Lung cancer is one of the leading causes of cancer-related deaths worldwide and poses a major public health challenge in India. In the North-East region of India, lung cancer is particularly common, and many patients are diagnosed at an advanced stage when surgery is not possible.

In such situations, radiotherapy, with or without chemotherapy, is often given with the aim of controlling the disease and improving survival. However, there is very limited information from this region on how well these treatments work in routine clinical practice and what side effects patients experience.

This study aims to review and analyze the treatment outcomes of lung cancer patients who received definitive (curative-intent) radiotherapy, with or without concurrent chemotherapy, at a tertiary cancer centre in North-East India. By examining existing medical records, the study will assess survival outcomes, patterns of disease recurrence, and treatment-related toxicities in real-world conditions.

The importance of this research lies in addressing a significant gap in regional data. Most available evidence guiding lung cancer treatment comes from Western countries or other parts of India, which may not fully reflect the patient population, disease characteristics, and resource limitations of North-East India. Understanding outcomes in this specific setting is essential to ensure that treatment strategies are appropriate, effective, and feasible for local patients.

The findings of this study are expected to help clinicians better understand what can realistically be achieved with definitive radiotherapy and chemoradiotherapy in this region. The results may guide future treatment planning, improve patient counseling, and support the development of context-appropriate protocols in resource-limited settings. Ultimately, the study has the potential to contribute to improved quality of care and outcomes for lung cancer patients in North-East India.