By Matthew Niemeyer M.D.
In September 2014, a man in his early 60s visited my interventional radiology team at Tysons Corner Medical Center. An MRI showed the 2.8-centimeter mass in his liver was cancerous, so we performed a microwave ablation procedure, which literally burns the tumor. Today, he is cancer-free.
Microwave ablation is innovative radiology in action. If patients with cancer in their liver or another organ want treatment, we often recommend this procedure because it’s the best option for patients’ safety, comfort and results.
That was not always the case. The field of interventional radiology has been around for roughly 60 years, but radiologists have made minimally invasive procedural breakthroughs in oncology only over the past two decades. These breakthroughs especially include transarterial chemoembolization (focusing and limiting chemotherapy to the tumorous artery) and ablation procedures (using energy to kill cancer tissue without resorting to surgery).
Microwave ablation, the newest and most innovative ablation method, involves heating tissue until cells die. Interventional radiologists channel microwaves through a probe inserted through the skin and into an ablation zone. The tumor heats up so much that it shrinks significantly after being exposed to the microwaves. The procedure takes about one hour, and the average patient needs six hours to recover and one week to return to normal activities. Patients typically return one month later for a postoperative evaluation to assess their recovery and treatment response.
The advantages: Patients are spared surgery, can go home the same day and don’t need sutures—they have only a small scar. Complications are also minimized because the procedure involves only a skinny probe inserted through a tiny incision in the skin.
Interventional radiologists often conduct microwave ablation to treat oncology patients—foremost those with liver-dominant disease—as an alternative to chemotherapy, radiation and other therapies.
While cryoablation and the more entrenched radiofrequency ablation have been the prevailing ablation methods, our team began performing microwave ablation four years ago because of its advantages in comparison to these other methods. It can be done faster and with more consistency, equipment is easier to use, and it lets us treat larger tumors in more areas of the liver. In addition, patients are spared the grounding pads needed in radiofrequency procedures, which sometimes burn skin. Early clinical studies tracking patients for up to three years have demonstrated that microwave ablation yields outcomes equal to or better than radiofrequency. Studies tracking patients’ longer-term outcomes after receiving microwave ablation haven’t been completed.
We considered these factors when handling the case of the man in his early 60s with the cancerous tumor in his liver. After explaining what his MRI results meant and discussing the options for treatment that best fit his health and personal priorities, we contemplated removing the lesion via surgery, transplanting his liver or administering intra-arterial chemo. We ultimately suggested he undergo microwave ablation because the mass was smaller than 3 centimeters and because the lesion’s location would have amplified the risk of surgery. In the meantime, our colleagues in the liver transplant clinic placed him on a waitlist. We performed the ablation procedure, and he was cancer-free at each six-month follow-up appointment until April, when he received a new liver.
More health systems are now adopting microwave ablation, and it’s worth patients’ consideration as well.
Matthew Niemeyer is a board-certified radiologist with Mid-Atlantic Permanente Medical Group. He completed a fellowship in interventional and vascular radiology at Northwestern Memorial Hospital (Illinois) and performs outpatient procedures at Kaiser Permanente’s Tysons Corner and Largo Medical Centers and inpatient procedures at Holy Cross Hospital.