National Institutes of Health (NIH) research being presented at ISET focuses on a technology that works like a Global Positioning System (GPS) to help interventional physicians navigate inside the body, taking the guesswork out of minimally invasive biopsies and cancer treatment.
Electromagnetic (EM) tracking helps doctors pinpoint tumours, enabling more accurate biopsies and targeting of therapies such as radiofrequency ablation. This is the first report using the technology to biopsy and treat kidney tumours.
Nadine Abi-Jaoudeh, attending physician at NIH, is presenting research at ISET on 18 patients with multiple kidney tumours: 10 undergoing biopsy and eight undergoing treatment with radiofrequency ablation (RFA), which involves placing a needle in the tumour and heating it until it is destroyed or “cooked.” These patients are difficult to treat because they have many benign and malignant tumors. It is challenging but important in these patients to biopsy or treat the exact tumor in question. Exact needle positioning is crucial, however these tumours may not be readily visible on non-contrast CT and ultrasound, which are the usual imaging techniques used in conventional minimally invasive biopsies and RFA.
With EM tracking, existing imaging studies – including magnetic resonance imaging (MRI), positron emission tomography (PET) and computed tomography (CT ) – can be superimposed and used in real time to guide physicians as they perform minimally invasive biopsies and RFA, much like a video game.
• Biopsy group: In 10 patients, EM tracking helped physicians differentiate suspicious tumours from others nearby. Three of the 10 patients had malignant tumours.
• RFA group: Six of eight patients (75 per cent) had successful RFA confirmed by lack of enhancement on contrast-enhanced CT. One patient had a recurrence five months later that was successfully treated with repeat RFA and one patient had incomplete RFA due to the presence of a nearby vital structure that prevented treatment.
“Nephron-sparing procedures (those that preserve kidney tissue) are extremely important, especially in patients with hereditary kidney cancer. EM tracking improves localisation of the tumours and needle during procedures which may improve outcome in these patients,” said Dr. Abi-Jaoudeh. “This technology isn’t widespread yet, but it is becoming much more widely available, and has great promise.”
