Poking Holes in Cancer — One Electric Current at a Time

Pictured: Stephen Solomon

Interventional Radiologist Stephen Solomon

Cancer researchers constantly strive to expand the arsenal of weapons to treat the disease, particularly for people with tumors that aren’t responsive to conventional treatments. One such option is a minimally invasive approach called thermal ablation, which involves placing a needle into a tumor and applying extreme heat or cold, which kills the cancer while preserving healthy tissue. In addition to destroying tumors, thermal ablation may actually activate immune cells to attack the cancer.

Memorial Sloan Kettering now has one of the biggest ablation programs in the United States, says Stephen Solomon, Chief of the Interventional Radiology Service and Director of the Center for Image-Guided Interventions. “We’re treating approximately 300 people a year, frequently on an outpatient basis that allows patients to go home after the procedure the same day.”

However, thermal ablation cannot be used in some patients.

“Thermal ablation can cause scarring in healthy tissue near the tumor, making it inappropriate for use on some tumors near blood vessels, nerves, bile ducts, and other sensitive structures,” says Mikhail Silk, a medical student at SUNY Downstate College of Medicine, in Brooklyn, who is conducting research in collaboration with the Interventional Radiology Service. “It also can fail to kill every cancer cell if the tumor abuts a major blood vessel because blood flow dissipates some of the extreme heat or cold emitted from the needle — a phenomenon called the heat sink effect.”

Punching Holes in Cells

Now a new, minimally invasive treatment that uses an electric current to punch tiny holes in cancer cell membranes is showing promise against challenging tumors. Called irreversible electroporation (IRE), the technique uses tiny needles to give cancer cells a jolt of electricity.

The electricity produces holes in the cell membranes, which disrupts the balance of molecules inside and outside the cells. IRE causes no scarring or inflammation in nearby healthy tissues, and there is no heat sink effect.

“Blood vessels and nerves are made not just of cells but also have protein structures surrounding them,” Dr. Solomon explains. “Because proteins don’t have electric membrane potential, these structures are largely protected from IRE, making it possible to destroy a tumor safely without destroying the structural integrity of an organ.”

IRE holds particular potential for treating liver, lung, and pancreatic cancers that are close to blood vessels and other sensitive structures — situations in which normal heat or cold ablation is not feasible.

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Encouraging Study Results

After validating the safety of IRE in animal studies, Memorial Sloan Kettering’s interventional radiologists and surgeons have begun using the procedure in select patients who are not eligible for other treatments — particularly, patients with cancer that has spread to the liver from other sites in the body.

Early results suggest IRE can be effective and safe. In the January 2014 issue of the Journal of Vascular Interventional Radiology, Dr. Solomon’s team reports that IRE was used successfully in 11 patients to treat a total of 22 small tumors that had spread to the liver from other locations. In 15 treatment sessions, the tumors — which had a median size of 3 centimeters — were destroyed with no major complications. Many of the tumors were located less than 1 centimeter from bile ducts, making thermal ablation too risky.

Memorial Sloan Kettering specialists will continue to explore IRE in other types of cancer, although in every case it needs to be compared with thermal ablation and other minimally invasive treatments. Dr. Solomon’s team recently received a grant from the National Institutes of Health to investigate the use of IRE in lung cancer, which they hope to begin in 2014.

A strong feature of the Interventional Radiology Service has been the addition of a biomedical engineer, Govind Srimathveeravalli, who has worked with the clinical team to optimize the use of IRE.

“For complete tumor destruction with IRE, it is important to achieve a uniform electric field within the target region,” Dr. Srimathveeravalli says. “As tumors are heterogeneous in nature, treatment planning for IRE can be a challenge to physicians. I use physics simulations and work with Dr. Solomon to develop guidelines for optimizing treatment plans. We also perform research to develop new devices that will extend the reach of IRE therapy to new anatomical locations.”

“Our research program will be focusing a lot of energy on developing and refining IRE over the next few years,” Dr. Solomon adds. “There are still important questions that need to be answered — such as whether IRE actually destroys all the cancer cells — but we hope it becomes another tool that physicians can rely on when nothing else is suitable.”

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Jasmine, there are several interventional radiologists who perform IRE at Memorial Sloan Kettering. However, the technology is still experimental and is mostly used in cases where doctors have few other options. When you meet with the physician for the appointment, they will be able to make a full clinical assessment and decide whether consulting with an interventional radiologist is appropriate for the case.

Exactly one year ago my husband diagnosed with tonsil cancer had 45 lymph nodes removed from his neck and robotic surgery to remove the tonsil cancer. Three nodes were positive. He received proton therapy and chemo. He was just told he has reoccurring Stage 2 in the lateral inferior orpharynx and superior hypopharynx. The doctor wants to remove his voice box. Is it possible to save it with another treatment?? Please help us to decide. Thank you.

Dear Ann, unfortunately, our experts can’t give personal medical advice on our blog. If you’d like to get a second opinion from one of our doctors, please do give us a call. The number is 800-525-2225, or you can learn more here: http://edit.mskcc.org/cancer-care/appointment. Thanks so much for reaching out, and we wish you and your husband the best.

Any updates on IRE results in lung cancer? (Adenocarcinoma)
Thank you!

Pilar, thank you for your question. IRE is currently being investigated in a clinical trial for use against lung cancer, but this initial trial is focusing on safety.

Are you taking patients with adenoid carcinoma, i.e. cancer in sub-lingual gland in the floor of the mouth for nanoknife treatment??

Valeriy, thank you for reaching out. In general, this technology is still experimental and it is too early to say which types of cancer it will be effective in treating. It is currently being used in cases where doctors have few other options. Memorial Sloan Kettering doctors have actually used the technology to treat patients with adenoid cystic carcinoma with lung lesions, but they would need to understand more about the individual patient to know whether this treatment is appropriate in a specific case.

If you would like to make an appointment for a consultation with one of our physicians, please call our Physician Referral Service at 800-525-2225.

Has there been any exploration into the use of IRE for very small infiltrating ducal carcinoma of the breast with no lymph node involvement as an alternative to radiation/surgery?

Helene, thank you for reaching out. We passed your question on to MSK interventional radiologist Stephen Solomon, who responds:

We have not used IRE in the breast. We have used other ablative forms such as cryoablation. The standard treatment for these lesions is surgery.

Can this procedure be used multiple tumors in the liver? By multiple I mean more than 5. Is there a size limitation on the tumor that can be treated?

Fred, thank you for your comment. We consulted with Dr. Solomon on your question, and he responded:

“We usually have alternate treatments when we get to 5 or more tumors. We also try to treat less than 3 cm targets.”

If you would like to make an appointment with a Memorial Sloan Kettering physician for a consultation, please call our Physician Referral Service at
800-525-2225 or go to http://www.mskcc.org/cancer­care/appointment.

Johns Hopkins is using IRE for locally advanced Pancreatic Tumors. When will that be done at MSK

Jeanne, thank you for reaching out. We consulted with Dr. Stephen Solomon, who responded that there are currently no plans at MSK to begin using IRE to treat pancreas cancer.

If you want to learn about other treatments for pancreas cancer at MSK, you can find out more here:


If you would like to make an appointment with a Memorial Sloan Kettering physician for a consultation, please call our Physician Referral Service at 800-525-2225 or go to http://www.mskcc.org/cancer­care/appointment.

I am a man nearly 70 years old living in the Netherlands no problems on toilet psa 5.3 enlarged prostate in state of the art mri nothing was found 12 biopts all good then later 16 biopts one of the biopts showed less than 10 percent cancer. Soon i will get 30 perineum biopts how can you remove the cancer with IRE or focal therapy ? Do you have a waiting list ? thanking you respectfully

Dear Wiet, we cannot offer medical advice on our blog, however we would recommend that you reach out to our International Center. The staff there can make arrangements for one of our specialists to do a medical records review by mail, or make an appointment for you to come to MSK for an in-person consultation. Please contact them directly via email at [email protected]. Learn more about the services we provide for our international patients at https://www.mskcc.org/experience/become-patient/international-patients. Thank you for reaching out to us.

Is this treatments still being used

My father was very recently diagnosed with Prostate Cancer, a localized tumor. He is asymptomatic.
PSA consistently ~1.5 ng/ml over last 5 yrs. PSAD: 0.06 ng/mL/cm3
Biopsy: Stage T2a (left). Gleason 8. Prolaris Score: 5.2.
MRI: prostate measures ~3.9 x 3.6 x 3.4 cm, estimated mass 25 g. PI-RADS category 5. 2.8cm x 1.4cm x 1.2cm lesion within posterior aspect of prostatic base and mid gland. suspected microscopic extracapsular extension and suspected early invasion of seminal vesicles.
CT Scan: no intraabdominal/pelvic metastases, no adenopathy.
Bone Scan: no osseous metastasis.
He is 80 years and otherwise in very good health, with no other medical conditions, vitals all fine. He has not received any treatment for the prostate tumor to date.
* Is he a candidate for Irreversible Electroporation?
He has not seen an oncologist, but his urologist advised that minimally invasive laparoscopic/robotic surgery and/or focal treatments (non-radiation) would be best options.
He was advised that the side effects of photon radiation treatment would be problematic, particularly with respect to urinary frequency, which he already is troubled by.
* Are hormone treatments used in combination with Irreversible Electroporation, as they often are with radiation treatments?
Thank you very much.

Thank you for reaching out. We consulted with one of our physicians about this situation and the possibility of irreversible electroporation, and he responded “Not a typical candidate for this. More likely for cryoablation.”

You can learn about these types of therapies at MSK here:


If you would like to make an appointment with a Memorial Sloan Kettering physician, please call our Physician Referral Service at
800-525-2225 or go to https://www.mskcc.org/experience/become-patient/appointment

Thanks for your comment.

Can this procedure be used on patients with cutaneous metastatic breast cancer?