Radiotherapy (RT) plays a major role in the management of lung cancer as most patients are not surgical candidates due to stage, fitness and comorbidities. In the last decade we have witnessed tremendous changes in the role of radiation for the radical treatment of lung cancer as a result of the optimisation of chemo-radiotherapy (CTRT) combinations and technological advances.

The technology available for RT planning, delivery and verification of lung cancer treatment is evolving at a fast pace. Unfortunately the evidence to demonstrate the benefit of such technology in terms of toxicity, local control, survival or quality of life is limited. Recent guidelines for the planning and execution of high-does RT for lung cancer have been published [De Ruysscher JCO 2010].

Patients with locally advanced NSCLC are generally treated with a combination of chemotherapy and RT (typically 55 Gy in 4 weeks in some UK centres or 60-66 Gy in 6-6.5 weeks) either delivered sequentially or concurrently. Concurrent CTRT is the standard of care in stage III NSCLC but the majority of patients are not suitable for this treatment based on performance status and comorbidities [De Ruysscher, Ann Oncol 2009]. Furthermore local control with current RT doses delivered with standard 3D conformal RT is poor with local progression-free survival rates of about 30 %, even with concurrent CTRT. Recent evidence has provided encouraging data that improved local control in lung cancer can lead to improvement in survival [Aupérin A. J Clin Oncol 2010]. The following strategies can be combined to improve outcome in locally advanced NSCLC include:

• Dose escalation (facilitated by the use of IMRT)
• Acceleration
• Dose redistribution based on functional imaging
• Individualisation of the dose (concept of isotoxic RT)
• Combination of RT with molecularly targeted agents leading to an increase in radiosensitivity