CT-guided interstitial brachytherapy of inoperable non-small cell lung cancer

Purpose

The aim of this study was to assess the technical feasibility, efficacy, and complications of CT-guided interstitial brachytherapy for treating inoperable non-small cell lung cancer (NSCLC).

Materials and methods

Twenty one patients were included in this prospective study. The median age was 72.6 years (57-85). Tumors were treated with brachytherapy that was positioned under CT-fluoroscopy. The treatment planning system (TPS) was used preoperatively to reconstruct three dimensional images of the tumor and to calculate the estimated seed number and distribution. The median matched peripheral dose (MPD) was 130 Gy (range, 100-160 Gy). All procedures were performed under local anesthesia. A follow-up CT was performed 6 weeks later and every 3 months post implantation.

Results

Follow-up period was 2-30 months. The mean diameter of the 21 lung tumors was 4.6 cm (range, 2.8-6.5 cm). The response rate of pain relief was 83.3% (10/12). The pain-free duration was 0-12 months (median: 6 months; 95% CI: 3-9 months). Overall responding rate (CR + PR) for this group of patients was 71.4%. Local tumor control rate was 85.7%. Six (28.6%) patients died as a result of primary tumor progression; thirteen (61.9%) patients died of multi-organ failure or other metastases. Two (9.5%) patients survived to follow-up. At the time of analysis, the median survival time for all patients was 10 months (95% CI: 6.6-13.4 months), with 1 year and 2 year survival rates were 42.4% and 6.5%, respectively. Median survival time for stage II, stage III, and stage IV was 20 months, 9 months, and 8 months, respectively. No major complications were observed. Minor complications (19%) included mild pneumothorax (n = 1), hemosputum (n = 1), pleural effusion (n = 1), and localized skin erythema (n = 1). None of these complications required further treatment, although hospital discharge was delayed. No ¹²⁵I seeds migrated to other tissues or organs.

Conclusion

Minimally invasive CT-guided interstitial brachytherapy is safe, useful, less complicated and considered as a palliative treatment option for inoperable non-small cell lung cancer.