title: Image-guided positioning in intracranial non-invasive stereotactic radiosurgery for the treatment of brain metastasis.
abstract: OBJECTIVE
  The aim of the study was to examine the feasibility of non-invasive image-guided radiosurgery to improve patient comfort and quality of life in stereotactic radiosurgery planning and treatment of patients with brain metastasis. Precise immobilization is a rule of thumb for stereotactic radiosurgery. Non-invasive immobilization techniques have the potential of improved quality of life compared with invasive procedures.
  
  
  METHODS
  A total of 92 lesions from 42 patients with brain metastasis were included in the study. After immobilization with a thermoplastic mask and a bite-block unlike the invasive frame-based procedure, planning computed tomography images were acquired and fused with magnetic resonance images. After contouring, intensity-modulated stereotactic radiosurgery (IM-SRS) planning was done, and the patients were re-immobilized on the treatment couch for the therapy procedures. While patients were on the treatment couch, kilovoltage-cone beam computed tomography images were acquired to determine setup errors and achieve on-line correction and then repeated after on-line correction to confirm precise tumor localization. The patients then underwent single-fraction definitive treatment.
  
  
  RESULTS
  For the 92 lesions treated, mean ± SD values of translational setup corrections in X (lateral), Y (longitudinal), and Z (vertical) dimensions were 0.7 ± 0.7 mm, 0.8 ± 0.7 mm, and 0.6 ± 0.5 mm, and rotational set-up corrections were 0.5 ± 1.1°, 0.06 ± 1.1°, and -0.1 ± 1.1° in X (pitch), Y (roll), and Z (yaw), respectively. The mean three-dimensional correction vector was 1.2 ± 1.1 mm.
  
  
  CONCLUSIONS
  Non-invasive image-guided radiosurgery for brain metastasis is feasible, and the non-invasive treatment approach can be routinely used in clinical practice to improve patients' quality of life.
authors.affiliation: Radiation Oncology Department, Dincoglan, Gulhane Military Medical Academy, Etlik, Ankara, Turkey. ferhatdincoglan@gmail.com
authors.forename: Ferrat
authors.initials: F
authors.lastname: Dincoglan
authors.forename: Murat
authors.initials: M
authors.lastname: Beyzadeoglu
authors.forename: Omer
authors.initials: O
authors.lastname: Sager
authors.forename: Kaan
authors.initials: K
authors.lastname: Oysul
authors.forename: Sait
authors.initials: S
authors.lastname: Sirin
authors.forename: Serdar
authors.initials: S
authors.lastname: Surenkok
authors.forename: Hakan
authors.initials: H
authors.lastname: Gamsiz
authors.forename: Bora
authors.initials: B
authors.lastname: Uysal
authors.forename: Selcuk
authors.initials: S
authors.lastname: Demiral
authors.forename: Bahar
authors.initials: B
authors.lastname: Dirican
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000556:secondary* / Q000601:surgery*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D007103:Immobilization / Q000379:methods; D008297:Male; D008875:Middle Aged; D011788:Quality of Life; D016634:Radiosurgery / Q000379:methods*; D025321:Surgery, Computer-Assisted; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome