Dosimetric analysis of ultrasound-guided high intensity focused ultrasound ablation for breast fibroadenomas: a retrospective study

Objective: To investigate the factors influencing the sonication dosage and efficiency of ultrasound-guided high intensity focused ultrasound (USgHIFU)for breast fibroadenomas. Materials and Methods: Forty-nine patients with 78 breast fibroadenomas who underwent USgHIFU were retrospectively analyzed. The energy efficiency factor (EEF) was set as dependent variable, and the factors possibly influencing the sonication dosage, including age, body mass index (BMI), fibro-adenoma size, distance from the shallow margin of the fibroadenoma to skin, distance from the deep margin of the fibroadenoma to pectoralis major, types of near field acoustic pathway, and Adler blood flow classification of ultrasound, were set as independent variables. The correlation between EEF and these independent variables were analyzed, and an optimal scaling regression model was established. Results: Fibroadenoma size, distance from the shallow margin of the fibroadenoma to skin and type of near field acoustic pathway had significant correlation with EEF (p<0.05). An EEF (<(y)over cap>) dosimetry model of (y) over cap=-0.496X(1) + 0.287X(2) + 0.203X(3) was established, in which X-1 stands for size of fibroadenoma, X-2 stands for the distance from shallow margin of the fibroadenoma to skin, and X-3 stands for type of near field acoustic pathway. The predicted EEF value was significantly related to actual EEF (R = 0.698, p = 0.000). Conclusions: Fibroadenoma size, distance from the shallow margin of the fibroadenoma to skin and type of near field acoustic pathway could be used as predictors to evaluate the dosage delivery of USgHIFU treatment for breast fibroadenomas.

Automated summary

This study investigates the factors influencing the sonication dosage and efficiency of ultrasound-guided high intensity focused ultrasound (USgHIFU) for breast fibroadenomas. The results show that fibroadenoma size, distance from the shallow margin of the fibroadenoma to skin, and type of near field acoustic pathway have significant correlation with the energy efficiency factor (EEF). A dosimetry model is established, which can be used to predict the dosage delivery of USgHIFU treatment for breast fibroadenomas.