Mesothelioma Photodynamic Therapy | Side Effects And Risks

Mesothelioma Photodynamic therapy uses a photosensitizing agent and light to kill mesothelioma cancer cells. Photodynamic therapy is a newer mesothelioma treatment that uses light energy to kill cancer cells. Treatment is by injecting a photosensitive drug into the patient before surgery. When cells are exposed to light, it activates the drug to kill the cancer cells.

What Is Photodynamic Therapy?

Photodynamic therapy (PTD) is a promising new mesothelioma treatment that is still being studied in clinical trials. As a light-based treatment, photodynamic therapy works by directing therapeutic light directly at the cancerous tumor, killing mesothelioma cells while causing less damage to the cells. surrounding healthy cells.

Because mesothelioma is one of the most difficult cancers to treat, there is no single treatment that can cure it. Instead, doctors combine multiple targeted treatments together in a specific order to build a tailored treatment plan that’s unique to each patient — including their genetic makeup. As a minimally invasive treatment, photodynamic therapy is considered one of the best therapies to perform before or during surgery as part of a multimodal treatment plan.

Photodynamic therapy plays an adjunct in the surgical resection of mesothelioma and has been shown to increase survival.

There are both pros and cons to using photodynamic therapy to treat mesothelioma. Because mesothelioma is treatable but not curable, doctors focus on modalities that work well with standard mesothelioma treatments such as surgery, radiation, and chemotherapy. treat. Traditional treatments alone won’t stop the spread of the disease, which is why the job of experimental treatments like PTD is to keep the mesothelioma cells at bay. colonize and prevent metastasis (spread to distant sites).

How Does Photodynamic Therapy Work?

Photodynamic therapy is performed during surgery when the chest cavity has been inserted and the tumor can be directly irradiated with a laser. It can be used in combination with other treatments, such as chemotherapy andsurgery, to fight cancer in many ways.

Treatment begins with the use of a photosensitizer, which is injected into the bloodstream before surgery. This drug is absorbed by cells, both healthy and cancerous, but stays in the cancer cells longer. After one to three days, the photosensitizer had left most of the healthy cells but remained in the mesothelioma cells. This is when light is used during surgery, usually through a laser, to activate the photosensitizer.

This light must have a specific wavelength and color to trigger a reaction in the drug. Example: Photofrin reacts to red light. When the drug is activated, it produces a highly reactive form of oxygen. Oxygen affects all nearby cancer cells, causing them to die. It can also damage a tumor’s blood vessels, thereby cutting off the nutrient supply and killing cancer cells.

Which Patients Are Eligible For Photodynamic Therapy?

Photodynamic therapy can only be used on areas of the body where light can reach, such as just under the skin or along the lining of internal organs. In the case of mesothelioma, this means it is used in surgery when the tumor is exposed. Therefore, this therapy is most effective in treating localized cancers that have not spread throughout the body. In addition, people with large tumors may not be suitable candidates for this therapy, as light cannot penetrate the entire tumor.

Side Effects And Risks Of Photodynamic Therapy

The side effects of photodynamic therapy are usually mild because the treatment is isolated from the body part affected by the mesothelioma and there is no cumulative toxicity. This means that PDT can be repeated without increasing the risk of side effects. The most common side effects are sensitivity to light and swelling, which can lead to difficulty breathing.

Risks Associated With Photodynamic Therapy

  • Difficulty breathing
  • Bronchitis
  • Hemoptisi
  • Fever
  • Light sensitivity
  • Pneumonia
  • Shortness of breath
  • Swelling in the treatment area

Doctors note that photosensitivity requires the most precautions and repeated care. Mesothelioma patients treated with PDT will be photosensitive for about 30 days after treatment. However, some patients have reported photosensitivity three months after PDT. The patient’s healthcare team will be able to better estimate how long they may be sensitive to light, depending on the size of the mesothelioma being treated and the length of treatment.

Precautions For Light Sensitivity Against

  • Complete errands after sunset if possible
  • Cover your skin when outdoors, even on cloudy days
  • Do not use reading lights
  • Limit time outdoors between 10 a.m. and 4 p.m. (when the sun is at its highest)

Before going to the hospital for treatment, family members should make sure to cover all the windows and skylights to prepare to welcome the patient home. In addition, patients should bring a long-sleeved shirt, long pants, gloves, sunglasses, and a wide-brimmed hat on the day of treatment. These items should be worn to cover as much skin as possible upon leaving the cancer center.

While photosensitivity can be an inconvenient side effect of PDT, its potential to prolong life and improve quality of life may make the treatment option worthwhile. Patients should discuss the possibility of participating in a PDT clinical trial with their mesothelioma specialiststo determine if they are eligible.

Photodynamic Therapy Learning Outcomes

Studies of photodynamic therapy in patients with pleural mesothelioma have been successful in recent years, but some early studies show no improvement with PDT. In a 1996 study, 63 pleural mesothelioma patients underwent surgery and chemotherapy, and half were also randomized to receive PDT. Based on PDT supplementation, the researchers found no significant difference in survival time. Patients lived an average of 14.1 months without PDT and 14.4 months with it.

A 2004 study showed a significant improvement in survival time when photodynamic therapy was added to surgery. Patients treated with surgery alone lived an average of 10 months, while those treated with surgery and PDT lived an average of 13 to 14 months. The researchers concluded that this therapy shows great promise in the successful treatment of mesothelioma and needs to be studied further.

A 2019 study published in the journal Photochemistry and Photobiology reported on the safety and outcomes of combining photodynamic therapy with proton radiation therapy and chemotherapy. Ten patients were included in the study and they have all diagnosed with stage 3 or 4 pleural mesothelioma. The median survival time was 30.3 months, which is a significant improvement. with an average life expectancy of 12 months.

A Canadian research team will publish their findings in 2021 on the potential of photodynamic therapy to treat metastatic disease in patients with mesothelioma. The new method uses immunotherapy combined with photodynamic therapy to shrink tumors throughout the body. In multimodality combination therapy with other treatments, a systemic immune response can improve outcomes for patients with metastatic mesothelioma.