Radiation Protection for X-Ray Technologists Linacs, radioactive substances and all the rest

*Radiation Protection for X-Ray TechnologistsLinacs, radioactive substances and all the rest John SaundersonConsultant Physicist / Radiation Protection Adviser

Beam energy - kV or MV?mid = 9%mid = 77%

Kilovoltage X-raygood for imaginggood for radiotherapy near skin surfaceMegavoltage X-raydeep therapyimaging poor, but possible for verification

Filament(heats up on prep.)TargetElectron production in the X-ray tubeApplied voltage chosen to give correct velocity to the electronsmAVoltage to arc 1 m air at STP = 3.4 MV

How to get megavoltage energy photons?Normal X-ray tube? - insulation needed too thick, arcing, etc.2-MeV Van de Graaff acceleratorVan de Graaff generator

How to get megavoltage energy photons?Normal X-ray tube? - insulation needed too thick, arcing, etc.Van de Graaff generatorRadioactive sources - Co-60 (1.2 MeV gamma rays)

Linear Accelerator (linac)Klystron or magnetron microwaveselectrons

Typical dose ratesFluoroscopy entrance dose rate < 50 mGy/min> 40 minutes to erythema threshold> 3 min to annual hand dose limit

Linac entrance dose rate > 2.4 Gy/min< 1 minute to erythema threshold< 4 seconds to annual hand dose limit

MV electrons / X-ray photons

MV electrons / X-ray photons

Photon or electron energyElectron rangeX-ray transmission6 MeV3 g/cm2= 2.6 mm Pb or = 30 mm H2O10% 55 mm Pb1% 110 mm Pb15 MeV10 g/cm2= 8.8 mm Pb or = 74 mm H2O10% 57 mm Pb1% 114 mm Pb

Parameters

Reference Field Beam Parameters

Electron Beam Parameters - 15x15cm Applicator and Std Insert

62.312.315.501.31.3100

93.513.558.102.12.099.8

124.935.0111.332.82.999.9

166.56.6315.093.03.999.2

208.038.2018.942.34.896.6

Electron 2003 Code of PracticeR50,D = 1.029 R50, I - 0.063 cm for 2 R50,I 10 cm R50,D = R50, I cm for R50,D < 4 cmE0 (MeV) = 0.818 + 1.935 R50,I + 0.040 R50,I2Zref = 0.6R50,D - 0.1 cm

PDD Curves

0.5123.65.5

0.511.93.65.5

0.511.93.65.4

0.51.11.93.65.4

0.61.11.93.65.5

0.61.11.93.65.5

0.71.11.93.75.5

11.11.93.75.5

1.91.123.75.6

3.21.123.85.6

5.71.223.85.6

9.31.42.145.5

14.41.82.14.15.6

20.62.42.34.35.6

27.33.42.54.65.6

35.74.92.95.15.6

44.37.13.55.75.7

52.910.14.66.55.7

61.413.45.87.45.8

7017.77.38.75.9

77.122.79.510.16

83.428.31211.66.1

88.834.21513.56.4

9340.51815.86.6

96.446.822186.9

98.653.126.120.77.5

99.859.130.423.78

10065.234.826.68.7

99.370.839.629.89.6

98.27644.433.110.5

96.480.648.936.411.4

94.384.953.839.812.7

92.188.658.743.414.1

89.991.663.146.815.7

87.894.167.450.417.5

85.896.271.45419.4

83.797.975.157.321.5

81.79978.760.823.6

79.799.68264.125.7

78.510084.867.228.2

7899.887.570.230.6

99.689.973.233

9991.975.835.4

98.393.778.237.9

97.495.380.640.3

96.496.582.842.9

95.497.684.945.6

94.498.486.748.3

93.498.988.450.8

92.499.39053.3

91.399.891.455.8

90.499.992.658.2

89.510093.760.6

88.599.994.862.9

87.699.795.665

86.799.496.367.2

85.799.29769.3

84.698.997.771.3

83.398.598.173.2

82.698.198.575

82.397.798.976.6

97.199.278.4

96.999.479.8

96.499.681.3

9699.782.7

95.699.884

95.110085.2

94.710086.6

94.399.987.7

93.810088.6

93.310089.5

9399.990.5

92.499.991.4

91.999.792

91.399.892.8

90.699.693.3

9099.494

89.199.594.5

8899.394.9

87.599.295.5

87.39995.9

98.996.2

98.996.6

98.697.1

98.497.3

98.397.6

98.297.9

97.898

97.798.3

97.398.4

97.198.7

96.898.9

96.499

96.199.2

95.699.3

95.199.4

94.599.6

93.799.6

92.699.6

92.499.7

92.299.7

99.7

99.9

99.8

100

99.9

99.9

100

100

99.8

99.8

99.8

99.8

99.6

99.5

99.5

99.4

99.2

99

98.8

98.6

98.3

98

97.6

97.2

96.7

96.1

95.4

94.4

94.1

93.9

CHH ELECTRON COMMISSIONINGDepth Dose Commissioning Dataset

Machine: CL3Detector: NACP-02Field Size: 15x15 cmTSD: 100 cmIonisation data converted to dose using OmniPro Accept AAPM TG51 algorithm

6MeV

9MeV

12MeV

16MeV

20MeV

Depth (cm)

PDD

CL3 Electron Depth Dose Curves (15x15cm)

6x6

Measured using Blue Phantom and NACP chamber with 1mm offset6/23/08

6MeV9MeV12MeV16MeV20MeV

Depth (mm)Depth (cm)PDDDepth (mm)Depth (cm)PDDDepth (mm)Depth (cm)PDDDepth (mm)Depth (cm)PDDDepth (mm)Depth (cm)PDD

39.94.00.559.96.01.179.98.01.999.910.03.3129.913.05

39.13.90.5595.91.1797.91.899.19.93.212912.95

38.13.80.5585.81.1787.81.8989.83.212812.85.1

37.13.70.5575.71.177.17.71.8979.73.312712.75.1

36.13.60.6565.61.176.17.61.8969.63.312612.65.1

35.13.50.654.95.51.1757.51.9959.53.312512.55.2

343.40.7545.41.1747.41.9949.43.312412.45.2

32.93.31.2535.31.173.17.31.993.19.33.412312.35.1

323.22525.21.1727.21.992.19.23.412212.25.1

313.13.5515.11.271.17.11.991.19.13.512112.15.2

303.06.1505.01.3707.02909.03.512012.05.2

292.99.9494.91.469.16.9289.18.93.711911.95.2

282.814.9484.81.868.16.82.1888.83.811811.85.3

272.721.4474.72.467.16.72.287.18.7411711.75.3

262.629.1464.63.466.16.62.5868.64.511611.65.3

252.537454.5565.16.5385.18.54.911511.55.4

242.445.8444.47.264.16.43.684.18.45.511411.45.3

22.92.354.2434.310.263.16.34.583.18.36.311311.35.4

222.262.8424.213.962.16.25.782.18.27.211211.25.4

212.170.3414.118.461.16.17.3818.18.511111.15.5

202.077.8404.023.560.16.09.2808.09.811011.05.6

191.984.2393.92959.15.911.778.97.911.510910.95.8

181.889.3383.835585.814.377.97.813.3108.110.86.1

171.793.2373.741.2575.717.5777.715.410710.76.3

161.696.5363.647.7565.621.275.97.617.610610.66.6

15.11.598.634.93.554555.525.474.97.519.910510.56.9

141.499.733.93.460.2545.429.8747.422.710410.47.5

131.310032.93.366535.334.372.97.325.410310.38.2

121.299.431.93.271.6525.238.9727.228.410210.29

10.91.198.130.93.176.6515.143.6717.131.410110.19.8

9.91.096.329.93.081.349.95.048.5707.034.510010.010.9

8.90.994.328.92.985.2494.953.1696.937.8999.912

7.90.892.127.92.888.9484.857.3686.840.9989.813

6.90.789.926.92.791.9474.761.9676.744979.714.3

5.90.687.625.92.694.3464.666.1666.647.2969.615.9

4.90.585.524.92.596.3454.570.1656.550.3959.517.5

3.90.483.423.92.497.843.94.473.7646.453.4949.419.2

2.90.381.322.92.398.9434.377.2636.356.4939.320.9

1.90.279.121.92.299.6424.280.6626.259.292.19.222.9

0.90.177.920.92.199.9414.183.4616.162.2919.124.8

-0.1-0.077.819.92.0100404.086606.064.890.19.026.8

18.81.999.7393.988.5595.967.589.18.929

17.91.899.1383.890.557.95.870.1888.831

16.91.798.5373.792.456.95.772.5878.733.4

15.91.697.7363.69455.95.67586.18.635.5

14.91.596.834.83.595.454.95.577.185.18.537.8

13.91.495.833.93.496.653.95.479.384.18.440.1

12.91.394.732.93.397.552.95.381.4838.342.1

11.91.293.631.93.298.351.95.283.382.18.244.2

10.81.192.630.93.198.850.95.18580.98.146.3

9.81.091.629.93.099.349.95.086.6808.048.4

8.80.990.828.82.999.648.94.988.2797.950.6

7.80.889.727.92.899.847.94.889.6787.852.8

6.80.788.826.92.710046.94.790.9777.754.9

5.80.687.825.92.699.945.94.69275.97.656.9

4.80.586.924.92.599.844.94.593.174.97.558.8

3.80.485.723.92.499.643.94.494.173.97.460.8

2.80.384.622.92.399.442.94.394.972.97.362.6

1.80.283.221.82.299.141.94.295.671.97.264.6

0.80.182.520.92.198.840.94.196.370.97.166.4

-0.1-0.082.419.92.098.439.94.097.1707.068.1

18.91.99838.93.997.6696.969.8

17.91.897.637.93.898686.871.4

16.91.797.336.93.798.4676.773.1

15.91.696.935.93.698.7666.674.7

14.91.596.534.83.599656.576.2

13.91.49633.83.499.3646.477.7

12.91.395.632.83.399.3636.379.1

11.91.295.231.83.299.6626.280.4

10.81.194.730.83.199.7616.181.7

9.81.094.429.83.099.8606.082.8

8.80.993.828.82.9100595.984.1

7.80.893.327.82.810057.95.885.2

6.80.792.826.82.799.956.95.786.1

5.80.692.325.82.610055.95.687.2

4.80.591.624.82.510054.95.588.2

3.80.490.923.82.499.953.95.489.2

2.80.39022.82.310052.95.390

1.80.288.921.82.299.951.95.290.8

0.80.188.420.82.199.950.95.191.6

-0.2-0.088.219.82.099.749.95.092.2

18.81.999.648.84.993

17.81.899.447.94.893.6

16.81.799.346.94.794.2

15.81.699.245.94.694.7

14.81.599.144.94.595.1

13.81.498.843.84.495.6

12.81.398.742.94.396

11.91.298.541.94.296.4

10.71.198.340.94.196.8

9.71.09839.94.097.2

8.70.997.838.93.997.6

7.70.897.537.93.897.6

6.70.797.136.93.797.9

5.70.696.635.93.698.2

4.70.59634.83.598.4

3.70.495.433.83.498.7

2.70.394.632.83.398.8

1.70.293.531.83.298.9

0.70.193.230.83.199.1

-0.3-0.093.229.83.099.2

28.82.999.4

27.82.899.5

26.82.799.6

25.72.699.7

24.82.599.6

23.82.499.8

22.82.399.8

21.82.299.9

20.82.199.9

19.82.099.9

18.81.999.9

17.81.8100

16.81.799.9

15.81.699.8

14.81.599.8

13.81.499.7

12.81.399.7

11.81.299.5

10.71.199.4

9.71.099.2

8.70.999.1

7.80.898.8

6.70.798.6

5.70.698.1

4.70.597.7

3.70.497.1

2.70.396.3

1.70.295.1

0.70.194.8

-0.3-0.094.9

10x10




39.94.00.659.96.01.179.98.01.899.910.03.5129.913.05.3

39.13.90.6595.91.1797.91.899.19.93.512912.95.3

38.13.80.6585.81.1787.81.8989.83.512812.85.4

37.13.70.6575.71.177.17.71.8979.73.512712.75.4

36.13.60.6565.61.276.17.61.8969.63.612612.65.4

35.13.50.754.95.51.2757.51.9959.53.612512.55.4

343.40.8545.41.2747.41.9949.43.612412.45.5

32.93.31.3535.31.273.17.31.993.19.33.612312.35.5

323.22.1525.21.2727.21.992.19.23.712212.25.5

313.13.6515.11.271.17.11.991.19.13.712112.15.4

303.06.3505.01.3707.02909.03.812012.05.5

292.910494.91.569.16.9289.18.93.911911.95.5

282.815.3484.81.868.16.82.1888.8411811.85.5

272.721.7474.72.567.16.72.387.18.74.211711.75.6

262.629.1464.63.566.16.62.5868.64.511611.65.6

252.537.3454.55.165.16.52.985.18.55.111511.55.6

242.446.2444.47.364.16.43.684.18.45.711411.45.7

22.92.354.6434.310.263.16.34.683.18.36.511311.35.7

222.263.2424.21462.16.25.782.18.27.611211.25.8

212.170.9414.118.361.16.17.4818.18.711111.15.8

202.078404.023.660.16.09.3808.010.111011.05.9

191.984.3393.929.359.15.911.778.97.911.910910.96.1

181.889.4383.835.2585.814.577.97.813.8108.110.86.3

171.793.3373.741.3575.717.9777.71610710.76.5

161.696.6363.647.8565.621.575.97.618.410610.66.8

15.11.598.734.93.554555.525.774.97.52110510.57.4

141.499.733.93.460.4545.429.7747.423.810410.48

131.310032.93.366.2535.334.672.97.326.910310.38.6

121.299.331.93.271.7525.239.2727.23010210.29.5

10.91.19830.93.176.8515.144.3717.133.210110.110.4

9.91.096.329.93.081.449.95.049.3707.036.710010.011.5

8.90.994.228.92.985.4494.954.1696.940.4999.912.6

7.90.89227.92.889484.858.6686.843.7989.814.2

6.90.789.626.92.792474.763.2676.747979.715.7

5.90.687.525.92.694.6464.667.4666.650.6969.617.3

4.90.585.224.92.596.5454.571.8656.554.1959.519.1

3.90.483.223.92.498.143.94.475.5646.457.4949.421

2.90.381.222.92.399.2434.379636.360.7939.323.3

1.90.279.121.92.299.8424.282.3626.263.892.19.225.4

0.90.17820.92.1100414.185.2616.166.8919.127.8

-0.1-0.077.619.92.099.8404.087.9606.069.890.19.030.1

18.81.999.5393.990.2595.972.689.18.932.6

17.91.899383.892.457.95.875.3888.835.1

16.91.798.2373.79456.95.777.7878.737.7

15.91.697.4363.695.555.95.680.286.18.640.2

14.91.596.334.83.596.954.95.582.485.18.542.8

13.91.495.333.93.49853.95.484.584.18.445.6

12.91.394.232.93.398.852.95.386.4838.348.2

11.91.293.131.93.299.351.95.288.182.18.250.7

10.81.19230.93.199.650.95.189.680.98.153

9.81.091.129.93.099.849.95.091.1808.055.5

8.80.990.128.82.910048.94.992.5797.957.9

7.80.889.127.92.810047.94.893.6787.860.2

6.80.788.326.92.799.946.94.794.5777.762.4

5.80.687.325.92.699.845.94.695.575.97.664.6

4.80.586.324.92.599.544.94.596.274.97.566.6

3.80.485.223.92.499.143.94.49773.97.468.6

2.80.384.222.92.398.842.94.397.572.97.370.5

1.80.282.821.82.298.541.94.298.171.97.272.5

0.80.182.220.92.198.140.94.198.570.97.174.4

-0.1-0.082.119.92.097.739.94.098.8707.076

18.91.997.338.93.999.1696.977.7

17.91.89737.93.899.4686.879.3

16.91.796.536.93.799.6676.780.7

15.91.696.135.93.699.6666.682

14.91.595.634.83.599.8656.583.2

13.91.495.233.83.499.9646.484.7

12.91.394.832.83.3100636.385.7

11.91.294.331.83.2100626.286.8

10.81.193.930.83.199.9616.187.7

9.81.093.429.83.0100606.088.6

8.80.99328.82.999.9595.989.4

7.80.892.527.82.899.957.95.890.3

6.80.79226.82.799.956.95.791

5.80.691.325.82.699.855.95.691.8

4.80.590.724.82.599.854.95.592.5

3.80.489.923.82.499.653.95.493.2

2.80.38922.82.399.552.95.393.7

1.80.287.821.82.299.551.95.294.2

0.80.187.520.82.199.450.95.194.7

-0.2-0.087.319.82.099.349.95.095.2

18.81.999.148.84.995.6

17.81.89947.94.896

16.81.798.946.94.796.4

15.81.698.745.94.696.6

14.81.598.644.94.596.9

13.81.498.343.84.497.3

12.81.398.242.94.397.6

11.91.29841.94.297.8

10.71.197.740.94.198

9.71.097.539.94.098.2

8.70.997.238.93.998.5

7.70.896.937.93.898.6

6.70.796.536.93.798.7

5.70.696.135.93.699

4.70.595.534.83.599.1

3.70.494.833.83.499.2

2.70.39432.83.399.2

1.70.292.931.83.299.5

0.70.192.730.83.199.6

-0.3-0.092.629.83.099.7

28.82.999.7

27.82.899.9

26.82.799.9

25.72.699.9

24.82.599.9

23.82.499.9

22.82.3100

21.82.2100

20.82.199.9

19.82.099.9

18.81.9100

17.81.8100

16.81.799.8

15.81.699.8

14.81.599.7

13.81.499.7

12.81.399.6

11.81.299.4

10.71.199.3

9.71.099

8.70.998.9

7.80.898.6

6.70.798.3

5.70.697.9

4.70.597.5

3.70.496.8

2.70.396.1

1.70.295

0.70.194.8

-0.3-0.094.6

15x15




39.94.00.559.96.0179.98.0299.910.03.6129.913.05.5

39.13.90.5595.91797.91.999.19.93.612912.95.5

38.13.80.5585.81787.81.9989.83.612812.85.4

37.13.70.5575.71.177.17.71.9979.73.612712.75.4

36.13.60.6565.61.176.17.61.9969.63.612612.65.5

35.13.50.654.95.51.1757.51.9959.53.612512.55.5

343.40.7545.41.1747.41.9949.43.712412.45.5

32.93.31535.31.173.17.31.993.19.33.712312.35.5

323.21.9525.21.1727.2292.19.23.712212.25.6

313.13.2515.11.171.17.1291.19.13.812112.15.6

303.05.7505.01.2707.02909.03.812012.05.6

292.99.3494.91.469.16.92.189.18.9411911.95.5

282.814.4484.81.868.16.82.1888.84.111811.85.6

272.720.6474.72.467.16.72.387.18.74.311711.75.6

262.627.3464.63.466.16.62.5868.64.611611.65.6

252.535.7454.54.965.16.52.985.18.55.111511.55.6

242.444.3444.47.164.16.43.584.18.45.711411.45.7

22.92.352.9434.310.163.16.34.683.18.36.511311.35.7

222.261.4424.213.462.16.25.882.18.27.411211.25.8

212.170414.117.761.16.17.3818.18.711111.15.9

202.077.1404.022.760.16.09.5808.010.111011.06

191.983.4393.928.359.15.91278.97.911.610910.96.1

181.888.8383.834.2585.81577.97.813.5108.110.86.4

171.793373.740.5575.718777.715.810710.76.6

161.696.4363.646.8565.62275.97.61810610.66.9

15.11.598.634.93.553.1555.526.174.97.520.710510.57.5

141.499.833.93.459.1545.430.4747.423.710410.48

131.310032.93.365.2535.334.872.97.326.610310.38.7

121.299.331.93.270.8525.239.6727.229.810210.29.6

10.91.198.230.93.176515.144.4717.133.110110.110.5

9.91.096.429.93.080.649.95.048.9707.036.410010.011.4

8.90.994.328.92.984.9494.953.8696.939.8999.912.7

7.90.892.127.92.888.6484.858.7686.843.4989.814.1

6.90.789.926.92.791.6474.763.1676.746.8979.715.7

5.90.687.825.92.694.1464.667.4666.650.4969.617.5

4.90.585.824.92.596.2454.571.4656.554959.519.4

3.90.483.723.92.497.943.94.475.1646.457.3949.421.5

2.90.381.722.92.399434.378.7636.360.8939.323.6

1.90.279.721.92.299.6424.282626.264.192.19.225.7

0.90.178.520.92.1100414.184.8616.167.2919.128.2

-0.1-0.07819.92.099.8404.087.5606.070.290.19.030.6

18.81.999.6393.989.9595.973.289.18.933

17.91.899383.891.957.95.875.8888.835.4

16.91.798.3373.793.756.95.778.2878.737.9

15.91.697.4363.695.355.95.680.686.18.640.3

14.91.596.434.83.596.554.95.582.885.18.542.9

13.91.495.433.93.497.653.95.484.984.18.445.6

12.91.394.432.93.398.452.95.386.7838.348.3

11.91.293.431.93.298.951.95.288.482.18.250.8

10.81.192.430.93.199.350.95.19080.98.153.3

9.81.091.329.93.099.849.95.091.4808.055.8

8.80.990.428.82.999.948.94.992.6797.958.2

7.80.889.527.92.810047.94.893.7787.860.6

6.80.788.526.92.799.946.94.794.8777.762.9

5.80.687.625.92.699.745.94.695.675.97.665

4.80.586.724.92.599.444.94.596.374.97.567.2

3.80.485.723.92.499.243.94.49773.97.469.3

2.80.384.622.92.398.942.94.397.772.97.371.3

1.80.283.321.82.298.541.94.298.171.97.273.2

0.80.182.620.92.198.140.94.198.570.97.175

-0.1-0.082.319.92.097.739.94.098.9707.076.6

18.91.997.138.93.999.2696.978.4

17.91.896.937.93.899.4686.879.8

16.91.796.436.93.799.6676.781.3

15.91.69635.93.699.7666.682.7

14.91.595.634.83.599.8656.584

13.91.495.133.83.4100646.485.2

12.91.394.732.83.3100636.386.6

11.91.294.331.83.299.9626.287.7

10.81.193.830.83.1100616.188.6

9.81.093.329.83.0100606.089.5

8.80.99328.82.999.9595.990.5

7.80.892.427.82.899.957.95.891.4

6.80.791.926.82.799.756.95.792

5.80.691.325.82.699.855.95.692.8

4.80.590.624.82.599.654.95.593.3

3.80.49023.82.499.453.95.494

2.80.389.122.82.399.552.95.394.5

1.80.28821.82.299.351.95.294.9

0.80.187.520.82.199.250.95.195.5

-0.2-0.087.319.82.09949.95.095.9

18.81.998.948.84.996.2

17.81.898.947.94.896.6

16.81.798.646.94.797.1

15.81.698.445.94.697.3

14.81.598.344.94.597.6

13.81.498.243.84.497.9

12.81.397.842.94.398

11.91.297.741.94.298.3

10.71.197.340.94.198.4

9.71.097.139.94.098.7

8.70.996.838.93.998.9

7.70.896.437.93.899

6.70.796.136.93.799.2

5.70.695.635.93.699.3

4.70.595.134.83.599.4

3.70.494.533.83.499.6

2.70.393.732.83.399.6

1.70.292.631.83.299.6

0.70.192.430.83.199.7

-0.3-0.092.229.83.099.7

28.82.999.7

27.82.899.9

26.82.799.8

25.72.6100

24.82.599.9

23.82.499.9

22.82.3100

21.82.2100

20.82.199.8

19.82.099.8

18.81.999.8

17.81.899.8

16.81.799.6

15.81.699.5

14.81.599.5

13.81.499.4

12.81.399.2

11.81.299

10.71.198.8

9.71.098.6

8.70.998.3

7.80.898

6.70.797.6

5.70.697.2

4.70.596.7

3.70.496.1

2.70.395.4

1.70.294.4

0.70.194.1

-0.3-0.093.9

20x20




39.94.00.659.96.0179.98.02.199.910.03.7129.913.05.6

39.13.90.6595.91797.92.199.19.93.612912.95.6

38.13.80.6585.81787.82.1989.83.712812.85.5

37.13.70.6575.71.177.17.72979.73.712712.75.7

36.13.60.6565.61.176.17.62969.63.712612.65.6

35.13.50.754.95.51.1757.52959.53.712512.55.6

343.40.8545.41.1747.42.1949.43.712412.45.6

32.93.31.3535.31.173.17.32.193.19.33.812312.35.7

323.22.2525.21.1727.22.192.19.23.812212.25.7

313.13.9515.11.271.17.12.191.19.13.912112.15.7

303.06.7505.01.2707.02.1909.0412012.05.7

292.910.7494.91.469.16.92.289.18.94.111911.95.8

282.816.4484.81.868.16.82.3888.84.211811.85.7

272.723.1474.72.567.16.72.587.18.74.411711.75.7

262.630.8464.63.766.16.62.9868.64.911611.65.7

252.539.3454.55.365.16.53.485.18.55.411511.55.8

242.448.2444.47.464.16.44.184.18.46.111411.45.8

22.92.356.5434.310.363.16.35.183.18.3711311.35.9

222.265.2424.213.862.16.26.682.18.28.111211.25.9

212.172.8414.118.461.16.18.3818.19.311111.16

202.079.5404.023.760.16.010.4808.010.911011.06.2

191.985.5393.929.359.15.91378.97.912.710910.96.3

181.890.3383.835.3585.815.977.97.814.7108.110.86.6

171.794.4373.741.8575.719.2777.716.910710.76.9

161.697.2363.648.6565.623.175.97.619.610610.67.4

15.11.599.134.93.555555.527.374.97.522.210510.57.8

141.410033.93.461.1545.431.3747.42510410.48.5

131.399.932.93.367.3535.335.972.97.32810310.39

121.29931.93.272.5525.240.6727.231.410210.29.9

10.91.197.730.93.177.5515.145.5717.134.810110.111

9.91.09629.93.082.549.95.050707.038.310010.012.2

8.90.994.128.92.986.3494.954.4696.941.7999.913.4

7.90.891.927.92.889.8484.859.2686.845.3989.814.9

6.90.789.626.92.792.7474.763.7676.749979.716.5

5.90.687.625.92.695.1464.667.9666.652.1969.618.1

4.90.585.524.92.597454.572656.555.6959.520.2

3.90.483.623.92.498.343.94.475.4646.458.8949.422.1

2.90.381.722.92.399.2434.378.8636.362.1939.324

1.90.279.821.92.299.9424.282.1626.265.292.19.226.3

0.90.178.820.92.1100414.184.9616.168.1919.128.8

-0.1-0.078.519.92.099.8404.087.7606.071.190.19.031.3

18.81.999.4393.990595.973.789.18.933.9

17.91.898.9383.89257.95.876.2888.836.4

16.91.797.9373.793.856.95.778.5878.739.1

15.91.697.1363.695.455.95.680.986.18.641.6

14.91.596.234.83.596.754.95.582.985.18.544.1

13.91.495.333.93.497.653.95.484.984.18.446.9

12.91.394.232.93.398.552.95.386.7838.349.6

11.91.293.331.93.29951.95.288.482.18.252.1

10.81.192.330.93.199.450.95.189.880.98.154.6

9.81.091.329.93.099.749.95.091.2808.056.9

8.80.990.328.82.999.948.94.992.4797.959.3

7.80.889.527.92.810047.94.893.6787.861.5

6.80.788.626.92.799.946.94.794.5777.763.9

5.80.687.825.92.699.745.94.695.475.97.666.2

4.80.586.924.92.599.544.94.596.174.97.568.2

3.80.485.923.92.499.343.94.496.873.97.470.3

2.80.384.822.92.39942.94.397.472.97.372.1

1.80.283.621.82.298.741.94.297.871.97.274

0.80.183.120.92.198.340.94.198.370.97.175.9

-0.1-0.082.819.92.09839.94.098.6707.077.5

18.91.997.538.93.999696.979.1

17.91.897.237.93.899.2686.880.6

16.91.796.936.93.799.4676.782

15.91.696.535.93.699.6666.683.4

14.91.596.134.83.599.7656.584.6

13.91.495.833.83.499.8646.485.9

12.91.395.432.83.3100636.387

11.91.29531.83.299.9626.287.8

10.81.194.730.83.199.9616.188.7

9.81.094.329.83.0100606.089.7

8.80.993.928.82.9100595.990.5

7.80.893.527.82.899.957.95.891.3

6.80.792.926.82.799.956.95.792

5.80.692.525.82.699.855.95.692.6

4.80.591.924.82.599.754.95.593.3

3.80.491.223.82.499.653.95.493.9

2.80.390.322.82.399.652.95.394.3

1.80.289.321.82.299.551.95.294.8

0.80.188.920.82.199.450.95.195.3

-0.2-0.088.819.82.099.349.95.095.8

18.81.999.248.84.996.1

17.81.899.147.94.896.5

16.81.798.946.94.797

15.81.698.745.94.697.2

14.81.598.644.94.597.4

13.81.498.343.84.497.6

12.81.398.242.94.397.9

11.91.29841.94.298.2

10.71.197.840.94.198.3

9.71.097.539.94.098.5

8.70.997.238.93.998.7

7.70.896.937.93.898.9

6.70.796.536.93.799.1

5.70.696.135.93.699.2

4.70.595.634.83.599.2

3.70.49533.83.499.5

2.70.394.132.83.399.5

1.70.293.131.83.299.6

0.70.192.830.83.199.7

-0.3-0.092.829.83.099.7

28.82.999.8

27.82.899.9

26.82.799.8

25.72.699.9

24.82.5100

23.82.499.9

22.82.3100

21.82.299.9

20.82.199.8

19.82.099.8

18.81.999.8

17.81.899.8

16.81.799.8

15.81.699.5

14.81.599.4

13.81.499.3

12.81.399.1

11.81.299

10.71.198.7

9.71.098.5

8.70.998.2

7.80.897.9

6.70.797.5

5.70.697.2

4.70.596.7

3.70.496

2.70.395.3

1.70.294.2

0.70.194

-0.3-0.093.8

25x25




39.94.00.559.96.01.179.98.0299.910.03.7129.913.05.7

39.13.90.5595.91.1797.9299.19.93.612912.95.7

38.13.80.5585.81.1787.82.1989.83.712812.85.8

37.13.70.5575.71.177.17.72.1979.73.712712.75.8

36.13.60.6565.61.176.17.62969.63.712612.65.8

35.13.50.654.95.51.1757.52959.53.712512.55.7

343.40.8545.41.1747.42949.43.712412.45.8

32.93.31.3535.31.173.17.3293.19.33.812312.35.8

323.22.1525.21.1727.2292.19.23.812212.25.8

313.13.9515.11.271.17.12.191.19.13.812112.15.8

303.06.5505.01.3707.02.1909.03.912012.05.9

292.910.3494.91.569.16.92.189.18.9411911.95.9

282.815.7484.81.868.16.82.2888.84.211811.85.9

272.722.3474.72.567.16.72.487.18.74.411711.75.8

262.629.8464.63.666.16.62.7868.64.911611.65.9

252.538454.55.365.16.53.285.18.55.311511.55.9

242.446.7444.47.664.16.43.984.18.46.211411.45.9

22.92.355434.310.763.16.34.883.18.3711311.36

222.263.4424.214.762.16.26.182.18.27.911211.26

212.171414.119.261.16.17.9818.19.211111.16.1

202.078.4404.024.360.16.09.9808.010.711011.06.2

191.984.4393.930.259.15.912.478.97.912.410910.96.4

181.889.7383.836.2585.815.377.97.814.4108.110.86.6

171.793.5373.742.4575.718.7777.716.810710.76.9

161.696.6363.648.9565.622.375.97.619.210610.67.3

15.11.598.834.93.555555.526.774.97.521.810510.57.7

141.499.933.93.461.5545.431.2747.424.710410.48.4

131.310032.93.367.2535.33672.97.327.810310.39.1

121.299.431.93.272.6525.240.6727.231.110210.210

10.91.198.130.93.177.5515.145.5717.134.310110.111

9.91.096.529.93.081.949.95.050.3707.037.710010.012.2

8.90.994.628.92.986494.955.3696.941.3999.913.5

7.90.892.527.92.889.7484.859.8686.844.9989.814.8

6.90.790.426.92.792.6474.764.2676.748.1979.716.5

5.90.688.125.92.695464.668.2666.651.6969.618.3

4.90.586.124.92.596.8454.572.5656.555.2959.520.3

3.90.484.223.92.498.343.94.476.2646.458.5949.422.2

2.90.382.422.92.399.2434.379.6636.361.8939.324.5

1.90.280.321.92.299.9424.282.9626.264.992.19.226.6

0.90.179.320.92.1100414.185.7616.167.8919.128.9

-0.1-0.079.119.92.099.8404.088.1606.070.790.19.031.1

18.81.999.5393.990.4595.973.489.18.933.8

17.91.899383.892.457.95.876.1888.836.5

16.91.798.2373.794.256.95.778.4878.739.3

15.91.697.4363.695.755.95.680.886.18.641.7

14.91.596.434.83.596.954.95.58385.18.544.3

13.91.495.533.93.49853.95.485.184.18.447

12.91.394.532.93.398.652.95.386.9838.349.4

11.91.293.531.93.299.351.95.288.682.18.252.1

10.81.192.530.93.199.650.95.190.280.98.154.6

9.81.091.629.93.099.949.95.091.5808.056.9

8.80.990.628.82.999.948.94.992.8797.959.4

7.80.889.827.92.810047.94.894787.861.8

6.80.788.826.92.710046.94.795777.763.9

5.80.687.925.92.699.845.94.695.775.97.666.3

4.80.58724.92.599.544.94.596.574.97.568.4

3.80.48623.92.499.243.94.497.173.97.470.4

2.80.38522.92.398.942.94.397.772.97.372.2

1.80.283.921.82.298.541.94.298.271.97.274.1

0.80.183.420.92.198.340.94.198.570.97.176

-0.1-0.083.319.92.09839.94.098.8707.077.7

18.91.997.638.93.999.2696.979.3

17.91.897.337.93.899.3686.880.7

16.91.796.936.93.799.6676.782.1

15.91.696.535.93.699.7666.683.5

14.91.596.134.83.599.8656.584.6

13.91.495.733.83.4100646.485.8

12.91.395.332.83.3100636.386.9

11.91.294.931.83.299.9626.287.9

10.81.194.630.83.199.9616.189

9.81.094.129.83.0100606.089.8

8.80.993.728.82.999.9595.990.6

7.80.893.327.82.810057.95.891.4

6.80.792.926.82.799.856.95.792.2

5.80.692.325.82.699.955.95.692.9

4.80.591.824.82.599.954.95.593.4

3.80.491.123.82.499.753.95.494.1

2.80.390.222.82.399.752.95.394.6

1.80.289.321.82.299.551.95.295.1

0.80.188.920.82.199.550.95.195.5

-0.2-0.088.819.82.099.449.95.095.8

18.81.999.348.84.996.3

17.81.899.147.94.896.7

16.81.79946.94.797

15.81.698.845.94.697.3

14.81.598.644.94.597.7

13.81.498.543.84.497.9

12.81.398.342.94.398.2

11.91.298.241.94.298.3

10.71.197.840.94.198.6

9.71.097.639.94.098.8

8.70.997.238.93.998.8

7.70.896.837.93.899.1

6.70.796.536.93.799.1

5.70.696.135.93.699.3

4.70.595.634.83.599.5

3.70.49533.83.499.4

2.70.394.232.83.399.6

1.70.293.331.83.299.7

0.70.193.230.83.199.8

-0.3-0.092.929.83.099.9

28.82.999.9

27.82.899.9

26.82.799.9

25.72.6100

24.82.599.9

23.82.4100

22.82.3100

21.82.299.9

20.82.199.9

19.82.099.8

18.81.999.8

17.81.899.7

16.81.799.6

15.81.699.6

14.81.599.4

13.81.499.3

12.81.399.1

11.81.298.9

10.71.198.7

9.71.098.4

8.70.998.2

7.80.897.9

6.70.797.6

5.70.697.1

4.70.596.6

3.70.495.8

2.70.395.1

1.70.294.3

0.70.193.9

-0.3-0.094

6E Plot

0.50.50.5

0.50.50.5

0.50.50.5

0.50.50.5

0.60.60.6

0.60.60.6

0.70.70.8

1.211.3

21.92.1

3.53.23.9

6.15.76.5

9.99.310.3

14.914.415.7

21.420.622.3

29.127.329.8

3735.738

45.844.346.7

54.252.955

62.861.463.4

70.37071

77.877.178.4

84.283.484.4

89.388.889.7

93.29393.5

96.596.496.6

98.698.698.8

99.799.899.9

100100100

99.499.399.4

98.198.298.1

96.396.496.5

94.394.394.6

92.192.192.5

89.989.990.4

87.687.888.1

85.585.886.1

83.483.784.2

81.381.782.4

79.179.780.3

77.978.579.3

77.87879.1


Machine: CL3Detector: NACP-02Energy: 6 MeVTSD: 100 cmIonisation data converted to dose using OmniPro Accept AAPM TG51 algorithm

6x6cm

15x15cm

25x25cm

Depth (cm)

PDD

CL3 6MeV Electron Depth Dose Variation with Field Size

9E Plot

1.111.1

1.111.1

1.111.1

1.11.11.1

1.11.11.1

1.11.11.1

1.11.11.1

1.11.11.1

1.11.11.1

1.21.11.2

1.31.21.3

1.41.41.5

1.81.81.8

2.42.42.5

3.43.43.6

54.95.3

7.27.17.6

10.210.110.7

13.913.414.7

18.417.719.2

23.522.724.3

2928.330.2

3534.236.2

41.240.542.4

47.746.848.9

5453.155

60.259.161.5

6665.267.2

71.670.872.6

76.67677.5

81.380.681.9

85.284.986

88.988.689.7

91.991.692.6

94.394.195

96.396.296.8

97.897.998.3

98.99999.2

99.699.699.9

99.9100100

10099.899.8

99.799.699.5

99.19999

98.598.398.2

97.797.497.4

96.896.496.4

95.895.495.5

94.794.494.5

93.693.493.5

92.692.492.5

91.691.391.6

90.890.490.6

89.789.589.8

88.888.588.8

87.887.687.9

86.986.787

85.785.786

84.684.685

83.283.383.9

82.582.683.4

82.482.383.3



6x6cm

15x15cm

25x25cm

Depth (cm)

PDD


12E Plot

1.922

1.81.92

1.81.92.1

1.81.92.1

1.81.92

1.91.92

1.91.92

1.91.92

1.922

1.922.1

222.1

22.12.1

2.12.12.2

2.22.32.4

2.52.52.7

32.93.2

3.63.53.9

4.54.64.8

5.75.86.1

7.37.37.9

9.29.59.9

11.71212.4

14.31515.3

17.51818.7

21.22222.3

25.426.126.7

29.830.431.2

34.334.836

38.939.640.6

43.644.445.5

48.548.950.3

53.153.855.3

57.358.759.8

61.963.164.2

66.167.468.2

70.171.472.5

73.775.176.2

77.278.779.6

80.68282.9

83.484.885.7

8687.588.1

88.589.990.4

90.591.992.4

92.493.794.2

9495.395.7

95.496.596.9

96.697.698

97.598.498.6

98.398.999.3

98.899.399.6

99.399.899.9

99.699.999.9

99.8100100

10099.9100

99.999.799.8

99.899.499.5

99.699.299.2

99.498.998.9

99.198.598.5

98.898.198.3

98.497.798

9897.197.6

97.696.997.3

97.396.496.9

96.99696.5

96.595.696.1

9695.195.7

95.694.795.3

95.294.394.9

94.793.894.6

94.493.394.1

93.89393.7

93.392.493.3

92.891.992.9

92.391.392.3

91.690.691.8

90.99091.1

9089.190.2

88.98889.3

88.487.588.9

88.287.388.8



6x6cm

15x15cm

25x25cm

Depth (cm)

PDD

CL3 12MeV Depth Dose Variation with Field Size

16E Plot

3.33.63.7

3.23.63.6

3.23.63.7

3.33.63.7

3.33.63.7

3.33.63.7

3.33.73.7

3.43.73.8

3.43.73.8

3.53.83.8

3.53.83.9

3.744

3.84.14.2

44.34.4

4.54.64.9

4.95.15.3

5.55.76.2

6.36.57

7.27.47.9

8.58.79.2

9.810.110.7

11.511.612.4

13.313.514.4

15.415.816.8

17.61819.2

19.920.721.8

22.723.724.7

25.426.627.8

28.429.831.1

31.433.134.3

34.536.437.7

37.839.841.3

40.943.444.9

4446.848.1

47.250.451.6

50.35455.2

53.457.358.5

56.460.861.8

59.264.164.9

62.267.267.8

64.870.270.7

67.573.273.4

70.175.876.1

72.578.278.4

7580.680.8

77.182.883

79.384.985.1

81.486.786.9

83.388.488.6

859090.2

86.691.491.5

88.292.692.8

89.693.794

90.994.895

9295.695.7

93.196.396.5

94.19797.1

94.997.797.7

95.698.198.2

96.398.598.5

97.198.998.8

97.699.299.2

9899.499.3

98.499.699.6

98.799.799.7

9999.899.8

99.3100100

99.3100100

99.699.999.9

99.710099.9

99.8100100

10099.999.9

10099.9100

99.999.799.8

10099.899.9

10099.699.9

99.999.499.7

10099.599.7

99.999.399.5

99.999.299.5

99.79999.4

99.698.999.3

99.498.999.1

99.398.699

99.298.498.8

99.198.398.6

98.898.298.5

98.797.898.3

98.597.798.2

98.397.397.8

9897.197.6

97.896.897.2

97.596.496.8

97.196.196.5

96.695.696.1

9695.195.6

95.494.595

94.693.794.2

93.592.693.3

93.292.493.2

93.292.292.9



6x6cm

15x15cm

25x25cm

Depth (cm)

PDD


20E Plot

55.55.7

55.55.7

5.15.45.8

5.15.45.8

5.15.55.8

5.25.55.7

5.25.55.8

5.15.55.8

5.15.65.8

5.25.65.8

5.25.65.9

5.25.55.9

5.35.65.9

5.35.65.8

5.35.65.9

5.45.65.9

5.35.75.9

5.45.76

5.45.86

5.55.96.1

5.666.2

5.86.16.4

6.16.46.6

6.36.66.9

6.66.97.3

6.97.57.7

7.588.4

8.28.79.1

99.610

9.810.511

10.911.412.2

1212.713.5

1314.114.8

14.315.716.5

15.917.518.3

17.519.420.3

19.221.522.2

20.923.624.5

22.925.726.6

24.828.228.9

26.830.631.1

293333.8

3135.436.5

33.437.939.3

35.540.341.7

37.842.944.3

40.145.647

42.148.349.4

44.250.852.1

46.353.354.6

48.455.856.9

50.658.259.4

52.860.661.8

54.962.963.9

56.96566.3

58.867.268.4

60.869.370.4

62.671.372.2

64.673.274.1

66.47576

68.176.677.7

69.878.479.3

71.479.880.7

73.181.382.1

74.782.783.5

76.28484.6

77.785.285.8

79.186.686.9

80.487.787.9

81.788.689

82.889.589.8

84.190.590.6

85.291.491.4

86.19292.2

87.292.892.9

88.293.393.4

89.29494.1

9094.594.6

90.894.995.1

91.695.595.5

92.295.995.8

9396.296.3

93.696.696.7

94.297.197

94.797.397.3

95.197.697.7

95.697.997.9

969898.2

96.498.398.3

96.898.498.6

97.298.798.8

97.698.998.8

97.69999.1

97.999.299.1

98.299.399.3

98.499.499.5

98.799.699.4

98.899.699.6

98.999.699.7

99.199.799.8

99.299.799.9

99.499.799.9

99.599.999.9

99.699.899.9

99.7100100

99.699.999.9

99.899.9100

99.8100100

99.910099.9

99.999.899.9

99.999.899.8

99.999.899.8

10099.899.7

99.999.699.6

99.899.599.6

99.899.599.4

99.799.499.3

99.799.299.1

99.59998.9

99.498.898.7

99.298.698.4

99.198.398.2

98.89897.9

98.697.697.6

98.197.297.1

97.796.796.6

97.196.195.8

96.395.495.1

95.194.494.3

94.894.193.9

94.993.994



6x6cm

15x15cm

25x25cm

Depth (cm)

PDD


Hull & East Yorks. CL1 & CL2

Tenth Value Layers / mmi.e. @ 80 kVp, 1 mm lead 90 mm concrete @ 15 MVx, 1 mm lead 8 mm concrete (lead 5 x density of concrete)

MaterialDensityZeff80kVp x15MVxConcrete2.412.5 (?)17.4 mm432 mmWater1.07.4278 mm620 mmLead11.4820.2 mm56 mmIron7.9261.0 mm108 mmTungsten19.374Uranium18.9592

Neutron ProductionBinding energy (BE) of neutrons 7-20 MeV (mostly)

Pb207B10

Neutron ProductionVery little neutron production below 10MVx

Binding energy (BE) of neutrons 7-20 MeV (mostly)Probability increases with (EX BE) up to (2 x BE)

Neutron ShieldingTVL neutrons ~ 400 cm lead (thermal)< 31cm concrete for medical linacs< 10 cm polythene(TVL for 15MVx is 43.2 cm)

Hull & East Yorks. CL1 & CL2

Neutron Activation

Neutron Activation ProductsPort1 m

Neutron Activation Products (2)Half livesAluminium 2.5 minutesBed end 9.2 minutesLinac head 8.4 minutesPlasterboard, water, Perspex no activity detected

Why 7.5 Sv/h ?TodayPost 2000, 6 mSv is unclassified person effective dose limit6mS/y / (7.5 Sv/h x 7.5h/d) = 100 d/yOriginally7.5 Sv/h x 8 h/d x 5 d/wk x 50 wk/y = 15mSvPre 1/1/2000, 15 mSv was unclassified person effective dose limit

Why 75 Sv/h ?RememberDose limit not like a speed limitOptimisationKeep doses As Low As Reasonably AchievableFollow local rules.75 Sv/h x 8 h/d x 5 d/wk x 50 wk/y = 150mSv/yEye dose limit = 150 mSv/ySkin dose limit = 500 mSv/y

Half-life no more than 81/2 minutesSo in hour, dose rate will be 10 times or more lower

Radioactive materialsIridium-192Used for brachytherapy in wire form0.1-0.7 MeV beta particles absorbed by platinum coating0.2-1.06 MeV gamma rays emitted (effective energy 0.4MeV)TVL = 12 mm Pb, 185 mm concrete

Smoke detector vs Flexitron

Smoke detectorAmericium-24137 kBq (kilobecquerels) @10 cm0.005 mSv/h @ 1 cmErythema threshold in 45 years Direct skin contact 0.2 mSv/hErythema threshold in > 1 yearHand dose limit in 1 month

Flexisource44 mGy/hour @ 100 cm44 x 1002/12 = 440,000 mGy/h @ 1 cm122 mGy/second @ 1 cmerythema threshold in 16 secshand dose limit in 1.2 secs(direct skin contact 1.2 - 72 Gy/s)400 GBq (gigabecquerels)400 trillion gamma rays per second

Radioactive PatientsPatients may be radioactive iftheyve been injected with or swallowed radioactive pharmaceuticalsthey have solid radioactive sources surgically implantedthey have been involved in an accident with radioactive materials .

Radioactive Decay - half life

Beginning

After 1 half life

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

(

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

After 2 half lives

(

After 3 half lives

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

(

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

After 4 half lives

(

After 5 half lives

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

(

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

( ( ( ( ( ( ( (

Nuclear Medicine ScanPatient injected with or swallows a radioactive pharmaceuticalGamma camera traces where that radiopharmaceutical is concentrated .

Thyroid treatments with radio-iodineHyperthyroidism / thyrotoxicosis overactive thyroid - 400 MBqThyroid cancer must destroy all tumour - 3000 MBqc.f. thyroid scan - 0.2 MBq.

Other unsealed source therapiesPhosphorus-32 for polycythemia (too many red blood cells)Yttrium-90 colloid for arthritic conditionsStrontium-90 for bone metastases.

Brachytherapy (radioactive implants)Intracavity afterloadingIridium wire afterloadingIridium pinsIodine-125 seeds .

HDR-microSelectron

Iridium Implant

Iodine-125 seeds in Prostate

Iridium-192Used for brachytherapy in wire form0.1-0.7MeV beta particles absorbed by platinum coating0.2-1.06MeV gamma rays emitted (effective energy 0.4MeV)TVL = 12mm Pb, 185mm concreteNew HDR Flexitron

Non-Ionising Radiations (briefly)e.g.lasersultravioletMRI scanners

Laser Device Classes & HazardsClass 1Class 1MClass 2Class 2MClass 3RClass 3BClass 4Applies to device as a whole.

Class 1no risk to eyes (including using optical viewing instruments)no risk to skin(either low power device or totally encased)

Class 1M no risk to the naked eyeno risk to skin

Class 2no risk to eyes for short term exposure (including using optical viewing instruments)no risk to skin(visible, so blink response protects)(may cause dazzle or flash blindness)

Class 2Mno risk to naked eye for short time exposureno risk to skin

Class 3Rlow risk to eyes no risk to skin(risk for intentional intrabeam viewing only)(may be a dazzle hazard)

Class 3Bmedium to high risk to eyeslow risk to skin(aversion response protects skin, or must be focussed to such a small spot that pin-prick effect only)

Class 4high risk to eyes and skinlow risk to skin(diffuse reflection may be hazardous)(possible fire hazard)

DIR 690 - 1290 L4

1/10000th of 690-1290 nm laser light transmitted

Laser

Wavelength

Suitable?

CO2

10600 nm

(

Ho:YAG

2100 nm

(

Nd:YAG

1060 nm

(

LaserTripter

504 nm

(

Argon

477 or 515 nm

(

Risk Assessments

HEYH Trust CP137Health & Safety at Work Policy- Lasers -Includes safety of class 3B and class 4 lasers

UVEye hazard, skin hazardDermatologyTL01 and PUVA

UV treatment of psoriasis0.00010.0010.010.1110250275300325350375400Wavelength / nmRelative effectErythemaclearance of psoriasisUVAUVBUVC

Relative Spectral Power of UV Therapy lamps

30/11/08*

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