Monday, 20 February 2017

Redistribution

«Reassortment. The radiosensitivities of cells vary according to phases of the cell cycle.» «The duration of the cell cycle phases are: G1 = 1.5–14 h, S = 6–9 h, G2 = 1–5 h, and M = 0.5–1 h. The most sensitive are M and G2. The most resistant is S.» «Cells in the resistant phases of the cell cycle may progress into the sensitive phases in the next fraction, when radiation is given in fractions. Therefore, the probability of tumor cells to be exposed to radiation at sensitive phases increases. This probability will continue for the whole treatment, and the benefit from radiation will
increase.»
Bibliographic reference: Beyzadeoglu M, Ozyigit G, Selek U. Radiation Oncology. 1st ed. Berlin: Springer; 2012:112-114.