KEY POINTS
- This single-center retrospective study included 56 patients with stage IA–IIIC NSCLC and severe or very severe pulmonary dysfunction, defined as FEV1 <40% predicted or DLCO <40% predicted, treated from 2020–2024. Patients were unsuitable for or declined surgery and radical external-beam radiotherapy and required KPS >60.
- CT-guided iodine-125 implantation used a PTV defined as GTV plus 5 mm, with a planned D90 of 120–140 Gy. A mean 52.6 seeds were implanted through 5.57 needles per patient, with seed activity approximately 0.73 mCi; postoperative verification found 55.4% achieved D90 ≥120 Gy.
- At one year, 14 patients achieved complete response and 20 partial response, producing an objective response rate of 60.7% and disease-control rate of 67.9%. Median overall survival was 18 months and median progression-free survival 13 months.
- A dose-response signal was observed. Patients achieving complete response had substantially higher D90 than those without complete response (141.4 vs 118.9 Gy; p=0.0004). D90 predicted complete response with AUC 0.804, while the predefined ≥120-Gy threshold remained independently associated with better overall survival (HR 0.67; p=0.032) and progression-free survival (HR 0.64; p=0.006).
- Among stage IIA–IIIC patients, those receiving postoperative systemic treatment had median overall survival of 28.0 versus 13.5 months and median progression-free survival of 20.0 versus 8.5 months. Because systemic treatment was not randomized and patients declining it differed clinically and socioeconomically, these comparisons are highly confounded.
- Pulmonary function was notably preserved. Baseline FEV1 was approximately 36% predicted and was significantly higher at three and 12 months, while DLCO remained statistically unchanged through 12 months. KPS likewise showed no significant deterioration, remaining around 65 at baseline and 64.8 at 12 months.
- The major procedural toxicity was pneumothorax requiring drainage in 14/56 patients (25%); risk was 34.4% with visible pulmonary bullae versus 12.5% without. Radiation pneumonitis occurred in 5.4%, all below grade 3; there were no grade ≥3 radiation pneumonitis events and no treatment-related deaths.
CLINICAL TAKEAWAY
For NSCLC patients with profoundly impaired lung function who cannot undergo surgery or conventional radical RT, CT-guided iodine-125 implantation produced meaningful tumor control without measurable deterioration in residual pulmonary function. The signal is clinically interesting, but selection bias, heterogeneous systemic therapy, post-hoc dose-response analyses and the absence of a control group make comparative efficacy against SBRT or other local therapies unknown.