| PurpOSe:The radiological presentation of brain metastases from lung cancer following radiotherapy is complicated and makes it difficult for clinicians to evaluate treatment efficacy and determine prognOSis.This study used MRI monitoring of imaging changes following treatment of brain metastases and investigated the imaging signs associated with evaluation of treatment efficacy and determination of prognOSis following radiotherapy for brain metastases from lung cancer.Methods:A total of 60 non-small cell lung cancer patients with brain oligometastases were selected.MRI scans were conducted within 2 weeks before radiotherapy and 3,6,9,12,18,24,and 30 months after radiotherapy.The tumor and peritumoral edema diameters,Cho/Cr values in the MRS sequence,whether the Lip peak value is elevated,whether the island sign is present,and whether a high-signal ring appears on T2 fluid attenuation imaging were recorded for each metastasis before and after radiotherapy at each time point.The COX proportional hazards regression model was used for multifactorial analysis of factors influencing survival rate.The t-test for independent samples was used for comparison between groups.Results:Mortality risk was higher when the time of appearance of the maximum value of peritumoral edema diameter was shorter,number of island signs was lower,and when brain metastases did not present as "tumor progression" on imaging.The 14 patients with a survival period shorter than 1 year and a total of 25 lesions(group 1)had a significant difference in average value of peritumoral edema diameter at 9 months after radiotherapy compared to patients with a survival period longer than 2 years(group 3),with the value for group 1 larger than for group 3(p<0.05).There was a significant difference in ADC value at 3 and 6 months after radiotherapy,with the value for group 1 less than for group 3(p<0.05).The number of elevated Lip peak values at 9 and 12 months after radiotherapy differed between the two groups(p<0.05).The number of T2 fluid attenuation imaging high-signal rings at 12 months after radiotherapy differed between the two groups(p<0.05).There was no significant difference in average tumor diameter and average Cho/Cr values between the two groups.Conclusion:After radiotherapy for brain metastases,patients with the island sign,late appearance of the maximum value of peritumoral edema diameter,and metastases presenting as "tumor progression" on imaging had longer survival periods.T2 fluid attenuation high-signal rings,elevated Lip peaks,and reduced ADC values indicate necrosis following radiotherapy for brain metastases.Increased diameter of metastases and Cho/Cr>2 on MRS cannot serve as reliable indicators of brain metastasis progression. |
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