[18F]HX4 PET/CT Imaging for Detection of Hypoxia

Inclusion Criteria: * Patients with: 1. biopsy proven non-small cell carcinoma of the lung \>2.5 cm in size with any T and N status but M0 who have elected to undergo radical radiotherapy or chemo-radiotherapy with curative intent or 2. squamous cell carcinoma of the upper aerodigestive tract with a primary tumour or nodal mass \>2. 5 cm in size, with any T and N status but M0 who have elected to undergo radical radiotherapy or chemo-radiotherapy with curative intent. * Participant must be willing and able to give informed consent for participation in the study. * Patients must be 18 years old or above. * Eastern Cooperative Oncology Group (ECOG) performance status of 0, 1 or 2. * Have normal renal function, defined by creatinine clearance of \>60 mL/min. * Able to remain still in the supine position on the scanner bed for the 40 minute duration of the examination. * Able (in the Investigators opinion) and willing to comply with all study requirements. * Willing to allow his or her General Practitioner and hospital consultant, if appropriate, to be notified of participation in the study Exclusion criteria * Patients who are scheduled for surgery prior to radiotherapy will not be included. * Female participant who is pregnant, lactating or planning pregnancy during the course of the study. * Chronic kidney disease stage III or worse, as defined by the NKF clinical practice guidelines (GFR \<60 mL/min per 1.73 m3 for 3 months or more). * Any other significant disease or disorder which, in the opinion of the Investigator, may either put the participants at risk because of involvement in the study, or may influence the result of the study, or the participant's ability to participate in the study. * Participants who have been involved in another research study involving an investigational product in the past 12 weeks. * Previous surgery or radiotherapy to the upper aerodigestive tract or lung, which in the opinion of the Investigators could compromise the data. * Previous cancer diagnosis.