Results, problems and prospects of photodynamic therapy in thoracic oncology based on a series of observations

Background. Intraoperative photodynamic therapy (IPDT) is considered a promising approach to the combined treatment of patients with malignant intrathoracic tumors. However, compliance with the treatment protocol remains a concern for specialists. These concerns are primarily related to dosimetry issues on geometrically complex surfaces using special diffusers. Objective. Evaluation of the effectiveness of endoscopic and intrapleural IFDT in the complex treatment of malignant tumors of intrathoracic localization based on a series of our own clinical observations. Material and methods. From 2017 to 2023, intrapleural photodynamic therapy (IPDT) was performed on 18 patients (6 men and 12 women) with pleural carcinomatosis of various etiologies at the Sokolov North-Western District Scientific and Clinical Center of the Federal Medical and Biological Agency of Russia and the Saint-Petersburg State Phthisiopulmonology Research Institute. All patients underwent video-assisted thoracoscopic pleurectomy, followed by an intrapleural IPDT session. Endobronchial photodynamic therapy (EPDT) was performed on seven patients with lung cancer with signs of obstructive atelectasis due to tumor spread and one patient with central squamous cell carcinoma in situ of the left lower lobe bronchus. Results. Following pleurectomy supplemented with intravascular photodynamic therapy (IPDT), all patients demonstrated a positive clinical effect, stopping fluid accumulation in the pleural cavity. In all cases, EPDT resulted in resolution of obstructive atelectasis due to a reduction in the endobronchial tumor component. A patient with squamous cell carcinoma in situ of the left lower lobe bronchus demonstrated complete tumor regression. Conclusion. IFDT improves the outcomes of comprehensive treatment for patients with malignant pleural lesions of various etiologies, effectively reducing the incidence of complications such as recurrent hydrothorax. However, the lack of a standard protocol for the procedure makes it difficult to reproducibly and non-systematically utilized. The lack of accessible intracavitary navigation and dosimetry systems further complicates the procedure and the evaluation of its effectiveness.