Evaluating the Efficacy of Machine Performance Checks as an Alternative to Winston-Lutz Quality Assurance Testing in the TrueBeam Linear Accelerator with HyperArc.

HyperArc is a preferred technique for treating brain metastases, employing a single isocenter for multiple lesions. Geometrical isocentricity in the TrueBeam linear accelerator with HyperArc is crucial. We evaluated machine performance checks (MPCs) as an alternative to the Winston-Lutz (WL) test to verify the treatment isocenter. Between January and July 2023, we assessed 53 data points using MPC and Winston-Lutz tests. The isocenter size obtained from the MPC and its sum, including the rotation-induced couch shift, were compared with the maximum total delta value from the Winston-Lutz test. The maximum total delta was 0.68 ± 0.10 mm, while the isocenter size was 0.28 ± 0.02 mm. The sum of the isocenter size and rotation-induced couch shift measured by MPC was 0.61 ± 0.03 mm. During the Winston-Lutz test (without couch rotation), the maximum total delta value was 0.56 ± 0.13 mm. A t-test analysis revealed a significant difference in the isocenter size averages between the Winston-Lutz and MPC outcomes, whereas the Pearson's correlation coefficient yielded no correlation. Our study highlights the necessity for separate MPC and Winston-Lutz tests for isocenter verification. Therefore, the Winston-Lutz test should precede stereotactic radiosurgery for isocenter verification.

Circulating Tumor DNA Analysis on Metastatic Prostate Cancer with Disease Progression.

The positivity rate of circulating tumor DNA (ctDNA) next-generation sequencing (NGS) varies among patients with metastatic prostate cancer (mPC), complicating its incorporation into regular practice. This retrospective study analyzed the ctDNA sequencing results of 100 mPC patients from May 2021 to March 2023 to identify the factors associated with positive ctDNA. Three custom gene panels were used for sequencing. Overall, 63% of the patients exhibited tier I/II somatic alterations, while 12% had pathogenic/likely pathogenic germline alterations. The key genes that were altered included AR, TP53, RB1, PTEN, and APC. Mutations in BRCA1/2, either germline or somatic, were observed in 21% of the patients. Among the metastatic castration-resistant prostate cancer (mCRPC) patients, the ctDNA-positive samples generally showed higher median prostate-specific antigen (PSA) levels and were more likely to be at the radiographic and clinical progressive disease stages, although they were not significantly associated with PSA progression. Our results suggest that ctDNA analysis could detect meaningful genetic changes in mPC patients, especially during disease progression.

Surveillance spilled Chironomidae (Diptera) larvae from drinking water treatment plants in South Korea using morphogenetic species analysis and eDNA metabarcoding.

Chironomid larvae (Diptera: Chironomidae) are tremendous indicator species that can tolerate a broad range of environmental conditions, from polluted to unimpaired water ecosystems. These species are ubiquitously observed in all bioregions and can even be found in drinking water treatment plants (DWTPs). Detection of chironomid larvae in DWTPs is a critical issue because their presence may be indicative of the water quality in the supply of tap water for human consumption. Therefore, the aim of the present study was to identify the chironomid communities that reflect the water quality of DWTPs and develop a biomonitoring tool to detect biological contamination of the chironomids in DWTPs. To do so, we investigated the identity and distribution of chironomid larvae in seven DWTP areas using morphological identification, DNA barcoding, and sediment environmental DNA (eDNA) analysis. A total of 7924 chironomid individuals encompassing three subfamilies and 25 species of 19 genera were identified in 33 sites within the DWTPs. The Gongchon and Bupyeong DWTPs were dominated by Chironomus spp. larvae, which were correlated with low levels of dissolved oxygen in the water. In the Samgye DWTP and Hwajeong DWTP, Chironomus spp. were almost absent, and instead, Tanytarsus spp. were abundant. Additionally, the Gangjeong DWTP was dominated by a Microtendipes sp., and two species of Orthocladiinae (a Parametriocnemus sp. and a Paratrichocladius sp.) were found only in the Jeju DWTP. We also identified the eight most abundant Chironomidae larvae found in the DWTPs. Furthermore, eDNA metabarcoding of DWTP sediment indicated the presence of different eukaryotic fauna and confirmed the presence of chironomids in DWTPs. These data provide useful morphological and genetic information regarding chironomid larvae that can be used for the water quality biomonitoring of DWTPs to support the supply of clean drinking water.

DEVELOPMENT OF SAFETY ASSESSMENT CODE FOR DECOMMISSIONING WASTE RECYCLING AND DISPOSAL.

In Korea, 10 units of nuclear power plants are projected for decommissioning by 2030, which will consequently generate a large amount of decommissioning waste. It could bring about a lack in the capacity of the radioactive waste disposal facility. In this paper, a computational code, REcycling and DIsposal Safety Assessment has been developed for the safety assessment regarding the recycling and disposal of the decommissioning waste. It is composed of two modules: dose assessment module and maximum allowance concentration estimation module. The dose assessment module is intended to evaluate the exposure doses from radioactive nuclides in the wastes for each recycling or disposal scenario. The maximum allowance concentration estimation module has the function to translate the nuclides concentrations in the wastes from the exposure doses received by the end user for each scenario. The concentration of each nuclide provides the basis for the development of the technical criteria in accordance with the annual dose limit.

Bifidobacterial carbohydrate/nucleoside metabolism enhances oxidative phosphorylation in white adipose tissue to protect against diet-induced obesity.

BACKGROUND: Comparisons of the gut microbiome of lean and obese humans have revealed that obesity is associated with the gut microbiome plus changes in numerous environmental factors, including high-fat diet (HFD). Here, we report that two species of Bifidobacterium are crucial to controlling metabolic parameters in the Korean population. RESULTS: Based on gut microbial analysis from 99 Korean individuals, we observed the abundance of Bifidobacterium longum and Bifidobacterium bifidum was markedly reduced in individuals with increased visceral adipose tissue (VAT), body mass index (BMI), blood triglyceride (TG), and fatty liver. Bacterial transcriptomic analysis revealed that carbohydrate/nucleoside metabolic processes of Bifidobacterium longum and Bifidobacterium bifidum were associated with protecting against diet-induced obesity. Oral treatment of specific commercial Bifidobacterium longum and Bifidobacterium bifidum enhanced bile acid signaling contributing to potentiate oxidative phosphorylation (OXPHOS) in adipose tissues, leading to reduction of body weight gain and improvement in hepatic steatosis and glucose homeostasis. Bifidobacterium longum or Bifidobacterium bifidum manipulated intestinal sterol biosynthetic processes to protect against diet-induced obesity in germ-free mice. CONCLUSIONS: Our findings support the notion that treatment of carbohydrate/nucleoside metabolic processes-enriched Bifidobacterium longum and Bifidobacterium bifidum would be a novel therapeutic strategy for reprograming the host metabolic homeostasis to protect against metabolic syndromes, including diet-induced obesity. Video Abstract.

10-mer and 9-mer WALK Peptides with Both Antibacterial and Anti-Inflammatory Activities.

Natural antimicrobial peptides (AMPs) are multifunctional host defense peptides (HDPs) that are valuable for various therapeutic applications. In particular, natural and artificial AMPs with dual antibacterial immunomodulatory functions emerged as promising candidates for the development of therapeutic agents to treat infectious inflammation. In an effort to develop useful AMP variants with short lengths and simple amino acid composition, we devised a de novo design strategy to generate a series of model peptide isomer sequences, named WALK peptides, i.e., tryptophan (W)-containing amphipathic-helical (A) leucine (L)/lysine (K) peptides. Here, we generated two groups of WALK peptide isomers: W2L4K4 (WALK244.01~WALK244.10) and W2L4K3 (WALK243.01~WALK243.09). Most showed apparent antibacterial activities against both Gram-positive and Gram-negative bacteria at a concentration of approximately 4 µg/mL along with varied hemolytic activities against human red blood cells. In addition, some exhibited significant anti-inflammatory activities without any significant cytotoxicity in macrophages. Collectively, these results suggest that the two selected peptides, WALK244.04 and WALK243.04, showed promise for the development of antibacterial and anti-inflammatory agents.

Identification of Bacterial Communities in Laboratory-Adapted Glyptotendipes tokunagai and Wild-Stream-Inhabiting Chironomus flaviplumus.

Chironomidae (chironomid) are one of the dominant families in freshwater ecosystems, and they plays an important role in the food web. They have been used as an indicator for water quality assessment, as they are resistant to diverse environmental pollutants. In this study, we identified the microbiomes of two chironomid species to see if there are any endogenous bacterial groups which could contribute to the host survival. The studied species are Glyptotendipes tokunagai, a model species cultivated in a laboratory-controlled environment, and Chironomus flaviplumus captured in a field stream in Yeosu, Korea. DNAs were extracted from the whole body of the individual species, and the 16S rRNA gene was amplified. The amplified products were sequenced using an Illumina MiSeq platform. The microbiomes of G. tokunagai were homogeneous, having 20% of the core amplicon sequence variants overlapping between replicates sampled from different water tanks. In contrast, none of the core amplicon sequence variants overlapped in C.flaviplumus. In both chironomid groups, potential symbionts were identified. Dysgonomonas, which can degrade complex carbon sources, was found in more than half of the total microbiomes of G. tokunagai. Tyzzerella and Dechloromonas, which have been suggested to detoxify environmental pollutants, were identified in the microbiome of C.flaviplumus. This study can help elucidate the life strategies of chironomids in polluted or organic-rich environments.

Fabrication of 3D printed head phantom using plaster mixed with polylactic acid powder for patient-specific QA in intensity-modulated radiotherapy.

This study aimed to fabricate a heterogeneous phantom replicating the commercial Rando phantom by mixing plaster powder and polylactic acid (PLA) powder. Producing a heterogeneous phantom using Plaster and PLA is cheaper because it can be easily obtained in the commercial market. Additionally, patient-specific Quality Assurance can be easily performed because the phantom can be produced based on the patient's CT image. PLA has been well studied in the field of radiation therapy and was found to be safe and effective. To match the mean Hounsfield unit (HU) values of the Rando phantom, the bone tissue was changed using plaster and 0-35% PLA powder until an appropriate HU value was obtained, and soft tissue was changed using the PLA infill value until an appropriate HU value was obtained. Bone tissue (200 HU or higher), soft issue (- 500 to 200 HU), and air cavity (less than - 500 HU) were modeled based on the HU values on the computed tomography (CT) image. The bone tissue was modeled as a cavity, and after three-dimensional (3D) printing, a solution containing a mixture of plaster and PLA powder was poured. To evaluate the bone implementation of the phantom obtained by the mixture of plaster and PLA powder, the HU profile of the CT images of the 3D-printed phantom using only PLA and the Rando phantom printed using only PLA was evaluated. The mean HU value for soft tissue in the Rando phantom (- 22.5 HU) showed the greatest similarity to the result obtained with an infill value of 82% (- 20 HU). The mean HU value for bone tissue (669 HU) showed the greatest similarity to the value obtained with 15% PLA powder (680 HU). Thus, for the phantom composed of plaster mixed with PLA powder, soft tissue was fabricated using a 3D printer with an infill value of 82%, and bone tissue was fabricated with a mixture containing 15% PLA powder. In the HU profile, this phantom showed a mean difference of 61 HU for soft tissue and 109 HU for bone tissue in comparison with the Rando phantom. The ratio of PLA powder and plaster can be adjusted to achieve an HU value similar to bone tissue. A simple combination of PLA powder and plaster enabled the creation of a custom phantom that showed similarities to the Rando phantom in both soft tissue and bone tissue.

Effects of Potato Protein Isolated Using Ethanol on the Gelation and Anti-Proteolytic Properties in Pacific Whiting Surimi.

Pacific whiting is a primary species utilized for surimi processing in the Pacific Northwest of the US. However, endogenous protease in Pacific whiting surimi deteriorates the quality during slow cooking. The demand for clean-labeled and economically competitive protease inhibitors has been increasing. In the present study, the anti-proteolytic effect of potato protein isolate (PPI), a by-product from the potato starch industry, prepared using 20% ethanol on the endogenous protease activity of Pacific whiting (PW) surimi was investigated. The ohmic heating method was carried out for a better assessment of the anti-proteolytic activity of inhibitors. A factorial design was carried out in which the independent variables were the four types of inhibitors and their concentration (0, 0.5, 1, 2, and 3% w/w) at two heating conditions. The heating condition was used as a blocking factor. All experiments were randomized within each block. The addition of 2% PPI which demonstrated the highest anti-proteolytic activity among five different concentrations significantly increased the breaking force, penetration distance, and water retention ability of PW surimi gel as the endogenous proteases were effectively inhibited when heated ohmically at 60 °C for 30 min prior to heating up to 90 °C. In addition, SDS-PAGE disclosed that PPI successfully retained the intensity of myofibrillar heavy chain (MHC) protein of PW surimi gels even under the condition at which proteases could be activated at 60 °C. The whiteness of gels was not negatively affected by the addition of PPI. Comparing all samples, a denser and more ordered microstructure was obtained when PPI was added. A similar trend was found from the fractal dimension (Df) of the PPI-added gel's microstructure. Therefore, PPI could be an effective and non-allergenic protease inhibitor in PW surimi leading to retaining the integrity of high gel quality.

Optimized Adaptive Radiotherapy with Individualized Plan Library for Muscle-Invasive Bladder Cancer Using Internal Target Volume Generation.

The bladder is subject to filling variation, which poses a challenge to radiotherapy (RT) delivery. We aimed to assess feasibility and clinical outcomes in patients with bladder cancer treated with adaptive RT (ART) using individualized plan libraries. We retrospectively analyzed 19 patients who underwent RT for muscle-invasive bladder cancer (MIBC) in 2015-2021. Four planning computed tomography (CT) scans were acquired at 15-min intervals, and a library of three intensity-modulated RT plans were generated using internal target volumes (ITVs). A post-treatment cone-beam CT (CBCT) scan was acquired daily to assess intra-fraction filling and coverage. All patients completed the treatment, with 408 post-treatment CBCT scans. The bladder was out of the planning target volume (PTV) range in 12 scans. The volumes of the evaluated PTV plans were significantly smaller than those of conventional PTV. The 1-year and 2-year overall survival rates were 88.2% and 63.7%, respectively. Of eight cases that experienced recurrence, only two developed MIBC. There were no grade 3 or higher RT-related adverse events. ART using plan libraries and ITVs demonstrated good survival outcomes with a high local control rate. Irradiated normal tissue volume and treatment margins may be reduced through this approach, potentially resulting in lower toxicity rates.

Prospective Study of 4 Gy Radiotherapy for Orbital Mucosa-Associated Lymphoid Tissue Lymphoma (FORMAL).

External beam radiotherapy is effective for stage I orbital mucosa-associated lymphoid tissue lymphoma (MALToma). Hence, very-low-dose radiotherapy is increasingly being investigated. We conducted a single-center prospective phase II trial to evaluate the effectiveness of very-low-dose radiotherapy of 4 Gy (2 Gy × 2 fractions) in pathologically confirmed stage I orbital MALToma. In this first prospective trial, patients with complete response were observed after 3-6 months of follow-up. For patients without complete remission, a radiation dose of 24 Gy/12 fractions was additionally delivered. The primary endpoint was complete response rate; secondary endpoints were overall survival, local control, and progression-free survival. Seventeen patients were screened and three patients refused enrollment during October 2018-October 2021. Thus, 14 patients (17 eyes) were analyzed (median follow-up, 28.2 months). The overall response rate was 100% (complete remission: 11 lesions; partial remission: six lesions). In all lesions with residual disease, additional radiation therapy (dose: 24 Gy) was performed. One local failure was observed. Therefore, 4 Gy ultralow-dose radiation therapy for orbital MALToma was safely performed with a planned second-line treatment in patients without complete remission. This is the first prospective study to report the effectiveness of ultralow-dose radiotherapy of 4 Gy for stage I orbital MALToma treatment.

Efficacy and Optimal Pressure of Continuous Positive Airway Pressure in Intensity-Modulated Radiotherapy for Locally Advanced Lung Cancer.

We aimed to determine the optimal pressure of continuous positive airway pressure (CPAP) for radiotherapy (RT) through changes in the dosimetric parameters and lung volume according to pressure. Patients with locally advanced lung cancer, who underwent CPAP during computed tomography (CT) simulation, were included. The air pressure was raised in five steps of 4, 7, 10, 14, and 17 cmH2O and a CT scan was performed at the baseline and at each pressure step, accompanied by contouring and RT planning. Paired t- and Wilcoxon signed rank tests were used to compare the volumetric and dosimetric parameters according to pressure and interpressure. A total of 29 patients were selected, and 158 CT datasets were obtained. The lung volume increased significantly at all pressures (p < 0.01). The Dmean of the lung decreased significantly from 7 cmH2O (p < 0.01), the V5, V10, V15, and V20 of the lung decreased significantly from 7 cmH2O with increasing pressure, and the Dmean and V5 of the heart decreased significantly from 14 cmH2O with increasing pressure. The V50 showed no significant differences at any pressure. We recommend the use of at least 7 cmH2O with 14 cmH2O as the optimal pressure to achieve the effect of heart preservation.

Profiling Analysis of Filter Feeder Polypedilum (Chironomidae) Gut Contents Using eDNA Metabarcoding Following Contrasting Habitat Types-Weir and Stream.

We analyzed the dietary composition of Polypedilum larvae among two contrasting habitats (river and weir). Our approach was (i) to apply eDNA-based sampling to reveal the gut content of the chironomid larvae, (ii) the diversity of gut contents in the two aquatic habitats, and (iii) assessment of habitat sediment condition with the food sources in the gut. The most abundant food was Chlorophyta in the gut of the river (20%) and weir (39%) chironomids. The average ratio of fungi, protozoa, and zooplankton in river chironomids gut was 5.9%, 7.2%, and 3.8%, while it was found decreased to 1.2%, 2.5%, and 0.1% in weir chironomids. Aerobic fungi in river midge guts were 3.6% and 10.34% in SC and IS, while they were in the range of 0.34-2.58% in weir midges. The hierarchical clustering analysis showed a relationship of environmental factors with food contents. Abiotic factors (e.g., pH) in the river and weir habitats correlated the clustered pattern with phytoplankton and minor groups of fungi. This study could help understand the food source diversity in the chironomid and habitat environmental conditions by using eDNA metabarcoding as an effective tool to determine dietary composition.

Efficacy of an Integrated Mobile Application System for Patients with Radiation Therapy: A Pilot Study.

The use of IT applications for patients undergoing radiotherapy is limited. This study aimed to develop an integrated system for communication between patients and radiation oncologists using IT technology and report the first test results for the system "Assisted Radiation Oncology Mobile Application" (AROMA). This system consisted of a manager program, a server running on a PC, and a mobile application on a smartphone. A prospective survey was conducted to evaluate the usefulness of this system from October 2020 to January 2021. The survey consisted of a specific questionnaire on basic information and application use by the patients. The management program was designed such that the user (doctor) edits the treatment schedule, member (patient and doctor) information, self-management, disease information, and side effect questionnaire. The mobile application for patients consisted of the current schedule, treatment schedule calendar, side effect questionnaire, side effect management method, and disease information entered by the doctor. A total of 41 patients were enrolled in this study. The mean adverse event response time was 4.4 days. In the survey, the mobile application received positive views (8.6/10 points). Most responses related to the side effect reporting function (94%) and communication using the application (91%) were positive. Satisfaction with the application design and each menu item was high, with an average of ≥8 and ≥8.5 points in most cases, respectively. The survey showed good satisfaction with the design, operability, and reporting system. Therefore, the system can facilitate communication between patients and radiation oncologists in the future.

Transcriptional Responses of Stress-Related Genes in Pale Chub (Zacco platypus) Inhabiting Different Aquatic Environments: Application for Biomonitoring Aquatic Ecosystems.

Pale chub (Zacco platypus) is a dominant species in urban rivers and reservoirs, and it is used as an indicator to monitor the effects of environmental contaminants. Gene responses at the molecular level can reflect the health of fish challenged with environmental stressors. The objective of this study was to identify correlations between water quality factors and the expression of stress-related genes in Z. platypus from different lake environments (Singal and Juam Lakes). To do so, transcriptional responses of genes involving cellular homeostasis (heat-shock protein 70, HSP70; heat-shock protein 90, HSP90), metal detoxification (metallothionein, MT), and antioxidation (superoxide dismutase, SOD; catalase, CAT) were analyzed in the gill and liver tissues of Z. platypus. HSP70, HSP90, and MT genes were overall upregulated in Z. platypus from Singal Lake, which suffered from poorer water quality than Juam Lake. In addition, gene responses were significantly higher in Singal Lake outflow. Upregulation of HSP70, HSP90, and MT was significantly higher in Z. platypus gills than in the liver tissue. In addition, integrated biomarker response and heatmap analysis determined correlations between expression of biomarker genes or water quality factors and sampling sites of both lakes. These results suggest that stress-related genes used as multiple biomarkers may reflect spatial characteristics and water quality of different lake environments, and they can be used for biomonitoring and ecological risk assessment.

Reproducibility and Step-By-Step Learning Curve of Retroperitoneal Video-Assisted Mini-Laparotomy Surgery for Living Donor Nephrectomy: A Single-Center Experience.

OBJECTIVES: Living donor transplant techniques must ensure donor safety and minimize complications. To achieve this goal, in 2003, we developed a new surgical procedure named video-assisted mini-laparotomy surgery for living donor nephrectomy. Video-assisted mini-laparotomy surgery standardizes the retroperitoneal mini-laparotomy technique as an alternative to open surgery. We have previously reported on video-assisted mini-laparotomy surgery techniques for use in kidney surgery. However, there are no reports of video-assisted mini-laparotomy surgery performed at other institutions. Therefore, we introduced video-assisted mini-laparotomy surgery at another institution, and here, we report on our experience. MATERIALS AND METHODS: We evaluated a consecutive series of 38 donors who underwent video-assisted mini-laparotomy living donor nephrectomy at National Health Insurance Service Ilsan Hospital from August 2016 to November 2019. All 38 patients were enrolled. Perioperative data and outcomes were retrospectively analyzed. We recorded perioperative and postoperative data, including operative time, estimated blood loss, and duration of hospital stay. RESULTS: The mean operative time was 144.35 ± 22.79 minutes, and the mean warm ischemia time was 184.35 ± 4.97 seconds. Mean estimated blood loss was 72.85 ± 60.81 mL. At 12 months after video-assisted mini-laparotomy surgery, the mean posttransplant serum creatinine level was 1.05 ± 0.18 mg/dL, and estimated glomerular filtration rate (according to the Modification of Diet in Renal Disease study equation) was 71.9 ± 10.34 mL/min/1.73 m2. There was no intraoperative or postoperative complication. CONCLUSIONS: Previous studies reported that video- assisted mini-laparotomy surgery has a steep learning curve and is difficult to reproduce. However, video- assisted mini-laparotomy surgery is a feasible and safe technique at our institution. Video-assisted mini- laparotomy surgery is a solo surgery that can be safely performed by any surgeon with prior kidney surgery experience.

Setup uncertainties and appropriate setup margins in the head-tilted supine position of whole-brain radiotherapy (WBRT).

Various applications of head-tilting techniques in whole-brain radiotherapy (WBRT) have been introduced. However, a study on the setup uncertainties and margins in head-tilting techniques has not been reported. This study evaluated the setup uncertainties and determined the appropriate planning target volume (PTV) margins for patients treated in the head-tilted supine (ht-SP) and conventional supine position (c-SP) in WBRT. Thirty patients who received WBRT at our institution between October 2020 and May 2021 in the c-SP and ht-SP were investigated. The DUON head mask (60124, Orfit Industries, Wijnegem, Belgium) was used in the c-SP, and a thermoplastic U-Frame Mask (R420U, Klarity Medical & Equipment Co. Ltd., Lan Yu, China) was used in the ht-SP. Daily setup verification using planning computed tomography (CT) and cone-beam CT was corrected for translational (lateral, longitudinal, and vertical) and rotational (yaw) errors. In the c-SP, the means of systematic errors were -0.80, 0.79, and 0.37 mm and random errors were 0.27, 0.54, and 0.39 mm in the lateral, longitudinal, and vertical translational dimensions, respectively. Whereas, for the ht-SP, the means of systematic errors were -0.07, 0.73, and -0.63 mm, and random errors were 0.75, 1.39, 1.02 mm in the lateral, longitudinal, and vertical translational dimensions, respectively. The PTV margins were calculated using Stroom et al.'s [2Σ+0.7σ] and van Herk et al.'s recipe [2.5Σ+0.7σ]. Appropriate PTV margins with van Herk et al.'s recipe in WBRT were <2 mm and 1.5° in the c-SP and <3 mm and 2° in the ht-SP in the translational and rotational directions, respectively. Although the head tilt in the supine position requires more margin, it can be applied as a sufficiently stable and effective position in radiotherapy.

Clinical performance of FractionLab in patient-specific quality assurance for intensity-modulated radiotherapy: a retrospective study.

BACKGRUOUND: This study was aimed at comparing and analyzing the results of FractionLab (Varian/Mobius Medical System) with those of portal dosimetry that uses an electronic portal imaging device. Portal dosimetry is extensively used for patient-specific quality assurance (QA) in intensity-modulated radiotherapy (IMRT). METHODS: The study includes 29 patients who underwent IMRT on a Novalis-Tx linear accelerator (Varian Medical System and BrainLAB) between June 2019 and March 2021. We analyzed the multileaf collimator (MLC) DynaLog files generated after portal dosimetry to evaluate the same condition using FractionLab. The results of the recently launched FractionLab at various gamma indices (0.1%/0.1 mm-1%/1 mm) are analyzed and compared with those of portal dosimetry (3%/3 mm). RESULTS: The average gamma passing rates of portal dosimetry (3%/3 mm) and FractionLab are 98.1 (95.5%-100%) and 97.5% (92.3%-99.7%) at 0.6%/0.6 mm, respectively. The results of portal dosimetry (3%/3 mm) are statistically comparable with the QA results of FractionLab (0.6%/0.6 mm-0.9%/0.9 mm). CONCLUSION: This paper presents the clinical performance of FractionLab by the comparison of the QA results of FractionLab using portal dosimetry with various gamma indexes when performing patient-specific QA in IMRT treatment. Further, the appropriate gamma index when performing patient-specific QA with FractionLab is provided.

Omitting surgery in esophageal cancer patients with complete response after neoadjuvant chemoradiotherapy: a systematic review and meta-analysis.

BACKGROUND: Neoadjuvant chemoradiotherapy (nCRT) followed by surgery is a standard treatment modality for locally-advanced esophageal cancer. However, patients who achieve clinical complete response (cCR) after nCRT have been reported to have better prognosis. Further, the role of surgery in these patients is controversial. Thus, this meta-analysis aimed to evaluate whether surgery is still useful in patients with cCR after nCRT. METHODS: We systematically reviewed the MEDLINE, PubMed, Embase, Cochrane library, and Scopus databases for studies on surgical efficacy in complete responders after concurrent chemoradiotherapy for esophageal cancer. The publication date was set to January 1, 2010-January 31, 2020. The hazard ratio (HR) and risk ratio were used to compare the 2-year overall survival (OS), disease-free survival (DFS), incidence of locoregional failure, distant metastasis, and treatment mortality between the nCRT and nCRT plus surgery groups. RESULTS: Six articles involving 609 patients were included. There was a significant benefit of nCRT for OS (HR = 0.80, 95% confidence interval [CI] 0.64-0.99, p = 0.04), but not for DFS (HR = 1.55, 95% CI 0.35-6.86, p = 0.56). The nCRT group tended to have lower mortality than the nCRT plus surgery group (risk ratio = 0.15, 95% CI 0.02-1.18, p = 0.07). CONCLUSION: Omitting surgery provides better OS in complete responders after nCRT. Adding surgery could increase the morbidity and mortality and decrease the quality of life. Thus, nCRT alone could be a feasible approach for patients with cCR.

Complete mitochondrial genome of Chironomus flaviplumus (Diptera: Chironomidae) collected in Korea.

The complete mitochondrial genome of Chironomus flaviplumus was sequenced. The circular mitochondrial genome is 15,739 bp and consists of 13 protein-coding, two ribosomal RNAs, and 22 transfer RNA genes (GenBank accession no. MW770891). Results of phylogenetic analysis indicate that the species clustered with other species of the family Chironomidae. This study is helpful to the identification of C. flaviplumus larvae, which is difficult to be identified by morphology.