MEASUREMENT OF NEUTRON AMBIENT DOSE EQUIVALENT IN PROTON RADIOTHERAPY WITH LINE-SCANNING AND WOBBLING MODE TREATMENT SYSTEM

• DOI: 10.1093/rpd/ncx056
• Publication Date: 2017-04-07T07:08:00Z
• Authors: Sangmin Lee; Chaeyeong Lee; Eun Hyuk Shin; Sungkoo Cho; Dae-Hyun Kim; Youngyih Han; Doo Ho Choi; Sung-Joon Ye; Jin Sung Kim
• Keywords: Isocenter; Pencil-beam scanning; Equivalent dose; Dose profile

The primary objective of this study was to measure secondary neutron dose during proton therapy using a detector that covers the entire energy range produced in therapy. We analyzed and compared treatment with passive scattering line scanning. ambient equivalents were measured 190 MeV wobbling line-scanning beam. center plastic water phantom (30 × 30 60 cm3) placed at isocenter. A Wide-Energy Neutron Detection Instrument (WENDI-2) located 1m from isocenter four different angles (0°, 45°, 90° 135°). Both modes multipurpose pencil beam scanning dedicated nozzles used obtain spread-out Bragg peak 10-cm-width for measurements. equivalent H*(10) value normalized by therapeutic For mode mode, highest values 1.972 0.099 mSv/Gy, respectively. successfully six positions generated WENDI-2. These reference data could be reduction methods other analysis advanced near future.