Particle Therapy 2017

Repopulation

Conventionally RT delivery: repopulation evident 3 – 4 weeks after initiation For tumor cells, repopulation partly counteracts the cell killing effect of RT (potential doubling time of tumors !) Repopulation essential for normal tissue recovery ! Hypofractionation

Hypofractionated RT delivery: repopulation complete within 1 – 2 weeks Negligible or no substantial role after high dose SBRT !