-  Vibha

Chaswal
(07-15-2008 – 09/11/2008)
 

The resident should gain an understanding of the accuracy and precision of
each radiation measurement system, as well ...
  Know

dosimetric systems
  Have a feel for numbers you see in any
dosimetric calculations routinely in the clinic
  L...
  Ion

Chambers
  Electrometers
  MOSFET
  Diodes
  Films
  Water tank (?)
  Linearity
  Stem

effect
  Polarity effect
  Angular dependence
  Collection Efficiency
  Signal to Noise ratio b/...
  SNR

b/w three electrometers
  Leakage –
  cable current (from IC cable alone and from IC
cable and tri-axial cable t...
  Linearity
  Sensitivity

or nominal response
  Reproducibility
  SSD/Instantaneous dose rate/pulse rate
dependence
...
  Linearity
  Sensitivity
  Fading

effect
  Dose uncertainty
  Entrance and exit doses vs PPC measured dose
  Repro...
  H

and D curve for the XV film
  H and D curve of the EDR film
  Depth dependence of film
  SNR and variance or resp...
  Accuracy

and precision of detector positioning
  Reproducibility
  Energy

dependence
  Dose rate dependence
  Comparison of profiles and PDD by each
  Photons vs Electrons
  EDR fil...
CPE
failure

RE*

imperfect
CPE

Perfect CPE

•  CPE = concept
permanently engraved
•  Perfect CPE = inside
the head dissi...
Thank you very much!
Upcoming SlideShare
Loading in …5
×

Clinical Reference Dosimetry

774 views

Published on

Published in: Health & Medicine
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
774
On SlideShare
0
From Embeds
0
Number of Embeds
14
Actions
Shares
0
Downloads
36
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Clinical Reference Dosimetry

  1. 1. -  Vibha Chaswal (07-15-2008 – 09/11/2008)
  2. 2.   The resident should gain an understanding of the accuracy and precision of each radiation measurement system, as well as its appropriate application.   Commissioning of Dose Measurement Systems           Commissioning of 3D Water Tank Ion chamber Dosimetry System Effects               Ion Chambers / Electrometers Film Metal Oxide Semiconductor Field Effect Transistor (MOSFET) Leakage Stem Effect Signal-to-noise for different chamber volumes Variation with bias level and polarity at different dose rates Variation with changes in water temperature Perform dose profile measurements with each detector and compare results. Manual Film Densitometry   H&D curve creation (10x10 field size, 6VM x-rays)     depths of 1.5 cm and 10 cm in solid water, EDR2 film and XV
  3. 3.   Know dosimetric systems   Have a feel for numbers you see in any dosimetric calculations routinely in the clinic   Learn to design experiments to understand concepts   Assign applications to dosimeters – which one for which
  4. 4.   Ion Chambers   Electrometers   MOSFET   Diodes   Films   Water tank (?)
  5. 5.   Linearity   Stem effect   Polarity effect   Angular dependence   Collection Efficiency   Signal to Noise ratio b/w three ion chambers   nC/cc/cGy of cylindrical ion chambers
  6. 6.   SNR b/w three electrometers   Leakage –   cable current (from IC cable alone and from IC cable and tri-axial cable together)   with and without connecting assembly to ion chambers
  7. 7.   Linearity   Sensitivity or nominal response   Reproducibility   SSD/Instantaneous dose rate/pulse rate dependence   Temperature dependence   Field size dependence Missed out on: Angular dependence
  8. 8.   Linearity   Sensitivity   Fading effect   Dose uncertainty   Entrance and exit doses vs PPC measured dose   Reproducibility
  9. 9.   H and D curve for the XV film   H and D curve of the EDR film   Depth dependence of film   SNR and variance or response along a film, tested using XV film
  10. 10.   Accuracy and precision of detector positioning   Reproducibility
  11. 11.   Energy dependence   Dose rate dependence   Comparison of profiles and PDD by each   Photons vs Electrons   EDR films and Water tank
  12. 12. CPE failure RE* imperfect CPE Perfect CPE •  CPE = concept permanently engraved •  Perfect CPE = inside the head dissipation of concept •  Imperfect CPE = over the head transmission of concept 0 1 2 3 4 5 6 7 8 Weekly interactions * No chargers produced initially, it is all a steady state bliss
  13. 13. Thank you very much!

×