Comparison of carbon-ion passive and scanning irradiation for pancreatic cancer.
To compare carbon-ion beam dose distribution between passive and scanning radiation therapies for locally advanced pancreatic cancer.



Thirteen pancreatic cancer patients were included in this study. Four types of treatment planning with respiratory gating were calculated for each patient: a four-field box with passive irradiation (Plan 1), scanning irradiation (Plan 2), a three-field (150°, 180° and 210°) protocol with passive irradiation (Plan 3), and scanning irradiation (Plan 4). The irradiation plans each delivered 55.2Gy (RBE) to the planning target volume (PTV) and were compared with respect to doses to the PTV and organs at risk (OARs).



Plan 3 exceeded the dose assessment metrics to the spinal cord. Scanning irradiation plans (Plan 2 and, particularly, Plan 4) offered significantly reduced dosage to the stomach and the duodenum compared with passive irradiation.



Three-field oblique scanning irradiation for pancreatic cancer has the potential to reduce gastrointestinal exposure and influence of peristalsis on dose distribution.
Research Center for Charged Particle Therapy, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan; Department of Radiation Oncology, Graduate School of Medicine, Chiba University, Japan.
Miho
M
Shiomi
Research Center for Charged Particle Therapy, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan.
Shinichiro
S
Mori
Ion-Beam Therapy Center, SAGA HIMAT Foundation, Japan.
Makoto
M
Shinoto
Ion-beam Radiation Oncology Center in Kanagawa, Kanagawa Cancer Center, Japan.
Yuko
Y
Nakayama
Research Center for Charged Particle Therapy, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan; Department of Radiation Oncology, Graduate School of Medicine, Chiba University, Japan.
Tadashi
T
Kamada
Research Center for Charged Particle Therapy, National Institute for Quantum and Radiological Science and Technology, Chiba, Japan; Department of Radiation Oncology, Graduate School of Medicine, Chiba University, Japan. Electronic address: yamada.shigeru@qst.go.jp.
Shigeru
S
Yamada
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D063193:Heavy Ion Radiotherapy / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D058958:Organs at Risk / Q000528:radiation effects; D010190:Pancreatic Neoplasms / Q000532:radiotherapy*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods*; D016896:Treatment Outcome
Carbon-ion radiotherapy; Pancreatic cancer; Radiation dosimetry