title: Experimental verification of proton beam monitoring in a human body by use of activity image of positron-emitting nuclei generated by nuclear fragmentation reaction.
abstract: Proton therapy is a form of radiotherapy that enables concentration of dose on a tumor by use of a scanned or modulated Bragg peak. Therefore, it is very important to evaluate the proton-irradiated volume accurately. The proton-irradiated volume can be confirmed by detection of pair-annihilation gamma rays from positron-emitting nuclei generated by the nuclear fragmentation reaction of the incident protons on target nuclei using a PET apparatus. The activity of the positron-emitting nuclei generated in a patient was measured with a PET-CT apparatus after proton beam irradiation of the patient. Activity measurement was performed in patients with tumors of the brain, head and neck, liver, lungs, and sacrum. The 3-D PET image obtained on the CT image showed the visual correspondence with the irradiation area of the proton beam. Moreover, it was confirmed that there were differences in the strength of activity from the PET-CT images obtained at each irradiation site. The values of activity obtained from both measurement and calculation based on the reaction cross section were compared, and it was confirmed that the intensity and the distribution of the activity changed with the start time of the PET imaging after proton beam irradiation. The clinical use of this information about the positron-emitting nuclei will be important for promoting proton treatment with higher accuracy in the future.
authors.affiliation: Particle Therapy Division, Research Center for Innovative Oncology, National Cancer Center, Kashiwa, Kashiwa-shi, Chiba, Japan. tnishio@east.ncc.go.jp
authors.forename: Teiji
authors.initials: T
authors.lastname: Nishio
authors.forename: Aya
authors.initials: A
authors.lastname: Miyatake
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Inoue
authors.forename: Tomoko
authors.initials: T
authors.lastname: Gomi-Miyagishi
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kohno
authors.forename: Satoru
authors.initials: S
authors.lastname: Kameoka
authors.forename: Keiichi
authors.initials: K
authors.lastname: Nakagawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Ogino
mesh_terms: D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D049268:Positron-Emission Tomography / Q000295:instrumentation* / Q000379:methods; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging* / Q000532:radiotherapy*; D061766:Proton Therapy; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods; D051598:Whole Body Imaging / Q000295:instrumentation / Q000379:methods*; D011522:Protons
chemical_list: D011522:Protons
references.citation: Phys Med Biol. 2006 Mar 7;51(5):1249-60
references.pmid: 16481691
references.citation: Science. 1978 Jun 9;200(4346):1151-3
references.pmid: 17745105
references.citation: Phys Med Biol. 2003 Apr 7;48(7):875-89
references.pmid: 12701892
references.citation: Radiother Oncol. 2004 Dec;73 Suppl 2:S96-8
references.pmid: 15971319
references.citation: Phys Med Biol. 2003 Aug 7;48(15):2269-81
references.pmid: 12953897
references.citation: Phys Med Biol. 2000 Nov;45(11):N151-6
references.pmid: 11098922
references.citation: Int J Radiat Oncol Biol Phys. 2002 Aug 1;53(5):1388-91
references.pmid: 12128141
references.citation: Phys Med Biol. 1996 Jan;41(1):177-96
references.pmid: 8685254
references.citation: Med Phys. 2006 Nov;33(11):4190-7
references.pmid: 17153398
references.citation: Med Phys. 1999 Jun;26(6):992-1006
references.pmid: 10436901
references.citation: Med Phys. 2005 Apr;32(4):1070-82
references.pmid: 15895592
references.citation: J Nucl Med. 2001 May;42(5):808-17
references.pmid: 11337581
references.citation: Phys Med Biol. 2002 Jan 7;47(1):21-36
references.pmid: 11814225