1. Clinical Electron Dosimetry
John Spindler, CMD
Louise Francis, CMD

2. History of Electron Therapy
Early clinical use
Modern clinical use
Electron vs Orthovoltage Treatment

3. Electron Production How are electrons produced Useful energy range
Electron Scattering

4. Electron Production

5. Electron Characteristics
Relatively uniform dose distribution within first few centimeters of tissue followed by rapid fall off.
Less skin sparing and less penetrating .
Constriction of higher isodose lines and ballooning of lower isodose lines.
Bremsstrahlung tail.

6. Electron Characteristics

9. Electron Characteristics

10. Electron Characteristics
Practical Range
Rp(cm)=MeV/2
Therapeutic Range
90%isodose=MeV/4
80%isodose=MeV/3

11. Electron Characteristics3 4

12. Clinical Applications
Choosing electron energy rule of thumb
Consider not only what you are trying to treat, but also what you may be trying to avoid
Remember to include adequate margin when drawing electron fields

13. Electron Monitor Units%