Background and Objectives: Arterial dissection during endovascular therapy rarely occurs but can be lethal. A fabric-based covered graft stents yield poor clinical outcomes. A novel balloon-expandable stent with biodegradable film graft for overcoming these issues was evaluated in a rabbit iliac artery model.Method: Eighteen rabbits with iliac artery dissections were induced by balloon over-inflation on angiography (Ellis type 2 or 3) and treated using the test device (3.0×24 mm). Subsequently, survived twelve animals underwent histologic examinations and micro-computed tomography (CT) at 0, 2, 4, and 8 weeks and 3, 6, 9, and 12 months and angiography at one-year. Results: There were no adverse cardiovascular events during the one-year. Early-stage histologic examination revealed complete sealing of disrupted vessels by the device, exhibiting mural hematoma, peri-stent red thrombi, and dense infiltration of inflammatory cells. Mid- and long-term histologic examination showed patent stents with neointimal hyperplasia over the stents (% area stenosis: 11.8 at 2 weeks, 26.1 at 1 month, 29.7 at 3months, 49.2 at 9 months, and 51.0 at 1 year), along with mild peri-strut inflammatory response (Grade: 1–2 at mid-term and 0–1 at long-term). The graft film became scarcely visible after six months. Both CT and angiography revealed no instances of thrombotic occlusion or in-stent restenosis (% diameter stenosis: 5.7 at 2 weeks, 12.3 at 1 month, 14.2 at 3 months, 25.1 at 9 months, and 26.6 at 1 year). Conclusions The novel balloon-expandable stent with a biodegradable film graft demonstrates feasibility in managing severe artery dissection and preventing lethal vascular events in animal model.

Background and Objectives: We analyzed the data of oropharyngeal squamous cell carcinoma (OPSCC) patients who had transoral surgery with/without adjuvant therapy and experienced recurrence. From the data, the treatment outcomes and prognostic factors of recurrent OPSCC were evaluated, and the predictive factors related to successful salvage treatment were identified.Subjects and Method We used data from patients who were diagnosed with OPSCC and received transoral surgery at the hospital from January 2005 to December 2019. Results: The 5-year survival rate of patients with recurrent OPSCC was 43.9%. The predictors of successful salvage treatment were adjuvant therapy and the p16 status. The 5-year survival rate following salvage treatment for patients who had recurrent OPSCC and also tested p16-positive was 64%; however, it was only 30% for patients who had recurrent OPSCC and tested p16-negative. The 5-year survival rate was 22% for patients who received adjuvant therapy and 64% for those who did not receive it. Conclusion In OPSCC patients who recurred after transoral surgery with/without adjuvant therapy, the salvage treatment success rate was 45%. In recurrent cancer, the HPV status was an important factor associated with successful salvage treatment, as the success rate of salvage treatment was remarkably high in patients who did not receive adjuvant therapy. Thus, we verified that it is crucial to conduct an initial surgery with clear margins and determine the optimal criteria for adjuvant therapy.

Background and Objectives: We analyzed the treatment results and prognostic factors of stage IV oral tongue squamous cell carcinoma (OTSCC) patients and explored the existence of subgroups with distinctive prognoses. In addition, the outcome of salvage therapy was analyzed in recurrent cases, and the survival rates and prognostic factors were investigated.Subjects and Method This study was conducted on patients who were diagnosed with OTSCC and underwent surgery at our hospital between June 2005 and January 2020. A total of 144 patients with stage IV OTSCC was enrolled. Results: A total of 64 recurrences, local (6), regional (21), distant metastasis (33), and locoregional (4), occurred. Seventy-five patients died because of disease progression during the course of study. The 5-year recurrence-free survival rate was 54.5%, and the 5-year disease-specific survival rate was 49.2%. Surgical margins, lymphovascular invasion (LVI), T classification, and lymph nodes (LNs) metastasis exhibited significant correlation with mortality. LVI and advanced T were statistically important factors for predicting distant metastasis. The treatment outcome of the T4N0 patient group without LN metastasis fared the best, while the treatment outcome of the T4N1-3 patient group with advanced T and N findings was the worst. Conclusion The major type of treatment failure in stage IV OTSCC patients was distant metastasis, and the related predictors of distant metastasis were LVI and advanced T. In the stage IV OTSCC patient group, there were subgroups with distinct prognosis according to the combination of T and N classification. The T4N0 group had the best survival rate, and the T4N1-3 group had the worst prognosis.

Background and Objectives: Arterial dissection during endovascular therapy rarely occurs but can be lethal. A fabric-based covered graft stents yield poor clinical outcomes. A novel balloon-expandable stent with biodegradable film graft for overcoming these issues was evaluated in a rabbit iliac artery model.Method: Eighteen rabbits with iliac artery dissections were induced by balloon over-inflation on angiography (Ellis type 2 or 3) and treated using the test device (3.0×24 mm). Subsequently, survived twelve animals underwent histologic examinations and micro-computed tomography (CT) at 0, 2, 4, and 8 weeks and 3, 6, 9, and 12 months and angiography at one-year. Results: There were no adverse cardiovascular events during the one-year. Early-stage histologic examination revealed complete sealing of disrupted vessels by the device, exhibiting mural hematoma, peri-stent red thrombi, and dense infiltration of inflammatory cells. Mid- and long-term histologic examination showed patent stents with neointimal hyperplasia over the stents (% area stenosis: 11.8 at 2 weeks, 26.1 at 1 month, 29.7 at 3months, 49.2 at 9 months, and 51.0 at 1 year), along with mild peri-strut inflammatory response (Grade: 1–2 at mid-term and 0–1 at long-term). The graft film became scarcely visible after six months. Both CT and angiography revealed no instances of thrombotic occlusion or in-stent restenosis (% diameter stenosis: 5.7 at 2 weeks, 12.3 at 1 month, 14.2 at 3 months, 25.1 at 9 months, and 26.6 at 1 year). Conclusions The novel balloon-expandable stent with a biodegradable film graft demonstrates feasibility in managing severe artery dissection and preventing lethal vascular events in animal model.

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.

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.

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.

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.

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.

Background and Objectives: We analyzed the data of oropharyngeal squamous cell carcinoma (OPSCC) patients who had transoral surgery with/without adjuvant therapy and experienced recurrence. From the data, the treatment outcomes and prognostic factors of recurrent OPSCC were evaluated, and the predictive factors related to successful salvage treatment were identified.Subjects and Method We used data from patients who were diagnosed with OPSCC and received transoral surgery at the hospital from January 2005 to December 2019. Results: The 5-year survival rate of patients with recurrent OPSCC was 43.9%. The predictors of successful salvage treatment were adjuvant therapy and the p16 status. The 5-year survival rate following salvage treatment for patients who had recurrent OPSCC and also tested p16-positive was 64%; however, it was only 30% for patients who had recurrent OPSCC and tested p16-negative. The 5-year survival rate was 22% for patients who received adjuvant therapy and 64% for those who did not receive it. Conclusion In OPSCC patients who recurred after transoral surgery with/without adjuvant therapy, the salvage treatment success rate was 45%. In recurrent cancer, the HPV status was an important factor associated with successful salvage treatment, as the success rate of salvage treatment was remarkably high in patients who did not receive adjuvant therapy. Thus, we verified that it is crucial to conduct an initial surgery with clear margins and determine the optimal criteria for adjuvant therapy.