Podcast: LITT explained
Laser interstitial thermal therapy (LITT) is an emerging technique to treat primary and metastatic brain tumors that can be hard to reach with conventional surgery. LITT is performed by implanting a laser catheter into the tumor and heating it to temperatures high enough to kill the tumor.
The catheter is implanted using advanced computer imaging techniques. The laser is guided through the catheter with real-time MRI, allowing neurosurgeons to limit thermal energy delivery only to the tumor. Most patients can go home the day after treatment and can quickly return to normal activities.
Laser interstitial thermal therapy is minimally invasive. It typically requires only a 2-millimeter incision in the scalp, and takes only a few minutes to perform.
LITT can also help patients who do not respond to stereotactic radiosurgery or have radiation necrosis (tissue death caused by radiation treatment).
BY Lori Baker
Surgeons at MD Anderson are using extreme heat and cold as their weapons against some forms of cancer.
They’re finding that the minimally invasive treatments are working as well as, if not better than, standard cancer treatments for many patients. Recovery is dramatically quicker.
Quality of life is better. Patients are more satisfied.
Turning up the heat on spinal cord tumors
Instead of performing a standard surgery by making a large skin incision with extensive muscle dissection and bone removal, Tatsui inserts a small laser probe – about the size of a pencil lead –into the tumor. Once in place, intense heat scorches the cancer cells. A specially equipped MRI, located in the same operating room, allows Tatsui to precisely control where the treatment is delivered. This protects nearby vital organs and immediately verifies that the tumor has been destroyed.
“We use the heat to kill the cancer cells, and the MRI mapping allows us to precisely apply the laser only inside the tumor, protecting the spinal cord and nerves,” Tatsui says. “Recovery from this procedure is very quick – a day or two rather than weeks, which allows patients to resume their chemotherapy quicker as well.”
The procedure, called laser interstitial thermal therapy (LITT), has been traditionally used at MD Anderson to treat hard-to-reach brain tumors. Tatsui has expanded its use to include for the first time treatment of spinal metastasis with spinal cord compression. He has adapted some of the instruments and techniques to accommodate the procedure and their use next to the MRI’s high power magnetic field.
It takes longer to prepare for the procedure than to destroy the tumor. The probe is activated for about two minutes and generates heat of between 123 and 185 degrees Fahrenheit. The MRI shows the heat rippling out from the center of the probe, spreading inside the tumor as it turns green, yellow, orange and finally red.
Tatsui has performed the procedure on more than 70 patients, some of whom had limited or no options since they weren’t considered candidates for standard surgery due to the advanced stage of their disease.
“LITT is a game-changer,” Tatsui says.
Treatment leaves breast cancer out in the cold
At the other end of the thermometer is cryoablation, which freezes cancer cells to death.
Cryoablation is a treatment option for prostate cancer, kidney cancer, lung cancer and liver cancer. Also it’s used for non-cancerous breast tumors called fibroadenomas. Given its effectiveness for these types of benign tumors, doctors wanted to test expanding the treatment to breast cancer.
MD Anderson and other sites conducted a clinical trial that included women with early-stage breast cancer whose tumors were 2 centimeters or smaller.
“At MD Anderson, 100% of all tumors in trial patients were destroyed through cryoablation,” says Rosa Hwang, M.D., the lead investigator for the clinical trial here.
“Everyone, including the patient, watches in real time as an ice ball forms around the tumor and freezes it from the inside out. It’s visually amazing,” Hwang says.
Rather than undergoing a traditional surgery to remove their tumors, patients are treated in an outpatient room. Cryoablation is so painless, the patient remains awake while the doctor uses ultrasound imaging to guide a thin, needle-like device through the skin and into the tumor. Once in place, liquid nitrogen at 40 degrees below zero Fahrenheit freezes the cancer cells for six minutes. The cells are frozen again for six minutes following a two-minute rest. The probe is removed, and a Band-Aid-like bandage is placed over the tiny incision. The entire procedure takes less than 30 minutes.
Recovery is instantaneous. Some women report going shopping or out to eat directly from the procedure.For the clinical trial, patients still had to have what was left of their tumors surgically removed and examined to ensure all cancer cells were destroyed. Hwang says another trial without the post-cryoablation surgery is in development. The goal is to have cryoablation replace surgery as the standard of care for patients with early-stage breast cancer.
“This is a huge advance, and I think it could be the wave of the future,” Hwang says.
A longer version of this story originally appeared in Messenger, MD Anderson’s quarterly publication for employees, volunteers, retirees and their families.
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