Breast ImagingE2316. Image-Guided Cryoablation of Breast Tumors
Klevos G1,2, Net J1,2, Yepes M1,2, Feliciano Y1,2, Collado Mesa F.1,2 1. University of Miami, Miami, FL; 2. Jackson Memorial Hospital, Miami, FL
Address correspondence to G. Klevos (email@example.com)
Background Information: The diagnosis of breast cancer has evolved from detection of palpable disease to routine identification of asymptomatic disease during screening mammography. Breast cancer treatment has in turn evolved from radical resection of disease that was clinically evident to less morbid, less aggressive, and more targeted surgical, radiation, and axillary therapy. Cryoablation is emerging as a minimally invasive approach in the treatment of breast cancer by minimizing the cosmetic and functional deformity of the breast resulting from scar formation, volume changes, nipple displacement, sensation changes, and skin or scar retraction due to surgery. An outpatient, office-based treatment for early stage breast cancer could yield significant benefits in terms of patient convenience, quality of life, and time away from work or other responsibilities.
Educational Goals/Teaching Points: Cryoablation is performed by placing a cryoprobe at the center of a tumor. A cryoprobe is a high-pressure, closed-loop gas expansion system in which the metal probe is insulated, except for the tip. The cryoprobe is rapidly cooled by liquid nitrogen or Argon. Target freezing temperatures of –190 to –160°C are achieved. An ideal cryoablation candidate is one with a lesion size up to 4 cm for benign tumors and up to 1.5 cm for malignant tumors, at least 3–5 mm of space between the lesion and surface of breast, patients who are not good candidates for surgery or general anesthesia, and patients concerned about cosmesis.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques: The procedure is performed in an office outpatient setting. Local anesthesia is given and ultrasound imaging is used to locate the tumor. The cryoprobe is placed percutaneously through a small (3 mm) incision. A controlled ice ball is formed. The freeze-thaw-freeze cycle fully ablates the tumor in situ. The probe is removed and a small sterile bandage is applied. The tissue is naturally resorbed over time. There are several advantages with this procedure. First, there is 100% complete tumor ablation within the ablation zone, and no adverse effect on mammogram or ultrasound interpretation. Cryoablation has been known to induce a tumor specific immune response stimulated by damaged cells, which may contribute to controlling distant systemic metastases. The procedure is done under ultrasound or MRI guidance, which is an easy addition to office equipment. In addition, cryoablation is a minimally invasive procedure that conserves breast shape, can be done in an outpatient or office setting in under 30 minutes using local anesthesia and a single 3-mm incision, and recovery time is 1 day.
Conclusion: Cryoablation is a minimally invasive treatment modality for benign and malignant breast tumors with a distinct advantage of potentially obviating the need for surgery in a select subset of patients and thereby resulting in improved cosmetic outcomes. It can be performed on an outpatient basis, under local anesthesia, with little to no recovery time. It is more cost- effective compared to surgery. The best clinical results for malignant tumors are achieved when small (up to 1.5 cm) luminal A tumors are treated with an in situ component of less than 25%.