title: Carbon-ion pencil beam scanning for thoracic treatment - initiation report and dose metrics evaluation.
abstract: Carbon-ion beam scanning has not previously been used for moving tumor treatments. We have commenced respiratory-gated carbon-ion radiotherapy (CIRT) in the thoracic and abdominal regions under free-breathing conditions as a clinical trial. This study aimed to investigate this treatment in the lungs in comparison with passive scattering CIRT. Five patients had thoracic tumors treated with carbon-ion scanned beams using respiratory gating. We analyzed the actual treatments and calculated passive scattering treatment plans based on the same planning CT. We evaluated tumor size until 3 months post treatment and each treatment plan regarding dose delivered to 95% of the clinical target volume (CTV-D95), mean lung dose, percentage of lung receiving at least 5 Gy (RBE) (Lung-V5), Lung-V10, Lung-V20, heart maximum dose (Dmax), esophagus Dmax, cord Dmax and skin Dmax. Obvious tumor deterioration was not observed up to 3 months post treatment. The dose evaluation metrics were similar item by item between respiratory-gated scanned CIRT and passive scattering CIRT. In conclusion, scanned beam CIRT provided treatments equivalent to passive scattering CIRT for thoracic tumors. Increased sample numbers and longer-term observation are needed.
authors.affiliation: Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan Department of Radiology, The University of Tokyo Hospital, Tokyo, Japan mstk117@gmail.com.
authors.forename: Masataka
authors.initials: M
authors.lastname: Karube
authors.affiliation: Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Mori
authors.affiliation: Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsuji
authors.affiliation: Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan.
authors.forename: Naoyoshi
authors.initials: N
authors.lastname: Yamamoto
authors.affiliation: Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan.
authors.forename: Mio
authors.initials: M
authors.lastname: Nakajima
authors.affiliation: Department of Radiology, The University of Tokyo Hospital, Tokyo, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Nakagawa
authors.affiliation: Research Center Hospital for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1, Anagawa, Inage-ku, Chiba, Chiba 263-8555, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kamada
mesh_terms: D000368:Aged; D005260:Female; D056973:Four-Dimensional Computed Tomography; D063193:Heavy Ion Radiotherapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011879:Radiotherapy Dosage; D013909:Thorax / Q000528:radiation effects*
keywords: carbon-ion radiation therapy; clinical trial; respiratory phase–controlled scanning beam treatment; thoracic treatment