VAB and MRI Following Percutaneous Ultra-Sound Guided Cryoablation for Primary Early-Stage Breast Cancer: A Pilot Study in Japan

Objective: This study aimed to evaluate the feasibility, safety, and cosmetic outcomes of percutaneous cryoablation (PCA) of breast intraductal carcinoma (IDC) lesions, as well as post-cryoablation magnetic resonance imaging (MRI) as a follow-up tool for detection of residual malignancies and local recurrences. Methods: Eight female patients underwent percutaneous ultrasound-guided cryoablation of breast IDC tumors under local anesthesia without subsequent resection. All patients received radiation- and endocrine therapies (RT, ET). The patients were followed using vacuum-assisted biopsy (VAB), mammography (MG), magnetic resonance imaging (MRI), and Moire Topography for cosmetic outcomes. VAB was performed 6 months following cryoablation treatment for cases 1 and 2 (after starting radiation- and endocrine-therapies) or one month after PCA (cases 3, 4, 5, 6 and 7), prior to RT and ET. One patient declined VAB. Results: Mean age of the patients was 61.9 years, SD 7.7, ages range 53 - 72 years. Mean tumor size was 10.3 mm, SD 2.74, ranged 6.8 - 14.5 mm, median follow-up time was 28 months (range 13 - 34 months). No residual or recurrent malignancies were detected. One minor adverse event was observed: A skin redness in the ablated area; MRI at one-month post-cryotherapy showed various degrees of thermal burns in all patients in the pectoralis major muscle, which were not symptomatic and were resolved by 6 months following PCA. Decrease of fat necrosis areas in the vicinity of ablated ex-tumor was traced with MRI (mean size 54.9 mm, mean decrease after 2 years was 58%) and validated with VAB. Conclusions: Percutaneous cryoablation of early-stage low-risk breast cancer tumors smaller than 15 mm potentially presents a potential substitute for lumpectomy, offering encouraging short- to mid-term oncology results with good cosmesis outcomes. Patients would be able to benefit from local anesthesia in an outpatient setting and a shorter recovery period.