Photodynamic therapy may be used to treat other cancers and diseases in the future. Studies are now in progress to test the use of PDT for several types of cancer and pre-cancerous conditions, including cancers of the:

• skin
• cervix
• bladder
• prostate
• bile duct
• pancreas
• stomach
• brain
• head and neck

Newer photosensitizing drugs now being studied may have advantages over the ones now being used:

• They may be able to treat tumors that are deeper under the skin or in body tissues.

• They may be more selective for cancer cells as opposed to normal cells.

• They may collect in cancer cells more quickly, reducing the time need between getting the drug and receiving the light therapy.

• They may be removed from the body more quickly, reducing the time people need to worry about photosensitivity reactions.

Researchers are also looking at different types of lasers and other light sources. Some newer agents may respond to small doses of radiation as well as to light. This could allow doctors to use smaller amounts of radiation than the doses used in standard radiation therapy, which could lead to fewer side effects.

Another exciting area of research is in the use of PDT as an addition (adjuvant) to current therapy to make it more effective. One way to do this may be to use PDT intraoperatively (during surgery) to help prevent the recurrence of cancer on large surface areas such as the pleura (lining of the lung) and the peritoneum (lining of the abdomen), common sites of spread for some types of cancer.

Some day PDT may be used to help treat larger solid tumors as well. A technique known as interstitial therapy involves using imaging tests (such as CT scans) to guide fiber optics directly into tumors using needles. This may be especially useful in areas that would require major surgery. Early results of studies of interstitial therapy in head and neck, liver, and pancreas tumors are promising.

PDT has been used for the past 30 years and doctors know that it works. PDT takes very little time, is often done as an outpatient, can be accurately targeted to the affected area, can be repeated, and has no long-term side effects. It also isn't as expensive or invasive as some other cancer treatment options. These are just a few of the advantages of PDT. Researchers continue to look for ways to improve this cancer treatment and find ways to combine it with other treatments to get even better results.

Revised: 03/20/2007