Dose Calculation

Question 1

What are the two common materials for phantom?

Answer 1

Lucite, Polystyrene

Question 2

What is the Mayneord F Factor?

Answer 2

Mayneord F Factor is used to calculate the PDD curve at a new SSD.

Question 3

What is tissue-air ratio (TAR)?

Answer 3

TAR tissue air ratio is the ratio of dose at depth in the phantom to dose in free space at the same point.

Question 4

TAR at Dmax is equal to

PDD
BSF (Back Scatter Factor)
TPR (Tissue Phantom Ratio)
SAR (Scatter Air Ratio)

Answer 4

BSF (Back Scatter Factor)

Question 5

Define BSF (Back Scatter Factor)

Answer 5

BSF is simply the tissue TAR (tissue air ratio) at the depth of maximum dose on central axis of the beam.

It is defined as the ratio of the dose on central axis at the depth of maximum dose to the dose at the same point in free space.

Question 6

Describe the dose distribution difference between electron vs photon

Answer 6

https://plasticsurgerykey.com/radiotherapy/

Question 7

TMR (Tissue Max Ratio) is a special case of:

TPR (Tissue Phantom Ratio)
SAR (Scatter Air Ratio)
SMR
Backscatter factor

Answer 7

TPR