Determination of Soft Tissue Breakpoint Based on Its Temperature Enhancement Pattern: In Vivo and In Vitro Experiments

The breakpoint of fresh commercial meats and in vivo mice has been assessed using tissue temperature enhancement pattern. A 1 cm length and 0.1 cm diameter gold rod was implanted in fresh chicken breast, beef, fish, and in vivo Mus musculus white mice and was insonated with ultrasound. The temperature enhancement of gold rods was measured with a needle type thermistor over a temperature range from 35 to 50 °C. From these results the breakpoints were determined by plotting the gold rod temperature versus ultrasound exposure duration using the interception point of two curves fitted by a linear regression equations of thermal response above and below 43 °C. The linear correlation coefficients for all fitted curves lie within 0.985 and 0.997. The breakpoints were found to be 42.1 ± 1.1, 42.3 ± 0.9, 42.6 ± 0.8 and 43.5 ± 0.6 for fish, chicken breast, beef and in vivo Mus musculus white mice, respectively. The interception of the thermal response curves above and below 43 °C. Soft tissue temperature enhancement pattern has demonstrated to be a fast method to determine breakpoint. It denotes the temperature where cells may start to be destroyed and may be used to spot the startup point in dosimetry of hyperthermia cancer therapy.