What compound is administered intravenously in photodynamic therapy?

In photodynamic therapy (PDT), protoporphyrin derivative, specifically porfimer sodium, is administered intravenously. This compound acts as a photosensitizer that gets selectively taken up by cancerous tissues. When exposed to specific wavelengths of light, the activated photosensitizer generates reactive oxygen species that lead to localized destruction of the targeted cells.

Porfimer sodium is particularly effective because it has a high affinity for tumor tissues, improving the selectivity of the therapy compared to other compounds. The ability to activate it with laser light allows for minimal damage to surrounding healthy tissues, making PDT a targeted treatment option. This mechanism relies on both the chemical properties of porfimer sodium and the precision of light delivery, making it a staple in certain oncological treatments.

Other compounds, such as fluorescein and indocyanine green, are used in different contexts, such as imaging or diagnostics rather than direct therapeutic roles in PDT. Chlorophyll derivatives, while they also have photosensitizing properties, are not routinely used in clinical settings for PDT as porfimer sodium is. Therefore, the administration of protoporphyrin derivative (porfimer sodium) is foundational to the effectiveness of photodynamic therapy.