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Normal Tissue Tolerance
• The maximum radiation dose or intensity of
fractionated radiotherapy that is deemed to
produce an acceptable level of normal tissue
toxicity.
• Often specified as the dose that can be delivered
with a risk of damage no higher than 5% at 5 years
(TD5/5) or the dose that can be delivered with a
risk no higher than 50% at 5 yrs (TD50/5).
• Emami (1991) reviewed the tolerances for partial
and whole organ irradiation.
•
Q
uantitative
E
stimates of
N
ormal
T
issue
E
ffects in
C
linic : Joint AAPM-ASTRO initiative published
• Int J Rad Oncol Biol Physics 76 No.3 supplement
2010