[Efficacy of permanent interstitial implantation of 125I seeds for solitary brain metastasis from non-small cell lung carcinoma].

BACKGROUND & OBJECTIVE: Some studies have already showed that whole brain irradiation (WBI) could cause radiation brain damage. It is necessary to explore a novel treatment modality to replace whole brain irradiation without influencing the therapeutic efficacy. The purpose of this study was to assess the therapeutic efficacy and radiation brain damage of permanent interstitial implantation of 125I seeds following tumor resection for solitary brain metastasis from non-small cell lung carcinoma (NSCLC).

METHODS

Sixty-seven patients with solitary brain metastasis from non-small cell lung carcinoma were randomly assigned into two groups: Thirty-two cases(47.8%) were treated with resection and permanent interstitial implantation of 125I seeds(I), and 35(52.2%) received whole brain irradiation and local-small-field radiation (C). All patients were biopsy-verified non-small cell lung carcinoma, including 42 squamous cell carcinomas and 25 adenocarcinomas. They all were solitary brain metastasis from non-small cell lung carcinoma diagnosed by CT or MRI. After resection of solitary brain metastasis, different numbers of 125I seeds were implanted according to some parameters in group I. In group C, 35 patients received whole brain irradiation to a total dose of 30-39 Gy/3-4 weeks, 2-3 Gy/fraction, 5 fractions/week followed by a boost of 15-25 Gy/2-3 weeks through local-small fields.

RESULTS

The local control rate, the recurrent rate, and the median recurrent time were 96.9%, 15.6%, and 9 months in group I, and 82.9%, 17.1%, and 7 months in group C, respectively. The differences were no significant (P > 0.05). The median survival time, the 1-year survival rate, and the 1-year mortalities were 12 months, 40.6%, and 28.1% in group I, and 9 months, 31.4%, and 37.1% in group C, respectively. The differences were significant(P < 0.05). Acute irradiation response and radiation brain damage were markedly milder in group I than in group C.

CONCLUSIONS

The results from this study show that resection and permanent interstitial implantation of 125I seeds for solitary brain metastasis from non-small cell lung carcinoma can not only improve the survival rates and decrease the mortalities, but also reduce radiation brain damage to improve the life quality. It is a good and effective modality, especially for younger patients. However, further study for long-term effect is needed.