The goal of this clinical research study is to learn about ways to possibly reduce scanning errors when using 4-dimensional computed tomography (4D CT) scans to check lung function in patients with esophageal or lung cancer.

Study Procedure:

By using 4D CT scans, researchers can create images that show how air moves through the lungs. This new method to check lung function may make better images than the standard methods. Researchers will compare 4 images of how air moves through your lungs and 1 image while you hold your breath.

Study Groups:

If you are found to be eligible to take part in this study (if the screening test is applicable) and you agree to take part in this study, you will be enrolled in 1 of 2 study groups, depending on when you join the study. There will be up to 18 participants in each group. In the first group, researchers will test several different methods to create images of how air moves through the lungs. Researchers will then select the most successful methods from the first group and try to do them again with the second group.

Study Visits:

You will have up to two visits for this study. At these visits, you will have four 4DCT scans performed (for Group 1) or five scans (for Group 2) using both the 4DCT and spiral CT, while you are breathing normally. You will also have 1 scan while you hold your breath for less than 20 seconds. The CT scans will take about 5 minutes each to complete. If the spiral CT scans for Group 2 cannot be completed on the same day as the 4DCT scans, you will be asked for your willingness to return at a later day to complete these.

The 4D CT scan will cover the entire chest area using the standard dose of radiation. A 2-inch plastic box will be placed on top of your chest to track the motion of your chest while you breathe during each scan. Some parts of your chest will be scanned up to 2 more times based on your breathing.

The entire scanning session will take about 45 minutes to complete.

Length of Participation:

Your active participation on the study will be over when you have completed your study visit.

Follow-Up Phone Call:

Within 7 days after your last study visit, the study staff will call you to ask about any side effects you may be having. This call should last about 2 minutes.

If anything unusual is found in the imaging, your cancer doctor will be told so that you can receive follow-up.

This is an investigational study. The CT scans used in this study are delivered using FDA-approved and commercially available systems. Creating images of how air moves through the lungs from 4D CT scans is considered investigational.

Up to 36 patients will take part in this study. All will be enrolled at M. D. Anderson.

Inclusion Criteria:

1. Patients must sign consent for the study.
2. Patients with pathologic diagnosis of esophagus or lung cancer.
3. Patient who plan to receive radiation therapy treatment at MD Anderson.
4. Patient >/=18 years of age

Exclusion Criteria:

1. Presence of an implanted electronic device.
2. Women who are pregnant or lactating, due to possible adverse effects on the developing fetus or infant.