A method for embedding cells on radiochromic film for in vitro high-precision radiation dosimetry.

backgroundA central challenge in classical radiobiology experiments, where dishes are plated with cells and then irradiated, is that the radiation dose deposited to the cells is often subjected to systematic and random errors. One method to validate the dose to cells is to use radiochromic film underneath or above the plated cells to estimate the dose given to the culture. PURPOSE: To explore the feasibility of seeding cells directly onto radiochromic film, enabling precise characterization of cellular responses to microscopic fluctuations in radiation intensity. This technique decreases the challenge of registration, improving the correlation between individual cell and their received radiation dose.

methodsWe investigate several adhesives and strategies for adhering spindle cells on a thin layer atop the film. After finding a robust approach, we develop a novel strategy for absolute dose calibration to the cell-film substrates. Finally, we evaluate this approach using a standard radiobiology assay by exposing cell films to uniform doses and comparing the cell colony survival fraction with established and published data.

resultsEasily obtainable gelatin and 3D printing adhesives provide substrates and adhesives for cell colony formation. Calibration and sample film data from traditional flatbed scanners used for film dosimetry, confocal microscopes, and a novel calibration method can be used to measure the dose to the films.

conclusionsUsing a film-to-dose calibration methodology, we show that cell colony assay experiments can be conducted directly on radiochromic film without significant spatial variation.