Investigation of single beam ultrasound sensitivity as a monitoring tool for local hyperthermia treatment in breast cancer

Local Hyperthermia treatment (LHT) holds great promise as an adjuvant method in combating breast cancer. In LHT treatment, cancerous tissue is exposed to supraphysiological temperature in order to destroy the tissue directly or improve their susceptibility to other treatment regimes. To observe the progression of tissue necrosis during LHT treatment, a temperature elevation monitoring system is important. Single beam ultrasound (SBUS) is a convenient, non-invasive, and radiation free method that is relatively simple compared to other imaging modalities. Therefore, this study investigates the sensitivity of SBUS towards microstructural tissue changes during LHT treatment. Ex-vivo experiments are conducted on both normal and pathological breast tissues harvested from carcinogenic induced animal models. These tissue samples are exposed to high temperatures ranging from 37 o C to 55 o C. Different sets of samples were used for each temperature range. For each temperature group, 11 samples were used and tested. Protein concentrations in all the samples are then quantitatively measured for in-depth correlation and sensitivity analysis. Microscopic histological analysis and comparison with B-Mode ultrasound are also carried out for verification purposes. Result shows that there is a significant correlation between attenuation level and total protein concentration in pathological tissues with an observed value of 0.617 and p- value of 0.0001. Histological analysis indicates that cellular-level damage seen in pathological tissue samples is much more significant compared to normal tissues. Comparison with B-Mode ultrasound shows consistent mean grey scale and attenuation trends during LHT treatment, which supported the findings obtained using the SBUS method.