Researchers have identified 3 risk factors that predicted high risk for symptomatic brain metastases in patients with extensive-disease small cell lung cancer (ED-SCLC), according to a new study. Identification of these risk factors may help stratify patients by risk for use of prophylactic cranial irradiation (PCI).
The study included 190 patients diagnosed with ED-SCLC who underwent FDG PET/CT and brain MRI prior to treatment. PCI was used in 27.9% of patients.
With a median follow-up of about 10 months, those patients with a presence of extrathoracic metastases, hypermetabolism of bone marrow of spleen on FDG PET, and those with high neutrophil-to-lymphocyte ratio were all at high risk of symptomatic brain metastases.
Among high-risk patients, the use of PCI was found to significantly improve brain metastasis-free survival compared with patients who did not have PCI (1-year rate, 94.7% vs 62.1%; P =.001). There was no significant difference in brain metastasis-free survival among low-risk patients.
Despite this improvement in brain metastasis-free survival, no difference in overall survival was seen in patients at high risk for metastases that underwent PCI.
The researchers pointed out that the retrospective nature of this study, and the small number of patients both limited its results.
Based on the results of the study, the researchers concluded that “selective use of PCI in ED-SCLC according to the risk stratification is recommended. However, prospective trials with a larger population are needed to validate the use of prognostic index for predicting brain metastases.”
Chung JH, Kang SY, Wu HG, et al. Risk stratification of symptomatic brain metastases by clinical and FDG PET parameters for selective use of prophylactic cranial irradiation in patients with extensive disease of small cell lung cancer [published online February 7, 2020]. Radiother Oncol. doi: 10.1016/j.radonc.2020.01.009