Radiofrequency Ablation of Primary Lung Cancer: Results From an Ablate and Resect Pilot Study

Abstract

Study objectives: The role of radiofrequency ablation (RFA) for primary lung cancer remains poorly defined. The purpose of this “ablate and resect” pilot study was to evaluate the safety of performing RFA in patients with primary non-small cell lung cancer (NSCLC) and to characterize the histologic changes in tumor tissue following such ablation. Design: This prospective study was undertaken at a single institution, and 10 patients were accrued from June 2002 to June 2003. Eligible patients included those with clinical stage I or II disease. RFA of the tumor was performed through a standard thoracotomy followed by conventional lobectomy and lymph node dissection. Extent of cell death was determined histologically. Measurements and results. Following the exclusion of two patients, the treated portions of eight tumors were examined for tumor cell viability. Gross inspection and routine histologic staining could not reliably identify the “immediately ablated” tissue. However, using a supravital staining technique, the treated areas from seven of the eight tumors (87.5%) demonstrated > 80% nonviability (100% nonviability was noted in the treated areas from three of the eight tumors). No bleeding or thermal complications were noted at the time of RFA, and none of the patients had skin burns at the electrode dispersive pad sites. Conclusions: RFA of primary NSCLC is feasible and can be performed safely in the setting of an open thoracotomy. Complete tumor cell necrosis, as determined by supravital staining, was noted in the treated areas from three of eight tumors (37.5%). Such complete ablation was observed in the treated areas from smaller tumors (< 2 cm), whereas the treated areas from larger tumors demonstrated incomplete ablation. Additional investigation with histopathologic correlation is needed to fully assess the long-term efficacy of RFA for NSCLC. Study objectives: The role of radiofrequency ablation (RFA) for primary lung cancer remains poorly defined. The purpose of this “ablate and resect” pilot study was to evaluate the safety of performing RFA in patients with primary non-small cell lung cancer (NSCLC) and to characterize the histologic changes in tumor tissue following such ablation. Design: This prospective study was undertaken at a single institution, and 10 patients were accrued from June 2002 to June 2003. Eligible patients included those with clinical stage I or II disease. RFA of the tumor was performed through a standard thoracotomy followed by conventional lobectomy and lymph node dissection. Extent of cell death was determined histologically. Measurements and results. Following the exclusion of two patients, the treated portions of eight tumors were examined for tumor cell viability. Gross inspection and routine histologic staining could not reliably identify the “immediately ablated” tissue. However, using a supravital staining technique, the treated areas from seven of the eight tumors (87.5%) demonstrated > 80% nonviability (100% nonviability was noted in the treated areas from three of the eight tumors). No bleeding or thermal complications were noted at the time of RFA, and none of the patients had skin burns at the electrode dispersive pad sites. Conclusions: RFA of primary NSCLC is feasible and can be performed safely in the setting of an open thoracotomy. Complete tumor cell necrosis, as determined by supravital staining, was noted in the treated areas from three of eight tumors (37.5%). Such complete ablation was observed in the treated areas from smaller tumors (< 2 cm), whereas the treated areas from larger tumors demonstrated incomplete ablation. Additional investigation with histopathologic correlation is needed to fully assess the long-term efficacy of RFA for NSCLC.