Updated January 2014
Guideline: Prophylactic cranial irradiation for limited stage patients with response to treatment decreases the risk of brain metastases and prolongs survival.
Level of Evidence: I
The rationale for prophylactic cranial irradiation (PCI) is that most chemotherapeutic agents do not cross the blood-brain barrier into the central nervous system in adequate doses to prevent frequent occurrence of brain metastases. The incidence of brain metastases drops from about 25-30% to 5-10% with the addition of PCI. Neurotoxicity (dementia, ataxia) associated with prophylactic cranial irradiation has been described particularly when chemotherapy is given concurrently or after brain irradiation. However, randomized prospective data demonstrate that the incidence of neurological morbidity is not clearly worse in SCLC cohorts given prophylactic cranial irradiation than those not irradiated. However, the attrition of patients from recurrences leaves a small fraction of long-term survivors for analysis. Late neurologic damage with neurocognitive side effects cannot be excluded particularly in patients existing neurological disease or vascular disease. Meta-analysis on 987 patients randomized to receive or not receive PCI has demonstrated a statistically significant benefit with respect to brain metastases-free survival (RR=0.46), disease-free survival (RR=0.75) and overall survival (RR=0.84). This corresponds to a 5.4% increase in 3-year survival rate (Auperin 1999).
Patient Selection for PCI
PCI is recommended for limited stage patients that have responded to induction therapy and have no pre-existing neurological morbidity (such as cerebrovascular disease, dementia, Parkinson's Disease).
PCI should be delivered after completion of induction thoracic irradiation and all chemotherapy.
The dose-fractionation for PCI is 25 Gy in 10 fractions (Le Pechoux 2009).
Auperin A, Arriagada R, Pignon JP, et al. Prophylactic cranial irradiation for patients with small cell lung cancer in complete remission. N Engl J Med 1999;341:476-84.
Le Pechoux C, Dunant A, Senan S, et al. Standard-dose versus higher-dose prophylactic cranial irradiation in patients with limited-stage small-cell lung cancer in completer remission after chemotherapy and thoracic radiotherapy : a randomised clinical trial. Lancet 10: 467-475, 2009