title: A technique to reduce low dose region for craniospinal irradiation (CSI) with RapidArc and its dosimetric comparison with 3D conformal technique (3DCRT).
abstract: We proposed a method to reduce the volume of normal tissues irradiated by low doses in patients receiving CSI with RapidArc (RA) using Avoidance-Sector technique (RA+AS) and to compare its dosimetric implications with RA using full-arc (RA+FA) and 3D conformal technique (3DCRT). Four patients of CSI were retrospectively planned with 3DCRT, RA+FA, and RA+AS. Conformity-Index (CI), Homogeneity-Index (HI), and Paddick Gradient-Index (GI) were calculated. Quantitative evaluation was done using DVH analysis for PTVs and OARs. When compared with 3DCRT, GI, CI, and HI were favorable to RA based techniques. In comparison with 3DCRT the doses to OARs were lower with RA+AS with the difference being statistically significant in most instances. RA+AS significantly decreases the dose to OARs and their volumes receiving low doses in comparison with RA+FA and 3DCRT.
authors.affiliation: Department of Medical Physics and Radiation Safety, International Oncology Center, Fortis Hospital, Noida, Uttar Pradesh, India.
authors.forename: Roopam
authors.initials: R
authors.lastname: Srivastava
authors.forename: Gagan
authors.initials: G
authors.lastname: Saini
authors.forename: Pramod Kumar
authors.initials: PK
authors.lastname: Sharma
authors.forename: Manish
authors.initials: M
authors.lastname: Chomal
authors.forename: Anchal
authors.initials: A
authors.lastname: Aagarwal
authors.forename: Sapna
authors.initials: S
authors.lastname: Nangia
authors.forename: Madhur
authors.initials: M
authors.lastname: Garg
mesh_terms: D061888:Craniospinal Irradiation / Q000379:methods*; D006801:Humans; D011874:Radiometry / Q000379:methods; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods; D020266:Radiotherapy, Conformal / Q000379:methods*; D050397:Radiotherapy, Intensity-Modulated / Q000379:methods; D012189:Retrospective Studies