CT-guided percutaneous cryotherapy of renal masses.

PURPOSE: To assess the results of initial and current techniques for percutaneous renal cryotherapy, including long-term imaging outcomes. MATERIALS AND METHODS: Computed tomography (CT)-guided percutaneous cryotherapy was performed on 49 masses in 48 outpatients and procedure comfort noted for each. These 49 masses included 36 primary renal cell carcinomas (RCCs), 3 oncocytomas, 1 angiomyolipoma, 6 renal inflammatory lesions, 2 benign parenchymal changes, and 1 colon cancer metastasis. All complications were graded according to standardized criteria. RESULTS: Patients received only local anesthesia and moderate sedation during the procedure and were discharged with minimal discomfort within 4-6 hours. All cryotherapy zones were well defined by CT during ablation as hypodense ice with an average diameter of 5.3 cm, covering an average tumor size of 3.3 cm. Average ablation zone diameters showed significant reduction over time (P < .001), becoming significantly less than the original tumor size by 12 months (P < .05). Major and minor complications were seen in 3 (6%) and 11 (22%) procedures, respectively. At a mean follow-up of 1.6 years (range, 1 week to 3.8 years) for primary RCC patients, four failures (11.1%) by imaging criteria were noted, but one proved to be inflammatory tissue at re-biopsy (estimated neoplastic failure rate = 3/36 = 8.3%). CONCLUSIONS: Percutaneous renal cryotherapy is a well-tolerated outpatient procedure that allows safe, CT monitoring of ice formation beyond visible tumor margins. With appropriate cryoprobe placements, a low failure rate appears less dependent on tumor size or location. Ablation volume involution was >80% after 6 months.

Cryotherapy for breast fibroadenomas.

PURPOSE: To assess freezing protocols, imaging, and clinical outcomes of percutaneous ultrasonographically (US)-guided cryotherapy for breast fibroadenomas. MATERIALS AND METHODS: Institutional review board approval and patient consent were obtained. Forty-two biopsy-confirmed fibroadenomas were treated in 29 patients (mean age, 27 years) by using a 2.4-mm cryoprobe inserted into the fibroadenoma with US guidance. The first seven patients underwent conscious sedation, but the other 22 patients required only local anesthesia. US and thermocouple monitoring of the procedure were performed to evaluate freeze protocols based on tumor size. Saline injections protected the skin and/or chest wall. US follow-up was performed at 1 week and at 1, 3, 6, and 12 months. Pre- and 12-month postcryotherapy mammograms were available for seven patients who were over 30 years old. chi(2) and Student t tests were used to assess frequency and mean differences, respectively. RESULTS: The 22 patients who underwent local anesthesia reported minimal discomfort. No significant complications were noted, and patients were very pleased with the resolution of palpable mass effect and cosmetic results. The average pretreatment fibroadenoma volume of 4.2 cm(3)+/- 4.7 (standard deviation) was reduced to 0.7 cm(3)+/- 0.8 at 12-month follow-up (73% reduction, P < .001). US produced excellent ice visualization beyond tumor margins, while thermocouples confirmed cytotoxic temperatures approximately 5 mm behind the visible leading edge. Two patients elected to undergo either removal or biopsy of a residual mass, which revealed a shrunken hyaline matrix with preserved collagenous architecture. Mammograms showed comparable resolution of mass effects with mild surrounding parenchymal reaction. CONCLUSION: Cryotherapy of fibroadenomas is a safe, effective, and virtually painless clinic-based (ie, outpatient) treatment option with good cosmesis.