Development of silicon-on-insulator direct electron detector with analog memories in pixels for sub-microsecond imaging.

We have developed a high-speed recordable direct electron detector based on silicon-on-insulator technology. The detector has sixteen analog memories in each pixel to record sixteen images with sub-microsecond temporal resolution. A dedicated data acquisition system has also been developed to display and record the results on a personal computer. The performance of the direct electron detector as an image sensor is evaluated under electron irradiation with an energy of 30 keV in a low-voltage transmission electron microscope equipped with a photocathode electron gun. We demonstrate that the detector can record images at an exposure time of 100 ns and an interval of 900 ns.

2-methacryloyloxyethyl phosphorylcholine polymer treatment prevents Candida albicans biofilm formation on acrylic resin.

PURPOSE: We aimed to evaluate the effectiveness of photoreactive 2-methacryloyloxyethyl phosphorylcholine (MPC) in inhibiting Candida albicans biofilm formation on polymethyl methacrylate (PMMA) and assess its mechanism and need for re-application by evaluating its interaction with salivary mucin and durability during temperature changes. METHODS: PMMA discs were used as specimens. The MPC coating was applied using the spray and cure technique for the treatment groups, whereas no coating was applied to the control. The MPC treatment (MT) groups were further differentiated based on the number of thermal cycles involved (0, 1000, 2500, and 5000). The optical density was measured to assess mucin adsorption (MA). Contact angle (CA) was calculated to evaluate surface hydrophilicity. The presence of MPC components on the PMMA surface was assessed using X-ray photoelectron spectroscopy (XPS). C. albicans biofilms were evaluated qualitatively (scanning electron microscope images) and quantitatively (colony-forming units (CFUs)). Statistical analysis was conducted using two-way analysis of variance and Tukey's multiple comparison test. RESULTS: MA rate and CA increased significantly in the MT groups, which exhibited significantly fewer CFUs and thinner biofilms than those of the control group. Based on the XPS, MA, and CFU evaluations, the durability and efficacy of the MPC coating were considered stable up to 2500 thermal cycles. Additionally, a significant interaction was observed between mucin concentration and MPC efficacy. CONCLUSIONS: The photoreactive MPC coating, which was resistant to temperature changes for approximately 3 months, effectively prevented C. albicans biofilm formation by modifying surface hydrophilicity and increasing mucin adsorption.

Association of volumetric-modulated arc therapy with radiation pneumonitis in thoracic esophageal cancer.

The lung volume receiving low-dose irradiation has been reported to increase in volumetric-modulated arc radiotherapy (VMAT) compared with three-dimensional conformal radiotherapy (3DCRT) for thoracic esophageal cancer, which raises concerns regarding radiation pneumonitis (RP) risk. This single institutional retrospective cohort study aimed to explore whether VMAT for thoracic esophageal cancer was associated with RP. Our study included 161 patients with thoracic esophageal cancer, of whom 142 were definitively treated with 3DCRT and 39 were treated with VMAT between 2008 and 2018. Radiotherapy details, dose-volume metrics, reported RP risk factors and RP incidence were collected. The RP risk factors were assessed via multivariate analysis. Dose-volume analysis showed that VMAT delivered more conformal dose distributions to the target volume (P < 0.001) and reduced V30 Gy of heart (57% vs 41%, P < 0.001) but increased V5 Gy (54% vs 41%, P < 0.001) and V20 Gy (20% vs 17%, P = 0.01) of lungs compared with 3DCRT. However, the 1-year incidence rates of RP did not differ between the two techniques (11.3% in 3DCRT vs 7.7% in VMAT, P = 0.53). The multivariate analysis suggested that the presence of interstitial lung disease (ILD) (P = 0.01) and V20 Gy of lungs ≥20% (P = 0.008) were associated with RP. Conclusively, VMAT increased the lung volume receiving low to middle doses irradiation, although this might not be associated with RP. Further studies are needed to investigate the effect of using VMAT for delivering conformal dose distributions on RP.

Novel Magnetic Attachment System Manufactured Using High-Frequency Heat Treatment and Stamp Technique: Introduction and Basic Performance.

Recently, a novel magnetic attachment with extremely low cost and high performance was developed. This article aims to introduce a novel magnetic attachment and to evaluate its basic eligibility for denture retention in clinical practice. The novel magnetic attachment system used in this study was the direct-bonding root-keeper-type Magteeth™ MT800 (MagneDesign, Nagoya, Japan). The retentive force without displacement (position 0) and after horizontal displacement to positions 0.5, 1, 1.5, 2, 2.5, and 3 mm were measured. The values relative to the retentive force without displacement were gradually decreased to 82.7 ± 16.3%, 68.8 ± 17.1%, 62.4 ± 15%, 47.2 ± 13.1%, 35.7 ± 9.9%, and 20.7 ± 6.5%, respectively. The retentive force and magnetic field strength did not change significantly after the load test (100 N load, 10,000 times). No new gap between the metal and resin was found in the root keeper- and magnet assembly-embedded blocks after the load test. Some scratches on magnetic assembly and root keeper surface, while no change in the resin texture after the load test were observed. Based on the findings of this preliminary study, this novel low-cost magnetic attachment exhibited favorable retention, strength, and durability for clinical use.

Preoperative chemoradiotherapy for locally advanced low rectal cancer using intensity-modulated radiotherapy to spare the intestines: a single-institutional pilot trial.

The irradiated volume of intestines is associated with gastrointestinal toxicity in preoperative chemoradiotherapy for rectal cancer. The current trial prospectively explored how much of the irradiated volume of intestines was reduced by intensity-modulated radiotherapy (IMRT) compared with 3-dimensional conformal radiotherapy (3DCRT) and whether IMRT might alleviate the acute gastrointestinal toxicity in this population. The treatment protocol encompassed preoperative chemoradiotherapy using IMRT plus surgery for patients with clinical T3-4, N0-2 low rectal cancer. IMRT delivered 45 Gy per 25 fractions for gross tumors, mesorectal and lateral lymph nodal regions, and tried to reduce the volume of intestines receiving 15 Gy (V15 Gy) < 120 cc and V45 Gy ≤ 0 cc, respectively, while keeping target coverage. S-1 and irinotecan were concurrently administered. Acute gastrointestinal toxicity, rates of clinical downstaging, sphincter preservation, local regional control (LRC) and overall survival (OS) were evaluated. Twelve enrolled patients completed the chemoradiotherapy protocol. The volumes of intestines receiving medium to high doses were reduced by the current IMRT protocol compared to 3DCRT; however, the predefined constraint of V15 Gy was met only in three patients. The rate of ≥ grade 2 gastrointestinal toxicity excluding anorectal symptoms was 17%. The rates of clinical downstaging, sphincter preservation, three-year LRC and OS were 75%, 92%, 92% and 92%, respectively. In conclusion, preoperative chemoradiotherapy using IMRT for this population might alleviate acute gastrointestinal toxicity, achieving high LRC and sphincter preservation; although further advancement is required to reduce the irradiated volume of intestines, especially those receiving low doses.

Treatment outcomes of implant-assisted removable partial denture with distal extension based on the Kennedy classification and attachment type: a systematic review.

BACKGROUND: Implant-assisted removable partial dentures (IARPDs) have recently become popular, but little information is available on the treatment outcomes based on the Kennedy classification and attachment types. OBJECTIVE: The objective of this review was to evaluate the treatment outcomes of IARPD delivered for distal extension edentulous areas based on the differences in the Kennedy classification and attachment type. MATERIALS AND METHODS: English-language clinical studies on IARPD published between January 1980 and February 2020 were collected from MEDLINE (via PubMed), the Cochrane Library (via the Cochrane Central Register of Controlled Trials), Scopus online database, and manual searching. Two reviewers selected the articles based on pre-determined inclusion and exclusion criteria, followed by data extraction and analysis. RESULTS: Eighty-one studies were selected after evaluating the titles and abstracts of 2410 papers. Nineteen studies were finally included after the perusal of the full text. Fourteen studies focused on Class I, 4 studies investigated both Class I and II, and only 1 study was conducted on Kennedy's class II. Eight types of attachments were reported. The ball attachment was the most frequently used attachment, which was employed in 8 of the included studies. The implant survival rate ranged from 91 to 100%. The reported marginal bone loss ranged from 0.3 mm to 2.30 mm. The patient satisfaction was higher with IARPD than with conventional RPDs or that before treatment. The results of prosthetic complications were heterogeneous and inconclusive. CONCLUSION: IARPD exhibited favorable clinical outcomes when used as a replacement for distal extension edentulous areas. The comparison between the clinical outcomes of Kennedy's class I and II was inconclusive owing to the lack of studies focusing on Kennedy Class II alone. The stud attachment was the most commonly used type in IARPDs. Overall, the different attachment systems did not influence the implant survival rate and patient satisfaction. Further high-quality studies are needed to investigate the attachment systems used in IARPD.

Long-term outcomes of an esophagus-preserving chemoradiotherapy strategy for patients with endoscopically unresectable stage I thoracic esophageal squamous cell carcinoma.

BACKGROUND AND PURPOSE: To assess the long-term outcomes of a multimodal approach for maximum esophagus preservation in operable patients with endoscopically unresectable stage I thoracic esophageal squamous cell carcinoma (ESCC). MATERIALS AND METHODS: The medical records of patients with stage I thoracic ESCC treated with our protocol between 1992 and 2005 were retrospectively reviewed. Our protocol consisted of neoadjuvant concurrent chemoradiotherapy, followed by either additional definitive chemoradiotherapy for good responders (CRT group) or surgery for moderate or poor responders (CRT-S group) after an interim appraisal. RESULTS: A total of 51 patients were analysed. The median age of the patients was 67 years. The median follow-up period was 124.8 months. After the interim assessment, 49 and 2 cases were assigned to the CRT and CRT-S groups, respectively. In the intent-to-treat analyses, overall survival (OS), disease-free survival (DFS), cumulative incidence for death from esophageal cancer, and that for loss of esophageal function were 78.9%, 53.5%, 10.5%, and 20.4% at 5 years, and 55.2%, 27.8%, 18.2%, and 22.9% at 10 years, respectively. Grade 3 late toxicities occurred with the following incidences: esophageal stenosis in 1 case, esophageal ulcer in 1 case, and pericardial effusion in 2 cases. No grade 4 or higher toxicities were observed. CONCLUSION: Long-term survival and esophagus preservation outcomes were favorable, with acceptable toxicities. Our results suggest that CCRT is an alternative treatment for majority of operable patients with endoscopically unresectable stage I thoracic ESCC in combination with salvage therapy.

Treatment of intrahepatic recurrence after hepatectomy for hepatocellular carcinoma.

BACKGROUND: Prognostic factors after treatment for intrahepatic recurrent hepatocellular carcinoma (RHCC) after hepatic resection (Hx) are controversial. The current study aimed to examine the impact of treatment modality on the prognosis of intrahepatic RHCC following Hx. METHODS: For control of variables, the subjects were 56 patients who underwent treatment for intrahepatic RHCC, three or fewer tumors, each measuring ≤3 cm in diameter without macroscopic vascular invasion (MVI), between 2000 and 2011. Retreatment consisted of repeat Hx (n = 23), local ablation therapy (n = 11) and transarterial chemoembolization or transcatheter arterial infusion (TACE/TAI) (n = 22). We retrospectively investigated the relation between type of treatment for RHCC and overall survival (OS) as well as disease-free survival (DFS). RESULTS: In multivariate (MV) analysis, the poor prognostic factors in DFS after retreatment consisted of disease-free interval (DFI) (≤1.5 y) (P = .011), type of retreatment (TACE/TAI) (P = .002), age (<65 y old) (P = .0022), perioperative RBC transfusion (P = .025), while those in OS after retreatment were DFI (≤1.5 y) (P < .0001). In evaluation of stratification for type of retreatment, DFS in the repeat Hx group was significantly better than those in the local ablation therapy group or the TACE/TAI group (P = .023 or P < .0001, respectively). CONCLUSIONS: DFI (≤1.5 y) was an independent poor prognostic factor in both DFS and OS, and repeat Hx for intrahepatic RHCC, few in number and size without MVI, seems to achieve the most reliable local control.

Definitive radiotherapy for secondary esophageal cancer after allogeneic hematopoietic stem cell transplantation.

The reports for secondary esophageal cancer treated by radiotherapy or chemoradiotherapy is few, however they potentially yield a cure for esophageal cancer. We report a case of definitive radiotherapy for a patient with secondary locally advanced unresectable esophageal cancer after hematopoietic stem cell transplantation for acute myeloid leukemia. Definitive radiotherapy for the current patient was completed with acceptable toxicity despite the poor general condition with long-term chronic graft-versus-host disease. Radiotherapy may be the definitive treatment for this population unfit for concurrent chemotherapy or surgery.

Change in antimicrobial susceptibility of pathogens isolated from surgical site infections over the past decade in Japanese nation-wide surveillance study.

Inappropriate antimicrobial therapy for surgical site infections (SSIs) can lead to poor outcomes and an increased risk of antibiotic resistance. A nationwide survey was conducted in Japan from 2018 to 2019 to investigate the antimicrobial susceptibility of pathogens isolated from SSIs. The data were compared with those obtained in 2010 and 2014-2015 surveillance studies. Although the rate of detection of extended-spectrum ß-lactamase producing strains of Escherichia coli was increased from 9.5% in 2010 to 23% in 2014-2015, the incidence decreased to 8.7% in 2018-2019. Although high susceptibility rates were detected to piperacillin/tazobactam (TAZ), the geometric mean MICs were substantially higher than to meropenem (2.67 vs 0.08 µg/mL). By contrast, relatively low geometric mean MICs (0.397 µg/mL) were demonstrated for ceftolozane/TAZ. Although the MRSA incidence rate decreased from 72% in the first surveillance to 53% in the second, no further decrease was detected in 2018-2019. For the Bacteroides fragilis group species, low levels of susceptibility were observed for moxifloxacin (65.3%), cefoxitin (65.3%), and clindamycin (CLDM) (38.9%). In particular, low susceptibility against cefoxitin was demonstrated in non-fragilis Bacteroides, especially B. thetaiotaomicron. By contrast, low susceptibility rates against CLDM were demonstrated in both B. fragilis and non-fragilis Bacteroides species, and a steady decrease in susceptibility throughout was observed (59.3% in 2010, 46.9% in 2014-2015, and 38.9% in 2018-2019). In conclusion, Japanese surveillance data revealed no significant lowering of antibiotic susceptibility over the past decade in organisms commonly associated from SSIs, with the exception of the B. fragilis group.

Incidence and Risk Factors of Symptomatic Radiation Pneumonitis in Non-Small-Cell Lung Cancer Patients Treated with Concurrent Chemoradiotherapy and Consolidation Durvalumab.

INTRODUCTION: Data on the risk factors for symptomatic radiation pneumonitis (RP) in non-small-cell lung cancer (NSCLC) patients treated with concurrent chemoradiotherapy (CCRT) and consolidation durvalumab are limited; we aimed to investigate these risk factors. MATERIALS AND METHODS: This multicenter retrospective study, conducted at 15 institutions in Japan, included patients who were ≥20 years of age; who started definitive CCRT for NSCLC between July 1, 2018, and July 31, 2019; and who then received durvalumab. The primary endpoint was grade 2 or worse (grade 2+) RP. RESULTS: In the 146 patients analyzed, the median follow-up period was 16 months. A majority of the patients had stage III disease (86%), received radiation doses of 60 to 66 Gy equivalent in 2-Gy fractions (93%) and carboplatin and paclitaxel/nab-paclitaxel (77%), and underwent elective nodal irradiation (71%) and 3-dimensional conformal radiotherapy (75%). RP grade 2 was observed in 44 patients (30%); grade 3, in four patients (3%); grade 4, in one patient (1%); and grade 5, in one patient (1%). In the multivariable analysis, lung V20 was a significant risk factor, whereas age, sex, smoking history, irradiation technique, and chemotherapy regimen were not. The 12-month grade 2+ RP incidence was 34.4% (95% confidence interval [CI], 26.7%-42.1%); the values were 50.0% (95% CI, 34.7%-63.5%) and 27.1% (95% CI, 18.8%-36.2%) in those with lung V20 ≥ 26% and < 26%, respectively (P = .007). CONCLUSION: The incidence of grade 2+ RP was relatively high in this multicenter real-world study, and its risk increased remarkably at elevated lung V20. Our findings can aid in RP risk prediction and the safe radiotherapy treatment planning.

Association of Chemoradiotherapy With Thoracic Vertebral Fractures in Patients With Esophageal Cancer.

Importance: The association of chemoradiotherapy (CRT) with a thoracic vertebral fracture in patients with esophageal cancer is unknown. Objective: To determine whether CRT is associated with thoracic vertebral fractures in patients with esophageal cancer. Design, Setting, and Participants: This retrospective cohort study included patients with clinical stages I to III thoracic esophageal cancer who visited the Kyoto University Hospital, Kyoto, Japan, from January 1, 2007, to December 31, 2013. Data were analyzed from April 6, 2018, to June 4, 2020. Exposures: Chemoradiotherapy (CRT group) or surgery or endoscopic treatment (non-CRT group). Main Outcomes and Measures: The main outcome of this study was the cumulative incidence rate of thoracic vertebral fractures in 36 months. The incidence rate was calculated taking censoring into account. Possible risk factors, including CRT, were explored in the multivariable analysis. The association of irradiated doses with fractured vertebrae was also evaluated. Results: A total of 315 patients (119 for the CRT group and 196 for the non-CRT group) were included. The median age of patients was 65 (range, 32-85) years. Fifty-six patients (17.8%) were female and 259 (82.2%) were male. The median observation time was 40.4 (range, 0.7-124.1) months. Thoracic vertebral fractures were observed in 20 patients (16.8%) in the CRT group and 8 patients (4.1%) in the non-CRT group. The 36-month incidence rate of thoracic vertebral fractures was 12.3% (95% CI, 7.0%-19.1%) in the CRT group and 3.5% (95% CI, 1.3%-7.5%) in the non-CRT group (hazard ratio [HR], 3.41 [95% CI, 1.50-7.73]; P = .003). The multivariable analysis showed that the HR of the thoracic vertebral fracture in the CRT group to non-CRT group was 3.91 (95% CI, 1.66-9.23; P = .002) with adjusting for sex, 3.14 (95% CI, 1.37-7.19; P = .007) with adjusting for age, and 3.10 (95% CI, 1.33-7.24; P = .009) with adjusting for the history of vertebral or hip fractures. The HR of the thoracic vertebral fracture for a 5-Gy increase in the mean radiation dose to the single vertebra was 1.19 (95% CI, 1.04-1.36; P = .009). Conclusions and Relevance: This study found that chemoradiotherapy was associated with thoracic vertebral fractures in patients with esophageal cancers. A reduced radiation dose to thoracic vertebrae may decrease the incidence of fractures.

Reliability of Screening Methods to Diagnose Oral Dryness and Evaluate Saliva Secretion.

In this study, we evaluated the reliability and reproducibility of widely implemented salivary flow rate and oral dryness tests. In experiment 1, twenty young and healthy Japanese participants volunteered to participate. For each participant, the oral moisture (OM) level, unstimulated whole saliva volume (U-WSV), and stimulated whole saliva volume (S-WSV) were measured at the same time on two separate days. In experiment 2, twenty-seven patients who were over 65 years of age volunteered to participate. The OM level and U-WSV were measured at the same time on two separate days. In Experiment 1, the intra-class correlation coefficients (ICCs) corresponding to the S-WSV, U-WSV, and OM level were 0.23, 0.28, and 0.16, respectively, for the young participants. In Experiment 2, the ICCs corresponding to the U-WSV/spitting and OM level were 0.83 and 0.12, respectively, for the older participants. The results of Bland-Altman analysis confirmed the absence of systematic error, with the exception of the OM level results in Experiment 2, which indicated systematic bias. In conclusion, we believe that there is currently no consistent and reliable screening test for assessing salivary flow rate and oral dryness, although the spitting test was determined to be highly reliable.

Effect of polishing protocols on the surface roughness of polyetheretherketone.

The purpose of this study was to evaluate the influence of various polishing protocols on the surface roughness of polyetheretherketone (PEEK) and identify an effective polishing method of dental prostheses at the chairside. The PEEK specimens were assigned to seven groups with different protocols: no additional polishing (NT); polishing using a rubber point (C); polishing using "silky shine" (S); polishing using "aqua blue paste" (A); protocol C followed by protocol S (CS); protocol C followed by protocol A (CA); and protocol C followed by protocols S and A (CSA). The surface roughness (Sa and Ra) of the polished surfaces was measured. The surface roughness decreased in the following order of groups: NT, C, S, CS, CSA, CA, and A. In Groups C and S, wide deep pits formed by abrasive grains of SiC paper were observed, whereas only fine linear structures were observed on the surface in other groups. With respect to the polishing protocol of PEEK, clinically acceptable surface roughness was obtained using a soft polishing brush and agent for more than 3 min.

A Preoperative Scoring System to Predict Carcinoma in Patients with Gallbladder Polyps.

INTRODUCTION: A preoperative scoring system to predict carcinoma in patients with gallbladder polyps (GBPs). METHODS: Preoperative parameters of patients with GBPs who underwent cholecystectomies were used to construct a scoring system to ascertain the risk of malignancy (reference group). The scoring system developed from this approach was applied to the validation group. RESULTS: In the reference group, 11.5% of patients had carcinomas, in whom the median age was 68 years and the polyp size was 16.9 mm. According to the univariate analysis, the significant factors for carcinoma were age ≥65 years, the presence of gallstones, polyp size ≥13 mm, solitary polyp, and sessile polyp. Age ≥65 years and polyp size ≥13 mm were significant factors according to the multivariate analysis. From these results, we developed a preoperative scoring system to predict carcinoma. The patients were divided into 1 of 2 groups: low-risk and high-risk and their malignancy rates were 4.1 and 61.1% respectively (p < 0.001). In the validation group, the malignancy rate was higher for those in the high-risk group (p = 0.016). CONCLUSIONS: The proposed preoperative scoring system based on simple clinical variables appears to be useful for predicting malignancy in patients with GBPs.

A Case Report of Locally Advanced Anal Cancer with Solitary Cutaneous Nodular Metastasis in the Ipsilateral Labia Majora Treated with Definitive Chemoradiotherapy.

Cutaneous metastasis from anal cancer is rare at the initial diagnosis. There is a dearth of information on definitive treatment for anal cancer with cutaneous metastasis. We report the case of a 63-year-old female with locally advanced anal cancer and solitary cutaneous nodular metastasis in the right labia majora identified at the initial diagnosis that was successfully treated with definitive chemoradiotherapy. She arrived at our hospital with complaints of an enlarging perineal itching nodule. Genital and rectal examination detected an anal tumor with perineal and rectal invasion. The biopsy specimen indicated it was a squamous cell carcinoma that was accompanied by right inguinal and external iliac lymph nodal metastases and solitary cutaneous nodular metastasis in the ipsilateral labia majora. She was diagnosed with anal cancer, clinical T3N1M1, stage IV (UICC-TNM 7th). She had good performance status and effective organ function. She received definitive chemoradiotherapy with irradiation fields that included the primary tumor, pelvic lymph nodal metastases, and solitary cutaneous genital metastasis. After completing the planned treatment, all tumors vanished without recurrences at 42 months after treatment. In conclusion, patients with locally advanced anal cancer may suffer genital cutaneous metastasis that develops with lymphatic drainage from the anus to the inguinal lymph nodes. Anal cancer with solitary genital cutaneous nodular metastasis can be considered as a local-regional disease and can be treated with chemoradiotherapy. Chemoradiotherapy achieved a cure in our case.

Impact of Bile Exposure Time on Organ/space Surgical Site Infections After Pancreaticoduodenectomy.

BACKGROUND/AIM: Organ/space surgical site infections (SSIs) are critical complications of pancreaticoduodenectomy. We investigated the impact of the time between division of the common hepatic duct and completion of biliary reconstruction [bile exposure (BE) time] on the occurrence of post-pancreaticoduodenectomy organ/space SSI. PATIENTS AND METHODS: Sixty-one patients who underwent pancreaticoduodenectomy were retrospectively studied. The impact of perioperative variables and BE time on organ/space SSI occurrence was analyzed. RESULTS: Organ/space SSIs occurred in 17 patients (28%). Patients were divided into two groups according to BE time. The incidence of organ/space SSIs was significantly higher in the long BE time group than in the short BE time group (42% versus 13%, p=0.0127). Multivariate analysis revealed that long BE times [odds ratio (OR)=4.8; p=0.0240] and soft pancreatic texture (OR=16.5; p=0.0106) were independent risk factors for organ/space SSIs. CONCLUSION: Long BE time is a risk factor for post-pancreaticoduodenectomy organ/space SSIs. Shortening BE time may reduce organ/space SSI occurrence.

Effect of Surface Treatments on Shear Bond Strength of Polyetheretherketone to Autopolymerizing Resin.

These days, new prosthodontic materials are appearing with the development of digitalization. Among these, the use of polyetheretherketone (PEEK) as the clasp of removable partial dentures has been proposed. The adhesive strength between the PEEK and acrylic resin influences the probability of denture fracture. To investigate the effect of PEEK surface treatments on the shear bond strength to acrylic resin, five surface treatment conditions of PEEK were analyzed: 1. no treatment; 2. ceramic primer application; 3. Al2O3 sandblasting; 4. Rocatec; and 5. Rocatec with ceramic primer application, comparing with a metal primer-treated Co-Cr alloy. Two kinds of autopolymerizing resin (Unifast II and Palapress Vario) were used as bonding materials. The specimens were evaluated to determine the bond strength. Rocatec treatment with ceramic primer application yielded the highest bond strengths (12.71 MPa and 15.32 MPa, respectively, for Unifast II and Palapress Vario). When compared to a metal primer-treated Co-Cr alloy, the bond strength of PEEK to Unifast II was similar, whereas it was about 60% of that to Palapress Vario. Rocatec treatment, combined with ceramic primer, showed the highest bond strength of PEEK to acrylic resin. Treatment of PEEK will enable its use as the clasp of removable dentures and the fixation of PEEK prostheses.

Intensity-modulated radiotherapy for cervical esophageal squamous cell carcinoma without hypopharyngeal invasion: dose distribution and clinical outcome.

Hypopharyngeal invasion would be a key finding in determining the extent of the irradiation fields in patients with cervical esophageal squamous cell carcinoma (CESCC). This study aimed to investigate the clinical outcomes of chemoradiotherapy using simultaneous integrated boost intensity-modulated radiotherapy (SIB-IMRT) omitting upper cervical lymph nodal irradiation in CESCC without hypopharyngeal invasion, and the dosimetric superiority of SIB-IMRT to 3D conformal radiotherapy (3DCRT). We retrospectively identified 21 CESCC patients without hypopharyngeal invasion [clinical Stage I/II/III/IV (M1LYM); 3/6/5/7] (UICC-TNM 7th edition) who underwent chemoradiotherapy using SIB-IMRT between 2009 and 2015. SIB-IMRT delivered 60 Gy to each primary tumor and the metastatic lymph nodes, and 48 Gy to elective lymph nodal regions, including Levels III and IV of the neck, supraclavicular, and upper mediastinal lymphatic regions, in 30 fractions. The overall survival rate, locoregional control rate, and initial recurrence site were evaluated. 3DCRT plans were created to perform dosimetric comparisons with SIB-IMRT. At a median follow-up of 64.5 months, the 5-year locoregional control and overall survival rates were 66.7% and 53.4%, respectively. Disease progressed in eight patients: all were locoregional progressions and no patients developed distant progression including upper cervical lymph nodal regions as initial recurrence sites. The planning study showed SIB-IMRT improved target coverage without compromising the dose to the organs at risk, compared with 3DCRT. In conclusion, omitting the elective nodal irradiation of the upper cervical lymph nodes was probably reasonable for CESCC patients without hypopharyngeal invasion. Locoregional progression remained the major progression site in this population.

Nutritional and clinical outcomes of chemoradiotherapy for clinical T1N0M0 esophageal carcinoma.

Purpose: Whether nutritional assessment and management improves clinical outcomes in patients with clinical T1N0M0 esophageal squamous cell carcinoma (ESCC) who undergo chemoradiotherapy remains to be demonstrated. This study aimed to determine the nutritional status of such patients pre- and post-chemoradiotherapy and its clinical outcomes. Patients and methods: This single institutional retrospective study included patients who underwent chemoradiotherapy for clinical T1N0M0 ESCC using serum albumin concentrations and body weights evaluated pre- and post-chemoradiotherapy from January 2005 to December 2016. The nutritional risk index (NRI) score was used to quantify the nutritional status: NRI score ≥100: no risk, 97.5-100: mild risk, 83.5-97.5: moderate risk, and <83.5: major risk. NRI categories pre-and post-chemoradiotherapy were compared using Wilcoxon signed rank test. Local-regional control (LRC), overall survival (OS), and cause-specific survival (CSS) rates were calculated using Kaplan-Meier method. The effect of pre-chemoradiotherapy NRI score and decreased NRI category during chemoradiotherapy on OS was evaluated using log-rank test. Results: Among the 492 patients with ESCC who underwent chemoradiotherapy, 44 were included in this study. Among these, 21 patients exhibited a pre-chemoradiotherapy NRI score of <100. During chemoradiotherapy, the NRI score decreased from 100.5 to 94.5, and the median NRI category significantly decreased by 2 (p<0.0001). With a median follow-up of 72 months, the 5-year LRC, OS, and CSS rates were 79.8%, 88.9%, and 96.8%, respectively. The pre-chemoradiotherapy NRI score of <100 and decreased NRI category during chemoradiotherapy did not significantly affect OS. Conclusion: Patients with clinical T1N0M0 ESCC without dysphagia were at risk of undernutrition pre- and post-chemoradiotherapy. The current study's results justify further clinical nutritional research for this population, and that clinicians consider nutritional support for this population.