Relationship Between MRI Findings And The Pathological Type Of The Primary Tumor Of Brain Metastases

Background:Brain metastases accounted for3.5-10%of the brain tumor, Lung cancer isthe most common primary tumor[1]. The final cause of death in patients with brainmetastases of lung cancer is more common in systemic metastasis of lung cancerthan intracranial spread or recurrence of brain metastases.Therefore, it isimportant to treat the primary tumor in patients with brain metastases. On theother hand, the treatment programs for the different histological types of lungcancer are not the same. Therefore, clarify pathologic type of lung cancer totake different treatment programs is very favorable for the prognosis ofpatients. But in some cases it is difficult to identify the histologic typeof the primary lung tumor by biopsy or surgery. Great help will be provide forclinical treatment if we can infer the pathological type of lung cancer imagingfindings of brain metastases. This paper conducted retrospective analysis onMRI characteristics of patients suffering from brain metastases of three commonhistological types of lung cancer, and to investigate the relationship betweenMRI findings and the histologic type of the primary tumor of brain metastases.Materials and Method:50cases of patients with brain metastases of lung cancer confirmed byclinical and imaging follow-up or pathology were enrolled, from May.2010toDec.2012, Tumor Hospital of Jilin Province. Primary tumor（lung cancer）ofcases were confirmed by pathology, and divided into24cases of adenocarcinoma,10cases of squamous carcinoma and16cases of small cell lung carcinoma. Allthe cases have been double-blind read by two physicians，retrospectivelyanalyzed the imaging performance. Record number，size, location, hemorrhageand cystic change, performance of DWI and contrast enhancement of lesions, and severity of edema around lesions in each group, then draw the table. SPSS17.0and chi-square (p<0.05) was used to make the significant analysis.rusults:1.size and number: Solitary brain metastases were more common in brainmetastases of lung squamous cell carcinoma compared with the other two types,and brain metastases of lung squamous cell carcinoma had larger lesions. Bothof the difference were statistically significant.2. location: Brain metastaseswere more common in frontal and parietal regions.There was no correlationbetween location of brain metastases and the primary tumor pathological type.3.hemorrhage and cystic change: The number of hemorrhage and cystic lesionsof brain metastases of lung squamous cell carcinoma tumor was so small thatsquamous cell carcinoma and adenocarcinoma were combined into non-small celllung cancer group to statistically analyzed in order to ensure test reliability.Incidence of hemorrhage lesions in small cell lung carcinoma was higher thanin non-small cell lung carcinoma. Incidence of cystic lesions was no significantdifference in brain metastases of different types of lung cancer.4. performanceof DWI: compared with non-small cell lung cancer (including adenocarcinoma andsquamous cell carcinoma), more brain metastases of small cell lung cancer wererestricted diffusion.5. performance of contrast enhancement: ring-likeenhancement and nodular enhancement lesions is most common in brain metastases.brain metastases of adenocarcinoma usually presents nodular enhancement, andbrain metastases of Squamous cell carcinoma and small cell lung cancer usuallypresents ring-like enhancement.6. severity of edema: In the threehistopathological type, it was the highest rate of serious edema for brainmetastases of squamous cell cancer.Conclusion:Location of brain metastases and incidence of cystic lesions has nosignificant difference in brain metastases of different types of lung cancer.And the number, size, hemorrhage, performance of DWI and contrast enhancement of lesions, and severity of edema around lesions in each group had statisticallysignificant difference. Therefore, MRI features may be used to evaluatehistopathological type of lung cancer of brain metastases for patients whosehistopathological type of cancer could not be confirmed by biopsy or surgeryto guide clinical treatment.