Radio-guided technique for removing lung nodules

Doctors in Italy have developed a way of removing potentially cancerous lung nodules using a form of radioactive imaging.

The team from Santa Croce e Carle Hospital in Cuneo used a technique called radio-guided surgery, where the tiny nodules were injected with a radioactive substance and identified using CT scanning and a gamma-radiation probe.

The single pulmonary nodules can then be removed by video-assisted thoracoscopic surgery (VATS), where a camera is used inside the lung to guide the surgical instruments.

Because the targets are smaller than 3cm in diameter and can be as small as 1.5mm, VATS techniques alone can be insufficient to locate the nodules, especially if they are located deep in the lungs.

‘This technique can be used in a lot of hospitals because the gamma probe is used in breast surgery,’ Dr Luca Bertolaccini told The Engineer.

He said radio-guided surgery was more precise than other techniques used previously, such as marking the area with an injection of ink or identifying the target with a hookwire and using ultrasound or MIR to guide the surgical instruments.

To pinpoint the nodules, the team inserted a needle into the correct part of the lung, guiding it with a CT scan. The doctors then injected a solution of microspheres of human albumin serum (a protein found in blood plasma) labelled with technetium-99m, an isotope that emits gamma radiation.

The team then used another CT scan, and a technique called gamma scintigraphy using external gamma cameras, to confirm the precise staining of the nodule with the radioactive solution.

The surgeons could then remove the nodules using a thorascopic grasp, guided by an internal gamma probe that would ensure they took out all the radioactive-labelled tissue.

Bertolaccini and his colleague Dr Alberto Terzi used the technique to localise nodules in 19 trial patients, taking an average of six minutes to detect each nodule with the gamma probe.

Radio-guided surgery has previously been used for mapping melanoma and breast and other cancers. The Italian team adapted the technique as a way of supporting video-assisted thoracoscopic surgery.