Koji Masui

Dr. Koji Masui

orcid

Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 December 2018 in Radiation Oncology
Verified
Journal Article
Open access
PDF file
GSGen Suzuki
Gen Suzuki
Hideya YamazakiHideya Yamazaki
Hideya Yamazaki
NANorihiro Aibe
Norihiro Aibe
KMKoji Masui
Koji Masui
NSNaomi Sasaki
Naomi Sasaki
KYKei Yamada
Kei Yamada
The standard treatment for superficial esophageal cancer (SEC) involving muscularis mucosal (T1a-MM) or submucosal (T1b) invasion has been the surgical resection of the esophagus. However, esophagectomy with extended lymph node dissection is highly invasive. Recent reports have shown that endoscopic submucosal dissection (ESD) followed by chemoradiotherapy (CRT) has promising results and might become a new therapeutic approach. This retrospective study aimed to elucidate the efficacy and safety of this new treatment. Patients with clinical stage T1b tumor without apparent metastasis treated with ESD followed by CRT from 2014 to 2017 (the CRT group) were included. The outcomes on disease-free survival (DFS) of this group were compared with those of consecutive patients in a historical control group who underwent ESD followed by esophagectomy (the esophagectomy group) between 2008 and 2015. Of 32 patients analyzed, 16 were in the CRT group and 16 with similar stage cancer were in the esophagectomy group. Radiotherapy was completed in all patients, and the incidence of grade ≥ 3 nonhematologic adverse events was 6%. The 2-year overall survival rates were 100%, and locoregional control was achieved in all patients in the CRT group, and the 2-year DFS rates were 88 and 100% for the CRT and esophagectomy groups, respectively, without significant differences. Our data confirmed our new approach as being safe and effective for locoregional control and may provide a nonsurgical treatment option for patients with clinical stage T1b tumors.

1 July 2015 in Brachytherapy
Verified
Journal Article
Closed access
ケ吉ケン 吉田さん
ケン 吉田さん
Hideya YamazakiHideya Yamazaki
Hideya Yamazaki
TKTadayuki Kotsuma
Tadayuki Kotsuma
TTTadashi Takenaka
Tadashi Takenaka
KMKoji Masui
Koji Masui
ETEiichi Tanaka
Eiichi Tanaka

1 January 2015 in Brachytherapy
Verified
Journal Article
Closed access
ケ吉ケン 吉田さん
ケン 吉田さん
Hideya YamazakiHideya Yamazaki
Hideya Yamazaki
TTTadashi Takenaka
Tadashi Takenaka
TKTadayuki Kotsuma
Tadayuki Kotsuma
SMShunsuke Miyake
Shunsuke Miyake
ETEiichi Tanaka
Eiichi Tanaka

28 February 2022 in Cancers
Verified
Journal Article
Open access
PDF file
TKTetsuya Kokabu
Tetsuya Kokabu
KMKoji Masui
Koji Masui
YTYosuke Tarumi
Yosuke Tarumi
NNNaoki Noguchi
Naoki Noguchi
KAKohei Aoyama
Kohei Aoyama
TMTaisuke Mori
Taisuke Mori
This study aimed to evaluate the efficacy and safety of computed tomography-magnetic resonance imaging (CT-MRI)-guided multi-catheter interstitial brachytherapy for patients with bulky (≥4 cm) and high-risk, stage IIB–IVB advanced cervical cancer. Eighteen patients who underwent concurrent chemoradiotherapy with multi-catheter interstitial brachytherapy between September 2014 and August 2020 were enrolled. The prescribed dose of external beam radiotherapy was 45–50.4 Gy, and the brachytherapy high-dose-rate aim was 25–30 Gy per 5 fractions. The endpoints were four-year local and pelvic control rates, four-year disease-free and overall survival rates, and the adverse events rate. The median follow-up period was 48.4 months (9.1–87.5 months). Fifteen patients received concurrent cisplatin therapy (40 mg/m2, q1week). Four (22.2%), seven (38.9%), and seven (38.9%) patients had stage II, III, and IV cervical cancer, respectively. Pelvic and para-aortic lymph node metastases were observed in 11 (61.1%) and 2 (11.1%) patients, respectively. The median pre-treatment volume was 87.5 cm3. The four-year local control, pelvic control, disease-free survival, and overall survival rates were 100%, 100%, 81.6%, and 87.8%, respectively. Three (16.7%) patients experienced grade 3 adverse events, and none experienced grade 4–5 adverse events. CT-MRI-guided multi-catheter interstitial brachytherapy could be a promising treatment strategy for locally advanced cervical cancer.

Verified
Journal Article
Open access
PDF file
GSGen Suzuki
Gen Suzuki
Hideya YamazakiHideya Yamazaki
Hideya Yamazaki
NANorihiro Aibe
Norihiro Aibe
KMKoji Masui
Koji Masui
NSNaomi Sasaki
Naomi Sasaki
KYKei Yamada
Kei Yamada
Angiosarcoma of the face and scalp (ASFS) is an extremely aggressive tumor that frequently metastasizes, often leading to death. The neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) are inflammatory markers that predict outcome of various cancers. We aimed to examine the relationship between pretreatment inflammatory markers and ASFS outcome. We included 17 patients with ASFS and a control group of 56 age- and gender-matched healthy individuals. Total white blood counts, neutrophil, lymphocyte, monocyte, and platelet counts were recorded; NLR, PLR, and LMR were calculated. Kaplan–Meier curves were used to calculate overall survival (OS) and distant metastasis-free survival (DMFS). Optimal cut-off values for each inflammatory marker were calculated using receiver operating curve analysis. Median follow-up was 22 months (range, 6–75). There was a statistically significant difference in absolute neutrophil counts and NLR between patient and control groups. Two-year OS and DMFS rates were 41% and 35%, respectively. In patients with tumors < 10 cm, PLR was highly correlated with DMFS, with the 2-year DMFS for those with a high PLR being 50% compared with 100% for those with a low PLR (p = 0.06). This study suggests that PLR is superior to NLR and LMR, and is a clinically useful marker in patients with ASFS with small tumors.

13 April 2021 in Cancers
Verified
Journal Article
Open access
PDF file
Hideya YamazakiHideya Yamazaki
Hideya Yamazaki
GSGen Suzuki
Gen Suzuki
KMKoji Masui
Koji Masui
NANorihiro Aibe
Norihiro Aibe
DSDaisuke Shimizu
Daisuke Shimizu
HOHaruumi Okabe
Haruumi Okabe
To examine the efficacy of dose escalating radiotherapy into patients with cT3b or T4 localized prostate cancer, we compared Group A (86 conventional dose external beam radiotherapy: EBRT group, treated with 70–72 Gy) and group B (39 high dose EBRT group (HDEBRT group, 74–80 Gy) and 124 high-dose-rate brachytherapy (HDR) + EBRT (HDR boost)) using multi-institutional retrospective data. The actuarial 5-year biochemical disease-free survival (bDFS) rate, prostate cancer specific survival rate (PSS), and overall survival rate (OS) were 75.8%, 96.8%, and 93.5%. Group B showed superior 5-year bDFS rate (81.2%) as compared to the group A (66.5%) (p < 0.0001) with a hazard ratio of 0.397. Equivocal 5-year PSS (98.3% and 94.8% in group B and group A) and OS (both 93.7%) were found between those groups. Accumulated late grade ≥ 2 toxicities in gastrointestinal and genitourinary tracts were similar among those three groups. Therefore, both HDEBRT and HDR boost could be good options for improving the bDFS rate in cT3–T4 localized prostate cancer without affecting PSS and OS.