Optimal gantry angles and field sizes in kilovoltage cone-beam tomosynthesis for set-up of women with breast cancer undergoing radiotherapy treatment
Received 14 May 2009; received in revised form 30 September 2009; accepted 3 October 2009. published online 18 November 2009.
Abstract
Optimal beam geometry for kilovoltage cone-beam tomosynthesis (CB-TS) imaging for the set-up of 20 patients with breast cancer was analyzed and presented for prone and supine scenarios. Gantry angles and field sizes that allow maximum clearance and minimum dose to normal organs from kilovoltage imaging were determined for medial and lateral arcs. Optimal CB-TS arc span may vary depending on patient geometry, particularly on the separation between the cavity and the chest wall. CB-TS arc angles ⩾40° were found to be optimal for the cavity to chest wall separation d>3cm for supine set-up and d>7cm for prone set-up. Maximum required jaw openings were 20×14cm2. Recommendations are provided for clinical implementation of CB-TS imaging for breast cancer patients.
aDepartment of Radiation Oncology, Boston, MA, USA
bDepartment of Radiation Oncology, University of Heidelberg, Mannheim, Germany
Corresponding author. Address: Department of Radiation Oncology, Brigham and Women’s Hospital and Harvard Medical School, 75 Francis St., Boston, MA 02115, USA.
ABSTRACT