Masaharu Hata

Prof. Dr. Masaharu Hata


Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

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

Representative Publications

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1 July 2007 in International Journal of Radiation Oncology - Biology - Physics (IJROBP)
Verified
Journal Article
Closed access
MHMasaharu Hata
Masaharu Hata
KTKoichi Tokuuye
Koichi Tokuuye
KKKenji Kagei
Kenji Kagei
SSShinji Sugahara
Shinji Sugahara
HNHidetsugu Nakayama
Hidetsugu Nakayama
YAYasuyuki Akine
Yasuyuki Akine

24 June 2005 in Cancer
Verified
Journal Article
Open access
PDF file
MHMasaharu Hata
Masaharu Hata
KTKoichi Tokuuye
Koichi Tokuuye
SSShinji Sugahara
Shinji Sugahara
KKKenji Kagei
Kenji Kagei
HIHiroshi Igaki
Hiroshi Igaki
YAYasuyuki Akine
Yasuyuki Akine
BACKGROUND: Treatment modalities for patients with hepatocellular carcinoma (HCC) who have portal vein tumor thrombus (PVTT) are limited and controversial; furthermore, the prognosis for these patients is extremely poor. The authors conducted a retrospective review to determine the role of proton beam therapy in the treatment of patients who had HCC with PVTT.METHODS: Twelve patients with HCC who had tumor thrombus in the main trunk or major branches of the portal vein (clinical T3–T4N0M0) were treated with proton beam therapy. At the time they received proton beam irradiation, patients ranged in age from 42 years to 80 years (median, 62 years), and their tumors ranged in size from 40 mm to 110 mm (median, 60 mm) in greatest dimension. A total dose of 50–72 gray (Gy) (median, 55 Gy) in 10–22 fractions was delivered to the tumors, including PVTT.RESULTS: All tumors that were treated with proton beam therapy remained controlled at a median follow‐up of 2.3 years (range, 0.3–7.3 years). Among 12 patients, 10 patients had new liver tumors outside the irradiated volume 0.1–2.4 years after proton beam therapy, and 3 patients also had distant metastases; consequently, 8 patients died of disease, and 2 patients were salvaged by further therapies. The remaining two patients were alive with no evidence of disease 4.3 years and 6.4 years after proton beam therapy. The progression‐free survival rates were 67% at 2 years and 24% at 5 years. The median progression‐free survival was 2.3 years. According to the Acute Radiation Morbidity Scoring Criteria (Radiation Therapy Oncology Group), therapy‐related toxicity ≥ Grade 3 was not observed.CONCLUSIONS: Proton beam therapy for patients with HCC who had PVTT was feasible and effective. It appeared to improve survival and local control significantly for these patients. Cancer 2005. © 2005 American Cancer Society.

18 July 2006 in Cancer
Verified
Journal Article
Open access
PDF file
MHMasaharu Hata
Masaharu Hata
KTKoichi Tokuuye
Koichi Tokuuye
SSShinji Sugahara
Shinji Sugahara
NFNobuyoshi Fukumitsu
Nobuyoshi Fukumitsu
THTakayuki Hashimoto
Takayuki Hashimoto
YAYasuyuki Akine
Yasuyuki Akine
BACKGROUND.: The authors conducted a retrospective review to define the usefulness of proton beam therapy for patients who had hepatocellular carcinoma (HCC) with limited treatment options.METHODS.: Twenty‐one patients with HCC for whom other treatment modalities either were contraindicative or were unfeasible because of coexisting diseases and unfavorable conditions received proton beam therapy. Four patients had renal failure, 2 patients had severe heart disease, 9 patients had severe cirrhosis, 1 patient had aplastic anemia, 1 patient had a dissecting abdominal aortic aneurysm before treatment, and 4 patients had bleeding tendency or unresectable tumors. Moreover, 2 of the latter 4 patients were allergic to iodine, and 2 other patients were unable to be catheterized for transcatheter arterial chemoembolization. Hepatic tumors were solitary in 14 patients and multiple in 7 patients, and the tumors ranged in greatest dimension from 25 mm to 100 mm (median, 40 mm). No patient had regional lymph node or distant metastasis. Total doses of 63 grays (Gy) to 84 Gy (median, 73 Gy) in 13 to 27 fractions (median, 18 fractions) were used for tumor treatments.RESULTS.: All but 1 of the irradiated tumors were controlled at a median follow‐up of 3.3 years. The objective response rate was 81%, and the primary site‐control rate was 93% at 5 years. Eleven patients had intrahepatic recurrences, and 2 patients had distant metastases in the lungs. Four of 11 patients with intrahepatic recurrences received a second course of proton beam therapy, and all recurrent tumors were controlled. The overall and cause‐specific survival rates were 62% and 82% at 2 years, respectively, and 33% and 67% at 5 years, respectively. Grade ≥3 therapy‐related toxicities were not observed.CONCLUSIONS.: Proton beam therapy was safe and effective for a variety of patients with HCC. The current results suggested that this method was tolerable and effective, even for patients with HCC who had limited treatment options. Cancer 2006. © 2006 American Cancer Society.

3 December 2013 in Annals of Oncology
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Journal Article
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MHMasaharu Hata
Masaharu Hata
IKI. Koike
I. Koike
HWH. Wada
H. Wada
EME. Miyagi
E. Miyagi
TKT. Kasuya
T. Kasuya
TIT. Inoue
T. Inoue
Extramammary Paget's disease (EMPD) is a relatively rare malignancy, and there are few reports related to radiation therapy. In the present study, we investigated the outcome of radiation therapy for EMPD. Forty-one patients with EMPD in the genitalia underwent radiation therapy with curative intent. Fifteen patients had regional lymph node metastases before radiation therapy, but none had distant metastasis. Total doses of 45–80.2 Gy (median, 60 Gy) were delivered to tumor sites in 23–43 fractions (median, 33 fractions). At a median follow-up period of 41 months, 16 patients had developed recurrences, including 5 with local progression within the radiation field and 12 with lymph node or/and distant metastases outside the radiation field. The local progression-free and disease-free rates were 88% and 55% at 3 years, and 82% and 46% at 5 years, respectively. Nine patients died at 6–73 months after irradiation; the causes of death were tumor progression in five patients, infectious pneumonia in two, renal failure in one and old age in one. The overall and cause-specific survival rates were 93% and 96% at 3 years, and 68% and 84% at 5 years, respectively. Tumor invasion into the dermis and regional lymph node metastasis were significant prognostic factors for both distant metastasis and survival. No therapy-related toxicities of grade ≥3 were observed. Radiation therapy is safe and effective for patients with EMPD. It appeared to contribute to prolonged survival owing to good tumor control, and to be a promising curative treatment option.

1 December 2006 in Strahlentherapie und Onkologie
Verified
Journal Article
Open access
PDF file
MHMasaharu Hata
Masaharu Hata
KTKoichi Tokuuye
Koichi Tokuuye
SSShinji Sugahara
Shinji Sugahara
NFNobuyoshi Fukumitsu
Nobuyoshi Fukumitsu
THTakayuki Hashimoto
Takayuki Hashimoto
YAYasuyuki Akine
Yasuyuki Akine
Hepatocellular carcinoma (HCC) patients with severe cirrhosis are usually treated with supportive care because of their poor prognosis. However, the survival of severe cirrhotic patients has recently improved due to advanced treatments. The aim of this study was to define the role of proton beam therapy for HCC patients with severe cirrhosis. 19 HCC patients with Child-Pugh class C cirrhosis received proton beam therapy. The hepatic tumors were solitary in 14 patients and multiple in five, and the tumor size was 25–80 mm (median 40 mm) in maximum diameter. No patient had regional lymph node or distant metastasis. Total doses of 50–84 Gy (median 72 Gy) in ten to 24 fractions (median 16) were delivered to the tumors. Of the 19 patients, six, eight and four died of cancer, liver failure and intercurrent diseases, respectively, during the follow-up period of 3–63 months (median 17 months) after treatment. A remaining patient was alive with no evidence of disease 33 months after treatment. All but one of irradiated tumors were controlled during the follow-up period. Ten patients had new intrahepatic tumors outside the irradiated volume. The overall and progression-free survival rates were 53% and 47% at 1 year, respectively, and 42% each at 2 years. Performance status and Child-Pugh score were significant prognostic factors for survival. Therapy-related toxicity of grade 3 or more was not observed. Proton beam therapy for HCC patients with severe cirrhosis was tolerable. It may improve survival for patients with relatively good general condition and liver function.

1 February 2012 in International Journal of Radiation Oncology - Biology - Physics (IJROBP)
Verified
Journal Article
Closed access
MHMasaharu Hata
Masaharu Hata
IKIzumi Koike
Izumi Koike
MOMotoko Omura
Motoko Omura
JMJiro Maegawa
Jiro Maegawa
IOIchiro Ogino
Ichiro Ogino
TITomio Inoue
Tomio Inoue