Stereotactic radiosurgery such as whole-brain or non-whole-brain gamma knife becomes an important treatment option after the development of brain metastases from tumors, but the median survival of patients remains limited. However, Kondziolka et al. from the University of Pittsburgh School of Medicine reported longer survival in some patients treated with this approach.
To clarify which clinical or therapeutic factors are associated with long-term survival in these patients, the Beijing Second Artillery Gamma Knife Center conducted a retrospective study of data from 677 patients who underwent radiation therapy for tumor brain metastases between 2007 and 2009. For those patients who survived more than 4 years after treatment, the investigators analyzed factors such as cerebral and extracerebral treatment modalities, imaging presentation, treatment-related morbidity, symptoms, and follow-up care, and compared them with those whose survival was shorter than 3 months.
The results showed that a total of 44 patients (6.5%) survived more than 4 years (mean 69 months) after radiation therapy, 16 of whom were still alive at the end of follow-up. The most common primary lesions were lung (15), breast (9), kidney (7), and cutaneous melanoma (6). 18 patients (41%) had lesions involving two or more extracerebral organs, and 10 patients (23%) had extracerebral lesions The remaining 7 patients (16%) had only brain lesions. Imaging data showed that 99 (74%) of the total 133 tumor lesions were reduced in size, 22 (17%) were unchanged, and the remaining 12 (9%) were enlarged. Compared with 100 patients with survival shorter than 3 months after treatment, these patients with longer survival had higher initial KPS values (P=0.01), fewer metastatic lesions in the brain (P=0.04) and fewer extracranial lesions (P