The Effect of Irradiation Setup Conditions on Cell Viability in Tumor Cell Cultures: An Investigation on Multi-well Plates

Air gaps in multi-well cell culture plates can disrupt electronic equilibrium and introduce uncertainties in delivered dose during in vitro irradiation experiments. This study evaluated the impact of different bottom-up irradiation setups on short-term cell viability using an RW3 solid water phantom system. MCF-7 cells were irradiated with 6-MV photons (200-cGy) under four experimental configurations. One-way ANOVA demonstrated no statistically significant differences among setups [F(3,8)=0.503, p=0.691]. Tukey HSD post-hoc analysis confirmed the absence of significant pairwise differences (p>0.05). A subsequent power analysis (η2=0.159; Cohen's f=0.434) revealed an observed power of 0.15. These findings indicate that additional bolus or RW3 configurations do not significantly affect short-term cell viability when bottom-up geometry and appropriate buildup conditions are maintained.