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PTFE wedge
LCW-300 with XRV-2000 Falcon 2D Detector Phantom

The LCW-300 is a PTFE dual wedge that can be used to measure Proton beam and X-ray depth-dose relationships. It was specifically designed to quickly provide accurate proximal edge measurements of an ion beam’s Bragg peak penetration range. The height of 171 mm allows proton beam equivalent penetration depths in water of up to 300 mm to be captured on a detector. The LCW-300 enables a wide range of Bragg peak measurements to be taken quickly with a typical average accuracy of 0.5 mm.

The chevron wedges overlap so that measurements on the edge of one range can be duplicated at the beginning of the next. The wedge angle of 45 degrees enables symmetrical measurements to be made on each side of the center line and averaged for greater precision. Each wedge is 24 mm thick.

The small 152.5 × 205 mm footprint allows the LCW-300 to be placed above the scintillator of any Logos Systems 2D detector, including the XRV-2000 Falcon, XRV-3000 Eagle, and the XRV-4000, so that measurements can be taken quickly and easily. A set of rotation hardware is available to mount the wedge securely on Logos Systems 2D detectors in order to take measurements at any gantry angle.

The PTFE composition of the LCW-300 has a water equivalent density of 1.8 for direct proton range verification up to 300 mm. More energetic beams can be accommodated by padding the bottom surface with additional PTFE, acrylic or tissue equivalent plastic. The patent pending design may be enhanced with additional chevrons, so please contact us for custom configurations.

Features and Benefits:

  • Quick Bragg peak measurement of water equivalent Proton beam penetration depths up to 300 mm
  • 171 mm tall
  • PTFE composition
  • Full range Bragg peak measurements in under 5 minutes
  • Measurement accuracy typically 0.5 mm
  • Measures Proton and X-ray beam depth-dose relationships
  • Mounting hardware available for XRV-2000/3000/4000 for use at any gantry angle
  • Compatible with film
  • Automated image analysis and software measurement
  • 35 energy layer Excel analysis template provided
Overall dimensions total 171 millimeters tall by 152.4 millimeters wide. The six chevron wedges are 115 millimeters wide, and the peak of each chevron is 20 millimeters below the next.
LCW-300 Dimensions (mm)

treatment room laser alignment

LCW-300 with XRV-4000

The LCW-300 is aligned with the treatment room lasers on the XRV-2000, XRV-3000, or XRV-4000 phantoms so that the Logos Systems software can perform automatic measurements of the symmetrical Bragg peak regions produced on the scintillator below the target.

WinLVS BeamWorks Strata processing beams

Automated Capture and Measurement within WinLVS

The WinLVS capture software has a built-in scripting language that facilitates automatic real-time capture of the multi-energy even-dose delivery pattern needed for Bragg peak range measurements.

After each layer has been delivered, WinLVS merges the captured PBS image streaks to form complete radiographs. Once the 35 layers of the plan have been delivered, the Bragg peak regions on the radiographs are isolated and measured with the CSV formatted data being output to file. This CSV file can then be imported into an Excel template where the Bragg peak penetration depths are calculated.


LCW-300 Chevron Data Summary

Average Chevron Bragg Penetration Depth (mm) vs. Proton Beam Energy (MeV)
line graph

y = 0.0278x1.7244
R2 = 1

LCW-300/XRV-4000 Data from 35 energy layer diagnostic plan starting at 189 MeV and moving downwards to 121 MeV:
Defined EnergiesLayerPlan Layer Energy (MeV)Post Snout Energy (MeV)DeltaChevron BPD (mm)DeltaAvg. Energy BPD (mm)DeltaDelta BPD (mm)Absolute Delta BPD (mm)
1891189186.85 228.8477 230.41076 1.5630421.563042
187.12187.1184.95-1.9225.2981-3.54957226.32624-4.084521.0280951.028095
185.23185.2183.05-1.9221.3971-3.90102222.27308-4.053170.8759480.875948
183.34183.3181.15-1.9217.2609-4.13622218.25134-4.021740.9904350.990435
181.45181.4179.25-1.9213.48-3.78092214.26112-3.990220.7811320.781132
179.56179.5177.35-1.9209.5802-3.89979210.30249-3.958630.7222930.722293
177.57177.5175.35-2205.5626-4.01762206.16974-4.132750.6071640.607164
175.68175.6173.45-1.9201.5439-4.01869202.27623-3.893510.732350.73235
173.69173.6171.45-2197.6449-3.89903198.21222-4.064010.5673710.567371
171.610171.6169.45-2194.3198-3.32509194.18361-4.02861-0.136150.136152
169.611169.6167.45-2190.3385-3.98122190.19051-3.9931-0.148040.148039
167.612167.6165.45-2186.0855-4.25302186.23302-3.957490.1474840.147484
165.613165.6163.45-2182.1472-3.9383182.31124-3.921780.1640060.164006
163.514163.5161.35-2.1178.2086-3.9386178.23194-4.07930.0232990.023299
161.515161.5159.35-2174.2711-3.93756174.38372-3.848210.112650.11265
159.916159.9157.75-1.6171.2881-2.98301171.33111-3.052620.0430420.043042
158.317158.3156.15-1.6168.0653-3.22272168.30162-3.029480.2362820.236282
156.718156.7154.55-1.6165.4398-2.62557165.29533-3.00629-0.144430.144434
155.119155.1152.95-1.6161.9784-3.4614162.3123-2.983040.3339250.333925
153.520153.5151.35-1.6159.3541-2.62431159.35257-2.95973-0.001490.00149
151.921151.9149.75-1.6157.1599-2.19417156.41622-2.93635-0.743670.743674
150.322150.3148.15-1.6154.0274-3.13247153.5033-2.91292-0.524120.524119
148.123148.1145.95-2.2150.0509-3.97651149.53643-3.96688-0.514480.514485
146.224146.2144.05-1.9146.5564-3.49455146.14637-3.39006-0.409990.409989
143.625143.6141.45-2.6141.8577-4.69863141.56145-4.58492-0.296290.296287
141.426141.4139.25-2.2138.0023-3.85546137.73092-3.83053-0.271360.271356
139.127139.1136.95-2.3134.0254-3.97686133.77452-3.9564-0.25090.250899
136.828136.8134.65-2.3130.1698-3.8556129.86764-3.90688-0.302180.302176
134.429134.4132.25-2.4126.314-3.8558125.84393-4.02371-0.470090.470093
132.130132.1129.95-2.3122.8593-3.45471122.03891-3.80502-0.82040.820405
129.731129.7127.55-2.4119.0083-3.851118.12196-3.91695-0.886360.886359
127.232127.2125.05-2.5114.9943-4.014114.10017-4.02179-0.894140.894142
124.833124.8122.65-2.4110.8592-4.13509110.29556-3.80461-0.563660.563661
122.334122.3120.15-2.5106.9675-3.89172106.39138-3.90419-0.576130.57613
12135121118.85-1.3104.8993-2.06825104.38507-2.0063-0.514180.514184
 Average-3.89833 Average0.497045
 Standard. Deviation.0.229846 Standard. Deviation.0.352387
 Max.1.563042
 Min.0.00149
Total Depth: 94.8223 mm
Average Layer Depth: 3.647012 mm