Currently used in clinical practice beam rate changes have no significant effect on the reduction of clonogenic capacity of PNT1A cells in vitro

Rep Pract Oncol Radiother. 2021 Dec 30;26(6):1051-1056. doi: 10.5603/RPOR.a2021.0134. eCollection 2021.

Abstract

Background: Due to the lack of selectivity of ionizing radiation between normal and cancer cells, it is important to improve the existing radiation patterns. Lowering the risk of cancer recurrence and comfort during treatment are priorities in radiotherapy.

Materials and methods: In the experiment we used dose verification to determine the irradiation time calculated by a treatment planning system for 6XFFF and 10XFFF beams. Cells cultured under standard conditions were irradiated with a dose of 2 Gy at different beam rates 400 MU/min, 600 MU/min, 800 MU/min, 1000 MU/min, 1400 MU/min, 1600 MU/min and 2400 MU/min using 6XFFF, 10XFFF and 6XFF beams.

Results: The experiment was aimed at comparing the biological response of normal prostate cells after clinically applied radiation patterns. No statistically significant differences in the cellular response were observed. The wide range of beam rates as well as the beam profiles did not significantly affect cell proliferation.

Conclusions: High beam rates, without significantly affecting the clonogenic capacity of cells, have an impact on the quality of patient's treatment. With the increasing beam rate the irradiation time is shortened, which has an important impact on patients' health. This experiment can have a practical significance.

Keywords: dose-rate; profile beam; prostate; radiobiology; radiotherapy.