Publications by authors named "Masashi Tomida"

There are several causes of heart failure during pregnancy and the peripartum period, which include peripartum cardiomyopathy, Takotsubo cardiomyopathy or stress cardiomyopathy, exacerbation of a preexisting cardiomyopathy, and acute myocarditis. It is important to determine the cause of the heart failure as the medical treatment may be different based on the diagnosis. However, it has been sometimes challenging to diagnose the cause because of the limited diagnostic tools, especially in pregnant women.

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Cognitive decline and alopecia after radiotherapy are challenging problems. We aimed to compare whole brain radiotherapy (WBRT) plans reducing radiation dose to the hippocampus and scalp between helical tomotherapy (HT) and intensity-modulated proton therapy (IMPT). We conducted a planning study of WBRT for 10 patients.

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Objective: We compared radiotherapy plans among helical tomotherapy (HT), volumetric-modulated arc therapy (VMAT), and intensity-modulated proton therapy (IMPT) for angiosarcoma of the scalp (AS).

Methods: We conducted a planning study for 19 patients with AS. The clinical target volume (CTV) 1 and CTV2 were defined as the gross tumor volume with a specific margin and total scalp, respectively.

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Stereotactic body radiation therapy (SBRT) using recently introduced multileaf collimators (MLC) is preferred over circular collimators in the treatment of localized prostate cancer. The objective of this study was to assess the clinical usefulness of MLCs in prostate SBRT by comparing the effectiveness of treatment plans using fixed collimators, variable collimators, and MLCs and by ensuring delivery quality assurance (DQA) for each. For each patient who underwent conventional radiation therapy for localized prostate cancer, mock SBRT plans were created using a fixed collimator, a variable collimator, and an MLC.

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The application of neoadjuvant androgen deprivation (NAD) in prostate cancer leads to a reduction in prostate volume, and the trends in volume reduction differ according to the treatment duration of NAD. A reduction in volume during external beam radiation therapy may lead to the exposure of normal tissues to an unexpected dose. In fact, prostate volume reductions have primarily been reported in European and American institutions.

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Metal dental restoration materials cause dose enhancement upstream and dose disturbance downstream of the high-density inhomogeneous regions in which these materials are used. In this study, we evaluated the impact of a dental metallic crown (DMC) on intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) for head and neck cancer. Additionally, the possibility of sparing the oral mucosa from dose enhancement using an individual intraoral mouthpiece was evaluated.

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