Can photodynamic therapy treat NSCLC?

Share on Pinterest

PDT, also called light therapy or light-activating therapy, is a type of cancer treatment. The treatment involves adding a light-sensitizing agent, or photosensitizer, to the body and using concentrated light to kill cancerous cells.

Doctors give the photosensitizer a few days to circulate in the bloodstream. Using a camera on a bronchoscope to guide them, they then administer laser light to the now-sensitive cancer cells, killing them.

NSCLC is the most common type of lung cancer, making up about 80–85% of all cases.

A range of treatments is available for NSCLC, with the best option varying depending on the stage of the cancer, its rate of progression, and the goal of treatment.

PDT may have a role to play in treating NSCLC in some specific cases, such as in the very early stages of the disease. Research from 2021 notes that people with only small lesions under 1 centimeter long may be good candidates for PDT. In these cases, where PDT can effectively eliminate the cancer, this treatment should cure the disease.

Once NSCLC has progressed, doctors may still consider adding PDT as a part of therapy.

One of the major benefits of PDT is that it does not compromise future treatments, making it a possible adjunct therapy in necessary cases. People who undergo PDT can still have other forms of cancer therapy at a later stage.

PDT may also help treat airway blockages resulting from advanced, inoperable lung cancer. Research from 2019 notes that in a prospective trial investigating the effects of adding PDT to radiation therapy, the combined treatment was much more effective than radiation therapy alone in opening the airways.

Only 10% of people in the radiation therapy group experienced a complete opening of their airways in comparison with 70% of those in the combined treatment group.

PDT may also have a role in palliative care for those with advanced cancers. Research from 2021 notes that PDT is an alternative to chemotherapy or radiation therapy for palliative care. The authors explain that as a stand-alone treatment, it achieved an overall 87% response rate and improved quality of life.

In every case, doctors will discuss all options with the person before making recommendations. If PDT is right for a person with NSCLC or they qualify for new clinical trials, the doctor will talk them through the next stages.

Everyone’s experience of the procedure may be slightly different, but the information below gives a person an idea of what to expect.

Leading up to treatment

Before the treatment, a doctor will explain the procedure and go over any questions that the person wishes to ask.

At this stage, the person should tell the doctor about all of the drugs and supplements that they take, in case anything will potentially interact with the procedure or the photosensitizer.

Days before the procedure, the doctor will give the person a photosensitizing agent in the form of either a solution that the person swallows or a liquid that a healthcare professional injects into the vein. The photosensitizer will circulate the body in the bloodstream.

Within about 48 hours of administering the light-sensitizing medicine, the person will go to the hospital for treatment.

During treatment

A doctor will first administer sedative medication to help the person relax. In some cases, they may recommend using general anesthesia.

Then, they will feed a tube called a bronchoscope into the airways. The bronchoscope carries a small camera and laser light through the airways toward the tumor.

Using a video feed from the camera to locate the tumor, the doctor will use the laser to shine low power light waves at the tumor. The action of the photosensitizer in the body makes the cells very sensitive to this light, and this process destroys the cancerous cells.

After treatment

After receiving PDT, the person stays at the hospital until the sedative or anesthetic wears off. Once they are fully alert and recovered, the person will go home, usually on the same day.

A few days after the main treatment, doctors will need to remove the dead cells that the procedure has left in the body. They will use a process called endoscopy to pull dead cells from the airways out of the body.

Although PDT is generally safe, the treatment has some risks, including possible side effects.

Light sensitivity

Lasting light sensitivity is the main drawback to PDT. The photosensitizer circulates the whole body, making the cells very sensitive. This can lead to damage if the person does not take the necessary precautions to avoid it, which include:

• avoiding sunlight when possible
• avoiding very bright lights indoors
• covering all areas of exposed skin whenever they go outside
• wearing sunglasses that protect from UV light at all times during exposure to light

Completely avoiding light may not be possible, as the body can stay sensitive to light for weeks after the procedure. However, it is important to take steps to avoid damage to the eyes and skin from bright indoor light or sunlight whenever possible.

Anyone who suspects that they have sustained damage as a result of light exposure should let a doctor know.

Pain and malaise

Pain may occur from the procedure itself. In addition, some people may experience pain in the chest or throat from the bronchoscope. Doctors may recommend pain relievers for pain that is not severe. Anyone experiencing severe pain after the procedure should talk with a doctor.

The person may also experience general malaise or a sick feeling. It may be hard for them to describe the feeling beyond noting that they feel unwell. This feeling may pass with time, but if it makes daily tasks difficult, it is advisable to talk with a doctor. They may recommend some medications to ease the feeling.

Bleeding

Some bleeding may occur after the procedure. Blood may appear in the sputum, or a person may simply taste blood but not see any. This bleeding should resolve in a few days. Anyone who experiences prolonged bleeding or regularly coughs up blood should see a doctor.

In some cases, a person may also experience swelling around the treated area.

Recovery from PDT can vary in each case depending on how the person responds to treatment and what, if any, side effects they experience. They may be sensitive to light for weeks following the treatment, but this and the other effects of the treatment should taper off with time.

In very early cases where doctors are able to kill the tumor completely with PDT, this therapy may cure the cancer.

In other cases, people’s outlook can vary widely. PDT as palliative care may provide lasting comfort for some if it can open the airways and improve other treatment outcomes.

In cases of regressing cancer, the tumor may grow back and block the airways. In these cases, the person may need to undergo PDT again. A doctor can offer advice on all of the available treatment options.

Research from 2021 notes that experts consider PDT a new and promising antitumor strategy. However, the authors highlight the need for more extensive clinical trials to help develop the therapy.

One of the main drawbacks to the therapy is the intense and long lasting sensitivity to light. To this end, researchers have called for more efficient tools to photosensitize only the cancerous cells. They note that recent advancements in nanotechnology have enabled the early development of more targeted photosensitizers that attach to specific tumor cells. These may greatly improve the procedure by reducing the side effects and risks of PTD, as well as making its targeting more accurate.

More clinical and preclinical trials are underway to explore these options.

Photodynamic therapy can play a role in treating some cases of NSCLC. In the very early stages of the disease, it may be curative. In other cases, it may improve the outcomes of other therapies and the person’s quality of life and outlook.

There are some drawbacks to the therapy, such as a long lasting sensitivity to light. Future research may find ways to reduce these risks and expand the role of PDT in lung cancer treatment.