Gonzalez Kd

Focused microwave phased array thermotherapy for ablation of early-stage breast cancer: results of thermal dose escalation

Background: Tumor ablation as a means of treating breast cancer is being investigated. Microwave energy is promising because it can preferentially heat high-water-content breast carcinomas, compared to adipose and glandular tissues.Methods: This is a prospective, multicenter, nonrandomized dose-escalation study of microwave treatment. Thermal dose was measured as (1) thermal equivalent minutes (cumulative equivalent minutes; CEM) of treatment relative to a temperature of 43°C and (2) peak tumor temperature. Microwaves were guided by an antenna-temperature sensor placed percutaneously into the tumor. Outcomes measured were pathologic response (tumor necrosis) side effects.Results: Twenty-five patients (mean age, 57 years) were enrolled. The mean tumor diameter was 1.8 cm. Tumoricidal temperatures (>43°C) were reached in 23 patients (92%). Tumor size was unchanged after thermotherapy (P = not significant). Pathologic necrosis was achieved in 17 (68%) patients. Complete necrosis of the invasive component was achieved in two patients. One hundred forty CEM is predictive of a 50% tumor response, and 210 CEM is predictive of a 100% tumor response (P = .003). Univariate linear regression predicts that peak tumor temperatures of 47.4°C and 49.7°C cause a 50% tumor response and a 100% tumor response, respectively.Conclusions: Thermotherapy causes tumor necrosis and can be performed safely with minimal morbidity. The degree of tumor necrosis is a function of the thermal dose. Future studies will evaluate the impact of high doses of thermotherapy on margin status and complete tumor ablation.

Success of sentinel lymph node mapping after breast cancer ablation with focused microwave phased array thermotherapy

BACKGROUND Breast cancer tumor ablation as part of a multimodality approach in the treatment of breast cancer is the subject of recent interest. This study was conducted to determine if the ability to perform sentinel node biopsy was impaired after thermal-induced ablation of breast cancer. METHODS We studied patients who had sentinel node biopsy after preoperative focused microwave phased array for breast cancer ablation. RESULTS Twenty-one patients with T1-T2 breast cancer and clinically negative axilla underwent wide local excision and sentinel node biopsy guided by blue dye and sulfur colloid. Surgery was done an average of 17 days after microwave ablation. Fifteen of 22 patients (68%) had histologic evidence of tumor necrosis. Sentinel lymph node mapping was successful in 19 of 21 patients (91%). Axillary metastases were detected in 42% of cases. CONCLUSIONS This study documents successful sentinel lymph node mapping for patients treated with antecedent local tumor ablation using focused microwave phased array ablation.

Percutaneous excisional biopsy of palpable breast masses under ultrasound visualization.

Abstract:  A palpable breast mass is a common reason for surgical consultation. Our goal was to determine whether ultrasound‐guided vacuum‐assisted core biopsy (US‐VACB) is safe and effective in completely removing presumed benign palpable breast masses. We conducted a cohort study of 201 consecutive patients with presumed benign palpable masses who underwent removal with US‐VACB. The main outcome measured was the successful removal of palpable masses. Palpable masses were successfully removed with US‐VACB in 99% of cases; 2% were cancer and 7.5% were atypical ductal hyperplasia or phyllodes tumor. Two clinical recurrences representing a seroma were seen on follow‐up. US‐VACB is safe and effective in the initial diagnosis and management of presumed benign palpable breast masses. It provides the benefits of percutaneous biopsy and the palpable abnormality no longer remains.