Purpose: To assess whether percutaneous radiofrequency (RF) ablation of unresectable pulmonary malignancies is safe and technically feasible and to evaluate the usefulness of computed tomographic (CT) nodule densitometry as a tool for following up tumors after ablation.
Materials and methods: Twelve patients (seven men and five women; mean age, 60.6 years) with unresectable disease (because of poor lung reserve or multifocality) underwent nodule CT densitometry and CT-guided percutaneous RF ablation of 19 lung tumors (six [32%] tumors were adenocarcinoma, one (5%) was large cell carcinoma, two (10%) were bronchoalveolar carcinoma, four (21%) were colorectal carcinoma, and six (32%) were sarcoma less than 50 cm2 in area (range, 0.25-35.00 cm2). No patients had symptoms of their disease before RF ablation. Follow-up CT densitometry was scheduled for 1, 3, 6, and 12 months after RF ablation. Lesions were evaluated for change in area and contrast enhancement at follow-up CT.
Results: RF ablation was well tolerated by all patients. Intraprocedural complications included 12 cases of pneumothoraces (two patients required chest tube placement, while 10 were asymptomatic and required no further treatment), two cases of pleural effusion, and two cases of moderate pain (one case during and one case both during and after the procedure). Mean follow-up was 4(1/2) months (range, 1-12 months). In the eight patients with 3-month follow-up, lesion size increased in two and remained stable in six. Mean contrast enhancement, however, decreased from 46.8 HU (range, 19-107 HU) at baseline to 9.6 HU (range, 0-32 HU) at 1-2-month follow-up. In the one patient with 12-month CT densitometry follow-up, lesion enhancement was less than 50% of that at baseline, and lesion diameter remained stable.
Conclusion: These preliminary results show that percutaneous RF ablation is a safe and technically feasible management option for unresectable pulmonary malignancies. CT densitometry may have potential for future use as a noninvasive method of following up tumors after RF ablation.