1. Long-term clinical outcomes after 12-fractionated carbon-ion radiotherapy for localized prostate cancer
- Author
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Sato, Hiraku, Kasuya, Goro, Ishikawa, Hitoshi, Nomoto, Akihiro, Ono, Takashi, Nakajima, Mio, Isozaki, Yuka, Yamamoto, Naoyoshi, Iwai, Yuma, Nemoto, Kenji, Ichikawa, Tomohiko, Tsuji, Hiroshi, Hiraku, Sato, Goro, Kasuya, Hitoshi, Ishikawa, Akihiro, Nomoto, Takashi, Ono, Mio, Nakajima, Yuka, Isozaki, Naoyoshi, Yamamoto, Yuma, Iwai, Kenji, Nemoto, and Hiroshi, Tsuji
- Abstract
There are no clinical reports of long-term follow-up after carbon-ion radiotherapy (CIRT) using a dose of 51.6Gy (relative biological effectiveness [RBE]) in 12 fractions for localized prostate cancer, or of a comparison of clinical outcomes between passive and scanning beam irradiation. A total of 256 patients with localized prostate cancer who received CIRT at a dose of 51.6Gy (RBE) in 12 fractions using two different beam delivery techniques (passive [n=45] and scanning [n=211]), and who were followed for more than 1year, were analyzed. The biochemical relapse-free (bRF) rate was defined by the Phoenix definition, and the actuarial toxicity rates were evaluated using the Kaplan-Meier method. Of the 256 patients, 41 (16.0%), 111 (43.4%), and 104 (40.6%) were classified as low, intermediate, and high risk, respectively, after a median follow-up of 7.0 (range 1.1-10.4) years. Androgen deprivation therapy was performed in 212 patients (82.8%). The 5-year bRF rates of the low-, intermediate-, and high-risk patients were 95.1%, 90.9%, and 91.1%, respectively. The 5-year rates of grade 2 late gastrointestinal and genitourinary toxicities in all patients were 0.4% and 6.3%, respectively. No grade ≥3 toxicities were observed. There were no significant differences in the rates of bRF or grade 2 toxicities in patients who received passive irradiation versus scanning irradiation. Our long-term follow-up results showed that a CIRT regimen of 51.6Gy (RBE) in 12 fractions for localized prostate cancer yielded a good therapeutic outcome and low toxicity rates irrespective of the beam delivery technique.
- Published
- 2021