Electromagnetic bronchoscopy guided microwave ablation for early stage lung cancer presenting as ground glass nodule

Abstract

Background: Patients with early-stage lung cancer are sometimes medically inoperable, and for patients with multiple primary lung cancers, surgical resection alone sometimes proves to be impractical. Local treatments like microwave ablation (MWA) are investigational alternatives for these patients. Most reported MWA procedures for lung cancers are performed percutaneously under CT guidance. MWA navigated by electromagnetic bronchoscopy (ENB) has been limitedly studied. In this study, we aimed to evaluate the safety and feasibility of MWA under ENB guidance in patients with inoperable early-stage lung cancers or multiple primary lung cancers which cannot be completely resected.

Methods: From June 2019 to December 2020, preliminary attempts of ENB-guided MWA were made in five medically inoperable patients with a single early-stage lung cancer and ten patients with multiple primary lung cancers which were difficult to resect at the same time. For patients with concomitant pulmonary nodules which needed surgical resection, thoracoscopic resections were performed following ENB-guided MWA. The safety, feasibility, and technique effectiveness of treatments were evaluated.

Results: ENB-guided MWA for 15 ground glass nodules (GGNs) in 15 patients was completed in accordance with the planned protocol. Biopsy of 13 GGNs showed malignancy. Five patients received simple ENB-guided MWA without simultaneous surgical resection and ten patients received simultaneous surgical resection for 13 concomitant pulmonary nodules. CT scan by the first postoperative week showed technique effectiveness of ablation for 11 nodules indicated for MWA. Four patients had mild complications after the procedure and recovered shortly after treatment.

Conclusions: For medically inoperable patients with a single GGN manifesting early-stage lung cancer and patients with multiple primary early-stage lung cancers which cannot be resected at the same time, ENB-guided MWA might be a safe and feasible alternative local treatment, whether combined with surgical resection or not. However, large, prospective, randomized, multicenter studies are needed to confirm its role in the treatment of early-stage lung cancer.

Keywords: Lung cancer; electromagnetic bronchoscopy (ENB); ground glass nodule (GGN); microwave ablation (MWA); video-assisted thoracoscopic surgery (VATS).

Figure 1

A 75-year-old male smoker with two nodules. (A) A 1.8- cm mGGN in left upper lobe (marked with red circle), was resected by left upper trisegmentectomy; (B) a 1.7- cm mGGN located in the central right upper lobe (marked with red circle), which required lobectomy for resection, was treated by ENB-guided MWA. mGGN, mixed ground glass nodule; ENB, electromagnetic bronchoscopy; MWA, microwave ablation.

Figure 2

A 65-year-old male smoker with two nodules. (A) A 1.2- cm solitary pulmonary nodule in right lower lobe (marked with red circle) was resected by right superior segmentectomy via VATS; (B) a 0.9- cm mGGN located in the central right upper lobe (marked with red circle), which required lobectomy for resection, was treated by ENB-guided MWA. VATS, video-assisted thoracoscopic surgery; mGGN, mixed ground glass nodule; ENB, electromagnetic bronchoscopy; MWA, microwave ablation.

Figure 3

A 72-year-old female with two nodules (A) A 2.1- cm solitary pulmonary nodule in right middle lobe (marked with red circle) was resected by right middle lobectomy via VATS; (B) a 1.7- cm mGGN (marked with red circle) located in the central right lower lobe, which required lobectomy for resection, was treated by ENB-guided MWA. VATS, video-assisted thoracoscopic surgery; mGGN, mixed ground glass nodule; ENB, electromagnetic bronchoscopy; MWA, microwave ablation.

Figure 4

Representative images of CT scans. (A) A 50-year-old female patient with a 1.1- cm mGGN on right lower lobe prior to MWA; (B) tumor lesion seen on CT on the first postoperative day: the ablation zone encompassed the lesion with a margin; (C) CT scan at 24 weeks after ENB-guided MWA: the ablation zone was replaced by parenchymal changes different from the original nodule. However, further follow-up CT scans are needed to confirm the effectiveness of ablation. CT, computed tomography; mGGN, mixed ground glass nodule; MWA, microwave ablation; ENB, electromagnetic bronchoscopy.

Figure 5

A 73-year-old female patient with previous history of right upper lobectomy and right mastectomy received combine treatment for two nodules in the same lobe. (A) The peripherally located nodule (marked with red circle) was resected by VATS wedge resection; (B) the mGGN (marked with red circle), which seemed not suitable for wedge resection or simple segmentectomy, was treated by MWA; (C) tumor lesion seen on CT on the first postoperative day: the ablation zone (marked with red circle) encompassed the MWA lesion with a margin; (D) CT scan at 24 weeks after ENB-guided MWA: the primary location of the lesion (marked with red circle) was replaced by parenchyma bands. mGGN, mixed ground glass nodule; MWA, microwave ablation; CT, computed tomography; ENB, electromagnetic bronchoscopy.