LINAC Commissioning and
Clinical Implementation Services

Aktina Medical Physics Group provides support to radiation oncology facilities that do not have on-site physicists to perform commissioning, or for those that prefer to expedite the clinical implementation of a new LINAC.

Our physicists will perform a timely radiation protection survey with the first beam-on of the LINAC and subsequently proceed with acceptance testing, data collection, TG-51 calibration of photon and electron beam output, beam modeling, data transfer to TPS, and TPS verification. If time is of outmost importance, our group will work double shifts in 24-hour rotations so that the interruption of patient treatments is minimized.

Comprehensive LINAC commissioning service typically includes:

Photon Beam Measurements for Each Energy

  • Depth dose curves for all field sizes
  • Dose profiles for all field sizes
  • Dose profiles extending outside the field for the determination of scatter dose and jaw transmission from the machine head components
  • The calibration output factor
  • Relative output factors (10cm depth) in-Water and in-air
  • The tray transmission factor and block and tray transmission factor (and MLC transmission if it exists)

Electron Beam Measurements for Each Energy

  • Depth dose measurement for determining Rp
  • Depth dose measurements for dose normalization
  • In-air cross-axis dose profile measurements
  • Determination of the virtual source to surface distance
  • Determination of Sigma-Theta-X
  • Cross-axis dose profile measurements in water
  • Cutout material transmission factor measurement
  • Output factor measurements

Additional Measured Data for Clinical Workbook

  • Photon PDD, TMR for 3×3 through 40×40 field sizes
  • Output factors for each PDD field size (measured at Dmax)

Beam Modeling Performed with the Following Goals

  • Central-axis depth doses reproduced to within 0.5% of the maximum value for depths between dmax and 20 cm
  • Central-axis depth doses reproduced to within 1.0% of the maximum value for depths greater than 20 cm
  • Central-axis depth doses reproduced to within 5% of the maximum value for depths less than dmax
  • Off-axis profiles in the low-dose-gradient region within the beam reproduced to within 2.0% of the central-axis value for depths less than 30 cm
  • Off-axis profiles in the low-dose-gradient region within the beam reproduced to within 5.0% of the central-axis value for depths greater than 30 cm
  • Off-axis profiles in the high-dose-gradient region ~penumbra! reproduced to within 2 mm

Deliverables

  • CDROM with data formatted for TPS, in ASCII format, and PDF of graphs and plots
  • Color report of all data (hardcopy – 2 copies)
  • TPS Modeling Parameters Report
  • Treatment Planning System verification report
  • TG51 Calibration report