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Prophylactic Cranial Irradiation for Small Cell Lung Cancer

Prophylactic Cranial Irradiation for Small Cell Lung Cancer

Question

Can you give me information and statistics on prophylactic cranial irradiation for prevention of small cell lung cancer? My husband is in remission and this procedure has been recommended. Thank you.

Answer

Barbara Campling, MD, Medical Oncologist, and Stephen M. Hahn, MD, Professor of Radiation Oncology at Penn Medicine, respond:

It's good to hear that your husband is in remission from his small cell lung cancer. As you probably know, small cell lung cancer has a tendency to spread outside the chest, and one of the most unpleasant sites of metastasis is the brain. In patients who have gone into remission with treatment, the chances of eventual recurrence in the brain are quite high, approximately 60% at two years. This is probably because the chemotherapy drugs that are used to treat small cell lung cancer do not penetrate brain tissue very well. The chance of recurrence in the brain can be reduced to 30-45% at two years by giving radiation to the brain, or approximately a 50% reduction in the development of brain metastasis compared with patients who do not receive prophylactic cranial irradiation (PCI). Prophylactic means preventive or protective, and cranial irradiation refers to treatment of the whole brain with the use of high-energy x-rays in order to destroy any potential microscopic cancer in this area.

Many individual studies have shown that this prophylactic treatment reduces the chance of cancer recurrence in the brain and the development of symptoms from brain metastasis. . PCI has also been shown to improve overall survival in patients who get PCI compared to those who do not. The downside of this treatment is that it can delay recovery from the treatment that has already been given, and it may also have a risk of causing cognitive impairment. This toxicity is not well understood because there have not been large, long-term studies on the side effects of PCI. Overall, however, PCI is recommended for patients with a good performance status and no preexisting neurocognitive impairments who have a complete response to treatment for limited-stage small cell lung cancer, as well as stable disease, partial response, or complete response to treatment for extensive-stage small cell lung cancer. You and your husband should discuss this in detail with his Radiation Oncologist.