SPECT/CT in Measuring Lung Function in Patients With Cancer Undergoing Radiation Therapy

Pulmonary Functional Imaging for Radiation Treatment Planning

This pilot clinical trial studies single photon emission computed tomography (SPECT)/computed tomography (CT) in measuring lung function in patients with cancer undergoing radiation therapy. Diagnostic procedures that measure lung function may help doctors find healthy lung tissue and allow them to plan better treatment.

PRIMARY OBJECTIVES:

I. To utilize SPECT/CT imaging with technetium Tc-99m microaggregated albumin (99mTc-MAA) and 99mTc-diethylenetriamine pentaacetic acid (99mTc-DTPA) to identify functional lung on serial imaging in patients receiving radiation treatment to the thorax, as well as to characterize reproducibility of perfusion and ventilation in non-irradiated lung tissue.

SECONDARY OBJECTIVES:

I. To estimate the dose response relationship on multiple spatial scales (global lung, regional lung, lung image voxel) between radiation dose and changes in lung ventilation and perfusion, both acutely (mid-radiation treatment) and long term (3 months post-treatment), using SPECT/CT imaging with 99mTc-MAA and 99mTc-DTPA.

II. To estimate the degree of radiation response in lung tissue with varying levels of function (i.e. compare radiation dose response of well ventilated and well perfused tissue against lung tissue with poor perfusion and ventilation).

TERTIARY OBJECTIVES:

I. To evaluate proton radiation therapy for functional lung sparing in lung cancers and other cancer in the thorax through treatment planning comparisons to conventional photon radiation therapy.

II. To evaluate the feasibility of incorporating standard-of-care fludeoxyglucose F 18 (18F-FDG) positron emission tomography (PET) images into proton and photon radiotherapy planning for dose escalation to functionally viable regions of gross thoracic disease.

OUTLINE:

Patients undergo 99mTc-MAA and 99mTc-DTPA SPECT/CT at baseline, mid-radiation therapy (up to 1 week post-treatment), and at 3-6 months post-treatment. Patients also undergo a pre-treatment 18F FDG PET/CT scan per standard of care.

After completion of study, patients are followed up periodically.

Inclusion Criteria:

• Cancer patients receiving radiation treatment to the thorax to at least 45 Gy; patient must have pathologic confirmation of diagnosis, or have an enlarging lung mass on at least two scans spaced 3 months apart, and FDG avidity on PET scan

• Patients must be planned for at least 45 Gy of thoracic radiation

• Patients are not required to have measurable disease; post-operative patients (patients who have had surgical resection of the lung) are eligible

• Patients must have pulmonary function as defined below:

  • Abnormal pulmonary function test within 3 months of study entry
  • Prior radiation to the lungs
  • Prior surgical resection of lung tissue (i.e. wedge resection, lobectomy, or pneumonectomy)
  • Clinical diagnosis of chronic obstructive pulmonary disease (COPD) or emphysema
  • Ongoing oxygen use

• There are no limits on prior therapy; patients are allowed to have prior chemotherapy, radiation therapy, and surgery; patients are allowed to have concurrent chemotherapy with radiation treatment; patients are allowed to have chemotherapy after radiation treatment; patients are not allowed to have planned lung resection after radiation

• Ability to understand and the willingness to sign a written informed consent document

• Patients will typically be enrolled on this trial prior to beginning the radiation treatment course; however, if a patient has had a SPECT/CT 99mTc-MAA and 99mTc-DTPA scan as part of routine medical care within 6 weeks prior to initiation of radiation treatment, he/she is eligible for trial enrollment up to the last day of the radiation treatment course

Exclusion Criteria:

• Patients must not be planned for lung resection after radiation therapy
• Patients receiving < 45 Gy radiation
• Patients who received radiation to the chest within the past 6 months
• Patients unable to tolerate a SPECT/CT 99mTc-MAA and 99mTc-DTPA scan
• Patients who are not planning to adhere to the required follow up schedule as outlined in this protocol
• Pregnant women
• Women of childbearing potential and men who are sexually active and not willing/able to use medically acceptable forms of contraception
• Patients unable to provide informed consent