Research progress on prophylactic cranial irradiation in patients with surgically resected small cell lung cancer

The incidence of small cell lung cancer (SCLC) is relatively low, which approximately accounts for 13%-20% of all types of lung cancers. SCLC is characterized by high-degree malignancy and high metastasis and recurrence rates within a short period of time. Upon the confirmed diagnosis, limited-stage SCLC approximately accounted for 30% of SCLC and merely 5% of these patients were eligible for surgery. Over half of the patients who obtained complete remission after chemoradiotherapy presented with brain metastases. The postoperative incidence of brain metastases in patients with stage I, II and III SCLC was 6%-14%, 13%-38% and 11%-36%, respectively. Prophylactic cranial irradiation (PCI) can enhance the overall survival rate of patients with complete remission after chemoradiotherapy and reduce the incidence of brain metastasis, which is a pivotal part of comprehensive treatment of limited-stage SCLC. However, the application of PCI remains controversial in clinical practice and the clinical efficacy for patients with surgically resected SCLC significantly varies. In this article, literature review was conducted and the research progress in this field was summarized. (authors)