Investigating the impact of alpha/beta and LET_d on relative biological effectiveness in scanned proton beams: An in vitro study based on human cell lines.

ABSTRACT:

Purpose

A relative biological effectiveness (RBE) of 1.1 is commonly used in clinical proton therapy, irrespective of tissue type and depth. This in vitro study was conducted to quantify the RBE of scanned protons as a function of the dose-averaged linear energy transfer (LET_d ) and the sensitivity factor (α/ß)_X . Additionally, three phenomenological models (McNamara, Rørvik, and Jones) and one mechanistic model (repair-misrepair-fixation, RMF) were applied to the experimentally derived data.

Methods

Four human cell lines (FaDu, HaCat, Du145, SKMel) with differential (α/ß)_X ratios were irradiated in a custom-designed irradiation setup with doses between 0 and 6 Gy at proximal, central, and distal positions of a 80 mm spread-out Bragg peak (SO

SUBMITTER: Mara E 

PROVIDER: S-EPMC7496287 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature