As a high-performance polymer, Polyetherketoneketone (PEKK) has good biocompatibility and excellent physical properties and is used in several areas, including dentistry. Many successful cases of implant-supported fixed prostheses with a PEKK framework have been reported; however, a long-term observation of the reported cases and discussion of complications are not available. In this case report, we present three cases of implant-supported fixed prostheses with a PEKK framework veneered with composite resin, lithium disilicate crown, and high-impact polymethyl methacrylate (PMMA), and discuss their 6-year follow-up results.

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: 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.

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.