‘Relationship between thermal dose and cell death for “rapid” ablative and “slow” hyperthermic heating’

AbstractAim: Thermal isoeffective dose (TID) has not been convincingly validated for application to predict biological effects from rapid thermal ablation (e.g., using >55 °C). This study compares the classical method of quantifying TID (derived from hyperthermia data) with a temperature-adjusted method based on the Arrhenius model for predicting cell survival in vitro, after either ‘rapid’ ablative or ‘slow’ hyperthermic exposures.Methods: MTT assay viability data was obtained from two human colon cancer cell lines, (HCT116, HT29), subjected to a range of TIDs (120–720 CEM43) using a thermal cycler for hyperthermic (>2 minutes, 55 °C). TID was initially estimated using a constant RCEM>43°C=0.5, and subsequently using RCEM(T), derived from temperature dependent cell survival (injury rate) Arrhenius analysis.Results: ‘Slow’ and ‘rapid’ exposures resulted in cell survival and significant regrowth (both...