@article{oai:repo.qst.go.jp:00081066,
 author = {Hagiwara, Yasuhito and Yamada, Shigeru and Isozaki, Yuka and Takiyama, Hirotoshi and Shinoto, Makoto and Kawashiro, Shohei and Bhattacharyya, Tapesh and Nemoto, Kenji and Tsuji, Hiroshi and Yasuhito, Hagiwara and Shigeru, Yamada and Yuka, Isozaki and Hirotoshi, Takiyama and Makoto, Shinoto and Shohei, Kawashiro and Bhattacharyya, Tapesh and Kenji, Nemoto and Hiroshi, Tsuji},
 journal = {Clinical and Translational Radiation Oncology},
 month = {Nov},
 note = {Background and purpose: Patients who receive carbon-ion radiotherapy (C-ion RT) for primary pancreatic
cancer may experience locoregional recurrence; however, the treatment options for such patients are
limited. We aimed to investigate the feasibility and efficacy of carbon-ion re-irradiation for patients with
pancreatic cancer who experienced recurrence after initial C-ion RT.
Materials and methods: Twenty-one patients with recurrent pancreatic cancer who underwent repeat Cion
RT between December 2010 and November 2016 at our institute were retrospectively evaluated. The
sites of post-initial C-ion RT failure were in-field central in 16 patients (76.2%) and marginal in 5 (23.8%).
The median doses of initial and repeat C-ion RT were both 52.8 Gy (relative biological effectiveness
[RBE]). Thirteen patients (61.9%) received concurrent chemotherapy with re-irradiation, while 11
(52.4%) received adjuvant chemotherapy.
Results: The median follow-up period after re-irradiation was 11 months. The 1-year local control,
progression-free survival, and overall survival rates were 53.5%, 24.5%, and 48.7%, respectively. Toxicity
data was obtained from the patients’ charts. Only 1 patient (4.8%) developed grade 3 acute toxicities
and none developed grade 3 late toxicities. Univariate analysis indicated that patients who received
adjuvant chemotherapy had significantly improved local control rates compared with those who did
not; the 1-year local control rates were 80.0% and 0.0%, respectively (P = 0.0469).
Conclusion: Repeating C-ion RT may be a reasonable option with tolerable toxicity for patients with
recurrent pancreatic cancers. Adjuvant chemotherapy appears to improve the local control rate. This is
the first study to examine re-irradiation using C-ion for recurrent pancreatic cancer after initial C-ion RT.},
 pages = {24--29},
 title = {Efficacy and feasibility of re-irradiation using carbon ions for pancreatic cancer that recurs after carbon-ion radiotherapy},
 volume = {26},
 year = {2020}
}