Prophylactic cranial irradiation in small and non-small-cell lung carcinoma

Abstract

At initial presentation, approximately 10–14 % of small-cell lung carcinoma (SCLC) patients manifest with radiologically evident brain metastases (BM) which arises up to 69 % at 2 years. Similarly, brain failures are reported in 21–54 % of all non-small-cell lung carcinoma (NSCLC) patients, and of these, the brain is the first site of relapse in 15–30 % cases. Although significant improvements have been achieved in local and distant control of both SCLC and NSCLC as a result of implementation of aggressive treatment modalities, unfortunately such aggressive treatments proved no noteworthy viability in lessening of overall brain or brain as the first site of relapse rates. Regarding its counteractive actions on BM emergence, the potential beneficial effects of prophylactic cranial irradiation (PCI) in patients with limited-stage SCLC (LS-SCLC), extensive-stage SCLC (ES-SCLC), and locally advanced NSCLC (LA-NSCLC) have been addressed with several randomized trials and meta-analysis. Based on the results of these investigations, PCI of 25 Gy (2.5 Gy in ten fractions) should be recommended for all medically fit LS- and ES-SCLC patients with any objective response to primary therapy in order to reduce BM incidence rates and to prolong OS times. Although the PCI studies in LA-NSCLC patients suggest significant reductions in BM incidence rates with PCI, yet in the absence of an established survival benefit, it is currently quite difficult to recommend its routine use in LA-NSCLC patients. However, future studies involving high-risk patients may prove worthy in determination of the exact impact if they are needed in order to reliably comment on the issue of PCI in LA-NSCLC patients.