Basic Clinical Radiobiology 2017

Early versus late reactions

Early reactions

Late reactions

Latency (Time to onset of clinical manifestion)

<90 days after onset RT; typically 3-9 weeks

>90 days after onset RT; typically 0,5-5 years

Not influenced by dose, but severity and duration of damage are dose-dependent Low (high α/β ~ 6-10 Gy) Shorter OTT leads to greater injury Typically transient, but consequential late reactions may occur

Inversely dependent on dose: higher dose leads to shorter latent period

Fractionation sensitivity

High (low α/β ~ 1-5 Gy)

Influence of overall treatment time (OTT)

No significant influence

Clinical course

Progressive and irreversible Compensation may occur Rehabilitation or treatment for complications may relieve

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