Robotic bronchoscope reaches tiny, hard-to-access lung tumors with high accuracy

A cutting-edge bronchoscope that is guided with the help of a robot can reach very small tumors growing in hard-to-reach parts of the lung, according to results of a gold-standard randomized-controlled trial that will be presented at the European Respiratory Society (ERS) Congress in Amsterdam, the Netherlands.

The robot-assisted bronchoscope also uses a specialized CT scanner to find tumors buried in the lungs, enabling doctors to take a biopsy and confirm whether they are cancerous. Being able to find and test these very early cancers gives patients the highest chances of being cured.

Results of the trial will be presented by Dr. Carolin Steinack, from a team of researchers led by Dr. Thomas Gaisl from University Hospital Zürich, Switzerland. Speaking ahead of the Congress, Dr. Gaisl said: "This technology is very advanced but also very expensive, so it's important to test whether it performs better than traditional bronchoscopy. To date, there has been no direct evidence that the cost of the system translates into better clinical outcomes."

The researchers conducted a clinical trial of 78 patients, who between them had a total of 127 abnormal growths at the outer edges of the lungs, where there is often no access via a connecting airway. These are extremely hard to reach with traditional bronchoscopes. The tumors were only 11mm wide on average and less than 15% had a connecting airway.

Half of the patients were randomly assigned to be tested with the new technology, known as robotic-assisted bronchoscopy with integrated cone-beam CT (CBCT). The other half were tested with the standard technology – a very thin bronchoscope that uses X-ray imaging for guidance.

Using the traditional technique, doctors were able to reach and take a biopsy for 23% of the tumors. Using the robot-assisted technology, doctors were able to reach and biopsy more than 84% of the tumors.

In cases where a biopsy was not successfully taken with the traditional technique, patients were then tested with the robot-assisted technology and, of these, almost 93% were successful.

In total, 68 patients were diagnosed with lung cancer and 50 of these had the very earliest form of the disease (stage 1A).

Dr. Steinack said: "Robotic-assisted bronchoscopy with CBCT achieved a diagnostic yield more than three times higher than conventional bronchoscopy. In clinical practice, this technology enables accurate diagnosis in patients for whom conventional bronchoscopy offers no viable option.

"Although only about 20 of these systems are currently in use across Europe, this is increasing. The technology allows specialists to access nearly any region of the lung, meaning that we can offer biopsy to more patients and diagnose cancers earlier when treatment is more likely to be effective."

In centers that see lots of patients with these tumors, I believe the benefits of this technology justify the investment. However, the robotic system should be reserved for small, hard-to-reach lesions, where conventional bronchoscopy is not an option."

Dr. Thomas Gaisl from University Hospital Zürich, Switzerland

The cost of the new system is around €1 million. Using the system adds around €2,000 to the cost of a single procedure.

The researchers say they will now investigate whether the same technology could also be used to combine diagnosis and treatment of lung tumor into one procedure, for example by locating a tumor and delivering radio waves or microwaves that can destroy cancerous tissue.

In a second study that will also be presented at the ERS Congress [2], the same research team compared different technologies for guiding bronchoscopes. In this research, the robot-guided system outperformed two other systems: a virtual 3D model of the patient's airways and a GPS-like system called electromagnetic navigation bronchoscopy.

Professor Aleš Rozman, Chair of the European Respiratory Society's expert group on interventional pulmonology and Head of the endoscopy department at University Clinic Golnik, Slovenia, who was not involved in the research, said: "Lung cancer kills around a quarter of a million people in Europe every year. Survival is typically much higher if patients are diagnosed when their cancer is still at an early stage, however, these very small tumors are often difficult to diagnose.

"This research shows that robot-assisted technology can help diagnose many more of these tiny tumors in hard-to-reach parts of the lungs. It's vital that we carry out this type of gold-standard research so that we can justify the significant additional cost of installing and using this equipment."