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After our coauthors described the first remote-access parathyroidectomy (RAP) series in 2000, several other approaches were developed. No systematic review has been performed to classify and evaluate RAP techniques. We performed a literature search using PubMed and Cochrane Library (CENTRAL). A total of 71 studies met our inclusion/exclusion criteria. RAP can be categorized into five approaches: (1) endoscopic and robotic axillary, (2) anterior chest, (3) transoral, (4) retroauricular, and (5) a combination of these approaches. The limited data in the literature suggest that the cure rates and safety of RAP are in no way inferior to those of open parathyroidectomy. Each approach has its advantages and disadvantages, and the recommendations for the selection of each approach are listed. The selection of approach methods might depend on the surgeon's experience and familiarity and the patient's preference and disease status.

Remote-access thyroidectomy (RAT) is becoming a more frequently used approach that can avoid scars in the neck and provide better cosmetic results than open surgery. However, there has been no surgical indication for RAT in patients who have a history of cervical treatment (surgery or irradiation), and the use of RAT has been avoided in such patients. Here, we report a case in which a remote-access endoscopic hemithyroidectomy and central lymph node dissection by the anterior chest approach was successfully performed in a patient with papillary thyroid carcinoma (a 77-year-old Japanese male) after he had undergone ipsilateral cervical radiation therapy to parotid gland cancer (mucoepidermoid carcinoma) thirteen years earlier. Regarding trocar insertion, a 30-mm skin incision was made in the left anterior chest approx. 5 cm below the clavicle. Two 5-mm trocars were inserted through the 30-mm incision. We then insufflated with carbon dioxide to 6 mmHg. One additional 5-mm trocar was placed cephalad to the 30-mm incision. When we performed this RAT, we detected no effect of the prior irradiation. To the best of our knowledge, this is the first report of RAT after irradiation. The cosmetic outcome of RAT is clearly superior, and the present case demonstrates that a RAT can be safely performed in carefully selected patients even after irradiation.

Purposes: To establish the appropriate staging system and assess the role of curative thyroidectomy alone (Surgery) vs. involved-site radiation therapy after open biopsy (OB-ISRT) in stage IE mucosa-associated lymphoid tissue (MALT) lymphoma. Methods: We examined the Tokyo Classification as a modified classification. This retrospective cohort study included 256 patients with thyroid MALT lymphoma; 137 underwent standard therapy (i.e., OB-ISRT) and were enrolled for the Tokyo classification. Sixty stage IE patients with the same diagnosis were examined to compare Surgery with OB-ISRT. Results: Overall survival (p = 0.0092) and relapse-free survival (0.00113) were significantly better in stage IE vs. stage IIE under the Tokyo classification. No OB-ISRT and Surgery patients died, but three OB-ISRT patients relapsed. The incidence of permanent complications was 28% in OB-ISRT (mainly dry mouth) and 0% in Surgery (p = 0.027). The number of painkiller prescription days was significantly greater in OB-ISRT (p < 0.001). During follow-up, the rate of the new appearance/change of the low-density area in the thyroid gland was significantly higher in OB-ISRT (p = 0.031). Conclusions: The Tokyo classification allows an appropriate discrimination between stages IE and IIE MALT lymphoma. Surgery can provide a good prognosis in stage IE cases; it also avoids complications, shortens painful periods during treatment, and simplifies ultrasound follow-up.

BACKGROUND: Remote-access thyroidectomy and its cosmetic merit have been widely accepted, but remote-access parathyroidectomy has not become common. There are few reports about the risks and effectiveness of a remote-access endoscopic parathyroidectomy. Herein, we evaluated the risks and benefits of total endoscopic parathyroidectomy (TEP) for patients with primary hyperparathyroidism (PHPT). We retrospectively compared the surgical outcomes of TEP and open minimally invasive parathyroidectomy (MIP). METHODS: We analyzed the cases of 28 patients with PHPT who were scheduled to undergo a MIP at Mita Hospital (Tokyo) during the period from April 2015 to March 2019, all of whom were presumed preoperatively to have a single adenoma. RESULTS: Eleven of the patients underwent a TEP (10 females, one male; mean age 54.2 years). The other 17 patients underwent an open MIP (11 females, 6 males; mean age 63.5 years). The younger patients and the females tended to select endoscopic surgery as their treatment. The operation time was significantly longer in the TEP group compared to the open MIP group (106 vs. 50 min; P

Remote-access total endoscopic thyroidectomy (TET) is a recently established approach that can avoid producing scars in the neck. There are no clear surgical indications for TET for benign nodules or for malignant tumors at present. We report a successful TET in a 50-year-old Japanese woman with follicular lymphoma of the thyroid gland after an open neck biopsy. She had been referred to us with a neck tumor noted 2 months earlier. Because of adhesion, we performed a combined resection of the thyroid and partial right sternohyoid muscle. To the best of our knowledge, there is no other report of a TET performed after open neck surgery. Our patient's case demonstrates that (a) the cosmetic outcome of TET is clearly superior to that of conventional open neck surgery, and (b) a TET can be suitable even for reoperation if carefully selected.

After our group described the first remote-access thyroidectomy series in 2000, the procedure has been further developed. Although a thoracoscopic approach with a conventional open cervical incision for thyroid goiters with mediastinal extension has been performed at many institutions, remote-access thyroidectomy for cervicomediastinal goiters has not been established. We have performed combined thoracoscopic and axillary subcutaneous endoscopic thyroidectomies (axillo-thoracic endoscopic thyroidectomies). Here, we describe a novel technique for performing a remote-access thyroidectomy for a cervicomediastinal goiter (CMG).The patients with CMGs who agreed to an axillo-thoracic endoscopic thyroidectomy at one of two hospitals in Japan underwent a remote-access thyroidectomy.We performed the axillo-thoracic endoscopic right or left hemithyroidectomy successfully, but most of the patients did not require the thoracoscopic procedure. None of the patients had complications, and none was converted to an open thyroidectomy.Most thyroid goiters with substernal extension can be removed by the axillary approach, but some cases require a thoracoscopic approach. The novel approach described herein (axillo-thoracic endoscopic thyroidectomy) enables the safe excision of a CMG with high patient satisfaction for selected patients.

In this papers, we study a hybrid power supply vehicle by biomass Free Piston Stirling Engine and solar panel. This hybrid power generation is composed of a solar photovoltaic system and Stirling engine (the free-piston Stirling engine generator). This uses biomass, such as wood pellets as the heat source. The Stirling engine produces about electrical power of 1kw. The combination of these two generations allows the production of electricity for 24 hours a day. The experimental results show that up to 1.6kW can be generated and the hybrid generation system can supply hot water of the volume of 200L.

Background Although lobectomy is considered acceptable as a primary surgical treatment for papillary thyroid carcinoma in properly selected patients, a standard treatment for postlobectomy lymph node recurrence has not been established. Here we compared the effectiveness of therapy with lymphadenectomy alone to that of treatment with completion thyroidectomy and lymphadenectomy followed by radioactive iodine. Methods This was a retrospective study of patients with papillary thyroid carcinoma who underwent surgery for lymph node recurrence in the period from January 2003 to December 2008, all of whom had previously undergone initial lobectomy with or without lymph node dissection. One-hundred and twenty-five patients were included in the primary analysis. Results Ninety-eight of these patients underwent lymphadenectomy alone (L group), and 27 received lymphadenectomy and completion thyroidectomy followed by radioactive iodine (LC&R group). The median follow-up time was 10.2 years. The overall survival, distant relapse-free survival, and lymph node relapse-free survival were not significantly different between the LC&R and L groups (P = .89, 0.58, and .22, respectively), whereas the LC&R group patients had significantly longer operation time, higher blood loss, and a higher rate of postoperative hypoparathyroidism compared with the L group (P Conclusion Compared with completion thyroidectomy and lymphadenectomy followed by radioactive iodine, lymphadenectomy alone was considered an acceptable therapeutic option which decreased the surgical disadvantages but did not decrease survival for at least 10 years after recurrence surgery for PTC patients with only lymph node recurrence.

Cervical esophageal cancer (CEC) patients whose larynx function cannot be preserved often undergo chemoradiotherapy, whereas those with residual or recurrent lesions undergo a pharyngo-laryngo-esophagectomy (PLE); however, some need to undergo a pharyngolaryngectomy with total esophagectomy (PLTE) for synchronous or metachronous esophageal cancer. We retrospectively evaluated the relationship between preoperative irradiation (or the extent of esophageal resection) and postoperative endocrine complications in CEC, including hypothyroidism and hypoparathyroidism. The cancers of 35 (5.4%) of 678 esophageal cancer patients with esophagectomy treated in 2000–2017 were CECs. We also analyzed the 17 cases of CEC patients who underwent PLE with thyroid lobectomy—11 with irradiation before PLE and 6 without irradiation. Seven patients underwent a PLTE. Hypothyroidism and hypoparathyroidism occurred in 14 and 12 patients, respectively. The hypothyroidism rate was significantly higher in patients with irradiation versus those without irradiation (100% vs. 50%; p = 0.010), and the hypoparathyroidism rate was significantly higher in the PLTE versus non-PLTE patients (100% vs. 50%; p = 0.026). The mean levothyroxine dosage was 1.60 μg/kg/day in the PLE patients post-irradiation. Irradiation appears to be a risk factor for hypothyroidism after PLE with thyroid lobectomy, while PLTE might have some effect on hypoparathyroidism. Due to vocal function loss, PLE patients may experience symptoms from endocrine complications. Levothyroxine treatment soon after PLE for post-irradiation patients and patients requiring as-needed calcium or vitamin D supplementation based on biochemical hypocalcemia for PLE (especially PLTE), may be effective in preventing symptomatic endocrine complications.

Background: The recurrent laryngeal nerve (RLN) can be injured during thyroid surgery, which can negatively affect a patient's quality of life. The impact of intraoperative anatomic variations of t...

Today, with the increase in greenhouse gases, the global environment has deteriorated. Terrible droughts and floods frequently break out among many parts of the world. In order to control the increasing greenhouse gas, renewable energy power generation such as wind power and solar energy has to be introduced rapidly.In this paper, a new optimal-and-robust control strategy, decoupling torque and magnetic flux of IM (Induction Generator and Motor) by ILQ (Inverse Linear Quadratic) design method with IRM (Inverse Reference Model), is proposed. Proposed method provides robust and independent optimal control of torque and magnetic flux even when the environment around the generator in such as wind generation changes.

Radioactive iodine (RAI) therapy has been the mainstay of treatment for papillary thyroid carcinoma (PTC) patients with distant metastasis (DM). Although tyrosine kinase inhibitors (TKIs) were introduced for the treatment of RAI refractory metastatic thyroid carcinoma several years ago, clinical outcomes for PTC patients with DM treated using RAI therapy remain unclear. We retrospectively examined 64 PTC patients (9 men, 55 women) with DM at diagnosis treated using RAI therapy without administration of any kind of chemotherapy or TKIs. Median age of patients was 58 years. Site of DM was the lungs (n = 59), bone (n = 3), and pleural dissemination (n = 2). No patients showed multiple-organ metastases at diagnosis. By the end of the study period, 21 patients had died of PTC. Cause-specific survival rates at 10, 15, and 20 years after initial surgery were 68.2%, 63.6% and 61.1%, respectively. Uni- and multivariate analyses identified age ≥55 years (HR 3.1, p = 0.023), site of DM other than the lungs (HR 13.4, p < 0.0001), and DM with no RAI avidity (HR 5.1, p = 0.0098) as factors independently associated with disease-related death. When analyses were restricted to patients with lung metastasis (n = 59), surgical non-curability was another independent risk factor (HR 5.2, p = 0.0047) in addition to age and RAI avidity. According to risk stratification analysis based on these risk factors, patients with site of DM other than the lungs or with lung metastasis showing ≥2 risk factors among age ≥55 years, DM with no RAI avidity, and surgical non-curability are expected to show higher mortality rates.

The low turnover rate of thyroid follicular cells and the lack of a long-term thyroid cell culture system have hampered studies of thyroid carcinogenesis. We have now established a thyroid organoid culture system that supports thyroid cell proliferation in vitro. The established mouse thyroid organoids performed thyroid functions including thyroglobulin synthesis, iodide uptake, and the production and release of thyroid hormone. Furthermore, transplantation of the organoids into recipient mice resulted in the formation of normal thyroid–like tissue capable of iodide uptake and thyroglobulin production in vivo. Finally, forced expression of oncogenic NRAS (NRASQ61R) in thyroid organoids established from p53 knockout mice and transplantation of the manipulated organoids into mouse recipients generated a model of poorly differentiated thyroid cancer. Our findings suggest that this newly developed thyroid organoid culture system is a potential research tool for the study of thyroid physiology and pathology including thyroid cancer.

We retrospectively examined patients with ultrasonographically occlusive acute proximal deep vein thrombosis (DVT). All patients were categorized into two groups on the basis of whether great saphenous vein (GSV) flow toward the common femoral vein was detected (flow [+]; n=10) or undetected (flow [-]; n=10). We investigated the relationship between the GSV flow pattern and DVT recanalization. Thrombus recanalization, which is defined as diameter reduction to lower than 40% of the vessel diameter, was confirmed in seven of the flow (+), and none of the flow (-). This study proposes that the GSV flow pattern may be a simple marker for the recanalization of proximal occlusive DVT.

Lenvatinib is a molecular-targeting agent that was recently approved in Japan for treatment of curatively unresectable, radioactive iodine-refractory, progressive differentiated thyroid cancer (DTC). Because only a few Japanese patients have received lenvatinib in clinical trials, there are limited domestic data on its safety and efficacy or prognostic factors. Therefore, a prospective observational study has been designed to collect safety and efficacy data in at least 300 patients with curatively unresectable DTC receiving lenvatinib therapy (24 mg/day), in order to find predictors of antitumor activity and survival. Patients with progressive curatively unresectable DTC refractory to radioiodine therapy will be enrolled and the primary endpoint will be overall survival. This study is designed to estimate the 95% confidence intervals of the 1-year and 2-year survival rates with a two-sided width of less than 10%. Secondary endpoints will be the time to treatment failure, time to strategy failure, progression-free survival time with clinical progressive disease, response rate, quality of life, safety, and patient reports. The ultimate goal is to obtain information for developing evidence-based guidelines for treatment of DTC, including recommendations on patient selection, dosages, and duration of treatment. This study has been registered with the UMIN Clinical Trials Registry (UMIN000022243).

In this paper, we study the control of output voltage of Free-Piston Stirling Engine Generator System, in that case a robust control voltage source is needed because the Stirling is normally used by connected to the grid. However, to solve the problem the ILQ (Inverse Linear Quadratic) can be used to realize robust voltage controller, in this paper we propose a new power generation system based on renewable energy sources specifically, wood pellet as the heat source. The experimental results show that up to 1.6kW can be generated from the generator system, and possible production of around 200L of hot water (45°C). In remote and rural areas, particularly, where it can be set as a stand-alone system or off-grid power system.

6070 Background: Lenvatinib is now available for unresectable radioactive iodine (RAI)-refractory differentiated thyroid cancer (DTC). However, toxicities are considerable and require frequent dose interruption and modification. Recently, planned drug holidays, which are dose interruptions in accordance with the timing of severe or intolerable adverse events, have been proposed to avoid severe adverse events due to lenvatinib (Tahara M.ESMO Open 2018). Our retrospective study demonstrated that progression-free survival (PFS) and overall survival (OS) were significantly longer in patients who used planned drug holidays than those who did not (Matsuyama C et.al, 2020 Annual Meeting of the Japan Association of Endocrine Surgeons). Methods: In this prospective observational study, patients with curatively unresectable and progressive RAI-refractory DTC were treated with lenvatinib in a real-world clinical setting. Lenvatinib was administered orally at a dose of 24 mg daily. Dose modification for toxicities were permitted. Primary endpoint was OS, and secondary endpoints were time to treatment failure (TTF), time to failure of strategy (TFS), PFS with clinical progressive disease, response rate, quality of life, safety, and patient reports. This study was registered with UMIN Clinical Trials Registry (UMIN000022243). Results: 262 patients were accrued. Of 255 evaluable, 153 were female; median age was 70 (range 27.0-88.0); histology was papillary thyroid carcinoma/follicular thyroid carcinoma/poorly DTC in 204/45/4; previous therapy was surgery/RAI/molecular targeted drug in 246/164/14; reason for initiation of lenvatinib was disease progression/unsuitable for RAI in 241/4. 1-year OS was 85.6% (95%CI: 80.6-89.4%); 1-year TTF rate was 74.9% (95%CI: 69.1-79.8%); 1-year TFS rate was 80.8% (95%CI: 75.4-85.2%); and 1-year PFS rate was 84.4% (95%CI: 79.3-88.4%). Overall response by RECIST was 3 (1.2%) in CR and 151 (61.9%) in PR. Most common grade 3 or 4 toxicities were hypertension (61.4%), hand foot syndrome (10.2%), fatigue (9.1%), anorexia (8.3%) and diarrhea (4.7%). Grade 5 toxicities occurred in 4 patients (fistula, hypoxia, respiratory failure, trachea stenosis). Of 253 patients evaluable for efficacy, 73 used planned drug holidays. TTF, TFS and PFS were significantly longer in patients who used planned drug holiday than those who did not (Table). Conclusions: Planned drug holiday for lenvatinib demonstrated significantly better clinical outcomes, including TTF, TFS and PFS, than daily oral administration. These data further support use of a planned drug holiday in RAI-refractory DTC patients receiving lenvatinib. Clinical trial information: 000022243. [Table: see text]

Proposed hybrid electric power generation system is constituted from Free Piston Stirling engine generator and solar photovoltaic system. Free Piston Stirling engine electric generator uses biomass, such as wood pellets as the heat source. This system produces maximum output of 1.6kW and $45^{\circ} C$ 200 L hot water with linear generator. This paper studied the control of output voltage of Free Piston Stirling Engine. ILQ (Inverse Linear Quadratic) control theory is used to keep output active power between 400W and 500W. In long range time constant of burning system and in short range time constant of electrical circuit, experiment yields temperature of FPSEG head between upper limit and lower limit.

Treatment of patients with liver metastasis of differentiated thyroid carcinoma (DTC) has not been sufficiently defined, because liver metastasis of DTC has been described mostly as case reports. Additionally, such patients are considered end-of-treatment responders. A relatively new approach using tyrosine kinase inhibitors (TKIs) may provide opportunities to manage systemic metastasis. This study aims to define the clinical features of DTC patients with liver metastasis and evaluate the benefits of TKIs. We retrospectively analyzed clinical features of 29 patients (mean age 67.8 years) diagnosed with liver metastasis of DTC at our institution between January 1981 and May 2017. All patients had distant metastasis at other organ sites upon diagnosis of liver metastasis; 41% of them developed new metastasis afterward. Management after diagnosis of liver metastasis comprised palliative care (48%), radioactive iodine therapy (28%), and TKI therapy (24%). The median survival after diagnosis of liver metastasis was only 4.8 months. Survival rates were significantly better in patients with performance statuses between 0 and 2 on the Eastern Cooperative Oncology Group scale at diagnosis of liver metastasis (n = 22, 76%) treated with TKI compared to those who were not (P = 0.017; log-rank test; hazard ratio 0.19). One-year survival rates were 71.4 and 26.7% for patients treated with or without TKI, respectively. Patients with liver metastasis had poor clinical prognosis. When other distant metastases existed at diagnosis of liver metastasis, TKI therapy was considered an effective therapeutic option for patients with liver metastasis of DTC.

We proposed combined electric and dynamic system based on the ILQ optimal control, which has high robust performance for induction motor drive. This method realizes an excellent speed control, even if the response of current-control loop is more than three times of the response of speed-control loop. When the motor parameters are varied, the ILQ optimal controller can hold more robust condition than previous method. This paper presents quantitative evaluations for robust stability and robust performance via μ-analysis. Generalized state equations for μ-analysis are derived and compare the ILQ control method with proposed PI method.

This paper proposes an optimal control system design for an Acrobot who has a single actuator at the elbow and no actuator at the shoulder; the system is underactuated because we desire to control two links of the Acrobot with only a single system input. The Acrobot is an unstable robot useful as a testbed for studying the theory and application of nonlinear control. The proposed control system consists of inverse linear quadratic (ILQ)design method. The numerical simulation is given to show the effectiveness of the proposed control system.

Visceral fat accumulation is regarded as one of the major phenotypes of metabolic syndrome. There have not been enough data on the relationship between the fish-eating habit and visceral adiposity. A total of 94 male participants received abdominal CT for the measurement of the visceral fat area (VFA), serum sampling for the fatty acid composition and questionnaires about their life-style. We divided the participants into two groups: whether they ate their fill (group F, n=70) or they ate in moderation (group M, n=24). Stepwise multiple linear regression analyses showed that usual alcohol consumption and lower daily physical activity in group F, and infrequent fish-eating and frequent fat-rich deserts in group M were the significant positive correlates with the VFA. The serum eicosapentaenoic acid (EPA)/arachidonic acid (AA) ratio showed significant correlation with the frequency of fish-eating in both groups. Interestingly, in group M, the serum EPA/AA ratio negatively correlated with the VFA, while it failed in group F. In conclusion, the present data suggest that the fish-eating habit might negatively associate with visceral fat accumulation only in those who are moderate in eating in the general population.

Although advanced thyroid carcinoma patients who cannot be cured by conventional therapy have lacked effective treatment, multitargeted tyrosine kinase inhibitors have recently become available. Phase 3 trials of lenvatinib showed a median time to objective response of 2 (95 % confidence interval (CI) 1.9-3.5) months, demonstrating that shrinks tumors rapidly. The phenomenon of immediate tumor shrink is known as early tumor shrinkage (ETS) which is related to clinical outcome in other malignancies. However, precisely when within 8 weeks lenvatinib starts to affect tumors remains unclear. In tumors near the carotid arteries, trachea, or esophagus, a rapid therapeutic effect can induce fistula formation or arterial bleeding. To prevent such treatment-emergent serious adverse events (SAE), early imaging evaluation seems to be very important. In this study, the point in time when lenvatinib started to shrink tumors was retrospectively investigated. The subjects were 16 patients who started lenvatinib administration between May and August 2015. Tumor size was evaluated by computed tomography (CT) scans frequently within the first 8 weeks according to the Response Evaluation Criteria In Solid Tumors (RECIST) guideline. Initial tumor response was defined as ≥ 10% tumor reduction. Serum thyroglobulin (Tg) level was monitored in 8 differentiated thyroid carcinoma (DTC) without TgAb patients. At the first evaluation, 13 patients (83.3 %) showed tumor reduction and that decreased with time. Thirteen patients (83.3 %) showed >10 % tumor reduction within 8 weeks. In all DTC patients, serum Tg level was markedly decreased. In conclusion, lenvatinib immediately shrinks tumors, the so-called ETS phenomenon. Therefore, careful attention should be paid to fistula formation from the early phase.

The proposed optimal control on the basis of both current and voltage of the buck-converter is designed to be based on Inverse Linear Quadratic (ILQ) design method with the resonant low pass filter, which eliminates the disturbance by appended disturbance compensator. The designed scheme is composed of the state equation, an optimal ILQ solution, the ILQ servo-system with the disturbance elimination, the optimal basic gain, the optimal condition, the transfer functions and the disturbance compensator. Our results show the proposed strategy is the stability and robust control and has been made to improve ILQ control for the disturbance elimination of the output response, which guarantees the optimal gains on the basis of polynomial pole assignment.

Up until now there have been no promising drugs for the treatment of advanced thyroid cancer, but the development of novel therapeutic agents is now anticipated as a result of the advent of molecular targeted drugs that inhibit tumor growth signals or angiogenesis. Against a background in which the development of numerous molecular targeted drugs for advanced thyroid cancer is being pursued worldwide, the development of sorafenib, vandetanib, and lenvatinib is currently also under way in Japan. All three of these compounds are undergoing phase 3 trials or have been approved abroad, and because they are in the final stage of development in Japan, they are expected to be introduced in clinical settings in the near future. After they have been introduced, it will be necessary to understand the differences between these compounds and to administer them to patients appropriately.

In this paper, we propose an optimal voltage control for single-phase inverter with resonant LC filter via type-2 ILQ servo-control by 2nd-order polynomial. The improved ILQ control enables to follow the time-variant sinusoidal reference-voltage without phase delay. The excellent voltage control is achieved through the suppression of resonant output voltage.

Item does not contain fulltext For patients with advanced, radioactive iodine-refractory differentiated thyroid cancer, current treatment guidelines recommend clinical trial enrollment or small-molecule kinase inhibitor therapy. However, details of patient management vary between countries depending on trial availability and national regulatory policies. Insufficient clinical trial data and variable disease characteristics challenge the creation of universal guidelines, and treatment plans often reflect regional influences. A multidisciplinary, multiregional panel of experts met to discuss regional approaches to managing patients with advanced, radioactive iodine-refractory differentiated thyroid cancer and the potential impact of emerging therapies on current treatment strategies. Despite process-oriented regional differences, the decision-making strategies were similar. Multidisciplinary teams used to manage high-risk patients varied in composition across regions, particularly regarding the responsible physician's specialty. Cytotoxic chemotherapy was viewed as limited in clinical benefit, and targeted agents as attractive, based on promising data. Panel members support clinical trial enrollment as the preferred treatment strategy for managing these patients.

Therapeutic strategy for patients with differentiated thyroid carcinoma (DTC) in Japan has differed from that in Western countries. Total thyroidectomy followed by radioactive iodine (RAI) ablation has been a standard therapy in Western countries, while limited thyroidectomy has been widely accepted in Japan. We newly established guidelines for clinical practice in treating thyroid tumors based on evidence from previous publications and the accumulation of data from patients in Japan. We present our therapeutic recommendations for DTC patients based on these guidelines. From the 55 clinical questions (CQ) in our guideline, we selected CQ regarding the treatment of DTC. We commented on each and compared it with the corresponding regions in Western guidelines. For papillary carcinoma, we strongly or moderately recommend total thyroidectomy for patients with tumors larger than 4 cm, clinical node metastasis, distant metastasis, or significant extrathyroid extension, while hemithyroidectomy is acceptable for T1N0M0 patients. In contrast to Western guidelines, routine central compartment dissection is recommended for papillary carcinoma in our guidelines. Completion total thyroidectomy is recommended for patients who were scheduled for hemithyroidectomy under a preoperative diagnosis of follicular neoplasm and were pathologically confirmed as having follicular carcinoma if the pathological diagnosis indicated widely invasive carcinoma or carcinoma having poorly differentiated components. RAI ablation is also recommended for DTC with aggressive clinicopathological features, but its indication is narrower than that in Western guidelines, not only because of the limitations on RAI, but also because it is our policy that patients without high-risk features do not require RAI ablation. It is important to treat DTC patients individually according to their clinicopathological features rather than uniformly. We hope that policies regarding the treatment of DTC patients in Western countries and Japan will find the optimal compromise in the future, leading to the best treatments for patients with thyroid carcinoma all over the world.

Clinical or subclinical hyperparathyroidism (HPT) is one of the most common endocrine disorders. In patients with HPT who meet the indications for parathyroidectomy, complete surgical resection of all hyperfunctioning parathyroid tissue is essential for the curative treatment. The conventional surgical approach is bilateral neck exploration, whereas minimally invasive parathyroidectomy has been made possible by the introduction of (99m)Tc-sestamibi scintigraphy for preoperative localization of parathyroid adenomas. In minimally invasive surgery, the surgeon expects some modalities that predict complete resection of all hyperfunctioning parathyroid glands. The prevalence rate of (99m)Tc-sestamibi scanning for single parathyroid adenoma was widely accepted as 85-95%. Moreover, the recent developing technology of semiconductor electronics has produced useful portable gamma-probes. Intraoperative navigation using these devices provides the possibility of easy and definitive identification of parathyroid nodules during the operation. In minimally invasive radioguided parathyroidectomy using gamma-probe, different protocols are based on different timing and doses of tracer injected. Each procedure is technically easy, safe, with a low morbidity rate, and has better cosmetic results and lower overall cost than conventional bilateral neck exploration. We have applied this technique in selected patients and achieved success comparable to that achieved with contemporaneously performed standard neck exploration. In the hands of a competent surgeon, the use of sestamibi scanning and radioguided parathyroidectomy in appropriately selected patients is a useful technique.

症例は60歳男性．2年前に大動脈炎症候群による大動脈弁閉鎖不全症，上行大動脈拡大に対して，大動脈弁置換術，上行大動脈置換術を受けた．以後ステロイドの内服を行いながら外来通院していたが，小脳梗塞で入院した．人工弁感染による弁輪部膿瘍と診断され，準緊急手術を施行した．手術では破壊された弁輪部を郭清・修復後，Ross手術を行い救命した．Ross手術は大動脈弁位人工弁感染に対する選択肢の一つと考えられた．

要旨下大静脈(IVC)浸潤を伴う癌に対する切除とIVC再建術では、安定した循環動態の確保が困難であり、至適補助手段はいまだ確立されていない。我々はIVC浸潤を伴う腎癌に対する癌切除・IVC再建術において、大腿静脈脱血-内頸静脈送血のV-Vバイパスを補助循環として6例に用いた。V -Vバイパス回路は遠心ポンプを組み込んだ閉鎖回路に、IVC切開時の出血に備えて吸引回路を接続したものを使用した。灌流指数はV-Vバイパス開始前の血圧を維持するように送血量を調節し、結果として0.8～1.OL/min/m2で適正な血圧を維持することができた。死亡例および重篤な合併症を起こした症例はなく、また、V-Vバイパス中の循環動態は安定していた。IVC切開時に多量の出血が起こった場合には、吸引回路で回収して迅速に閉鎖回路に返血できたので、安定した循環動態を維持することができた。IVC浸潤を伴う腎癌に対する切除・再建術において、V-Vバイパスを用いた補助循環は安定した循環動態下で手術を行うのに有用であった。

Although surgery has been the mainstay of treatment for patients with well-differentiated thyroid cancer, the extents of thyroid resection and lymph node dissection adopted in Japan differ from those in other countries. Furthermore, regarding the indications for postoperative radiation therapy and hormonal therapy, and treatment modalities for cancer recurrence, there are marked discrepancies between Japan and other countries. A questionnaire survey was thus conducted among domestic and overseas thyroid surgeons to ascertain the actual treatment policy for well-differentiated thyroid cancer in Japan and various foreign countries. For small papillary carcinomas of 2.0 cm or less (T1), thyroid resection was more extensive in foreign countries than in Japan, although the extent of lymph node dissection was limited in the former. For large papillary carcinomas exceeding 3.0 cm (T2), on the other hand, total thyroidectomy was the treatment of first choice for all overseas respondents, but of only 20% in Japan, despite lymph node dissection being more extensive in Japan than in other countries. Overseas surgeons were much more likely to favor postoperative TSH suppression therapy and high-dose (131)I therapy. For recurrence following surgery for papillary thyroid cancer, both domestic and overseas respondents indicated surgical resection to be the most common treatment option, and favored high-dose (131)I therapy as well. In Japan, however, high-dose (131)I therapy is available only in a few institutions. Such limited indications for high-dose (131)I therapy in Japan may reflect a discrepancy in the frequency of total thyroidectomy, a prerequisite for postoperative high-dose (131)I therapy, between Japan and other countries. This is the first questionnaire study conducted in both Japan and other countries in relation to treatment modalities for thyroid cancer. The results reveal that there is a clear disparity in treatment policies between Japan and foreign countries.

Purpose of review Based on recent advances in ultrasonography, color-Doppler sonography and ultrasound-guided fine needle aspiration biopsy, minimally invasive thyroidectomy has been widely employed for treating thyroid tumors. Minimally invasive procedures have recently been adopted for the surgical treatment of thyroid disease as a means of preventing prominent scars, hypesthesia and paresthesia. Recent findings We have developed axillary and anterior chest approaches for endoscopic thyroidectomy. The mean operating time for the endoscopic procedure was significantly longer than that for conventional open surgery. All patients who were treated using the axillary approach were satisfied with the cosmetic results. The incidence of complaints after endoscopic surgery is significantly lower than that after open surgery. The minimally invasive mini-incision approach has been performed under direct and endoscopic vision to minimize surgical invasiveness and improve cosmetic results. Our procedure differs from conventional thyroidectomy in requiring a 3-cm skin incision, and in not raising of a skin flap and not dissecting the sternohyoid muscle. Summary Endoscopic thyroidectomy is the procedure of choice in well selected patients with thyroid disease. The present indications for this procedure include benign follicular adenomas less than 4 cm in diameter, low-risk papillary carcinomas less than 10 mm, oxyphilic cell tumors less than 4 cm and Graves' disease as imaged on preoperative ultrasonography. The minimally invasive mini-incision approach is indicated for patients with low-risk, well differentiated carcinomas. Total thyroidectomy and bilateral modified neck dissection is possible, if the tumor is not large.