Pilot Study of Regional Lung Ventilation

Investigators hypothesize that a high resolution regional ventilation image (HRVI) based on 4D-CT imaging will correlate with the current low resolution state-of-the-art (SPECT-CT), which is the conventional way of measuring ventilation. HRVI may be a tool that could be widely used throughout the radiation therapy community because most radiation oncologists routinely employ 4D-CT technology in their own clinics. Investigators plan to test this hypothesis by comparing ventilation patterns on SPECT-CT images to HRVIs using a DICE analysis. As SPECT ventilation imaging is not included in our standard care, this study thus is designed as a pilot study.

Based on published data, the difference between the two methods for calculating the regional ventilation in the lower 50% ventilation volume is expected to have a standard deviation of about 0.1. Therefore, the 95% confidence interval for the difference in the regional ventilation between SPECT-CT and 4D-CT pre-treatment would have a width of no more than 0.14 if 10 patients are enrolled and as small as 0.10 when 20 patients are registered.

Inclusion criteria

• Patients that have early stage non-small cell lung cancer or clinical suspicion of the same in cases where the lesion is not amenable to biopsy but is enlarging and PET-positive. All patients are to be treated with stereotactic body radiation therapy as a monotherapy.
• Eligible patients must have appropriate staging studies identifying them as specific subsets of AJCC 7th edition stage I or II based on only one of the following combinations of TNM staging:

• T1a-b, N0, M0
• T2a, N0, M0
• T3 (invading the chest wall, <5 cm in diameter) N0 M0
• Must be at least 18 years of age
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-2
• Women of childbearing potential and male participants must use an effective contraceptive method such as condom/diaphragm and spermicidal foam, intrauterine device, or prescription birth control pills.

Exclusion criteria

• Patients with T2b tumors or T3 tumors >5 cm or patients with tumors involving the central chest/structures of the mediastinum;
• Primary tumor of any T-stage within or touching the zone of the proximal bronchial tree, defined as a volume 2 cm in all directions around the proximal bronchial tree (carina, right and left main bronchi, right and left upper lobe bronchi, bronchus intermedius, right middle lobe bronchus, lingular bronchus, right and left lower lobe bronchi.
• Direct evidence of regional or distant metastases after appropriate staging studies
• Patients with active systemic, pulmonary, or pericardial infection;
• Pregnant or lactating women, as treatment involves unforeseeable risks to the embryo or fetus.
• Patients that receive chemotherapy (induction or sequential)
• Psychiatric or addictive disorders that impair subject's voluntary ability to participate in informed consent or protocol procedures