplasm in the right BOT, presenting with throat discomfort. A simple excisional biopsy revealed proliferative nests of clear cells within a hyalinized fibrous connective tissue. The final diagnosis by immunohistochemistry was HCCC with a positive resection margin. Re-operation secured a safety margin, and the lesion was completely resected.

Prevalence, Treatment Status, and Comorbidities of Hyperthyroidism in Korea from 2003 to 2018: A Nationwide Population Study

Background@#This study aimed to investigate the changes of incidence and treatment of choice for hyperthyroidism from 2003 to 2018 and explore the treatment-related complications and concomitant comorbidities in South Korea using data from the National Health Insurance Service. @*Methods@#This is a retrospective observational study. Hyperthyroidism was defined as a case having two or more diagnostic codes of thyrotoxicosis, with antithyroid drug intake for more than 6 months. @*Results@#The average age-standardized incidence of hyperthyroidism from 2003 to 2018 was 42.23 and 105.13 per 100,000 men and women, respectively. In 2003 to 2004, hyperthyroidism was most often diagnosed in patients in their 50s, but in 2017 to 2018, people were most often diagnosed in their 60s. During the entire period, about 93.7% of hyperthyroidism patients were prescribed with antithyroid drugs, and meanwhile, the annual rates of ablation therapy decrease from 7.68% in 2008 to 4.56% in 2018. Antithyroid drug-related adverse events, mainly agranulocytosis and acute hepatitis, as well as complications of hyperthyroidism such as atrial fibrillation or flutter, osteoporosis, and fractures, occurred more often in younger patients. @*Conclusion@#In Korea, hyperthyroidism occurred about 2.5 times more in women than in men, and antithyroid drugs were most preferred as the first-line treatment. Compared to the general population, hyperthyroid patients may have a higher risk of atrial fibrillation or flutter, osteoporosis, and fractures at a younger age.

A Study on Lip Movements Area and Vowel Space Area According to the Depressive Disorders

Background and Objectives@#This study aims to investigate the lip movements area (LMA) and vowel space area according to depression.Materials and Method The participants diagnosed with voice disorders or thyroid cancer before treatment and surgery. All participants completed the depression questionnaire and recorded five vowels (/a, i, u, e, o/) phonation while shooting. Among the total 64 participants, there were 19 participants in the depressive disorders group and 45 participants in non-depressive group. The analysis parameters were LMA, vowel space areas (Area3 & Area5), formant centralization ratio (FCR), fundamental frequency (F0) and voice intensity (intensity). Multivariate analysis of variance (MANOVA) was applied, and age was treated as a covariate to correct for lip movement that could deteriorate as age increased. @*Results@#As a result of MANOVA, there was no significant difference between groups (p=0.517). Looking at the LMA, both male and female in the depressive disorder group showed a lower mean value than the non-depressive disorders group. The Area3 and FCR of the depressive disorder group were higher than those in the non-depressive disorders group, whereas for the Area5, the mean value of female in the depressive disorder group was higher than that of the non-depressive disorder group and the male’s non-depressive disorder group had a slightly higher mean value. @*Conclusion@#The voice intensity according to the presence or absence of depressive disorder was similar, but the depressive disorder group tended to show narrower oral area with smaller lip opening.

Mitochondrial Ribosomal Protein L14 Promotes Cell Growth and Invasion by Modulating Reactive Oxygen Species in Thyroid Cancer

Objectives@#. The mitochondrial ribosomal protein L14 (MRPL14) is encoded by a nuclear gene and participates in mitochondrial protein translation. In this study, we aimed to investigate the role of MRPL14 in thyroid cancer. @*Methods@#. We investigated the association between MRPL14 expression and clinicopathological features using The Cancer Genome Atlas (TCGA) and Chungnam National University Hospital (CNUH) databases. Functional studies of MRPL14, including proliferation, migration, invasion, mitochondrial oxidative phosphorylation and reactive oxygen species (ROS) production, were performed in papillary thyroid cancer (PTC) cell lines (B-CPAP and KTC-1). @*Results@#. Based on the TCGA dataset, PTC tissues lost mitochondrial integrity and showed dysregulated expression of overall mitoribosomal proteins (MRPs) compared with normal thyroid tissues. Of 78 MRPs, MRPL14 was highly expressed in thyroid cancer tissues. MRPL14 overexpression was significantly associated with advanced tumor stage, extrathyroidal extension, and lymph node metastasis. MRPL14 increased cell proliferation of thyroid cancer and promoted cell migration via epithelial-mesenchymal transition-related proteins. Moreover, MRPL14 knockdown reduced the expression of oxidative phosphorylation complex IV (MTCO1) and increased the accumulation of ROS. Cotreatment with a ROS scavenger restored cell proliferation and migration, which had been reduced by MRPL14 knockdown, implying that ROS functions as a key regulator of the oncogenic effects of MRPL14 in thyroid cancer cells. @*Conclusion@#. Our findings indicate that MRPL14 may promote cell growth, migration, and invasion by modulating ROS in thyroid cancer cells.

Transcriptomic Analysis of Papillary Thyroid Cancer: A Focus on Immune-Subtyping, Oncogenic Fusion, and Recurrence

Objectives@#. Thyroid cancer is the most common endocrine tumor, with rapidly increasing incidence worldwide. However, its transcriptomic characteristics associated with immunological signatures, driver fusions, and recurrence markers remain unclear. We aimed to investigate the transcriptomic characteristics of advanced papillary thyroid cancer. @*Methods@#. This study included 282 papillary thyroid cancer tumor samples and 155 normal samples from Chungnam National University Hospital and Seoul National University Hospital. Transcriptomic quantification was determined by high-throughput RNA sequencing. We investigated the associations of clinical parameters and molecular signatures using RNA sequencing. We validated predictive biomarkers using the Cancer Genome Atlas database. @*Results@#. Through a comparison of differentially expressed genes, gene sets, and pathways in papillary thyroid cancer compared to normal tumor-adjacent tissue, we found increased immune signaling associated with cytokines or T cells and decreased thyroid hormone synthetic pathways. In addition, patients with recurrence presented increased CD8+ T-cell and Th1-cell signatures. Interestingly, we found differentially overexpressed genes related to immune-escape signaling such as CTLA4, IDO1, LAG3, and PDCD1 in advanced papillary thyroid cancer with a low thyroid differentiation score. Fusion analysis showed that the PI3K and mitogen-activated protein kinase (MAPK) signaling pathways were regulated differently according to the RET fusion partner genes (CCDC6 or NCOA4). Finally, we identified HOXD9 as a novel molecular biomarker that predicts the recurrence of thyroid cancer in addition to known risk factors (tumor size, lymph node metastasis, and extrathyroidal extension). @*Conclusion@#. We identified a high association with immune-escape signaling in the immune-hot group with aggressive clinical characteristics among Korean thyroid cancer patients. Moreover, RET fusion differentially regulated PI3K and MAPK signaling depending on the partner gene of RET, and HOXD9 was found to be a recurrence marker for advanced papillary thyroid cancer.

A Multicenter, Randomized, Controlled Trial for Assessing the Usefulness of Suppressing Thyroid Stimulating Hormone Target Levels after Thyroid Lobectomy in Low to Intermediate Risk Thyroid Cancer Patients (MASTER): A Study Protocol

Background@#Postoperative thyroid stimulating hormone (TSH) suppression therapy is recommended for patients with intermediate- and high-risk differentiated thyroid cancer to prevent the recurrence of thyroid cancer. With the recent increase in small thyroid cancer cases, the extent of resection during surgery has generally decreased. Therefore, questions have been raised about the efficacy and long-term side effects of TSH suppression therapy in patients who have undergone a lobectomy. @*Methods@#This is a multicenter, prospective, randomized, controlled clinical trial in which 2,986 patients with papillary thyroid cancer are randomized into a high-TSH group (intervention) and a low-TSH group (control) after having undergone a lobectomy. The principle of treatment includes a TSH-lowering regimen aimed at TSH levels between 0.3 and 1.99 μIU/mL in the low-TSH group. The high-TSH group targets TSH levels between 2.0 and 7.99 μIU/mL. The dose of levothyroxine will be adjusted at each visit to maintain the target TSH level. The primary outcome is recurrence-free survival, as assessed by neck ultrasound every 6 to 12 months. Secondary endpoints include disease-free survival, overall survival, success rate in reaching the TSH target range, the proportion of patients with major cardiovascular diseases or bone metabolic disease, the quality of life, and medical costs. The follow-up period is 5 years. @*Conclusion@#The results of this trial will contribute to establishing the optimal indication for TSH suppression therapy in low-risk papillary thyroid cancer patients by evaluating the benefit and harm of lowering TSH levels in terms of recurrence, metabolic complications, costs, and quality of life.

Two Cases Using the Praat-Based Automatic Voice Analysis Program as an Alternative to CSL

There are a number of voice analysis programs around the world. Domestic voice analysis is performed by relying heavily on specific commercial program. We intend to develop coding for voice analysis using Praat and apply it to clinical practice. This study consisted of Experiment 1 and Experiment 2. Experiment 1 was the development of automated voice analysis coding based on Praat. The coding was largely divided into a recording, an analysis, and a storage section. Experiment 2 was applied to the voice analysis of 2 male patients pre- and post-operation with this coding. The analysis parameters of this coding provided 26 parameters for vowel /a/, nine parameters for sentence analysis, and a total of 4 parameters for voice range profile analysis. In two male patients, the pitch and the intensity increased, the voice quality improved, and the sentence length decreased after surgery. The coding was well made, so the output was good in real time. The code is automated as much as possible to block manual errors and increases convenience and efficiency by generating the result sheet in real time.

A Case of Anterior Cervical Intramuscular Schwannoma in the Strap Muscle / 대한이비인후과학회지

Schwannoma, also known as neurilemmoma, is a benign neoplasm that originates from any nerves wrapped with a sheath made of Schwann cells. Schwannoma occurring in the head and neck region is not rare, but schwannomas of the anterior neck, especially ansa cervicalis, are extremely rare that only 7 cases have been reported to date worldwide. Although rare, it should be considered in differential diagnosis of anterior cervical mass and may be confused with other cervical and thyroid mass. We report a case of intramuscular schwannoma in the sternohyoid muscle. Preoperative diagnosis was established with an ultrasound-guided core needle biopsy. Although it was removed entirely without connection to any other nerves identified or any complication, clinically, the mass was thought to be derived from the nerve. To our knowledge, this is the first case of the intramuscular schwannoma occurring from ansa cervicalis reported in the literature.

Clinical Significance of FDG PET-CT Scan at 12 Weeks after Curative Radiation Therapy in Patients with Head and Neck Cancer / 대한두경부종양학회지

Background/Objectives@#To evaluate clinical significance of FDG PET-CT for detection of residual cancer cells after curative radiation therapy or chemoradiotherapy for patients with squamous cell carcinoma (SCC) of Head and NeckMaterials & Methods: A retrospective analysis of patients with SCC of Head and neck with curative radiotherapy or chemoradiotherpy between June 2011 and Jan. 2019 was performed. Sixty patients were treated with Intensity-modulated radiotherapy (IMRT). The Metabolic responses were evaluated on the post-treatment FDG PET-CT at 12 weeks after curative radiotherapy completion. @*Results@#Median follow up was 51.5 months (3-102). The overall survival (OS), disease free survival (DFS), local control rate (LCR), and Distant metastasis free survival (DMFS) at 5 years were 80.5%, 80.1%, 87.7% and 89.1%. Metabolic CR was found in 43 (71.7%) and partial metabolic response (PR) was noted in 17 (14.6%). Metabolic CR was significantly correlated with OS, DFS, LCR, and DMFS. On multivariate analysis, Metabolic CR remained significant for DFS and LCR. @*Conclusion@#Metabolic CR on post-radiotherapy FDG PET-CT is highly predictive of increased DFS and LCR in patients with head and neck cancer.

Optimal Surgical Extent of Therapeutic Lateral Neck Dissection in Well-Differentiated Thyroid Carcinoma Patients with Clinical Lateral Lymph Node Metastasis

Regional neck metastases in well-differentiated thyroid carcinoma (WDTC) are relatively frequent. The prognostic effects of lymph node (LN) metastases remain controversial. However, it is well known that lateral LN metastasis is related to the recurrence of the disease. In general, when lateral neck LN metastasis is confirmed in WDTC patients, therapeutic lateral neck dissection is recommended. However, the optimal surgical extent of therapeutic lateral neck dissection in WDTC patients with clinical lateral LN metastasis is not clearly presented. Traditional comprehensive neck dissection including level II, III, IV and V even in patients with minimal lateral neck metastases may not be reasonable when considering both oncologic safety and functional aspects. There is controversy whether it is always necessary to perform level II and V LN dissection for all WDTC patients with clinical lateral LN metastasis. This is due to the fact that the likelihood of postoperative complications by the damage of the spinal accessory nerve increases with level II and level V dissection. Therefore, many studies have been reported on the possibility of omitting levels II (especially IIb) and V during therapeutic comprehensive lateral neck dissection.However, there have been no definite conclusions about it, and it is still debate. In this article, we reviewed to find out optimal lateral neck dissection range for WDTC patients with clinical lateral neck metastasis.