IP Fellows Reading List

Therapies for Early Stage or Locally Invasive Lung Cancer

Microwave Ablation

Efficacy and safety of transbronchial microwave ablation therapy under moderate sedation in malignant central airway obstruction patients with respiratory failure: a single-institution retrospective study

https://pubmed.ncbi.nlm.nih.gov/33629194/

Retrospective

Reference: Kashiwabara K, Fujii S, Tsumura S, Sakamoto K, Semba H. Efficacy and safety of transbronchial microwave ablation therapy under moderate sedation in malignant central airway obstruction patients with respiratory failure: a single-institution retrospective study. J Cancer Res Clin Oncol. 2021;147(9):2751-2757.

Background: This is a retrospective, single-center study evaluating the efficacy and safety of transbronchial microwave ablation for malignant central airway obstruction (MCAO).

PICO:

Population –

  • 38 patients with advanced NSCLC or metastatic disease causing a MCAO
  • Patients were grouped into a respiratory failure (RF) group (n = 10) and non-RF group (n = 28). Respiratory failure was defined as a PaO2/FiO2 ≤300

Intervention –

  • Transbronchial microwave ablation under moderate sedation. Authors chose to perform procedures under moderate sedation since MCAO can require emergent intervention and general anesthesia is not immediately available at many centers

Comparison –

  • None

Outcome –

  • Airway patency was successfully restored (i.e., >50% patent) in 95% of patients after their first TMA session
  • 79% of patients had symptomatic improvement and/or improvement in their performance score
  • 55% required more than one TMA treatment with patients needing a median of 2 sessions
  • 11% developed complications, including one major bleed, one moderate bleed, and two re-obstructions within 24 hours due to bronchial epithelial detachment (due to unintentional coagulation of normal mucosa)
  • Median follow-up was six months (range 0.6-88 months). Overall survival (OS) in the RF group was 7.1 months and 9.1 months in the non-RF group. The difference in OS was not statistically significant. However, when evaluating those who received post-TMA chemotherapy and/or radiotherapy, OS was significantly lower in the RF group compared to the non-RF group (7.1 vs 32.8 months)

Take home: TMA under moderate sedation is feasible and effective, even in the presence of respiratory failure. If normal mucosa is coagulated, close monitoring should be provided for at least 24 hours to ensure there is no recurrence of airway obstruction due to epithelial detachment.

Transbronchial microwave ablation of lung nodules with electromagnetic navigation bronchoscopy guidance-a novel technique and initial experience with 30 cases

https://pubmed.ncbi.nlm.nih.gov/34012778/

Clinical Trial

Reference: Chan JWY, Lau RWH, Ngai JCL, et al. Transbronchial microwave ablation of lung nodules with electromagnetic navigation bronchoscopy guidance-a novel technique and initial experience with 30 cases. Transl Lung Cancer Res. 2021;10(4):1608-1622.

Background: This study evaluates the safety and feasibility of a bronchoscopic approach to performing microwave ablation (MWA) of a pulmonary nodule.

PICO:

Population –

  • 25 patients with confirmed stage IA lung cancer or a highly suspicious pulmonary nodule that were inoperable or if the patient refused surgery

Intervention –

  • MWA of pulmonary nodules under the guidance of electromagnetic navigational bronchoscopy (n = 30 nodules)

Comparison –

  • None

Outcome –

  • 100% of procedures were technically successful, however 13.3% required double ablation to achieve ≥5 mm margins
  • No nodules had evidence of progression after a median follow-up of 12 months
  • Complications included pain (13.3%), pneumothorax requiring intervention (6.7%), post-ablation reaction (6.7%), pleural effusion (3.3%), and hemoptysis (3.3%)
  • Mean hospital length of stay was 1.73 days

Take home: Transbronchial MWA using navigational bronchoscopy is feasible for the treatment of pulmonary nodules and relatively safe compared to percutaneous MWA. Although authors report no evidence of progression on available follow-up imaging, only 50% of cases had been followed for 6 months or longer at the time of writing the paper. Further studies are needed to evaluate long-term transbronchial MWA efficacy.

Microwave ablation via a flexible catheter for the treatment of nonsurgical peripheral lung cancer: A pilot study

https://pubmed.ncbi.nlm.nih.gov/35166043/

Clinical Trial

Reference: Xie F, Chen J, Jiang Y, Sun J, Hogarth DK, Herth FJF. Microwave ablation via a flexible catheter for the treatment of nonsurgical peripheral lung cancer: A pilot study. Thorac Cancer. 2022;13(7):1014-1020.

Background: This is a prospective study evaluating the feasibility and safety of a navigational bronchoscopy-guided water-cooled microwave ablation catheter in the management of peripheral lung cancer.

PICO:

Population –

  • 13 patients with early-stage or multiple primary peripheral lung cancer(s) that were inoperable or refused surgery

Intervention –

  • Bronchoscopic microwave ablation using a flexible water-cooled microwave ablation antenna under the guidance of electromagnetic navigational bronchoscopy

Comparison –

  • None

Outcome –

  • 14 tumors, 8-40 mm in size (mean 20.4 mm) were treated in 19 sessions
  • Technical success was achieved in all cases. The complete ablation rate was 78.6% and 2-year local control rate was 71.4%. Median progression-free survival was 33 months
  • Two treatment-related complications occurred: a pneumothorax 4 hours post-ablation and a hydropneumothorax 15 days post-ablation, both requiring chest tube insertion

Take home: Transbronchial MWA of early lung cancer is feasible. Although the sample size in this study is small, rates of local control were similar to those reported for percutaneous MWA, while complication rates were lower. Further studies are needed before wider adoption into clinical practice.