| Description |
Breast cancer is the most diagnosed cancer worldwide. Early-stage localized cancers are currently treated with surgical lumpectomy and radiation. Focused ultrasound is a disruptive technology that can replace conventional surgical and radiation therapies to provide noninvasive cancer treatment. This study aims to quantitatively investigate the clinical value of implementing hybrid angular spectrum-based phase aberration correction in focused ultrasound breast cancer therapies. Heterogeneous, breast-tissue-mimicking phantoms were designed to recreate aberrations induced by breasts with various mammographic density classifications. Computational models of all phantoms were created to perform sample-specific phase aberration correction. Gold standard hydrophone tests were performed to assess phase aberration corrected and uncorrected acoustic fields after transmission through breast tissue-mimicking phantoms. These measurements were compared across all phantoms and to reference measurements taken in a water-only environment to assess focus-restoring ability. Thermoacoustic simulations using computer models generated from clinical data of human breasts were conducted to assess the impact of phase aberration correction on treatment efficacy in terms of targeting accuracy, precision, and completeness of ablation. Hydrophone data show that relative to the uncorrected acoustic fields, phase aberration corrected fields show a decrease in focusing error up to 42% and a quantitative restoration of focus shape, size, and intensity. Thermoacoustic simulation data show similar improvements, as well as increased completeness of ablation with decreased power output and a decrease in targeting error up to 50%. Hybrid angular spectrum-based phase aberration correction improves focus quality and energy deposition in focused ultrasound breast treatments. While phase aberration correction requires a patient-specific model, this method can improve indicators of treatment quality, providing the greatest improvement of targeting accuracy in patients with predominantly fatty or extremely dense breasts. Reduced power requirements may decrease patient pain, further facilitating clinical translation of this technology as a noninvasive treatment alternative for breast cancer. |
