It’s a case of kill the cancer, save the kidney.
More than 2,000 Canadians are diagnosed with kidney cancer each year. The standard treatment for renal cancer is total or partial nephrectomy – major surgery that removes the whole or part of the kidney.
With the improvement of medical imaging techniques, the detection of small renal tumours has increased, and new, less invasive procedures for their treatment have emerged. These include laparoscopic partial nephrectomy, cryoablation, high-intensity ultrasound and radiofrequency ablation (RFA).
RFA zaps kidney cancers with electrical currents, causing the tumors to disintegrate without the need for surgery. During the short (15-20 min.) treatment, patients are under general anesthesia. Guided by computed tomography (CT) or ultrasound, a thin needle is inserted through the skin and into a tumor. Electrodes deployed through the needle deliver electrical energy that heats and destroys the tumor.
“We use temperatures as high as 105¡C,” said St. Joseph’s Healthcare Hamilton urologist Dr. Eddie Matsumoto. “The heat is induced using high-frequency alternating current applied to generate ionic agitation. This latest technology cooks the tumour and cuts off its blood supply. A biopsy follow up shows that there is no cellular function, the tumour is dead.”
High school vice-principal Paul Clinton recently agreed to become one of the first patients in Canada to undergo laparoscopic RFA. As a smoker he’d been waiting for something to hit. After he was diagnosed with kidney cancer he thought, “This is it. But I feel completely blessed that the lesion on my kidney was discovered early and that Dr. Matsumoto was here to treat me.”
After treatment, patients spend a night in the hospital and go home the next day. The procedure can be repeated if new cancer appears. Over the following months, dead cells turn into a harmless scar.
Dr. Matsumoto is excited by the treatment. “The biggest benefit is that you’re maintaining the rest of the normal kidney, focusing only on the tumour itself.”
Radiofrequency ablation has also been used on liver, lung, bone and prostate cancers.
Not everyone is suitable for RFA. Surgery, such as partial nephrectomy and laparoscopic partial nephrectomy, laparoscopic nephrectomy and open nephrectomy, remains the treatment of choice (‘the gold standard’) for most kidney tumors; however, there are patients for whom radiofrequency ablation is the better choice. These include patients who have only one kidney, patients who have other medical conditions which might prevent surgery, and patients with multiple or deep-seated tumours. RFA is an option for patients with tumours that are less than 4cm in diameter.
“We compare everything we do to the gold standard,” said Dr. Matsumoto. “RFA is still an investigative procedure. But we’re in the business of optimizing treatment for our patients, and this treatment is an adjunct to the other procedures we offer at St. Joseph’s. Technology like this, which is non-invasive, is very appealing. A select group of patients will really benefit from RFA.”