Lung cancer is a significant global health challenge, ranking as the second most common cancer worldwide and the leading cause of cancer-related mortality. The majority of patients with lung cancer are treated with non-surgical therapies. Accurate response assessment for patients with lung cancer treated with is important in determining treatment efficacy and in recognizing treatment-related adverse effects. In this book chapter, we describe the role of quantitative imaging in response assessment for patients with lung cancer treated with chemotherapy, targeted therapies, and immunotherapies. We describe the current standard of care, along with new and emerging techniques.