Title: | A Single-Institution Prospective Study To Evaluate the Safety and Efficacy of Real-Time Image-Gated Spot-Scanning Proton Therapy (RGPT) for Prostate Cancer |
Authors: | Nishioka, Kentaro Browse this author →KAKEN DB |
Hashimoto, Takayuki Browse this author →KAKEN DB |
Mori, Takashi Browse this author |
Uchinami, Yusuke Browse this author |
Kinoshita, Rumiko Browse this author |
Katoh, Norio Browse this author |
Taguchi, Hiroshi Browse this author |
Yasuda, Koichi Browse this author |
Ito, Yoichi M. Browse this author |
Takao, Seishin Browse this author |
Tamura, Masaya Browse this author |
Matsuura, Taeko Browse this author →KAKEN DB |
Shimizu, Shinichi Browse this author →KAKEN DB |
Shirato, Hiroki Browse this author →KAKEN DB |
Aoyama, Hidefumi Browse this author →KAKEN DB |
Issue Date: | May-2024 |
Journal Title: | Advances in Radiation Oncology |
Volume: | 9 |
Issue: | 5 |
Start Page: | 101464 |
Publisher DOI: | 10.1016/j.adro.2024.101464 |
Abstract: | Purpose: In real-time image-gated spot-scanning proton therapy (RGPT), the dose distribution is distorted by gold fiducial markers placed in the prostate. Distortion can be suppressed by using small markers and more than 2 fields, but additional fields may increase the dose to organs at risk. Therefore, we conducted a prospective study to evaluate the safety and short-term clinical outcome of RGPT for prostate cancer.
Methods and Materials: Based on the previously reported frequency of early adverse events (AE) and the noninferiority margin of 10%, the required number of cases was calculated to be 43 using the one-sample binomial test by the Southwest Oncology Group statistical tools with the one-sided significance level of 2.5% and the power 80%. Patients with localized prostate cancer were enrolled and 3 to 4 pure gold fiducial markers of 1.5-mm diameter were inserted in the prostate. The prescribed dose was 70 Gy(relative biologic effectiveness) in 30 fractions, and treatment was performed with 3 fields from the left, right, and the back, or 4 fields from either side of slightly anterior and posterior oblique fields. The primary endpoint was the frequency of early AE (≥grade 2) and the secondary endpoint was the biochemical relapse-free survival rate and the frequency of late AE.
Results: Forty-five cases were enrolled between 2015 and 2017, and all patients completed the treatment protocol. The median follow-up period was 63.0 months. The frequency of early AE (≥grade 2) was observed in 4 cases (8.9%), therefore the noninferiority was verified. The overall 5-year biochemical relapse-free survival rate was 88.9%. As late AE, grade 2 rectal bleeding was observed in 8 cases (17.8%).
Conclusions: The RGPT for prostate cancer with 1.5-mm markers and 3- or 4- fields was as safe as conventional proton therapy in early AE, and its efficacy was comparable with previous studies. |
Rights: | http://creativecommons.org/licenses/by-nc-nd/4.0/ |
Type: | article |
URI: | http://hdl.handle.net/2115/91408 |
Appears in Collections: | 医学院・医学研究院 (Graduate School of Medicine / Faculty of Medicine) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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