title: Determination of dosimetric perturbations caused by aneurysm clip in stereotactic radiosurgery using gel phantoms and EBT-Gafchromic films.
abstract: Some radiotherapy patients are treated with titanium surgical aneurysm clips in the radiation field. This is of particular importance for stereotactic radiosurgery brain treatments, where the length of the blade of the clip may be comparable to the size of the radiation field. This study seeks to determine the extent of the dosimetric effects caused by surgical clips in stereotactic radiosurgery, using polyacrylamide gel phantoms and EBT type Gafchromic films. Using gel phantoms scanned with magnetic resonance imaging scanner, dose enhancement of around 20% was noted at distances less than 2 mm away from the clip surface. Gafchromic films showed about 6% variations in the dose up to few millimeters from the clip. These experimental results confirmed results predicted by Monte Carlo simulation techniques for higher density material surgical clips such as lead and platinum. Moreover, these experimental measurements clearly indicate dose reduction due to radiation attenuation behind the clip of about 4%.
authors.affiliation: School of Medical Sciences, RMIT University, Bundoora, Victoria 3083, Australia. moshi.geso@rmit.edu.au
authors.forename: M
authors.initials: M
authors.lastname: Geso
authors.forename: T
authors.initials: T
authors.lastname: Ackerly
authors.forename: S
authors.initials: S
authors.lastname: Brown
authors.forename: Z
authors.initials: Z
authors.lastname: Chua
authors.forename: C
authors.initials: C
authors.lastname: He
authors.forename: C J
authors.initials: CJ
authors.lastname: Wong
authors.forename: C E
authors.initials: CE
authors.lastname: Powell
authors.forename: A
authors.initials: A
authors.lastname: Ho
authors.forename: G
authors.initials: G
authors.lastname: Qiao
authors.forename: D H
authors.initials: DH
authors.lastname: Solomon
authors.forename: W
authors.initials: W
authors.lastname: Patterson
authors.forename: J M
authors.initials: JM
authors.lastname: Droege
mesh_terms: D016477:Artifacts; D005373:Film Dosimetry / Q000379:methods*; D005782:Gels; D006801:Humans; D002532:Intracranial Aneurysm / Q000532:radiotherapy* / Q000601:surgery*; D019047:Phantoms, Imaging; D016634:Radiosurgery / Q000379:methods*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013525:Surgical Instruments
chemical_list: D005782:Gels