Radiologic appearance and complications of percutaneous computed tomography-guided radiofrequency-ablated pulmonary metastases from colorectal carcinoma.
OBJECTIVE
To describe the morphologic appearance over time of percutaneously radiofrequency-ablated pulmonary metastases from colorectal cancer and to focus on the occurrence of the most common complications.


METHODS
Twenty patients have been treated with computed tomography (CT)-guided radiofrequency ablation (RFA) for 41 pulmonary metastases using the expandable 14-gauge StarBurst XL RF electrode along with the 1500 generator (RITA Medical Systems, Mountain View, CA). The average number of lesions per patient was 2.05, ranging from 1 to 4 lesions.


RESULTS
The typical feature of the radiofrequency-ablated site immediately after the procedure was a light bulb-shaped opacification surrounding the probe. This became a more spherically shaped feature over time and steadily decreased in size. At 3 months after RFA, the lesion was approximately the same size as at baseline. The lesion subsequently shrank within the following 3 months, usually with a small scar remaining. Pneumothorax occurred in 50% of the patients, and a chest tube was required in 50% of the patients affected. Cavitation occurred in 24% of the lesions. Intraparenchymal hemorrhage was observed in 7.5% of the cases.


CONCLUSIONS
Image-guided pulmonary RFA is a safe minimally invasive therapy modality with acceptable morbidity. Ablated lesion size usually exceeds the dimensions of the initial tumor for the first 3 months after ablation and continuously shrinks thereafter.
D017115:Catheter Ablation; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011030:Pneumothorax / Q000000981:diagnostic imaging / Q000209:etiology; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed