博士（医学）, 信州大学

Radiological sciences, Radiation Oncology

2024
Department of Radiology, associate professor

2017 - 2021
Senior Assistant Professor

2011 - 2017
Assistant professor

2011, 信州大学医学部大学院医学系研究科

Predictive Factors for Late Rectal Toxicity in Prostate Cancer Patients after Intensity Modulated Radiation Therapy
JINJI, Yuka; FUKAZAWA, Ayumu; SAKAI, Ayumi; KOIWAI, Keiichiro; FUJINAGA, Yasunari
The Shinshu Medical Journal, 71(3), 159-165, 10 Jun. 2023

A case of mediastinal mesenchymal tumor with pericytic neoplasm feature that responded to radiation therapy.
Muramoto M, Kanda S, Kobayashi T, Tamada H, Fukazawa A, Koiwai K, Koizumi T.
Thorac Cancer., 14(13), 1204-1207-1207, 2023

Nasal cavity tumor successfully treated with urgent combined proton and photon therapy to preserve visual function: A case study
Furui Y, Araya M, Masaki H, Koiwai K, Sato R, Miyairi Y, Chiba A, Komori K, Kurata T, Sakashita K.
Pediatr Blood Cancer, 70(11), e30570, 2023

Impact of upgraded radiotherapy system on outcomes in postoperative head and neck squamous cell carcinoma patients
Keiichiro Koiwai1, Dai Hirasawa1, Miyu Sugimura1, Yuuki Endo1, Kai Mizuhata1, Hironobu Ina1, Ayumu Fukazawa1, Ryosuke Kitoh2, Hironori Sakai3, Yasunari Fujinaga1
Reports of Practical Oncology and Radiotherapy, 27(6), 954-962, Dec. 2022
Lead

Impact of low-dose tadalafil on adverse events after low-dose-rate brachytherapy for prostate cancer: A bi-center randomized open-label trial
Minagawa, Tomonori; Oguchi, Tomohiko; Saitou, Tetsuichi; Fukazawa, Ayumu; Hashida, Iwao; Koiwai, Keiichiro; Iijima, Kazuyoshi; Kato, Haruaki; Ogawa, Teruyuki; Ishizuka, Osamu;
INTERNATIONAL JOURNAL OF UROLOGY, 28(4), 432-438, Apr. 2021

Nursing of patients with prostate cancer treated by brachytherapy : Needs of patients requiring from the nursing
佐々木 香里;堀内 宏樹;夘之原 美津妃;小岩井 慶一郎
Annals of nursing research, Shinshu University Hospital, 48(1), 14-17, Mar. 2021

Ten-Year Experience of Stereotactic Body Radiotherapy at a Single Institution: Impact of Technological Development on the Outcome of Patients With Early Lung Cancer
Koiwai, Keiichiro; Endo, Yuuki; Mizuhata, Kai; Ina, Hironobu; Fukazawa, Ayumu; Ozawa, Takesumi; Fujinaga, Yasunari;
TECHNOLOGY IN CANCER RESEARCH & TREATMENT, 19, 2020

Proton Beam Therapy for Adolescent Primary Central Nervous System Lymphoma With Residual Tumor After Intensive Chemotherapy: A Case Report
Komori, Kazutoshi; Saito, Shoji; Araya, Masayuki; Morita, Daisuke; Kurata, Takashi; Hirabayashi, Koichi; Tanaka, Miyuki; Koiwai, Keiichiro; Tauchi, Katsunori; Masaki, Hidekazu; Nakazawa, Yozo;
PRACTICAL RADIATION ONCOLOGY, 9(5), 333-337, 2019

Texture irregularity of pretreatment contrast-enhanced computed tomography as a predictive factor for developing esophageal stricture after chemoradiation therapy for esophageal squamous cell carcinoma
Keiichiro Koiwai, Hironobu Ina, Ayumu Fukazawa, Takesumi Ozawa and Masumi Kadoya
Medical Imaging and Radiology, 6(1), 1-5, 21 Jun. 2018, Refereed

Predictive Factors for Deterioration of Lower Urinary Tract Symptoms After Iodine-125 Brachytherapy in Prostate Cancer Patients
Fukazawa, Ayumu; Koiwai, Keiichiro; Ozawa, Takesumi; Matsushita, Hirohide; Kadoya, Masumi
The Shinshu Medical Journal, 66(2), 131-137, 10 Apr. 2018

Bronchial Mucoepidermoid Carcinoma Successfully Treated with Radiation Therapy: A Case Report
Kenichi Nishie, Masanori Yasuo, Hidekazu Takahashi, Yoko Ozawa, Kazunari Tateishi, Hiroshi Yamamoto, Keiichiro Koiwai, Takeshi Uehara, Gen Ideura and Masayuki Hanaoka
Oncology and Cancer Case Reports, 3(2), 1-4, 03 Jul. 2017, Refereed

Dosimetric Comparisons of Volumetric Modulated Arc Therapy with Three-Dimensional Conformal Radiation Therapy for Locally Advanced Non-Small Cell Lung Cancer
Ozawa, Takesumi; Koiwai, Keiichiro; Matsushita, Hirohide; Kadoya, Masumi
The Shinshu Medical Journal, 65(2), 93-98, 10 Apr. 2017

Outcomes of uterine cervical cancer patients with pelvic lymph node metastases after radiotherapy without boost irradiation of metastases
Yoshizawa, Eriko; Koiwai, Keiichiro; Ina, Hironobu; Fukazawa, Ayumu; Sakai, Katsuya; Ozawa, Takesumi; Matsushita, Hirohide; Kadoya, Masumi;
JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH, 43(4), 718-722, Apr. 2017

子宮癌における放射線治療の現状（臨床報告）
小岩井慶一郎
INNERVISION, 32(11), 74-75, 2017

子宮癌における放射線治療の現状（技術報告）
小岩井慶一郎
INNERVISION, 32(12), 84-85, 2017

ABO血液型不一致腎移植における移植腎放射線照射
MATSUSHITA, Hirohide; KOIWAI, Keiichiro; KADOYA, Masumi
The Shinshu Medical Journal, 64(3), 147-151, Jun. 2016

Palliative radiotherapy for Japanese patients with malignant melanoma: a single-institution experience
Koiwai, Keiichiro; Sasaki, Shigeru; Yoshizawa, Eriko; Ina, Hironobu; Fukazawa, Ayumu; Sakai, Katsuya; Ozawa, Takesumi; Matsushita, Hirohide; Kadoya, Masumi;
JAPANESE JOURNAL OF RADIOLOGY, 34(2), 125-129, Feb. 2016

Successful Concurrent Chemoradiotherapy with Cisplatin plus Vinorelbine for Locally Advanced Thymic Carcinoma
Toshirou Fukushimaa, Kazunari Tateishia, Masayuki Hanaokaa, Keiichirou Koiwai, Shigeru Sasakic, and Tomonobu Koizumi
Case Reports in Oncology, 7, 65–69, 24 Jan. 2014

Validity of reduced radiation dose for localized diffuse large B-cell lymphoma showing a good response to chemotherapy
Koiwai, K; Sasaki, S; Yoshizawa, E; Ina, H; Fukazawa, A; Sakai, K; Ozawa, T; Matsushita, H; Kadoya, M
JOURNAL OF RADIATION RESEARCH, 55(2), 359-363, 2014

子宮癌腔内照射を受ける患者の看護 : 患者の苦痛に焦点をあてて
柳揮裕子、窪田里絵、遠山理江、細田かず子、小岩井慶一郎
Annals of nursing research, Shinshu University Hospital, 41(1), 1-4, Mar. 2013

Treatment outcome of elderly patients with glioblastoma who received combination therapy
Shikama N, Sasaki S, Shinoda A, Koiwai K
Am J Clin Oncol, 35, 486-489, 2012

Validation of the total dysphagia risk score (TDRS) as a predictive measure for acute swallowing dysfunction induced by chemoradiotherapy for head and neck cancers
Koiwai, Keiichiro; Shikama, Naoto; Sasaki, Shigeru; Shinoda, Atsunori; Kadoya, Masumi
Radiother Oncol, 97, 132-135, 2010

P-2-34 放射線化学療法に抵抗性で外科的切除により根治が得られた食道癌リンパ節再発の1例(食道 術後合併症および再発,一般演題(ポスター),第64回日本消化器外科学会総会)
中山 中; 久保 直樹; 竹内 信道; 辻本 和雄; 伊藤 憲雄; 小岩井 慶一郎;
日本消化器外科学会雑誌, 42(7), 01 Jul. 2009

Risk Factors for Severe Dysphagia after Concurrent Chemoradiotherapy for Head and Neck Cancers
Koiwai, Keiichiro; Shikama, Naoto; Sasaki, Shigeru; Shinoda, Atsunori; Kadoya, Masumi
Japanese journal of clinical oncology, 39(7), 413-417, Jul. 2009

Relationship between the response to treatment and the prognosis of patients with aggressive lymphomas treated with chemotherapy followed by involved-field radiotherapy: Radiographic assessment
Sasaki, Shigeru; Shikama, Naoto; Koiwai, Keiichiro; Kadoya, Masumi;
Japanese journal of clinical oncology, 38(1), 43-48, Jan. 2008

Successful treatment of primary cardiac angiosarcoma with docetaxel and radiotherapy
Nakamura-Horigome, Miki; Koyama, Jun; Eizawa, Takayuki; Kasai, Hiroki; Kumazaki, Setsuo; Tsutsui, Hiroshi; Koiwai, Keiichiro; Oguchi, Kazuhiro; Kinoshita, Osamu; Ikeda, Uichi;
Angiology, 59(3), 368-371, 2008

Clinicopathologic features and histochemical analyses of proliferative activity and angiogenesis in small cell carcinoma of the esophagus
Koide, Naohiko; Saito, Hiroyasu; Suzuki, Akira; Sato, Toshiyuki; Koiwai, Keiichiro; Nakamura, Naoshi; Miyagawa, Shinichi;
JOURNAL OF GASTROENTEROLOGY, 42(12), 932-938, Dec. 2007

Dummy run for a phase II multi-institute trial of chemoradiotherapy for unresectable pancreatic cancer: Inter-observer variance in contour delineation
Yamazaki, Hideya; Nishiyama, Kinji; Tanaka, Eiichi; Koiwai, Keiichiro; Shikama, Nacto; Ito, Yoshinori; Arahira, Satoko; Tamamoto, Tetsuro; Shibata, Toru; Tamaki, Yoshio; Kodaira, Takeshi; Oguchi, Masahiko;
Anticancer Research, 27(4C), 2965-2971, 2007

胃悪性リンパ腫における照射方法の検討
小岩井慶一郎、佐々木茂、鹿間直人
日本放射線腫瘍学会誌, 18(3), 135-139, 25 Jul. 2006

What's going on 放射線 Locoregional radiation therapy in patients with high-risk breast cancer receiving adjuvant chemotherapy: 20-year results of the British Columbia randomized trial. Ragaz J, Olivotto IA, Spinelli JJ, Phillips N, Jackson SM, Wilson KS, Knowling MA, Coppin CM, Weir L, Gelmon K, Le N, Durand R, Coldman AJ, Manji M. J Natl Cancer Inst. 2005; 97: 116-26. PMID: 15657341.--閉経前でリンパ節転移を有する高リスク乳癌症例において、術後化学療法に加え術後照射を行うことで生存率が改善することを無作為化比較試験で示した論文
小岩井 慶一郎; 鹿間 直人;
Mebio oncology, 2(4), 96-98, 2005

頭蓋内胚細胞腫に対する放射線治療
鹿間 直人; 佐々木 茂; 西川 敦; 小岩井 慶一郎; 小口 正彦;
The Journal of JASTRO = 日本放射線腫瘍学会誌, 15(3), 165-170, 25 Sep. 2003

消化管間葉系腫瘍(GIST)の画像診断 : CTによる悪性度の評価
望月 健太郎; 植田 瑞穂; 塩沢 哲; 石亀 廣樹; 長谷川 実; 小岩井 慶一郎; 渡辺 俊一; 角谷 眞澄;
日本医学放射線学会雑誌, 63(5), 210-213, 25 May 2003

上咽頭癌における60Gyまでの照射期間が放射線治療成績に与える影響
荒川 和清; 鹿間 直人; 佐々木 茂; 篠田 充功; 西川 敦; 小岩井 慶一郎; 平瀬 雄一; 岡嵜 洋一; 小口 正彦; 角谷 眞澄; アラカワ カズキヨ; シカマ ナオト; ササキ シゲル; シノダ アツノリ; ニシカワ アツシ; コイワイ ケイイチロウ; ヒラセ ユウイチ; オカザキ ヨウイチ; オグチ マサヒコ; カドヤ マスミ; Arakawa Kazukiyo; Shikama Naoto; Sasaki Shigeru; Shinoda Atusunori; Nishikawa Ausushi; Koiwai Keiichirou; Hirase Yuichi; Okazaki Youichi; Oguchi Masahiko; Kadoya Masumi;
日本医学放射線学会雑誌, 63(1), 41-46, 25 Jan. 2003

Risk Factors for Local-Regional Recurrence Following Preoperative Radiation Therapy and Surgery for Head and Neck Cancer (Stage II–IVB)
Naoto Shikama, Shigeru Sasaki, Atsushi Nishikawa, Keiichirou Koiwai, Fuyumi Yoshino, Yuichi Hirase, Rei Kawakami, Masumi Kadoya, and Masahiko Oguchi
Radiology, 228(3), 789-94, 14 Jan. 2003

鼻腔原発非ホジキンリンパ腫における中枢神経浸潤の評価
鹿間 直人; 小口 正彦; 佐々木 茂; 篠田 充功; 西川 敦; 荒川 和清; 小岩井 慶一郎; 望月 健太郎; 山田 哲; 渡辺 智治; 角谷 眞澄; シカマ ナオト; オグチ マサヒロ; ササキ シゲル; シノダ アツノリ; ニシカワ アツシ; アラカワ カズキヨ; コイワイ ケイイチロウ; モチズキ ケンタロウ; ヤマダ アキラ; ワタナベ トモハル; カドヤ マスミ; Shikama Naoto; Oguchi Masahiko; Sasaki Sigeru; Shinoda Atsunori; Nishiwaka Atsushi; Arakawa Kazukiyo; Koiwai Keiichirou; Mochizuki Kentarou; Yamada Akira; Watanabe Tomoharu; Kadoya Masumi;
日本医学放射線学会雑誌, 61(7), 342-346, 25 Jun. 2001

131I-MIBGが全く集積しなかった褐色細胞腫の1例
小岩丼慶一郎、百瀬充浩、渡辺智治、佐々木茂、角谷員澄
臨床核医学, 34(3), 40-42, 01 May 2001

14.肺線維症に合併した肺癌の検討(第77回 中部肺癌学会)
小岩井 慶一郎; 川上 聡; 高島 庄太夫; 斉藤 彰俊;
肺癌, 40(7), 20 Dec. 2000