Abstract P1-02-07: Contrast-enhanced ultrasound for evaluation of therapeutic efficacy of radiofrequency ablation for primary breast cancer

Abstract

Abstract <Purpose> To evaluate therapeutic efficacy of percutaneous ultrasound (US) guided radiofrequency (RF) ablation therapy for primary breast cancer using contrast-enhanced US. <Methods and Materials> The study was approved by the institutional ethics committee, and written informed consent was obtained. Between January 2012 and April 2014, 25 patients with biopsy-confirmed T1 breast cancer underwent RF ablation therapy in one institution. We examined 25 patients with 25 T1 breast cancers by contrast-enhanced MRI/CT, and contrast-enhanced US before and after RF ablation therapy. US guided RF abltion was performed using a 17-gauge internally cooled electrode (Cool-TipTM, Valleylab, Boulder, CO, USA) under general anesthesia. After injection 0.015mL/kg body weight of Sonazoid®(perflubutane), contrast-enhanced US was performed at a low mechanical index (0.17-0.24). Therapeutic success was defined as a lack of contrast enhancement by contrast-enhanced MRI, US and non-viable cancer tissues by US guided vacuum assisted biopsy (VAB) or core needle biopsy (CNB). <Results> Contrast-enhanced US and MRI four weeks or more after RF ablation therapy showed ablation zones and adequate tumor necrosis in all 25 cancer lesions treated. Contrast-enhanced US made it possible to see that tumor vessels of treated lesions had disappeared after treatment. Contrast enhanced MRI showed a lack of stain with ring-like enhancement of ablation zone and non-viable tissues were seen by VAB and/or CNB in 25 ablation zones. <Conclusion> Contrast-enhanced US using Sonazoid® was useful modalities for evaluating the efficacy of RF ablation therapy in breast cancer lesions. Citation Format: Toshikazu Ito, Jyunji Okayama, Kumiko Uji, Masaaki Izukura. Contrast-enhanced ultrasound for evaluation of therapeutic efficacy of radiofrequency ablation for primary breast cancer [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P1-02-07.