clinical application of tcp ・ ntcp. lyman jt. complication probability as assessed from dosevolume...
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Clinical application of TCP・NTCP
Lyman JT. Complication probability as assessed from dosevolume histograms. Radiat Res Suppl 1985; 8:S13–S19.
Because of the large amount of data generated by 3D treatment planning, new tools are being developed for the evaluation and optimization of the plans. Estimates of the probability of local control of the tumor and for the probability of specific normal tissue complications are among the new tools. The normal tissue complication probability (NTCP) is based on clinical estimates of the tolerance doses for specific tissues/organs. These tolerance doses are assumed to apply for uniform partial and full volume irradiations delivered at 2 Gy per fraction and 5 fractions per week. A different tolerance dose may apply when the dose is delivered at a different dose per fraction and over a different period of time. This study evaluates the maximum change expected in the NTCP when the normal structure receives the dose at a different dose per fraction than the target volume due to different choices in the delivery of the daily fraction.
TCP & NTCP
Delivered dose
TCP
NTCP
TC
P o
r N
TC
P(%
)
100
75
50
25
Usefulness of TCP
Detection for the cold point in DVH
Cold point
Low
Usefulness of TCP and NTCP
Comparison of treatment plans
CFIMRT
IMRT
Usefulness of TCP and NTCP
Refine treatment plans
TCP 32.28 TCP 26.83NTCP 61.30% NTCP 14.91%