Risk Factor Study of Radiation Pneumonitis Focused on Subclinical Interstitial Lung Disease in Definitive Radiation Therapy for Non–Small Cell Lung Cancer: A Single-Institution Experience

Abstract

operating characteristics (ROC) analysis was used to determine the optimal cutpoint for dosimetric parameters. Results: We included 138 cases: 73 men (53.0%); median age 63 years (range, 42-83); predominantly NSCLC (N Z 114, 82.6%). Most patients received either platinum/etoposide (N Z 83, 60.1%) or carboplatin/taxol (N Z 48, 34.8%). Median RT dose was 61.2 Gy (range, 45-70 Gy). The rate of HT3+ was 41.3% (n Z 57). Increasing mean TVB dose (per Gy) was associated with a higher odds of developing HT3+ (OR Z 1.06, 95% CI Z 1.01-1.10, P Z 0.012). Increasing TVB V5-V40 was all significantly correlated with increased odds of developing HT3+. ROC analysis found that the optimal cutpoint for mean TVB dose was 23 Gy. The OR for developing HT3+ was 2.80-fold higher in patients with mean TVB dose >23 Gy compared to 23 Gy (95% CI Z 2.80-5.63, P Z 0.001). On multivariate analysis, increasing mean TVB dose, increasing age, and decreasing BMI were all statistically significantly associated with increased odds of developing HT3+. When excluding patients with SCLC, mean TVB dose and V5-V20 remained significantly associated with HT3+. Conclusion: We found that increasing TVB dose was associated with clinically significant HT in patients with lung cancer treated with CRT. This suggests that efforts to spare dose to the TVB may reduce rates of HT and potentially improve patient outcomes. Further prospective validation of these results is needed.

Application of a radiation pneumonitis prediction model in patients with locally advanced lung squamous cell cancer

“…Pre-existing radiological interstitial lung abnormalities (ILAs) are clinical risk factors for severe RP in patients with small cell lung cancer (11). RP tends to be more common in patients with subclinical interstitial lung disease (sILD), which includes undiagnosed patients who have ILA, as revealed by chest computed tomography (CT) scans (12,13). Current RP models do not adequately consider sILD and PE in patients treated with conventionally fractionated radiotherapy.…”