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Featured researches published by Tsuguhiro Miyashita.


Plastic and Reconstructive Surgery | 2009

Is Radiation Therapy for Keloids Acceptable? The Risk of Radiation-Induced Carcinogenesis

Rei Ogawa; Sumiko Yoshitatsu; Ken Yoshida; Tsuguhiro Miyashita

Background: Keloids have been treated by using radiation for over a century, and it is currently suggested that keloids are best treated by a combination of surgery and postoperative radiation therapy, although randomized controlled trials testing this are still lacking. However, plastic surgeons tend to avoid radiation therapy for keloids for fear of inducing malignant tumors. Thus, the authors searched for previous reports of associations between carcinogenesis and keloid radiation therapy, and examined the evidence-based opinions of radiation oncologists regarding the acceptability of using radiation to treat keloids. Methods: A computerized literature search was carried out using PubMed that included citations from MEDLINE and PubMed Central between 1901 and March of 2009. The following search terms were used: “keloid(s),” “hypertrophic scar(s),” “radiation,” “radiation therapy,” “radiotherapy,” “carcinogenesis,” “carcinoma,” “cancer,” “complications,” and “side effects.” Moreover, the references for each report were also retrieved. Results: The authors located five cases of carcinogenesis (i.e., fibrosarcoma, basal cell carcinoma, thyroid carcinoma, and breast carcinoma) that were associated with radiation therapy for keloids. However, it was unclear whether an appropriate dose of radiation was used and whether sufficient protection of surrounding tissues was provided. Moreover, a questionnaire study of radiation oncologists around the world revealed that approximately 80 percent considered radiation to be acceptable for treating keloids. Conclusions: The authors conclude that the risk of carcinogenesis attributable to keloid radiation therapy is very low when surrounding tissues, including the thyroid and mammary glands, especially in children and infants, are adequately protected, and that radiation therapy is acceptable as a keloid treatment modality.


Annals of Plastic Surgery | 2007

Postoperative Radiation Protocol for Keloids and Hypertrophic Scars : Statistical Analysis of 370 Sites Followed for Over 18 Months

Rei Ogawa; Tsuguhiro Miyashita; Hiko Hyakusoku; Satoshi Akaishi; Shigehiko Kuribayashi; Atsushi Tateno

Background:Before 2002, keloids and intractable hypertrophic scars were treated at our facility with postoperative irradiation of 15 Gy (the traditional protocol). Analysis of the therapeutic outcomes of patients treated with this protocol showed that the recurrence rates of keloids and intractable hypertrophic scars in the anterior chest wall, as well as the scapular and suprapubic regions, were statistically higher than at other sites, while the recurrence rates in earlobes were lower. Thus, we customized doses for various sites. This report describes our trial of postoperative radiation therapy. Methods:Between January 2002 and September 2004, 109 patients with 121 keloid and intractable hypertrophic scar sites were treated with surgical excision following the new protocol: electron-beam irradiation at total doses of 10, 15, or 20 Gy, depending on the site. The recurrence rates and toxicities were historically followed in 218 patients with 249 keloid and intractable hypertrophic scar sites treated with the old protocol of surgical removal followed by irradiation at 15 Gy (without variation by site). The minimal follow-up time was 18 months. Statistical analysis was performed using Fisher exact probability test. Results:Total recurrence rates were 29.3% before 2002 and 14.0% after 2003. The recurrence rate in the anterior chest wall was statistically reduced. Outcomes of earlobe did not differ between irradiation with 15 Gy or 10 Gy. Conclusions:Keloids and intractable hypertrophic scars should be treated with dose protocols customized by site. Our results suggest that keloid and intractable hypertrophic scar sites with a high risk of recurrence should be treated with 20 Gy in 4 fractions over 4 days and that earlobe should be treated with 10 Gy in 2 fractions over 2 days.


Journal of Nippon Medical School | 2016

Keloids and Hypertrophic Scars Can Now Be Cured Completely: Recent Progress in Our Understanding of the Pathogenesis of Keloids and Hypertrophic Scars and the Most Promising Current Therapeutic Strategy.

Rei Ogawa; Satoshi Akaishi; Shigehiko Kuribayashi; Tsuguhiro Miyashita

Keloids and hypertrophic scars are fibroproliferative disorders of the skin that are caused by abnormal healing of injured or irritated skin. It is possible that they are both manifestations of the same fibroproliferative skin disorder and just differ in terms of the intensity and duration of inflammation. These features may in turn be influenced by genetic, systemic, and local risk factors. Genetic factors may include single nucleotide polymorphisms, while systemic factors may include hypertension, pregnancy, hormones, and cytokines. The most important local factor is tension on the scar. Over the past 10 years, our understanding of the pathogenesis of keloids and hypertrophic scars has improved markedly. As a result, these previously intractable scars are now regarded as being treatable. There are many therapeutic options, including surgery, radiation, corticosteroids, 5-fluorouracil, cryotherapy, laser therapy, anti-allergy agents, anti-inflammatory agents, bleaching creams and make-up therapies. However, at present, we believe that the following combination of three therapies most reliably achieves a complete cure: surgery, followed by radiation and the use of steroid tape/plaster.


International Journal of Urology | 2000

Renal masses detected by general health checkup.

Narumi Tsuboi; Kazutaka Horiuchi; Go Kimura; Yukihiro Kondoh; Kazuhiro Yoshida; Taiji Nishimura; Masao Akimoto; Tsuguhiro Miyashita; Toshiyuki Subosawa

Abstract Background A total of 60 604 persons underwent a general health checkup at Toma Hospital, Saitama, Japan, between January 1993 and June 1997, and transabdominal ultrasonography (US) was performed on all persons. We investigated the usefulness of transabdominal US in detecting renal tumors during general health checkups.


Journal of Ultrasound in Medicine | 2009

Utility of Sonography for Evaluation of Clinical T1 and T2 Glottic Carcinoma

Shigehiko Kuribayashi; Tsuguhiro Miyashita; Munenaga Nakamizo; Toshiaki Yagi; Shin-ichiro Kumita

Objective. The aim of this study was to evaluate the prognostic impact of sonographically determined tumor features in relation to local control of clinical T1 and T2 glottic carcinoma treated by definitive radiation therapy. Methods. Between 1999 and 2005, 72 patients with T1 and T2 glottic carcinoma were evaluated by percutaneous sonography in terms of tumor detectability, maximum tumor dimension, involvement of the anterior commissure, presence of supraglottic, subglottic, or paraglottic spread, and thyroid cartilage invasion. Factor analyses for local control included clinical features, sonographic findings, and treatment factors. Results. Forty‐one lesions (57%) were detected as hypoechoic masses on sonography. For detectable T2 tumors, sonographic and laryngoscopic findings were in agreement in all cases with respect to spread to anatomic subsites. The 3‐year local control rate with radiation therapy alone was 82%. Univariate analysis of the sonographic characteristics revealed that the maximum tumor dimension and thyroid cartilage invasion predicted a loss of local control, whereas none of the clinical or treatment characteristics was significant. Multivariate analysis showed that thyroid cartilage invasion was an independent negative prognostic factor for local control. Conclusions. Sonography provides information about the likely outcome of radiation therapy for patients with clinical T2 glottic carcinoma, although its utility for T1 lesions is not proven. Thyroid cartilage invasion may be an independent negative predictor of the outcome.


Plastic and Reconstructive Surgery | 2015

Reply: Analysis of the Surgical Treatments of 63 Keloids on the Cartilaginous Part of the Auricle: Effectiveness of the Core Excision Method.

Rei Ogawa; Satoshi Akaishi; Teruyuki Dohi; Shigehiko Kuribayashi; Tsuguhiro Miyashita; Hiko Hyakusoku

Background: Treatments for keloids on the cartilaginous part of the auricle (i.e., the upper part of the ear excluding the earlobe) include surgical excision, cryosurgery, postoperative radiation therapy, steroid injection, taping stabilization, and pressure therapy. However, to date, there is no universally accepted treatment strategy for auricle keloids. Methods: In this retrospective cohort study, the 63 primary auricle keloids in all 57 patients who underwent surgery from 2006 to 2012 were included. Mild scars such as hypertrophic scars were excluded. All 63 scars were treated with surgery, namely, total excision or intralesional excision (core excision method), and postoperative adjuvant radiation therapy and self-managed scar stabilization with surgical tape. The postsurgical radiation therapy consisted of 15 Gy administered in three fractions over 3 days. The recurrence rates associated with the two surgical methods over 18 months of follow-up were recorded. Results: Of the 57 patients, 91.2 percent were women. Of the 63 lesions, 95.2 percent and 4.8 percent were caused by piercing and trauma, respectively. All were primary keloids. Before 2009, all lesions (n = 37) were treated by total excision. After 2009, all lesions (n = 26) were treated by core excision. These methods were associated with recurrence rates of 8.1 percent and 0 percent, respectively, although this difference did not achieve statistical significance (p > 0.05). The overall recurrence rate was 4.8 percent. Complications such as wound dehiscence and pigmentation during the 18-month follow-up period were not observed. Conclusion: Auricle keloids can be treated by customized plans consisting of appropriate surgical modalities, postoperative radiotherapy, and self-management. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.


Ultrasound in Medicine and Biology | 2003

Ultrasonographic demonstration of retropharyngeal lymph nodes: Preliminary report

Tsuguhiro Miyashita; Atsushi Tateno; Iskandar Ablimit; Munenaga Nakamizo; Tatsuo Kumazaki; Toshiaki Yagi

The aim of this study was to describe the results of ultrasonography of upper retropharyngeal lymph node (RPN) metastasis in patients with pharyngeal carcinomas. A total of 10 patients with metastatic RPN were examined using percutaneous ultrasound (US) with 3.5-MHz probes. Primary cancer sites were the nasopharynx in two patients, the oropharynx in three and the hypopharynx in five. Metastatic RPNs lay in the level of occipital bone in five patients, C1 in nine, and C2 in five. US images were compared with previously obtained computerized tomography (CT) images based on size and depth. In all of the 10 patients, metastatic RPNs were ultrasonographically demonstrated as hypoechoic masses. Nodal sizes ranged from 1.5 cm to 3.5 cm both in CT and in US. Depths of the RPN centers were from 3.5 cm to 7.0 cm in CT, and from 3.5 cm to 6.5 cm in US. Differences of sizes and depths between CT and US were from -0.5 cm to 0.5 cm and from 0.0 cm to 1.0 cm, respectively. RPNs that are 1.5 cm or more in size can be demonstrated with percutaneous US using CT guidance. This technique should be utilized for the purpose of monitoring in a radiation therapy setting.


Ultrasound in Medicine and Biology | 2001

Short-time ultrasound of head and neck squamous cell carcinoma under radiotherapy.

Tsuguhiro Miyashita; Atsushi Tateno; Junichi Horiuchi; Munenaga Nakamizo; Kenichi Sugizaki; Tatsuo Kumazaki

To evaluate the efficacy of ultrasonography for patients with head and neck squamous cell carcinoma before and during radiotherapy (RT), consecutive patients with macroscopic lesions were examined before and during RT. Each scan was performed percutaneously in a short time (less than 5 min). The demonstration rate of primary tumors and the largest node of previously known metastatic cervical nodes were measured. Of all 190 patients, 91 primary tumors were detected (47.9%). Primary tumors in oral cavity, oropharynx, hypopharynx and cervical esophagus were determined in over 70% and, for those of nasopharynx and larynx, the demonstration rates were 30% or less. Nodal metastases were visualized in 78 of 80 patients with regional metastases (97.5%). Using the above information, 73 patients (38.4%) received the benefit of radiation therapy. Short-time sonography is a valuable modality for patients with selected sites of head and neck cancers.


Journal of Radiation Research | 2011

Post-keloidectomy Irradiation Using High-dose-rate Superficial Brachytherapy

Shigehiko Kuribayashi; Tsuguhiro Miyashita; Yukiko Ozawa; Marie Iwano; Rei Ogawa; Satoshi Akaishi; Teruyuki Dohi; Hiko Hyakusoku; Shin-ichiro Kumita


Journal of Nippon Medical School | 2004

Implementation of Integrated Medical Curriculum in Japanese Medical Schools

Toshiro Shimura; Takumi Aramaki; Kazuo Shimizu; Tsuguhiro Miyashita; Koji Adachi; Akira Teramoto

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Rei Ogawa

Nippon Medical School

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