Inclusion Criteria
1. Age ≥ 18 at time of consent
2. Ability to provide written informed consent and HIPAA authorization
3. Stage III NSCLC per AJCC 8 th edition guideline, confirmed by pathologically diagnosis and PET/CT
4. To receive standard definitive concurrent chemoradiation therapy per NCCN guidelines CTO-IUSCCC-0896  Protocol Version Date: 11/21/2024 Page 8.

5. Tumor estimated to be within 2cm of heart contour or anticipated MHD>10Gy per treating physician.

Exclusion Criteria
1. Patients treated with stereotactic body radiotherapy (SBRT)
2. Prior thoracic radiotherapy

Exclusion for Coronary computed tomography angiography (CCTA)
1. a history of a severe anaphylactic reaction to iodinated contrast precludes a repeat contrast administration.
2. Renal insufficiency (defined as CrCl less than 30 mL/min/1.73 m2)
3. Inability to hold breath for more than 5 seconds.
4. Patients on radioactive iodine therapy
5.4 Exclusion for 13N-ammonia PET/CT Test
1. With contraindications for regadenoson stress test including:
a) Second-degree AV block, third-degree AV block, and sinus node disease (such as
sick sinus syndrome or symptomatic bradycardia) without a functioning
pacemaker*
Note: * Resting 12-lead EKG will be ordered at the time of enrollment to be
performed prior to PET/CT stress test.
b) Patients with bronchospastic diseases including asthma and chronic obstructive
pulmonary disease (COPD) who have an acute exacerbation or active wheezing
(a high-pitched, musical, adventitious lung sound produced by airflow through the
narrowed airways) on the day of PET CT exam.
c) Patients who are hyposensitive (systolic blood pressure less than 90 mm Hg) on
the day of exam