Photodynamic therapy: a novel treatment for primary brain malignancy.

Providing therapy that conserves healthy brain tissue while effectively killing cancerous tissue remains a major challenge in the treatment of primary malignant brain tumors. The most common primary brain malignancies tend to recur despite intensive therapy, and the side effects of radiotherapy and chemotherapy can have considerable influence on health and quality of life. Photodynamic therapy (PDT) is a new technology being investigated to fulfill the need for a targeted cancer treatment that may reduce tumor recurrence and extend survival with few adverse effects. An investigational treatment, PDT employs wavelength-specific light in combination with a photosensitizing agent. The photosensitizing agent accumulates in tumor cells and is activated by nonthermal light, producing radical oxygen species that locally kill tumor cells. The selectivity of the process makes PDT appealing in the brain, where conservation of healthy tissue is vital. The most widely studied photosensitizer causes several weeks of ocular and cutaneous photosensitivity. Nursing care of the PDT patient includes intracranial pressure monitoring, neurological assessment, and intensive patient and family education. Many new photosensitizing compounds and varying methods of light delivery are being studied. This technology shows promise for the treatment of primary brain malignancies.