title: Frame-based radiosurgery: Is it relevant in the era of IGRT?
abstract: OBJECTIVE
  To assess the setup errors and intrafraction motion in patients treated with frame-based and frameless stereotactic radiosurgery (SRS).
  
  
  METHODS
  Ten patients treated with frame-based and six patients treated with frameless radiosurgery were prospectively enrolled in the study. Leksell frame was used for frame-based and a customized uniframe orfit cast for frameless techniques. Cone beam computed tomography (CBCT) scans were taken immediately before and after each treatment to evaluate the positional accuracy and corrections applied with the use of hexapod couch for both groups.
  
  
  RESULTS
  The mean translational shifts with frame-based SRS were 1.00 ± 0.30 mm in the lateral direction (X), 0.20 ± 1.20 mm in craniocaudal direction (Y) and -0.10 ± 0.31 mm in the anteroposterior direction (Z). The rotational shifts for frame-based treatments were as follows: roll 0.32 ± 0.70, pitch 0.44 ± 0.66 and yaw 0.20 ± 0.4. For frameless SRS, translational shifts were -0.40 ± 0.90, 1.10 ± 1.10, and 0.50 ± 1.30 mm in X, Y, and Z directions, respectively, and rotational shifts were -0.11 ± 0.78, 0.20 ± 0.44, and 0.29 ± 0.35 in roll, pitch, and yaw, respectively. Intrafraction shifts with frame-based SRS were: X = 0.60 ± 1.80 mm, Y = 0.20 ± 0.60 mm, and Z = 0.00 ± 0.05 mm; and rotational shifts were: roll 0.01 ± 0.27, pitch 0.06 ± 0.15, and yaw 0.01 ± 0.09. For frameless SRS, these were: X = 0.11 ± 0.20 mm, Y = 0.20 ± 0.40 mm, and Z = 0.20 ± 0.20 mm and rotational shifts were: roll 0.09 ± 0.23, pitch 0.00 ± 0.12, and yaw 0.00 ± 0.09.
  
  
  CONCLUSIONS
  In our experience, set up accuracy of frameless SRS is as good as frame-based SRS. With availability of verification methods such as CBCT and hexapod couch, an accurate and precise treatment delivery is feasible with frameless techniques.
authors.affiliation: Division of Radiation Oncology, Medanta Cancer Institute, Gurgaon, Haryana, India. teji1960@gmail.com
authors.forename: Tejinder
authors.initials: T
authors.lastname: Kataria
authors.forename: Deepak
authors.initials: D
authors.lastname: Gupta
authors.forename: K P
authors.initials: KP
authors.lastname: Karrthick
authors.forename: Shyam Singh
authors.initials: SS
authors.lastname: Bisht
authors.forename: Shikha
authors.initials: S
authors.lastname: Goyal
authors.forename: Ashu
authors.initials: A
authors.lastname: Abhishek
authors.forename: H B
authors.initials: HB
authors.lastname: Govardhan
authors.forename: Kuldeep
authors.initials: K
authors.lastname: Sharma
authors.forename: Puneet
authors.initials: P
authors.lastname: Pareek
authors.forename: Aditya
authors.initials: A
authors.lastname: Gupta
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology / Q000601:surgery*; D054893:Cone-Beam Computed Tomography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016634:Radiosurgery / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D061089:Radiotherapy, Image-Guided / Q000639:trends; D013238:Stereotaxic Techniques / Q000295:instrumentation*