{'fraction_non_alphanumeric': 0.04563894523326572, 'fraction_numerical': 0.030933062880324543, 'mean_word_length': 4.872023809523809, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Percutaneous cryoablation of 40 solid renal tumors with US guidance and CT monitoring: initial experience.

PURPOSE
To retrospectively determine the safety and effectiveness of percutaneous cryoablation, monitored with computed tomography (CT), for the treatment of solid renal masses.


MATERIALS AND METHODS
This study was compliant with the Health Insurance Portability and Accountability Act and had institutional review board approval; informed consent was waived. From March 12, 2003, through August 4, 2005, 23 men and 17 women (mean age, 76 years +/- 9.7 [standard deviation]; range, 53-92 years), each with a single renal tumor, underwent one percutaneous cryoablation treatment session that combined ultrasonographic (US) guidance and CT monitoring. Technical success was defined as extension of the visible ice ball 5 mm beyond the tumor margin. Local tumor progression was defined as any tumor with intralesional enhancement or a serial increase in tumor size when compared with that on images obtained immediately after ablation. Tumor characteristics, complications, and follow-up were evaluated.


RESULTS
The maximum diameter of the 40 treated lesions ranged from 1.5 to 7.2 cm (mean, 3.4 cm +/- 1.3). Twenty (50%) of 40 tumors were 3 cm or larger in diameter. Nineteen tumors (48%) extended into the renal sinus fat. One complication (2%) conformed to a grade 3 event, as determined with the Common Terminology Criteria for Adverse Events (version 3.0) of the National Cancer Institute; the overall complication rate was 8%. Thirty-eight (95%) of 40 cryoablation procedures were technically successful. Twenty-nine patients underwent follow-up (mean, 8.0 months +/- 4.3; range, 1.2-18.4 months); no local tumor recurrence was found.


CONCLUSION
Percutaneous cryoablation with US guidance and CT monitoring is safe and effective for the treatment of solid renal tumors. Longer follow-up should provide further proof of the effectiveness of this technique.