Photodynamic therapy: a review

Area of Science:

• Oncology
• Photochemistry
• Biomedical Engineering

Background:

• Photodynamic therapy (PDT) is an emerging cancer treatment modality.
• It involves selective retention of a photosensitiser by tumour cells.
• PDT offers a distinct mechanism of action, complementary to existing therapies.

Purpose of the Study:

• To introduce photodynamic therapy (PDT) as a novel cancer treatment.
• To explain the mechanism of action involving photosensitisers and light activation.
• To highlight the therapeutic potential and ongoing research in PDT.

Main Methods:

• Intravenous injection of a photosensitiser drug.
• Selective accumulation of the photosensitiser in malignant tumour cells.
• Activation of the photosensitiser using specific wavelengths of light (e.g., red light for deeper penetration).

Main Results:

• Photosensitiser activation generates singlet oxygen, which oxidises neoplastic cells.
• Tumour cells are selectively targeted, minimising damage to adjacent normal tissue.
• Porfimer sodium, a photosensitiser, is approved for endobronchial and oesophageal tumours.

Conclusions:

• Photodynamic therapy (PDT) represents a significant advancement in cancer treatment.
• Its unique mechanism allows for repeated treatments and combination with other therapies.
• Ongoing research explores new photosensitisers and applications for various cancers and conditions like macular degeneration.