Physics Bucharest 2017

Example

100cm SSD spine field 8cm*15cm, Prescription single fraction 8Gy, prescribed to 7cm depth.

Calculated EqSq Look up in BIR supl 25: 10.3cm

“Willow” 6MV PDD* Output

Depth

Equivalent Square Field Size (cm)

(cm)

4

4.5

5

5.5

6

6.5

7

7.5

8

8.5

9

9.5 10 10.5

Dmax (1.5) 93.6 94.5 95.4 95.7 95.9 96.6 97.3 97.7 98.2 98.5 98.8 99.4 100.0 100.2 2.0 92.7 93.7 94.7 94.8 94.8 95.5 96.1 96.6 97.1 97.4 97.7 98.3 99.0 99.1 2.5 90.5 91.5 92.6 92.8 93.0 93.5 94.1 94.6 95.1 95.4 95.8 96.3 96.9 97.1 3.0 88.0 89.1 90.1 90.4 90.7 91.2 91.8 92.3 92.8 93.2 93.6 94.3 95.0 95.2 3.5 85.8 86.9 88.0 88.3 88.7 89.2 89.8 90.3 90.8 91.2 91.6 92.1 92.6 93.0 4.0 83.7 84.7 85.7 86.0 86.3 87.0 87.7 88.2 88.6 89.1 89.5 90.2 90.8 91.1 4.5 81.3 82.2 83.1 83.6 84.2 84.9 85.6 86.1 86.5 87.0 87.4 88.0 88.6 89.0 5.0 79.1 80.0 80.8 81.5 82.2 82.8 83.4 84.0 84.5 84.9 85.4 86.0 86.7 87.0 5.5 76.7 77.9 79.0 79.3 79.6 80.5 81.3 81.9 82.4 82.8 83.3 84.0 84.7 84.9 6.0 74.7 75.6 76.5 77.2 77.8 78.5 79.1 79.7 80.3 80.9 81.6 82.1 82.5 82.8 6.5 72.5 73.6 74.7 75.2 75.7 76.6 77.4 77.9 78.4 78.8 79.2 79.9 80.5 80.8 7.0 70.5 71.5 72.5 73.1 73.7 74.4 75.1 75.8 76.4 76.9 77.3 77.8 78.4 78.8 7.5 68.3 69.5 70.7 71.2 71.6 72.4 73.2 73.8 74.3 74.8 75.3 76.1 76.8 77.1 8.0 66.4 67.5 68.5 69.2 69.8 70.5 71.2 71.9 72.6 72.9 73.3 74.1 74.8 75.1 8.5 64.5 65.6 66.6 67.3 67.9 68.6 69.3 70.0 70.7 71.1 71.5 72.2 72.9 73.2 9.0 62.5 63.6 64.8 65.4 66.1 66.7 67.4 68.1 68.7 69.1 69.5 70.3 71.1 71.4 9.5 60.8 61.9 63.0 63.5 64.1 64.8 65.5 66.2 66.9 67.5 68.0 68.6 69.2 69.5 10.0 58.8 59.9 61.1 61.7 62.3 63.1 63.8 64.5 65.1 65.6 66.1 66.8 67.5 67.9 10.5 57.1 58.3 59.5 60.0 60.4 61.2 62.1 62.7 63.2 63.8 64.4 65.0 65.6 65.9 11.0 55.5 56.6 57.7 58.2 58.7 59.5 60.4 61.0 61.6 62.2 62.8 63.4 64.0 64.4 11.5 53.9 55.0 56.0 56.5 57.1 57.9 58.8 59.4 60.1 60.6 61.1 61.6 62.2 62.7 12.0 52.3 53.4 54.4 55.0 55.6 56.3 57.1 57.7 58.4 58.9 59.4 60.1 60.8 61.2

=1016.5

Max dose in many clinical settings for a single beam is 1000MU What do we do?

Basic Dose Caculation Principles 2012

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