Seiichi Yoshimoto

Dr. Seiichi Yoshimoto

orcid

Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

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

Representative Publications

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1 February 2021 in Radiotherapy and Oncology
Verified
Journal Article
Open access
KHKatsumi Hirose
Katsumi Hirose
AKAkiyoshi Konno
Akiyoshi Konno
JHJunichi Hiratsuka
Junichi Hiratsuka
SYSeiichi Yoshimoto
Seiichi Yoshimoto
TKTakahiro Kato
Takahiro Kato
YTYoshihiro Takai
Yoshihiro Takai
Boron neutron capture therapy (BNCT) can be performed without reactors due to development of cyclotron-based epithermal neutron source (C-BENS), which is optimized for treatment for deeper-seated tumors. The purpose of this study was to evaluate efficacy and safety of cyclotron-based BNCT with borofalan (10B) for recurrent or locally advanced head and neck cancer. In this open-label, phase II JHN002 trial of BNCT using C-BENS with borofalan (10B), patients with recurrent squamous cell carcinoma (R-SCC) or with recurrent/locally advanced non-squamous cell carcinoma (R/LA-nSCC) of the head and neck were intravenously administered 400 mg/kg borofalan (10B), followed by neutron irradiation. The tumor dose was determined passively as the mucosal maximum dose of 12 Gy-Eq. The primary endpoint was the objective response rate (ORR). Post-trial observational JHN002 Look Up study was planned for evaluating locoregional progression-free survival (LRPFS). Eight R-SCC and 13 R/LA-nSCC patients were enrolled. All R-SCC patients had prior radiotherapy with a median dose of 65.5 Gy (range, 59.4-76.0 Gy). The ORR for all patients was 71%, and complete response/partial response were 50%/25% in R-SCC and 8%/62% in R/LA-nSCC. The 2-year overall survival for R-SCC and R/LA-nSCC were 58% and 100%, respectively. The median LRPFS was 11.5 months for R-SCC. Frequently observed adverse events included alopecia (95%), hyperamylasemia (86%), and nausea (81%). These data suggest that BNCT using C-BENS with borofalan (10B) is a promising treatment option for patients with R-SCC or R/LA-nSCC of the head and neck.

1 March 2022 in Journal of Clinical Oncology
Verified
Journal Article
Open access
NKNAOMI KIYOTA
NAOMI KIYOTA
MTMakoto Tahara
Makoto Tahara
JMJunki Mizusawa
Junki Mizusawa
TKTakeshi Kodaira
Takeshi Kodaira
HFHirofumi Fujii
Hirofumi Fujii
N(Neck Cancer Study Group of the Japan Clinical Oncology Group (JCOG-HNCSG)
Neck Cancer Study Group of the Japan Clinical Oncology Group (JCOG-HNCSG)
PURPOSE: The standard treatment for postoperative high-risk locally advanced squamous cell carcinoma of the head and neck (LA-SCCHN) is chemoradiotherapy with 3-weekly cisplatin (100 mg/m2). However, whether chemoradiotherapy with weekly cisplatin (40 mg/m2) yields comparable efficacy with 3-weekly cisplatin in postoperative high-risk LA-SCCHN is unknown. PATIENTS AND METHODS: In this multi-institutional open-label phase II/III trial, patients with postoperative high-risk LA-SCCHN were randomly assigned to receive either chemoradiotherapy with 3-weekly cisplatin (100 mg/m2) or with weekly cisplatin (40 mg/m2) to confirm the noninferiority of weekly cisplatin. The primary end point of phase II was the proportion of treatment completion, and that of phase III was overall survival. A noninferiority margin of hazard ratio was set at 1.32. RESULTS: Between October 2012 and December 2018, a total of 261 patients were enrolled (3-weekly cisplatin, 132 patients; weekly cisplatin, 129 patients). At the planned third interim analysis in the phase III part, after a median follow-up of 2.2 (interquartile range 1.19-3.56) years, chemoradiotherapy with weekly cisplatin was noninferior to 3-weekly cisplatin in terms of overall survival, with a hazard ratio of 0.69 (99.1% CI, 0.374 to 1.273 [< 1.32], one-sided P for noninferiority = .0027 < .0043). Grade 3 or more neutropenia and infection were less frequent in the weekly arm (3-weekly v weekly, 49% v 35% and 12% v 7%, respectively), as were renal impairment and hearing impairment. No treatment-related death was reported in the 3-weekly arm, and two (1.6%) in the weekly arm. CONCLUSION: Chemoradiotherapy with weekly cisplatin is noninferior to 3-weekly cisplatin for patients with postoperative high-risk LA-SCCHN. These findings suggest that chemoradiotherapy with weekly cisplatin can be a possible treatment option for these patients.

20 June 2021 in Journal of Clinical Oncology
Verified
Journal Article
Closed access
YHYasuhisa Hasegawa
Yasuhisa Hasegawa
KTKiyoaki Tsukahara
Kiyoaki Tsukahara
SYSeiichi Yoshimoto
Seiichi Yoshimoto
KMKouki Miura
Kouki Miura
JYJunkichi Yokoyama
Junkichi Yokoyama
FGfor the HNCMM Research Group
for the HNCMM Research Group
PURPOSE: This study aimed to compare patients with early oral cavity squamous cell carcinoma (OCSCC) (tumor category [T] 1-2, node-negative, and no distant metastasis) treated with traditional elective neck dissection (ND) with those managed by sentinel lymph node biopsy (SLNB) using survival and neck function and complications as end points.METHODS: Sixteen institutions in Japan participated in the study (trial registration number: UMIN000006510). Patients of age ≥ 18 years with histologically confirmed, previously untreated OCSCC (Union for International Cancer Control TNM Classification of Malignant Tumors 7th edition T1-2, node-negative no distant metastasis), with ≥ 4 mm (T1) depth of invasion, were randomly assigned to undergo standard selective ND (ND group; n = 137) or SLNB-navigated ND (SLNB group; n = 134). The primary end point was the 3-year overall survival rate, with a 12% noninferiority margin; secondary end points included postoperative neck functionality and complications and 3-year disease-free survival. Sentinel lymph nodes underwent intraoperative multislice frozen section analyses for the diagnosis. Patients with positive sentinel lymph nodes underwent either one-stage or second-look ND.RESULTS: Pathologic metastasis-positive nodes were observed in 24.8% (34 of 137) and 33.6% (46 of 134) of patients in the ND and SLNB groups, respectively ( P = .190). The 3-year overall survival in the SLNB group (87.9%; lower limit of one-sided 95% CI, 82.4) was noninferior to that in the ND group (86.6%; lower limit 95% CI, 80.9; P for noninferiority < .001). The 3-year disease-free survival rate was 78.7% (lower limit 95% CI, 72.1) and 81.3% (75.0) in the SLNB and ND groups, respectively ( P for noninferiority < .001). The scores of neck functionality in the SLNB group were significantly better than those in the ND group.CONCLUSION: SLNB-navigated ND may replace elective ND without a survival disadvantage and reduce postoperative neck disability in patients with early-stage OCSCC.

27 February 2020 in Cancers
Verified
Journal Article
Open access
PDF file
NONaoyoshi Onoda
Naoyoshi Onoda
ISIwao Sugitani
Iwao Sugitani
KIKen-ichi Ito
Ken-ichi Ito
ASAkifumi Suzuki
Akifumi Suzuki
THTakuya Higashiyama
Takuya Higashiyama
SSShinichi Suzuki
Shinichi Suzuki
Background: The tumor–node–metastasis (TNM) classification system to categorized anaplastic thyroid cancer (ATC) was revised. Methods: The revised system was evaluated using a large database of ATC patients. Results: A total of 757 patients were analyzed. The proportion and median overall survival values (OS: months) for each T category were T1 (n = 8, 1.1%, 12.5), T2 (n = 43, 5.7%, 10.9), T3a (n = 117, 15.5%, 5.7), T3b (n = 438, 57.9%, 3.9), and T4 (n = 151, 19.9%, 5.0). The OS of the N0 and N1 patients were 5.9 and 4.3, respectively (log-rank p < 0.01). Sixty-three (58.3%) patients migrated from stage IV A to IV B by revision based on the existence of nodal involvement and 422 patients (55.7%) were stratified into stage IV B, without a worsening of their OS (6.1), leaving 45 patients (5.9%) in stage IV A with fair OS (15.8). The hazard ratios for the survival of the patients of stage IV B compared to stage IV A increased from 1.1 to 2.1 by the revision. No change was made for stage IV C (n = 290, 38.8%, 2.8). Conclusion: The revised TNM system clearly indicated the prognoses of ATC patients by extracting rare patients with fair prognoses as having stage IV A disease and categorized many heterogeneous patients in stage IV B.

29 June 2022 in Auris Nasus Larynx
Verified
Journal Article
Closed access
GOGo Omura
Go Omura
YHYoshitaka Honma
Yoshitaka Honma
YMYoshifumi Matsumoto
Yoshifumi Matsumoto
TSTakeshi Shinozaki
Takeshi Shinozaki
MIMai Itoyama
Mai Itoyama
SYSeiichi Yoshimoto
Seiichi Yoshimoto

1 April 2010 in Auris Nasus Larynx
Verified
Journal Article
Closed access
SYSeiichi Yoshimoto
Seiichi Yoshimoto
KKKazuyoshi Kawabata
Kazuyoshi Kawabata
HMHiroki Mitani
Hiroki Mitani