HSC 340 10-14-10 <ul><li>Photon Dose Distributions </li></ul><ul><ul><li>Single and multi-field distributions </li></ul></...
Photon Dose Distribution <ul><li>What are dose distributions? </li></ul><ul><ul><li>Pg. 528 PDD  </li></ul></ul><ul><ul><l...
Isodose distributions <ul><li>Open fields </li></ul><ul><li>Wedged fields </li></ul><ul><li>Multiple fields </li></ul><ul>...
Corrections <ul><li>Contour/Obliquity </li></ul><ul><ul><li>P’=P x {SSD+d m /SSD+d m +h} 2 </li></ul></ul><ul><li>Heteroge...
Treatment Planning Essentials <ul><li>Rationale for 3-D conformal  </li></ul><ul><ul><li>Overall goal to deliver 100% dose...
Algorithms <ul><li>Dose calc process </li></ul><ul><li>Data driven </li></ul><ul><ul><li>Bentley-Milan (rarely used) </li>...
Algorithms cont. <ul><li>What should an algorithm be evaluated on? </li></ul><ul><li>Calculation Algorithms </li></ul><ul>...
Treatment Planning Concepts <ul><li>Planning volumes </li></ul><ul><li>Read Box 25-2 on your own. </li></ul><ul><li>Prescr...
Treatment Planning Process <ul><li>Image </li></ul><ul><li>Contour </li></ul><ul><li>Delineate Treatment Fields </li></ul>...
Electron dose distributions <ul><li>Interactions are different from photon beam </li></ul><ul><li>Collisional and Radiatio...
Characteristics of e- beams <ul><li>Dose gradients of clinically useful e- beams </li></ul><ul><li>Shapes </li></ul>
Treatment Planning <ul><li>Rules of thumb </li></ul><ul><li>Surface characteristics </li></ul><ul><li>Build-up region char...
Irregular fields and e- beams <ul><li>Shielding </li></ul><ul><li>Internal shielding </li></ul><ul><li>Effects on dose </l...
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Hsc 340 10 14

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Hsc 340 10 14

  1. 1. HSC 340 10-14-10 <ul><li>Photon Dose Distributions </li></ul><ul><ul><li>Single and multi-field distributions </li></ul></ul><ul><ul><li>Corrections </li></ul></ul><ul><ul><li>Tx plan essentials </li></ul></ul><ul><li>Electron Dose Distributions </li></ul><ul><ul><li>Physics </li></ul></ul><ul><ul><li>Characteristics </li></ul></ul><ul><ul><li>Treatment Planning </li></ul></ul>
  2. 2. Photon Dose Distribution <ul><li>What are dose distributions? </li></ul><ul><ul><li>Pg. 528 PDD </li></ul></ul><ul><ul><li>Beam Profile </li></ul></ul><ul><ul><li>Flattening Filter </li></ul></ul><ul><li>What are isodose distributions? </li></ul>
  3. 3. Isodose distributions <ul><li>Open fields </li></ul><ul><li>Wedged fields </li></ul><ul><li>Multiple fields </li></ul><ul><ul><li>POP </li></ul></ul><ul><ul><li>Wedged pair </li></ul></ul>
  4. 4. Corrections <ul><li>Contour/Obliquity </li></ul><ul><ul><li>P’=P x {SSD+d m /SSD+d m +h} 2 </li></ul></ul><ul><li>Heterogeneity </li></ul><ul><ul><li>D actual= d 1 +d 2 +d 3 </li></ul></ul><ul><ul><li>d eff= p e d 1 +p e d 2 +p e d 3 </li></ul></ul><ul><li>Table 25-2 and table 25-3 </li></ul>
  5. 5. Treatment Planning Essentials <ul><li>Rationale for 3-D conformal </li></ul><ul><ul><li>Overall goal to deliver 100% dose to tumor and deliver 0% to critical structures. </li></ul></ul><ul><ul><li>Figure 25-12 </li></ul></ul><ul><li>3-D treatment planning & delivery methods </li></ul><ul><ul><li>Need CT </li></ul></ul><ul><ul><li>IMRT & 3D CRT </li></ul></ul>
  6. 6. Algorithms <ul><li>Dose calc process </li></ul><ul><li>Data driven </li></ul><ul><ul><li>Bentley-Milan (rarely used) </li></ul></ul><ul><li>Model driven </li></ul><ul><ul><li>ADAC Pinnacle </li></ul></ul><ul><li>2-D vs 3-D </li></ul><ul><ul><li>Pg. 25-4 </li></ul></ul>
  7. 7. Algorithms cont. <ul><li>What should an algorithm be evaluated on? </li></ul><ul><li>Calculation Algorithms </li></ul><ul><ul><li>Scatter Integration </li></ul></ul><ul><ul><li>Convolution Algorithm </li></ul></ul>
  8. 8. Treatment Planning Concepts <ul><li>Planning volumes </li></ul><ul><li>Read Box 25-2 on your own. </li></ul><ul><li>Prescriptions are often based on iso lines </li></ul><ul><li>DVH </li></ul>
  9. 9. Treatment Planning Process <ul><li>Image </li></ul><ul><li>Contour </li></ul><ul><li>Delineate Treatment Fields </li></ul><ul><li>Evaluate and Implement </li></ul>
  10. 10. Electron dose distributions <ul><li>Interactions are different from photon beam </li></ul><ul><li>Collisional and Radiation Interactions </li></ul><ul><li>Energy Dependence </li></ul><ul><li>Dependence of depth </li></ul><ul><li>Production of Clinically useful e- </li></ul><ul><li>Scattering foils vs. scanning beams </li></ul>
  11. 11. Characteristics of e- beams <ul><li>Dose gradients of clinically useful e- beams </li></ul><ul><li>Shapes </li></ul>
  12. 12. Treatment Planning <ul><li>Rules of thumb </li></ul><ul><li>Surface characteristics </li></ul><ul><li>Build-up region characteristics </li></ul><ul><li>Energy dependence </li></ul><ul><li>Distance correction factors </li></ul><ul><li>Effective point source </li></ul><ul><li>Virtual source </li></ul>
  13. 13. Irregular fields and e- beams <ul><li>Shielding </li></ul><ul><li>Internal shielding </li></ul><ul><li>Effects on dose </li></ul><ul><li>Tissue heterogeneity and dose </li></ul><ul><li>Gaps </li></ul><ul><li>Read Clinical Cases pg.559 </li></ul>

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