How air influences radiation dose deposition in multiwell culture plates: a Monte Carlo simulation of radiation geometry

A High-Throughput In Vitro Radiobiology Platform for Megavoltage Photon Linear Accelerator Studies

We designed and developed a multiwell tissue culture plate irradiation setup, and intensity modulated radiotherapy plans were generated for 96-, 24-, and 6-well tissue culture plates. We demonstrated concordance between planned and measured/imaged radiation dose profiles using radiochromic film, a 2D ion chamber array, and an electronic portal-imaging device. Cell viability, clonogenic potential, and g-H2AX foci analyses showed no significant differences between intensity-modulated radiotherapy and open-field, homogeneous irradiations. This novel platform may help to expedite radiobiology experiments within a clinical environment and may be used for wide-ranging ex vivo radiobiology applications.

A protocol for irradiation of cell lines cultured in multi-well plates: effect of air inhomogeneity on irradiated cell survival

Introduction: In multi-well cell culture plates, wells are bordered by air cavities. The air cavity inhomogeneities can reduce the amount of delivered dose. In this study, the effect of these cavities on cell survival was investigated.Materials and methods: A special phantom was designed to house the plates and air cavities were filled by water equivalent materials. Cultured melanoma cells were irradiated using 6MV photon for 200 cGy. MTT and clonogenic assay tests were used to evaluate cell survival.Results: Results of MTT assay showed mean survival percentage for irradiated cells in the first group, i.e. plates with air cavities, was 18.9% higher than the second group with air cavities filled with paraffin. Clonogenic assay results showed a maximum of 37% difference in the mean of number of colonies between the first group and the second group (p value < .05).Conclusions: The presence of air cavities in multi-well cell culture plates reduced radiation cell kill by up to 37%. To ensure the accuracy of delivered dose, it is necessary to replace the air cavities as well as the air surrounding the plates by a water equivalent material.