Frequently Asked Questions
What is cancer?
Cancer is an abnormal form of tissue that grows uncontrollably and can eventually cause damage to other parts of the body. Cancer cells usually exhibit damaged or altered DNA.
What is a tumor?
A tumor is an abnormal growth of cells. A benign tumor is generally harmless and is not cancerous. A malignant tumor is a cancerous growth.
What is thermal therapy?
Thermal therapy is the use of radiation or other forms of energy to heat a target tissue to cause damage. Many tumors are more susceptible to thermal therapy due to their high degree of vascularization and altered DNA, which reduces resistance to heat damage.
- At temperatures of 100 degrees Celsius or more, water in the tissue and in the intracellular compartments may vaporize and lead to rupture or explosion of cells or tissue components.
- At temperatures above 60 degrees Celsius, proteins and cellular components of the tissue become severely denatured and coagulate leading to cell and tissue death.
- At somewhat lower temperatures, generally above 45 degrees Celsius, prolonged exposure leads to the thermal denaturation of non-stabilized proteins such as enzymes. Though cell death is not immediate, destruction of critical enzymes leads eventually to cell death.
What is LITT?
Laser-induced interstitial thermal therapy (LITT) is a minimally invasive therapy for the treatment of solid tumors that uses laser light to destroy the affected tissue through heat. In LITT, fiber optics are placed directly into the tumor to deliver laser light energy within the desired region of treatment. After proper positioning of fibers target tissues are irradiated using infrared light. Absorption of light energy by the tissue volume results in volumetric heating which ultimately leads to thermal destruction of the tumor.
A particular advantage of LITT is that large amounts of energy may be delivered through small, flexible optical fibers to reach remote areas inside the body. LITT may be performed using a simple bare-tip optical fiber or with a shaped (for example, ball-tip) fiber. However, a high power density immediately adjacent to the fiber tip often leads to char formation which limits penetration of optical radiation into the tissue.
As an alternative, diffusing optical fiber applicators have been developed which emit light circumferentially into tissue over some length. Such fibers have the advantages of reduced power density and an increased optical delivery area.
In addition to a diffusing tip, some laser applicators may also include provision for cooling of either the applicator or the tissue adjacent to it. Cooled applicators can support higher power deposition rates and may be less likely to fail or burn up than un-cooled applicators.
Laser applicators for LITT may be inserted into target tissue using a number of image-guided techniques including x-ray fluoroscopy, ultrasound imaging, magnetic resonance imaging, or stereotaxic approaches. MRI in particular, is attractive because dynamic MRI can be used to infer temperature changes and/or other tissue changes as a potential means of feedback during the procedure.”
Minimally invasive LITT offer tremendous potential to minimize surgical complications, reduce recovery time and hospital stays, and decrease associated health care costs. LITT heats the tumor from the inside. The advantage is that the energy is applied directly to the tumor rather than passing through surrounding normal tissue. Also the energy deposition is more likely to be extended throughout the entire tumor.
What is MRI?
Magnetic Resonance Imaging (MRI) is a powerful technique that allows physicians to visualize the structure and function of the body. MRI uses a h3 magnetic field and radio waves to generate images of tissue.
What is a clinical trial?
A clinical trial is an ongoing study of new drugs or medical procedures, usually sponsored by a pharmaceutical or biotechnology company. The purpose of these studies is to determine if new treatments are safe and effective against specific types of diseases and illnesses. There are usually three phases of a clinical trial that measure safety, dosage and efficacy. If a treatment is proven to have a statistically significant impact, it will be considered for approval of the FDA (Food and Drug Administration). See our clinical trials page for more information on our clinical trials.
What is the Visualase procedure?
The Visualase System uses thermal laser ablation to coagulate soft tissues inside the body. A thin fiberoptic applicator is inserted into the center of the target tissue and delivery of laser energy causes the tissue to heat up. Unlike most LITT procedures, the Visualase procedure is performed while the patient is inside of a magnetic resonance imaging (MRI) system. While the laser energy is being delivered, MRI images are continually acquired and are converted into maps of the heat that is being delivered. In this way, your physician can monitor the progress of the procedure.
Does the Visualase procedure involve an operation?
Yes. In order to use the Visualase system, the laser applicator must be placed into the center of the target. However, since the laser applicator is very small in diameter (less than 2 mm), the surgical access is much less invasive than typical surgery. In fact, placing the applicator is similar to biopsy. For neurosurgical applications, standard stereotaxic techniques are used to reach the target through a 1/8” diameter hole.
How long does the Visualase procedure take?
The length of the procedure depends on the complexity and number of targets being treated. For a single applicator, placement usually takes about 15 minutes (with additional time for OR setup). Once the applicator is in place, you will be transferred to the MRI. After some preliminary imaging, the actual laser ablation portion takes about 15-20 minutes, and some additional follow-up imaging is then performed. Depending on whether or not the doctor used anesthesia during the placement, the amount of time required for anesthesia recovery and transport to MRI, and the amount of additional MRI imaging, the total procedure time can take from one to three hours.
Is the Visualase procedure FDA-approved?
The Visualase System and its components including the PhoTex laser, the Laser Applicator, and the MRI analysis software and workstation have all been cleared through the FDA “510(k)” pre-market notification mechanism. This means that FDA found that these components were substantially equivalent to other devices on the market and should therefore be able to be marketed for clinical use.
My health insurer says that this procedure is experimental. Why?
Some health insurers automatically label anything that is not standard of care as “experimental” and may initially refuse to pay for it. However, to say that the Visualase procedure is experimental is inaccurate. The Visualase thermal therapy system is an FDA-cleared medical device that your doctor is free to prescribe when he/she deems it appropriate.
How long will I be in the hospital after the procedure?
Exactly when you are discharged will be at the discretion of your doctor. So far, most Visualase patients have gone home the morning following the procedure.
What will I feel during the procedure?
Depending on the dose and type of anesthesia your doctor chooses, you may feel motion or pressure as he places the applicators. During the treatment in the MRI. You will hear the MRI machine working, and you will be provided ear plugs as it can be a little loud.
Is the Visualase procedure specifically indicated to treat my cancer?
No. The Visualase system is not specifically indicated for treatment of any type of cancer. However, the system is indicated for the destruction of soft tissues in many types of surgery, and your doctor may decide that this type of destruction is useful for treating your tumor.
I am interested in the Visualase procedure. Is there someone near me whom I can talk to?
There are physicians trained to use Visualase. If you are interested, we can review your case with these physicians. Please use our patient form.
FDA Statement