Vapor Ablation for Lung Lesions: An Interview With Arschang Valipour, MD

Arschang Valipour, MD, is a chest physician and intensivist at the Otto-Wagner-Spital Department of Respiratory and Critical Care Medicine in Vienna, Austria, as well as associate professor at Medical University of Vienna. He began using the InterVapor vapor ablation system (Uptake Medical) in 2009 as an investigator in the VAPOR trial for emphysema patients. For the recently completed STEP-UP (Sequential Segmental Treatment of Emphysema With Upper Lobe Predominance) randomized controlled trial, Otto-Wagner-Spital was the top enrolling site in Europe. Otto-Wagner Spital is now the first site to evaluate the adaptation of the technology for the ablation of lung tumors, and Uptake Medical published results of a first-in-human lung-tumor ablation performed by Dr. Valipour in October 2015. Interventional Oncology 360 asked Dr. Valipour to share some details on this new application.

IO360: Can you explain how the vapor therapy system works? What software and hardware are used?

Valipour: The Uptake Medical thermal vapor ablation for lung lesions system is a minimally invasive bronchoscopic treatment aimed at ablating lesions in the lung of patients with primary lung cancer or metastases. The system consists of a reusable vapor generator with a disposable catheter used to deliver heated water vapor bronchoscopically to targeted lung regions. During the procedure, the catheter is introduced bronchoscopically into the subsegment containing the lung tumor, where the catheter occlusion balloon is inflated and the vapor is delivered to the airway. Location confirmation with fluoroscopy or radial ultrasound, computed tomography (CT) confirmation is not required. Ablation duration is 8 seconds.

IO360: Could you give us some background on the way InterVapour has applications in an interventional oncology setting?

Valipour: The long-term goal of a bronchoscopic ablation technology should be to diagnose and treat early stages of lung cancer in the same procedure. This could be possible with vapor ablation. Vapor ablation has some very unique advantages:

• Minimally invasive (not percutaneous); 
• Delivery to the parenchyma via the bronchi (no need to pierce nodule);
• Ablation follows anatomical boundaries and includes margin;
• Small lung impact, multiple treatments possible
• Entire procedure <10 minutes, potentially applicable via conscious sedation.

Vapor ablation could be a unique tool for bronchoscopists to effectively address inoperable and surgically challenging patients. 

IO360: What kind of imaging or radiation dose is required for an ablation using vapor therapy?

Valipour: One high-resolution lung CT is required for pretreatment planning. CT imaging during the procedure is not required, and fluoroscopy or radial probe ultrasound can be used to confirm catheter placement. 

IO360: What are the goals of the current study?

Valipour: The current study is a treat-and-resect design in patients already scheduled for tumor resection. The objective of the study is to establish and confirm initial insight into the efficacy, safety, and feasibility of the Uptake Medical system for ablation of cancer tumors in the lung. Patients who are recommended for surgery and have a tumor ≤3 cm in diameter in the periphery of the lung are candidates. In the future, any patient with tumors ≤3 cm in the lung periphery could benefit from this technology. 

IO360: Please describe the actual procedure and results.

Valipour: Pretreatment planning was done before the case based on HRCT reconstructions. The patient underwent a standard bronchoscopy. A probe was placed in the target airway based on the treatment plan, and the correct location was confirmed with fluoroscopy. 

The probe was replaced with the catheter and 8 seconds of vapor was applied to the subsegment via the airway. The entire procedure took less than 10 minutes. Two hours later the region was resected. Gross and microscopic results showed a uniform field of ablation surrounding the targeted tumor. 

IO360: Is this therapy strictly a bridge to resection at present?

Valipour: After feasibility work is complete, it is envisioned that this approach would be a beneficial intervention to control lung tumors without the need for resection, especially in inoperable patients. 

IO360: What are some potential future oncologic applications, such as other locations in the body?

Valipour: Uptake Medical is a company focused on pulmonary applications. There may be future applications in asthma or tuberculosis that have not yet been investigated. Partner companies of Uptake Medical are applying vapor in other areas of the body, notably in the prostate for benign prostate hyperplasia and cancer (NxThera) and for uterine fibroids (Aegea).

IO360: Anything else about the system that’s important for interventional oncology clinicians to know?

Valipour: Vapor is a unique technology in that it can induce an ablative effect following anatomical boundaries. Wherever the vapor travels within the targeted subsegment, ablation occurs. But because the anatomy constrains the vapor, impact to neighboring tissue is prevented. This makes vapor ideally suited for treating hard-to-reach tumors, especially on the pleura, in an efficient and controlled manner. 

Additionally, vapor is a wet energy and does not thermally fix the tissue. This means ablated regions have the potential to completely resorb, leaving a mostly clear image. Additionally, because the tissue is not thermally fixed, it may have a unique ability to induce an antitumor immune response after local intervention. 

Editor’s note: Dr. Valipour reports no related disclosures.

Suggested citation: Ford J. Vapor ablation for lung lesions: an interview with Arschang Valipour, MD. Intervent Oncol 360. 2016;4(1):E4-E6.