Effect of 125I implantation on pulmonary function in impossible non-small cell lung cancer

Objective To evaluate pulmonary function and tumor volume before and after CT- guided radioactive 125I seed implantation in inoperable patients with and without chronic obstructive pulmonary disease(COPD) in early-stage(IA, IB) lung cancer. Methods From October 2013 to June 2018, 58 patients with early non-small cell lung cancer were treated with 125I radioactive seed implantation. Patients were divided according to the results of pre-treatment pulmonary function tests: 16 patients(10 males and 6 females) were included in the COPD groups and 42 patients(28 males and 14 females) were included in the No-COPD group. Changes in pulmonary function forced expiratory volume in one second, diffusing capacity of the lungs for carbon monoxide(DLCO), and forced vital capacity were detected within 2-6 months after operation. Statistical analysis was conducted via t test. Results The D90 was(114.3±10.2) Gy, the V90 was(92.3±7.2)%, and the matched peripheral dose was 112.8 Gy. The pretreatment and post treatment FEV% of the COPD and No-COPD groups were similar at a mean follow-up time of 6 months(t =0.70, 0.20, both P>0.05). The DLCO of the COPD group did not change after CT-guided radioactive 125I seed implantation treatment(t=1.11, P=0.563); however, DLCO significantly increased in the No-COPD group(t=2.29, P=0.019). There was no significant difference in the tumor volume between the COPD group and the No-COPD group before and after treatment(t=1.82, 1.26, both P>0.05), but the difference between the COPD group and the tumor volume of the No-COPD group was statistically significant before and after the treatment(t=5.78, 9.96, both P 110 Gy group(34 cases) and ≤110 Gy group(24 cases), differences in the FEV1% and FVC% of the COPD and No-COPD groups after implantation were not statistically significant(t=0.54, 0.37, 0.21, 0.22, all P>0.05). Conclusion 125I implantation therapy for inoperable non-small cell lung cancer does not seem to affect FEV1% and FVC% but can shrink tumor volume and improve DLCO in patients without COPD Key words: Carcinoma, non-smal-cell lung; Respiratory function tests; Iodine radioisotopes; Brachytherapy