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Carbon Ion Therapy of Prostate Cancer
https://repo.qst.go.jp/records/65095
https://repo.qst.go.jp/records/65095c34b09b5-c7b1-4ca0-ae6b-68304ec8ae7e
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2013-08-07 | |||||
| タイトル | ||||||
| タイトル | Carbon Ion Therapy of Prostate Cancer | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Tsuji, Hiroshi
× Tsuji, Hiroshi× 辻 比呂志 |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Introduction: The use of carbon ion radiotherapy (C-ion RT) for prostate cancer was started in 1995 using the Heavy-Ion Medical Accelerator in Chiba (HIMAC) at the National Institute of RadiologicalSciences (NIRS) in Japan. After two phase I/II dose escalation studies of 20 fractions over five weeks, a phase II study was initiated in April 2000 using the treatment techniques and the recommended dose fractionation established by the phase I/II studies. This study was successfully completed in October 2003, and the use of C-ion RT for solid tumors, including prostate cancer, was approved as "Advanced Medicine" by the Ministry of Health, Labor and Welfare of Japan. Thereafter, advances in hypofractionation have been made to provide an appropriate dose in shorter treatment periods of three or four weeks, and in addition, spot-scanning irradiation has also recently become available. Materials and Methods: According to the strategy used for advanced hypofractionation, C-ion RT of 16 fractions over four weeks was begun at the same time as the start of the phase II study (2000). A new trial with 12 fractions over three weeks was performed, and currently, all prostate cancer patients were treated with this fractionation using the spot scanning irradiation method. Patients were considered to be eligible if they had pathologically diagnosed T1b to T3b prostate cancer without metastases. The patients with low-risk prostate cancer were treated with C-ion RT alone, and the patients with intermediate-risk and high-risk prostate cancer were treated with C-ion RT combined with hormonal therapy for six months and ≥24 months, respectively. Results: A total of 1,733 patients underwent the carbon ion radiotherapy from the start of the first clinical trial until February 2013. Of those, 1,479 patients received the C-ion RT after the start of the phase II study, and were followed up more than six months. Four hundred and sixty-six out of these patients were treated with the C-ion RT in 20 fractions, 967 with 16 fractions and 46 under the new trial of 12 fractions. The overall survival rate of the entire group was 95.1% at five years and 79.6% at 10 years based on the Kaplan-Meier estimation. Notably, out of the 87 patients who died, only 18 died of primary prostate cancer. One hundred and eleven patients have met the criteria for biochemical failure according to the Phoenix criteria—that is, an increase in the PSA level over the nadir + 2.0. The five- and 10-year biochemical relapse-free rates were 90.7% and 83.0%, respectively. Out of 1,479 patients, 773 (52.3%) belonged to the high-risk group, and therefore, these outcomes are satisfactory with regard to the tumor control. Regarding the prognostic factors, the T-stage and Gleason score were found to have a significant influence on the biochemical relapse-free rate. Further, the T-stage, initial PSA level and Gleason score influenced the patient survival. Concerning the influence of the dose-fractionation of C-ion RT on the biochemical control, no difference was observed between the biochemical relapse-free rates for the 20-fraction and 16-fraction. Although the observation period for the 12-fraction group has been short and the patient number is small, none of the patients has developed a biochemical relapse to date. Regarding late radiation toxicities, the incidence of late gastrointestinal and genitourinary morbidities and of Grade 2 or worse morbidities in the 63.0 GyE/20 Fr and 57.6 GyE/16 Fr groups were 2.3% and 0.3% at the rectum, respectively, and those in the GU system were 9.3% and 2.6%, respectively. These results confirm the feasibility of further hypofractionated C-ion RT delivered in 16 fractions. Moreover, these results reveal that our assumption of the relative biological effectiveness of carbon ions and the equivalent dose calculated by the LQ model may be reasonable for the C-ion RT for prostate cancer. Conclusion: The outcomes of the C-ion radiotherapy at the NIRS strongly illustrate the fact that this treatment is an ideal therapeutic approach for prostatic cancer. Furthermore, the advances in hypofractionation are expected to contribute to a better outcome, and further shortening and promotion of streamlining can be expected in the future. |
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| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | The Cancer Symposium: Advanced Radiation Oncology Treatment Strategies with Photon, Proton, and Carbon Ion Radiation | |||||
| 発表年月日 | ||||||
| 日付 | 2013-08-02 | |||||
| 日付タイプ | Issued | |||||
