Thermoacoustic contrast of prostate cancer due to heating by very high frequency irradiation

Prostate cancer may be a good application for thermoacoustic imaging induced by very high frequency (VHF) radiation for several reasons. Mechanical properties of healthy and cancerous prostate tissue are well matched, so the assumption of constant sound speed is accurate. Signal production by VHF irradiation is proportional to ionic content, and ionic content of prostatic fluids produced by healthy tissue in the peripheral zone are approximately three times higher than in blood and plasma whereas cancer suppress ionic content of prostatic fluid. Signal strength is expected to decrease with extent of cancerous involvement. To test the utility of VHF-induced thermoacoustics to prostate cancer imaging we imaged fresh human prostate specimens ex vivo and compared to the gold standard, histology. Specimens were scanned immediately after radical prostatectomy performed as part of normal care.