Photodynamic therapy (PDT) is one of the most promising methods of treating localised tumours.

As co-author of the study published in BioNanoScience, Research Associate Ayrat Bilyalov explains, the work on photodynamic therapy has been ongoing for 5 years.

The group comprises medical professionals from Kazan Federal University and Medical Center of the Presidential Administration of Kazakhstan.

PDT can be used for treatment in almost all major locations as an independent method or in combination with traditional types of treatment (surgery, radiation, and chemotherapy).

Depending on the stage, nature and form of tumour growth, various laser irradiation options have been developed to increase the effectiveness of photodynamic therapy.

The method is based on the introduction of photosensitisers into the patient's body that selectively accumulate in the tumour tissue.

The main idea of this method is to produce singlet oxygen and other active radicals to destroy tumour cells.

In addition to the direct phototoxic effect on tumour cells, in photodynamic therapy, an important role in the destruction mechanism is also played by a reduction in the blood supply to the tumour tissue caused by damage to the endothelium and blood vessel thrombosis, and cytokine reactions caused by stimulation of the production of tumour necrosis factor, interleukins, activation of macrophages and leukocytes. 

The results of clinical and preclinical trials prove that PDT can be used in many types and localisations of tumours.

A quarter of a century has passed since the beginning of widespread clinical use of photodynamic therapy in Russia, but clear and unambiguous treatment recommendations are not yet available.

Limited possibilities of using photodynamic therapy as a part of high-tech medical care program and high costs of photosensitisers in most cases are the obstacles to the full implementation of the method in cancer centres.

A potential direction for the development of this technique is the search for new photosensitisers and the expansion of indications for the use of PDT.

A patent for fluorescent diagnostics of parathyroid tumours has already been obtained, and clinical trials are planned to study the effectiveness of PDT in a number of new locations of malignant tumours (bladder cancer, primary and metastatic liver cancer, localised and disseminated melanoma, etc.).

Source: Kazan Federal University