Enhancing dosimetric evaluation in In Vitro neoplastic cell irradiation

In radiobiology, studies on the irradiation of neoplastic cells in vitro are crucial for advancing treatment knowledge, specifically in neoplastic cells. These investigations aim to discover optimal doses, dose fractionation approaches, and potential concurrent treatment modalities to enhance damage to neoplastic cells. An experimental setup for cell culture irradiation was proposed with a focus on controlling the beam's build-up region and lateral and backscatter, coupled with an emphasis on the importance of a simple, reproducible, and standardized position. This setup comprises an acrylic plate with 96-well and plates of solid water. Computed tomography images of the setup were acquired in various configurations, these images were used to plan irradiation in the treatment planning system, employing two dose calculation algorithms AcurosXB and AAA, for the 6 MV LINAC with a 20 × 20 cm² field size and 100 cm of source-skin distance (SSD).

Radiochromic films (EBT3) were used to quantify a planned dose of 2 Gy to evaluate experimental dosimetry. Under the same conditions and geometry, the PENELOPE Monte Carlo simulation code was employed to validate the experimentally obtained data. Film dosimetry highlighted dose variations, with an uncertainty of 8 % in reported values, indicating that not all wells need to be filled for satisfactory absorption.

The results of simulations using the PENELOPE code validated the stability of our setup, emphasizing the importance of control in the build-up region and scattering factors. The experimental configuration allowed for obtaining a uniform dose distribution throughout the cell culture, even in the absence of a cell culture medium within each well of the culture plate.