Inclusion Criteria:  Age 18 years old or above Pathological or radiological diagnosis of non-small cell lung cancer Undergoing radical radiotherapy to the thorax using the following fractionations (55 Gray in 20 fractions, 54 Gray in 36 fractions or any Stereotactic Ablative Body Radiotherapy (SABR) fractionation that delivers a biological effective dose of greater than 100Gy10) as part of their primary lung cancer treatment at time of study enrolment Patients receiving concurrent and/or adjuvant systemic therapies are permitted Radiotherapy is delivered in the Beatson West of Scotland Cancer Centre Signed, written informed consent Willing and able to complete study processes  Exclusion Criteria:  Not fluent in English