Take a deep breath.
Top Line: How do you approach lung cancer in patients with interstitial lung disease?
The Study: ILD is known to increase the risk of severe pulmonary toxicity and mortality from radiation. The challenge is that patients with ILD have an increased risk of NSCLC, are often poor medical candidates for surgical management, and are at increased risk of toxicity and mortality from other forms of non-radiation treatment. Here’s a great primer on managing lung cancer in patients with ILD. First off, ILD is a broad term that, when used broadly, doesn’t really help us risk-stratify patients for radiation. Fibrotic ILD is the subset most likely to be associated with severe radiation toxicity. On high-resolution CT, fibrotic ILD is characterized by subpleural reticulation, traction bronchiectasis, and honeycombing as opposed to ground glass opacities, lack of fibrosis, and parenchymal sparing seen in non-fibrotic ILD. So what is the risk of severe toxicity with SBRT? In a study of ILD patients treated with lung SBRT, a V20 > 6.5% and mean lung dose > 4.5 Gy were associated with increased risk of mortality (~10→ 30%) and severe toxicity (20→ 40%). The ongoing ASPIRE-ILD trial quotes patients a 10% risk of mortality and 20% risk of ILD toxicity. Keys to making good treatment decisions are: get a high-resolution CT, request the help of pulmonology and get PFTs, optimize anti-fibrotic medical therapy before treatment, and use the ILD-GAP tool to assess mortality risk from ILD. With this approach, most patients would still benefit from standard treatment. However, in patients with a high baseline risk of ILD mortality or who require more extensive coverage for locally advanced disease, compromises may be necessary to balance the competing risks of lung cancer and treatment toxicity.
TBL: Use an informed approach to treating NSCLC in patients with ILD in order to minimize toxicity without compromising treatment. | Goodman, J Thorac Oncol 2020