title: [CT guidance125I seed implantation for pelvic recurrent rectal cancer assisted by 3D printing individual non-coplanar template].
abstract: Objective:To analyze the difference of dosimetric parameters between pre-plan and post-plan of125I radioactive seed implantation assisted by 3D printing individual non-coplanar template (3D printing template) for locally recurrent rectal cancer (LRRC).Methods:From February 2016 to April 2016, a total of 10 patients with locally recurrent rectal cancer received125I seeds implantation under CT guidance assisted by 3D printing template in Department of Radiation Oncology, Peking University Third Hospital.Each patient underwent CT simulation, three-dimentional treatment planning pre-implantation, 3D printing template design, radioactive seed implantation assisted by 3D printing template and dosimetric verification post implantation. The median activity of seed was 0.63 mCi (0.58 to 0.7 mCi) (2.15- 2.59×107Bq), and the median number of seeds was 80 (19 to 192). D90, D100, V100, V150, CI, EI, HI, D5cc, D2ccof bladder and bowel of pre-plan and post-plan were calculated, respectively.Pairedttest was used to evaluate the difference of dosimetric parameters between pre-plan and post-plan.Results:The median D90of pre-plan and post-plan were 13 761.0 and 12 798.8 cGy, respectively.The median D100of pre-plan and post-plan were 5 293.6 and 5 397.9 cGy, respectively.The median V100of pre-plan and post-plan were 90.0% and 90.0%, respectively.The median V150of pre-plan and post-plan were 63.8% and 62.4%, respectively.The median CI of pre-plan and post-plan were 0.73 and 0.67.The median EI of pre-plan and post-plan were 0.22 and 0.30, respectively. The median HI of pre-plan and post-plan were 0.29 and 0.31.The median bladder D2ccof pre-plan and post-plan were 3 088.8 and 4 240.4 cGy, respectively.The median bowel D2ccof pre-plan and post-plan were 7 051.6 and 7 903.9 cGy, respectively.Conclusions:3D printing template might be helpful for locally recurrent rectal cancer patients who received125I radioactive seed implantation assisted by 3D printing individual template.Seed implantation might have more chances to achieve prescription dose and dose limitation of organs at risk of pre-plan, which is important for precise implantation and quality control.
authors.affiliation: Department of Radiation Oncology, Peking University Third Hospital, Beijing 100191, China.
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.forename: J J
authors.initials: JJ
authors.lastname: Wang
authors.forename: Y L
authors.initials: YL
authors.lastname: Jiang
authors.forename: S Q
authors.initials: SQ
authors.lastname: Tian
authors.forename: Z
authors.initials: Z
authors.lastname: Ji
authors.forename: F X
authors.initials: FX
authors.lastname: Guo
authors.forename: H T
authors.initials: HT
authors.lastname: Sun
authors.forename: J H
authors.initials: JH
authors.lastname: Fan
authors.forename: Y P
authors.initials: YP
authors.lastname: Xu
mesh_terms: D001918:Brachytherapy; D006801:Humans; D009364:Neoplasm Recurrence, Local; D010388:Pelvis; D066330:Printing, Three-Dimensional; D011874:Radiometry; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D012004:Rectal Neoplasms; D014057:Tomography, X-Ray Computed; D001743:Urinary Bladder