A Translational Study Investigating PD-L1 Expression After Radiotherapy for Non-small Cell Lung Cancer

"Archival tumour biopsies will be analysed for baseline PD-L1 expression. Some participants will have a biopsy before radiotherapy if the archival biopsy is not suitable.~Participants will be required to undergo an additional mandatory biopsy of the irradiated site during the second week. Patients must have completed at least 1 week of the planned treatment before taking the biopsy.~Participants will also be asked for consent to donate 50ml blood pre biopsy (at baseline and week 2) and at the end of radiotherapy; as well as 10ml blood before #2 radiotherapy and weekly throughout treatment."