Controversies and progresses in prophylactic cranial irradiation for small cell lung cancer

Small cell lung cancer (SCLC) is a kind of highly invasive malignant neoplasm, which is characterized by short survival and high-risk cranial metastasis. Therefore, application of prophylactic cranial irradiation (PCI) is of clinical significance to reduce the incidence of brain metastasis and prolong the patients' survival on the basis of radio-and chemo-therapy. Nevertheless, the indications and clinical value of PCI have been controversial in recent years. These controversies mainly include the significance of PCI for extensive-stage SCLC, the indications of PCI for limited-stage SCLC and the alternative approaches for PCI. In this paper, the controversies and progresses of PCI applied in clinical practice are investigated and reviewed. (authors)