Biological Effects And Clinical Study Of Image-guided ¹²⁵I Seed Interstitial Brachytherapy In Lung Cancer

Experimental study of biological effects of ¹²⁵I seeds and 60 Co radiation on non-small cell lung cancer cellsObjective: To investigate the biological effects of ¹²⁵I seeds compared with 60 Co radiation on non-small cell lung cancer（NSCLC） cells A549 and normal bronchial mucosa epithelial cells BEAS-2B. Methods: A549 and BEAS-2B cells were exposed to ¹²⁵I seeds radiation and 60 Co radiation, respectively. The experimental groups were exposed to ¹²⁵I seeds radiation and 60 Co radiation at 2, 4, 6 and 8Gy, control groups were subjected to the same procedure without radiation（0Gy）. The survival fraction, cell apoptosis, cell cycle, and the expression of apoptosis related proteins were detected, respectively. Results: The surviving fraction of A549 and BEAS-2B cells induced by ¹²⁵I seeds radiation and 60 Co radiation were significantly decreased compared with control group. And the surviving fraction induced by ¹²⁵I seeds radiation was significantly lower than that of 60 Co radiation. A G1 arrest in A549 cell was observed after irradiation with ¹²⁵I seeds at 4, 6 and 8Gy. Both ¹²⁵I seeds radiation and 60 Co radiation led to a markedly increase of apoptotic cells at 4, 6 and 8Gy on A549 cells. ¹²⁵I seeds radiation led to a higher percentage of apoptotic cells than that of 60 Co radiation. Both ¹²⁵I seeds radiation and 60 Co radiation significant up-regulated the expression of Bax protein and down-regulated the expression of Bcl-2 protein at 4 and 8Gy on A549 cells, moreover the effects induced by ¹²⁵I seeds radiation were more obvious than that of 60 Co radiation. The apoptotic ratio and the expression of apoptosis-ralated protein in BEAS-2B cells had little difference between two types of radiation. Conclusions: Both ¹²⁵I seeds radiation and 60 Co radiation led to a remarkable growth inhibition and apoptosis promotion on NSCLC cells, ¹²⁵I seeds radiation was more prominent compared with 60 Co radiation. The imbalance of Bcl-2/Bax and the activation of Caspase-3、PARP proteins may play an important role in the antiproliferative effect induced by ¹²⁵I seeds radiation.The efficacy evalution of image-guided ¹²⁵I radioactive seed interstitial brachytherapy for advanced non-small cell lung cancer in clinical studyObjective: The aim of this study was to examine the clinical efficacy of image-guided ¹²⁵I radioactive seed implantation therapy in patients with advanced non-small cell lung cancer（NSCLC）.Methods: 28 patients with advanced NSCLC who had medical contraindications for surgical resection were treated with CT-guided iodine 125 seeds implantation between December 2013 and March 2015. Treatment planning system（TPS） was used to reconstruct 3-Dimensional image of lung tumor. According to the target imaging, the quantity and distribution of ¹²⁵I seeds were defined before treatment. The visual analog scale（VAS） was used to determine pain intensity one month before and after treatment. The karnofsky performance scale（KPS） was used as a measure of functional status before and after treatment. Tumor curative effect was evaluated according the the newly revised solid tumor curative effect evaluation in 2000. Serum CEA and CYFRA21-1 were detected by radioimmunoassay in NSCLCResults: Median implanted number of seeds was 25（range 8⁴5）. The tumor matched peripheral dose（MPD） was 80¹30Gy. Follow-up period was 1³7 months. Pain symptoms were significantly reduced post-treatment（P<0.05）. VAS decreased from 4.14±1.69 points before treatment to 2.29±1.41 points one month after treatment. Karnofsky score went up dramatically（P<0.05）. Median control time for all patients was 15.5 months. The 1-, 2-year cumulative local control rate were 58.04%, and 20.31%. The median survival period for all enrolled patients was 17 months. The 1-, 2-, and 3-year cumulative survival rates were 71.95%, 30.84%, and 6.17%. The levels of serum CEA and CYFRA21-1 were induced significantly（P<0.05） one and three months after planting. The mortality rate was 53.85% in increased levels group and 86.67% in decreased levels group in serum CEA detection. Similarly the mortality rate was 36.36% in increased levels group and 94.12% in decreased levels group in serum CYFRA21-1 detection. A small amount of bleeding of lung tissue was observed in all patients. 11 cases patients had pneumothorax with no obvious self-conscious symptoms and improved after conservative treatment. 5 patients appeared with small amount of blood in phlegm one week post-treatment and with no special handling to ease. No seed migration was found in radiographic follow-up. There were no serious complications such as haemoptysis, tracheal fistula and radioactive pneumonia detected during the follow-up period.Conclusions: The study suggested that CT-guided ¹²⁵I seeds implantation was a safe, effective, less complicated option in treating advanced NSCLC. However, this result required further evaluation to determine its long-term efficacy.