Indications for prophylactic cranial irradiation in patients with small cell lung cancer

Abstract

Brain metastases are one of the important causes of failure in the treatment of SCLC patients. Intracranial metastases are reported in 10% of the newly diagnosed SCLC pts. Further 20% brain metastases develop during therapy. Autopsy studies showed that 40%-60% of pts had evidence of intracranial spread at the time of death. The frequency of brain metastases increases with the duration of survival, reaching a probability of 80% after 2 years of observation. The high risk of brain metastases which developed in spite of chemotherapy was the reason of introducing PCI to the treatment. PCI reduces the risk of brain metastases to less than 10%, but unfortunately, does not prolong median survival. Probably this is due to the fact, that in the majority of cases the brain is one of many sites of metastases at the time of progression. In addition, in some pts brain metastases developed in spite of PCI and/or brain toxicity may develop after this treatment. Thus, up till now the role of PCI in the treatment of SCLC pts remains controversial. The indication for this treatment could improve if we have more exact information which pts have the greatest probability do develop metastases restricted to the brain only. This question was the main aim of our study.