Publications by authors named "Ken Takeda"

The lack of circulating biomarkers for tumor monitoring is a major problem in Ewing sarcoma management. The development of methods for accurate tumor monitoring is required, considering the high recurrence rate of drug-resistant Ewing sarcoma. Here, we describe a sensitive analytical technique for tumor monitoring of Ewing sarcoma by detecting circulating extracellular vesicles secreted from Ewing sarcoma cells.

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Urinary toxicities are one of the serious complications of radiotherapy for prostate cancer, and dose-volume histogram of prostatic urethra has been associated with such toxicities in previous reports. Previous research has focused on estimating the prostatic urethra, which is difficult to delineate in CT images; however, these studies, which are limited in number, mainly focused on cases undergoing brachytherapy uses low-dose-rate sources and do not involve external beam radiation therapy (EBRT). In this study, we aimed to develop a deep learning-based method of determining the position of the prostatic urethra in patients eligible for EBRT.

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Bone and soft-tissue sarcomas are rare malignancies with histological diversity and tumor heterogeneity, leading to the lack of a common molecular target. Telomerase is a key enzyme for keeping the telomere length and human telomerase reverse transcriptase (hTERT) expression is often activated in most human cancers, including bone and soft-tissue sarcomas. For targeting of telomerase-positive tumor cells, we developed OBP-301, a telomerase-specific replication-competent oncolytic adenovirus, in which the hTERT promoter regulates adenoviral E1 gene for tumor-specific viral replication.

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Article Synopsis
  • - The Unity magnetic resonance linear accelerator (MRL) allows for real-time adjustments in radiation treatment plans using adaptive radiotherapy, which is particularly beneficial for patients undergoing treatment for prostate cancer.
  • - A study evaluated the quality and reproducibility of MRgART plans in ten prostate cancer patients, finding that using more beams generally improved plan quality, but too many could reduce the consistency of meeting dose constraints.
  • - The results suggest that using five or fewer beams is not recommended for reliable treatment plans, and a careful balance of beam and segment numbers is essential for optimizing treatment quality and efficiency with the Unity MRL.
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In external radiotherapy of head and neck (HN) cancers, the reduction of irradiation accuracy due to HN volume reduction often causes a problem. Adaptive radiotherapy (ART) can effectively solve this problem; however, its application to all cases is impractical because of cost and time. Therefore, finding priority cases is essential.

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Radiotherapy for breast cancer has attracted attention in Western countries because radiation to the heart can cause cardiac events. The purposes of this study were to evaluate the relationship between radiotherapy after breast-conserving surgery and the frequency of cardiac events in Japanese patients and to investigate the risk factors of cardiac events after postoperative radiotherapy in those patients. Female patients who received postoperative radiotherapy following breast-conserving surgery between 2007 and 2012 at our hospital were evaluated.

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This study aimed to develop and validate a collapsed cone convolution for magnetic resonance-guided radiotherapy (CCCMR). The 3D energy deposition kernels (EDKs) were generated in water in a 1.5-T transverse magnetic field.

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Several studies have demonstrated the possibility of positive effects of exposure to music during pregnancy on mental function in humans and animals. Although there remains a core belief in the positive effects of music during pregnancy, the underlying neurobehavioral mechanisms of these effects remain unknown. In this study, we aimed to clarify the relationship between maternal nurturing behavior and the oxytocinergic system to elucidate the effect of music on mental health during pregnancy in an experimental investigation using animal models.

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A 72-year-old man, who was extremely short-statured, underwent robot-assisted laparoscopic prostatectomy (RARP) for treatment of localized prostate cancer (cT1cNOMO). We report a case of congenital vertebral tip dysplasia with type II collagen dysplasia in a patient who underwent robot-assisted radical prostatectomy. Congenital vertebral tip dysplasia is characterized by short stature, and in this case, the height was 130 cm, which was equivalent to that of an 8-year-old child.

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Background/aim: An association between leukotriene receptor antagonists (LTRA) and cancer has been previously reported, but the relationship between LTRA use and cancer prevention remains controversial. This study aimed to clarify the cancer-preventive effect of LTRA in Japanese patients with bronchial asthma.

Patients And Methods: We obtained information from a large populationbased medical information database to analyze data on patients who were newly diagnosed with bronchial asthma between 2006 and 2015.

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Early regression-the regression in tumor volume during the initial phase of radiotherapy (approximately 2 weeks after treatment initiation)-is a common occurrence during radiotherapy. This rapid radiation-induced tumor regression may alter target coordinates, necessitating adaptive radiotherapy (ART). We developed a deep learning-based radiomics (DLR) approach to predict early head and neck tumor regression and thereby facilitate ART.

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Article Synopsis
  • Developing effective experimental techniques is essential for assessing developmental toxicity to protect the brain.
  • The study introduces a novel double staining method (PAS-immunohistochemistry) that simplifies the detection and evaluation of brain perivascular macrophage abnormalities.
  • Maternal exposure to low doses of nanoparticles resulted in mild changes in perivascular macrophages, which were detectable, indicating a need for better diagnostic methods despite the absence of significant behavioral or neurotransmitter level changes.
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Particulate air pollution, containing nanoparticles, enhances the risk of pediatric allergic diseases that is potentially associated with disruption of neonatal immune system. Previous studies have revealed that maternal exposure to carbon black nanoparticles (CB-NP) disturbs the development of the lymphoid tissues in newborns. Interestingly, the CB-NP-induced immune profiles were observed to be different depending on the gestational period of exposure.

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Air pollution is associated with significant adverse health effects. Recent studies support the idea that inhalation of fine particles can instigate extrapulmonary effects on the cardiovascular system through several pathways. The systemic transfer of ultrafine particles (UFPs) or soluble particle components (organic compounds and metals) is of particular concern.

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Titanium dioxide nanoparticles (TiO-NP) are important materials used in commercial practice. Reportedly, TiO-NP exposure during pregnancy can affect the development of the central nervous system in mouse offspring; however, the underlying mechanism remains unknown. In the present study, we investigated the impact of prenatal TiO-NP exposure on global DNA methylation and mRNA expression patterns in the brains of neonatal mice.

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In recent years, an apparent decline in human sperm quality has been observed worldwide. One in every 5.5 couples suffers from infertility, with male reproductive problems contributing to nearly 40% of all infertility cases.

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Purpose: To evaluate the accuracy of electron transport in the magnetic field of Electron Gamma Shower version 5 (EGS5) by using the special Fano cavity test.

Methods: To simulate electron transport in the magnetic field, the trajectory of the electron was reconstructed with a short step length to restrict fractional energy loss, and the maximum user step length (mxustep) was set at 0.01 cm or 0.

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Background/aim: Recent experimental studies have reported that leukotriene receptor antagonists (LTRAs) might protect against dementia. However, few clinical studies have examined this in humans. This study assessed whether the use of LTRAs can prevent the onset of dementia in humans.

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We assessed the accuracy of deformable image registration (DIR) accuracy between CT and MR images using an open-source software (Elastix, from Utrecht Medical Center) and a commercial software (Velocity AI Ver. 3.2.

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Intractable late urinary toxicity is a serious complication after radiotherapy for patients with localized prostate cancer (LPC). We assessed clinical factors correlated with severe late urinary toxicity in LPC treated with curative image-guided intensity-modulated radiation therapy (IMRT). A total of 452 patients with LPC treated with IMRT between 2002 and 2016 were retrospectively analyzed.

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Radiotherapy for esophageal cancer entails high-dose irradiation of the myocardium owing to its close anatomical proximity to the esophagus. This study aimed to evaluate the dosimetric impact of functional avoidance planning for the myocardium with volumetric-modulated arc therapy (VMAT) in patients with esophageal cancer and determine the feasibility of functional planning. Ten patients with early stage esophageal cancer were included in this study.

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Background: Radiomics is a new technology to noninvasively predict survival prognosis with quantitative features extracted from medical images. Most radiomics-based prognostic studies of non-small-cell lung cancer (NSCLC) patients have used mixed datasets of different subgroups. Therefore, we investigated the radiomics-based survival prediction of NSCLC patients by focusing on subgroups with identical characteristics.

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The purpose of this retrospective study was to investigate survival outcomes and irradiated tumor control (local control [LC]) and locoregional control (LRC) after stereotactic body radiotherapy (SBRT) for T1 or recurrent T1 (rT1) kidney cancer. Twenty-nine nonconsecutive patients with 30 tumors were included. SBRT doses of 70 Gy, 60 Gy or 50 Gy in 10 fractions were prescribed with a linear accelerator using daily image guidance.

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Article Synopsis
  • This study aimed to assess myocardial damage caused by mediastinal radiation therapy in esophageal cancer patients using late gadolinium-enhancement MRI.
  • Nineteen patients were monitored before treatment, six months post-treatment, and 1.5 years post-treatment, analyzing changes in myocardial signal intensity based on the doses received.
  • Results indicated a significant dose-dependent increase in signal intensity changes for radiation doses exceeding 30 Gy, suggesting a need to minimize radiation exposure to the heart.
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