Most Proposed Topic :
HA Young Investigators Session (projects to be presented by and HA staff who had joined HA for less than 15 years)
Proposed Topic (Second preferred): :
Enhancing Partnership with Patients and Community (Projects initiated to engage patient and improve patient communication)
Authors: (including presenting author): :
Joyce W.Y. Chan(1), Aliss T.C. Chang(1), Ivan C.H. Siu(1), Rainbow W.H. Lau(1), CM Chu(2), Tony S.K. Mok(3), Calvin S.H. Ng(1)
Affiliation: :
(1)Division of Cardiothoracic Surgery, Department of Surgery, Prince of Wales Hospital, the Chinese University of Hong Kong (2)Department of Imaging and Interventional Radiology, Prince of Wales Hospital, the Chinese University of Hong Kong, (3)Department of Clinical Oncology, Prince of Wales Hospital, the Chinese University of Hong Kong
Introduction: :
With strong evidence for low-dose computer tomography (CT) scans screening in high risk populations, incidental discovery of lung nodule is becoming more common. Many of them are small, sub-solid, and harbour pre-malignant or early stage tumours. Local therapies as definitive treatment of these lesions is among the standard managements, especially in patients with surgical contraindications. Treatment modalities such as stereotactic body radiation therapy (SBRT), percutaneous ablation techniques for instance radiofrequency (RFA), microwave (MWA) and cryotherapy are highly effective and are associated with reasonable local control rates ranging from 64% to 69.8% at 2 years. However, these procedures are also associated with complications: SBRT carries up to 22.3% risk of radiation pneumonitis and pneumonia6, while percutaneous ablation techniques carry 11-52% risk of pneumothorax and bronchopleural fistula (BPF). In terms of energy source, radiofrequency relies heavily on electrical conductance of tissues, thus the high impedance of human lung tissue may limit its effectiveness.
Bronchoscopic ablation techniques utilizing radiofrequency energy for eradication of tumor cell have been described, with theoretical advantages of less pneumothorax/BPF due to non-trans-pleural route of entry, being able to reach peri-bronchial tissues easily, and having access to particular locations in lung which are otherwise difficult or impossible to reach. Meanwhile, microwave energy produces a larger and more predictable ablation zone, as it is minimally affected by impedance and has less heat-sink effects. Building upon our institute’s experience in lung nodule dye-marking and biopsy via electromagnetic navigation bronchoscopy (ENB), we identified a selected group of cases which are suitable for bronchoscopic microwave ablation under ENB guidance. Being one of the first centres to perform ENB microwave ablation in clinical setting, we retrospectively analyze data from the first cohort of patients who had completed the procedure.
Objectives: :
Transbronchial microwave lung ablation is a novel local therapy for early lung cancers and lung oligometastases in selected patients, who typically has high surgical risks or suffers from multifocal cancers. This is a single institute retrospective review of the 4-year result of transbronchial microwave ablation using electromagnetic navigation bronchoscopy guidance in the hybrid operating room.
Methodology: :
Between March 2019 and September 2023, 194 nodules in 128 patients were treated. Eligible lung nodules were either proven lung cancers, metastases, or radiologically suspicious. Safety and mid-term control rate of the technique were assessed.
Result & Outcome: :
Mean maximal diameter of lung nodules was 12mm (range 6-29mm), and bronchus sign was positive in 28.4% of them. Technical success rate was 100%, although 85 (43.8%) nodules required double ablation and 22 (11.3%) required triple or more ablation for adequate coverage. Mean minimal ablation margin was 6.2mm. Mean hospital stay was 1.55 days, 150 cases (77.3%) and 186 cases (95.9%) were discharged by post-ablation day 1 and 3 respectively. Complications included mild pain which did not require hospitalization (8.7%), pneumothorax requiring drainage (4.1%), post-ablation reaction (3.1%), pleural effusion (2.1%) and hemoptysis (2.1%). Mean follow up for all cases is 24.6 months. For the 131 nodules which had completed at least 1-year follow up computer tomography scan, 7 had complete response, 82 had partial response, 30 had stable disease, and 12 (9.2%) had local recurrence.
Transbronchial microwave ablation is a safe and novel ablative technique, and has encouraging mid-term local control rate.
