A Prospective Study to Evaluate Continuous Positive Airway Pressure Devices to Reduce Pulmonary Dose

Data collection and assessment on patients with left-sided breast cancer or undergoing lung stereotactic body radiation therapy (SBRT) utilizing continuous positive airway pressure (CPAP) devices.

Lung stereotactic body radiation therapy (SBRT) has emerged as a definitive treatment for patients with early-stage lung cancers as well as for patients with limited metastases to the lung. One challenge with the treatment of the lung is the risk of pulmonary toxicity, particularly for early-stage lungs cancers that are inoperable (those receiving primary lung SBRT) or those with metastatic cancers receiving systemic therapy that may impact pulmonary function (those receiving lung SBRT for metastatic cancers). Continuous positive airway pressure (CPAP) devices are commonly utilized for patients with obstructive sleep apnea. However, through the use of continuous pressure, lung volumes are increased. Preliminary data in patients undergoing breast radiation as well as lung radiation has demonstrated the safety and feasibility of such an approach, demonstrating increased lung volumes with decreases in heart dose6-8. Additional potential advantages of CPAP include increased ease of use for patients and the potential for cost savings as compared to traditional respiratory management techniques. This prospective study is to allow for the collection and assessment of data on patients with left-sided breast cancer or undergoing lung SBRT utilizing CPAP. This will allow for the assessment of lung doses with and without CPAP as well as cardiac doses. No additional changes to our standard of care breast or lung radiation will occur. With respect to the safety profile, CPAP is commonly used with limited toxicity concerns. The potential benefit of CPAP has reduced lung and heart doses and, consequently, radiation-related toxicities.

stereotactic body radiation therapy, continuous positive airway pressure, CPAP, radiation, cancer, lung, Deep inspiratory breath hold (DIBH)

All participants will undergo standard of care radiation treatment. One additional CT scan will be performed with the use of a CPAP device to determine effect on dosimetry.

Participants will come in for their regularly scheduled radiation planning and treatment. Participants will undergo three scans (with and without DIBH (i.e., free-breathing), with CPAP). Participants will also use the CPAP device before the CT scan, for which they will be educated and trained.

Participants will come in for their regularly scheduled radiation planning and treatment. Participants will undergo three scans (with and without DIBH (i.e., free-breathing), with CPAP). Participants will also use the CPAP device before the CT scan, for which they will be educated and trained.

Treatment during breath holds leads to longer treatment times for patients and radiation oncology departments

The primary objective will be to assess changes in lung dosimetry V5 on the affected side when using CPAP compared to free breathing will be measured in percentages.

The primary objective will be to assess changes in lung dosimetry V20 on the affected side when using CPAP compared to free-breathing will be measured in percentages.

The primary objective will be to assess changes in lung dosimetry mean lung on the affected side when using CPAP compared to free-breathing will be measured in Grays.

Simulation scans will be performed with CPAP and free breathing. The breast/chest wall, and tumors (lung SBRT), as well as lung and heart, will be contoured on each scan. Using the CPAP scan as a reference, we will assess breast/chest wall motion, lung tumor motion, and organ at risk (ex. heart, abdominal organs) motion with free-breathing scans for each patient and analyze by treatment site (breast vs. lung SBRT).

At the time of simulation, investigators will create a surface rendering with the patient using CPAP. Investigators will assess maintenance of inflation when using CPAP where all three dimensions will be measured during treatment by comparing the surface rendering obtained during simulation with CPAP to the surface during treatment with CPAP, assessing for the greatest changes over the course of each fraction.

Inclusion Criteria: Patients with left-sided breast cancers Patients must be undergoing left breast/chest wall radiation with or without regional nodal irradiation Patients undergoing lung SBRT Primary lung cancers Metastatic lung tumors Exclusion Criteria: Patients with right side breast cancer Patients who are unable to tolerate the CPAP device