Papers - SOMEYA Masanori

Treatment strategy for oropharyngeal carcinoma (from the standpoint of radiotherapy)

Koh-ichi Sakata, Masato Hareyama, Masanori Someya, Hisayasu Nagakura, Atsushi Oouchi, Katsushi Asano, Shinji Ooguro

Toukeibu Gan   30 ( 3 ) 419 - 422  2004

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In the treatment of oropharyngeal carcinoma, concomitant chemoradiotherapy using platium-based treatment schedules has yielded better results than radiotherapy alone and has been recently used by an increasing number of institutions. In the treatment of head and neck cancer including oropharyngeal cancer, salvage operation can be performed when radiotherapy fails to obtain locoregional control in some cases treated with radiotherapy alone. Such feasibility of salvage operation has influenced the decision on treatment modality and radiotherapy tends to be selected as a first-line treatment. However, salvage operation may be difficult to perform after concomitant chemoradiotherapy using platium-based treatments because the increased damage of the normal tissues by chemoradiotherapy may cause complications for the operation. Therefore, closer communication and more careful discussion between head and neck surgeons and radiation oncologists has become more important when the first-line treatment is decided. © 2004, Japan Society for Head and Neck Cancer. All rights reserved.

DOI

High-dose-rate intracavitary brachytherapy: results of analyses of late rectal complications.

Koh-ichi Sakata, Hisayasu Nagakura, Atushi Oouchi, Masanori Someya, Kensei Nakata, Mitsuo Shido, Kazumitsu Koito, Satoru Sagae, Ryuichi Kudo, Masato Hareyama

International journal of radiation oncology, biology, physics   54 ( 5 ) 1369 - 76  2002.12  [Refereed]  [International journal]

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PURPOSE: To examine the incidence of radiation-induced late rectal complications by analyzing the data of measured rectal doses in patients with cancer of the uterine cervix treated with high-dose-rate intracavitary brachytherapy. METHODS AND MATERIALS: We measured doses to the rectum in 105 patients with cancer of the cervix during high-dose-rate intracavitary brachytherapy with a semiconductor dosimeter that can measure five points in the rectum simultaneously. On the basis of these measurements, equivalent doses, to which the biologically equivalent doses were converted as if given as fractionated irradiation at 2 Gy/fraction, were calculated as components of the cumulative dose at five rectal points in intracavitary brachytherapy combined with the external whole pelvic dose. RESULTS: The calculated values of equivalent doses for late effects at the rectum ranged from 15 to 100 Gy (median 60 Gy for patients who did not develop complications and 76 Gy for patients who subsequently developed Grade II or III complications). When converted to a graph of absolute rectal complication probability, the data could be fitted to a sigmoid curve. The data showed a very definite dose-response relationship, with a threshold for complications at approximately 50 Gy and the curve starting to rise more steeply at approximately 60 Gy. The steepest part of the curve had a slope equivalent to approximately 4% incidence/1 Gy increase in equivalent doses. CONCLUSION: The radiation tolerance dose, 5% and 50% complication probability, was about 64 and 79 Gy, respectively. Our data almost agree with the prescribed dose for the rectum for the radiation tolerance doses on the basis of the recorded human and animal data. The probability of rectal complications increased drastically after the maximal rectal dose was >60 Gy.

PubMed

High-dose-rate versus low-dose-rate intracavitary therapy for carcinoma of the uterine cervix: a randomized trial.

Masato Hareyama, Koh-ichi Sakata, Atushi Oouchi, Hisayasu Nagakura, Mitsuo Shido, Masanori Someya, Kazumitsu Koito

Cancer   94 ( 1 ) 117 - 24  2002.01  [Refereed]  [International journal]

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BACKGROUND: This was a prospective randomized clinical trial undertaken at our institution to compare low-dose-rate (LDR) intracavitary radiation therapy versus high-dose-rate (HDR) intracavitary radiation therapy for the treatment of cervical carcinoma. METHODS: From January 1984 to December 1997, a total of 132 patients with Stage II or IIIB of invasive carcinoma of the uterine cervix were entered into this randomized study. Treatment arm by HDR or LDR was allocated according to the month of each patient's birth. External irradiation consisted of whole pelvis irradiation and pelvic irradiation. Doses of external irradiation for both groups were identical. The authors used 0.588 as the conversion factor of total intracavitary dose from LDR to HDR. RESULTS: The 5-year disease specific survival rates of Stage II and III patients treated with HDR were 69% and 51% whereas those with LDR were 87% and 60%, respectively. The 5-year pelvic recurrence free survival rates of Stage II and III patients treated with HDR were 89% and 73% whereas those with LDR were 100% and 70%, respectively. There was no significant difference in disease specific survival or pelvic recurrence free survival rates between HDR and LDR. The actuarial complication rate (Radiation Therapy Oncology Group Grade 3, 4, or 5) at 5 years was 10% in the HDR group and 13% in the LDR group, and the difference between the HDR and LDR groups was not statistically significant. CONCLUSIONS: The pelvic control or actuarial complication rates were comparable between HDR and LDR treatment. The difference between the disease specific survival rates for HDR and LDR was not statistically significant for Stage II or III, although in Stage II, patients treated with LDR appeared to have a better survival rate than those treated with HDR.

PubMed

A case of hepatocellular carcinoma: The feasibility of intravenous contrast enhanced ultrasonography in evaluating percutaneous microwave coagulation therapy

Naoki Hirokawa, Kazumitsu Koito, Sjsum, Kensei Nakata, Takeshi Ichimura, Masanori Someya, Takaharu Shounai, Naoya Yama, Hideki Hyoudou

Journal of Medical Ultrasonics   29 ( 1 ) J17 - J21  2002

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Precise evaluation of the effect of treatment after ablation of liver tumors is essential. We encountered a case of hepatocellular carcinoma (HCC) in which tumoral necrosis was fairly well detected by intravenous contrast-enhanced ultrasonography (EU). An eighty-year-old woman with chronic hepatitis C underwent ultrasonographic examination (US), in which B mode US detected an HCC nodule 11 mm in diameter. This nodule was well enhanced by EU using the dynamic flow method and an ultrasound system (Toshiba PowerVision 8000) on both vascular and perfusion images. After percutaneous microwave coagulation therapy, the nodule was not enhanced by this method or enhanced CT. We think that EU should be the first choice of examination after nonsurgical treatment of liver tumors, because EU is more convenient than CT or MR and may have the same diagnostic ability to evaluate tumor viability as CT or MR.

Four Cases of Meningeal Hemangiopericytoma Treated with Surgery and Radiotherapy

M. Someya

Japanese Journal of Clinical Oncology ( Oxford University Press (OUP) )  31 ( 11 ) 548 - 552  2001.11  [Refereed]

DOI