Patients with loco-regional NSCLC planned for curative treatment with chemoradiotherapy will be invited to participate in a prospective study; besides routine treatment, the patients will be followed with an ECG and cardiac MR for at least two years after radiotherapy treatment.

Definitive chemo-radiotherapy is the treatment of choice for loco-regional advanced non-small cell lung cancer (LA-NSCLC). However, the treatment is associated with a range of side effects with radiation pneumonitis and esophagitis. In addition, the toxicity of the heart in lung cancer patients treated with radiotherapy has been offered less consideration. Therefore, it is essential to investigate the possible early and late toxicity to the heart and the baseline cardiac status of these patients. This study will describe cardiac comorbidity before radiotherapy treatment by a thorough history. Furthermore, we will evaluate heart function and evaluate possible heart disease by an ECG and cardiac MR. Patients will be followed with ECG and cardiac MR for two years after radiotherapy, detecting structural changes caused by radiotherapy and subclinical disease after radiotherapy.

Inclusion Criteria:

• Age ≥ 18 Years
• Inoperable and histologically/cytologically verified NSCLC.
• Planned treatment with curative intent.
• Capable of completing study procedures ECG and Cardiac MR.
• Able of giving written and informed consent before study procedures are initiated.

Exclusion Criteria:

• Vulnerable patients.
• Patients with operable devices as pacemaker/ICD and cochlear implant or other conditions where MR scan is contraindicated.
• Claustrophobia.

Patients with locally advanced non-small-cell lung cancer will be included at the department of oncology at Odense University Hospital.