Through improved early detection and treatment, the number of long term breast cancer survivors continues to increase. There are now 2.8 million breast cancer survivors in the U.S. Florida alone adds over 9,000 women to the survivorship pool each year. Most receive radiation treatment (RT) of the affected breast and chest wall to reduce risk of recurrence. Even with advanced radiation techniques for dose conformality to minimize exposure of the highly sensitive lung, 14% of breast cancer patients treated with radiation develop clinical pulmonary toxicity, with 4% overall experiencing high grade clinical toxicity. Early diagnosis and intervention to mitigate lung radiation toxicity is increasingly important for the long term care of these survivors. The investigators' goal is to better identify breast cancer patients at high risk for experiencing severe pulmonary toxicity requiring medical intervention, provide a means to identify toxicity early on, and tailor treatment and/or early intervention on a per-patient basis.
This project involves repeat chest computed tomography (CT) imaging and blood draws in subjects with breast cancer with radiation treatment to the affected breast and chest wall. The investigators are studying women receiving one of 2 types of radiation, either conventional X-rays (IMRT) or protons at the University of Florida Health Proton Therapy Institute (UFHPTI). These subjects typically would not receive follow-up chest CTs as per standard of care. All subjects will have received a pre-treatment chest CT scan as part of the treatment planning process. The investigators will enroll 30 subjects in the X-ray treatment group and 25 subjects in the proton group. The investigative team has recently solved the technical challenges of extracting and characterizing lung vascular anatomy from clinical CT images of the chest and used these tools to characterize acute and chronic changes to pulmonary vascular structure in breast cancer patients receiving radiation to the chest wall for treatment of their cancer. In Aim 1 of this study the investigators will compare lung vascular damage in women treated with conventional radiation with those treated at the UFHPTI. In Aim 2 they will use blood samples of the subjects of Aim 1 to investigate the differential role of inflammatory cytokines in the initiation and progression of pulmonary vascular radiation response in conventional versus proton radiation exposures. Aim 3 compares vascular damage with clinical pulmonary function assessment using spirometry and diffusion capacity of carbon monoxide (DLCO). Aim 4 ties together Aims 1-3 by employing and extending existing mathematical models of radiobiological response to improve and solidify the scientific understanding of the biological mechanisms of radiation response.
Study Type
OBSERVATIONAL
Enrollment
41
Proton bean radiation therapy interact differently with tissue with the result that protons are absorbed completely within the tissue instead of primarily passing through the entire body. The maximal depth of penetration is dependent upon the incoming velocity (energy) of the protons. Proton therapy utilizes this property to deliver radiation with very little dose beyond the targeted lesion. The dose-rate will be managed as part of the standard of care.
The three-dimensional (3D) mapping of radiation dose distributions permits detailed assessment of local vascular damage as a function of treatment factors of dose, dose-rate. The dose-rate will be managed as part of the standard of care.
Computed Tomography (CT) Scan of the chest will be performed at 1, 3, 6, 12, 18 and 24 months
Pulmonary function test (PFT) will be performed at pre-treatment, and at 6 and 12 months.
Department of Radiation Oncology Davis Cancer Pavilion
Gainesville, Florida, United States
University of Florida Health Proton Therapy Institute
Jacksonville, Florida, United States
The lower dose limit for measurable change in number of small blood vessels as characterized from chest CT scans at 1,3,6, 12 and 24 months (= 2 years) and compared between proton versus X-ray radiation therapy.
The investigators seek to identify differences between the treatment modalities (proton versus X-ray) in regards to the lower dose limits for change in number of small blood vessels as measured from chest CT scans and quantified using the team's analysis technique.
Time frame: 2 years
Vessel number change dose-response relationship as measured from chest CT scans at 1,3,6, 12 and 24 months (= 2 years) and compared between proton versus X-ray radiation therapy.
Identify change in number of small blood vessels as measured from chest CT scans and quantified using the team's analysis technique, as a function of radiation dose exposure across the lung.
Time frame: 2 years
Recovery of number of small blood vessels as measured from chest CT scans acquired at 1,3,6, 12 and 24 months (= 2 years) and compared between proton versus X-ray radiation therapy.
Identify differences in temporal patterns of vessel regeneration following radiation exposure as a function of dose and of modality (proton versus X-ray).
Time frame: 2 years
Temporal patterns of blood cytokines following radiation exposure as measured from blood draws a pre-treatment and at 1,3,6, 12 and 24 months (= 2 years), and compared between proton versus X-ray radiation therapy.
Quantify differences in temporal patterns of levels of cytokines in the blood in breast cancer patients receiving conventional X-ray versus proton RT using serial blood draws that are time-matched with the CT chest scans.
Time frame: 2 years
Correlate change in number of small blood vessels as measured from chest CT scans at 1,3,6, 12 and 24 months (= 2 years) with clinical pulmonary function test outcomes at 6 and 12 months.
Correlate change in number of small blood vessels as measured from chest CT scans and quantified using the team's analysis technique, with clinical pulmonary function test (spirometry and diffusion capacity for carbon monoxide) outcomes to identify potential predictive value of early vascular changes to conventional clinical measures of late effects.
Time frame: 1 year
Compare incidence of long-term clinical grade 2 and higher radiation toxicity to the lung as documented in patient medical records and compared between proton versus X-ray radiation therapy.
The goal is to monitor long-term (\>8 year) incidence of clinical pulmonary toxicity in these subjects to identify any difference between X-ray and proton treatment methodologies.
Time frame: 8 years
Compare duration of overall survival and whether death was attributed to lung radiation toxicity as documented in patient medical records and compared between proton versus X-ray radiation therapy.
The goal is to monitor long-term (\>8 year) survival in these subjects to identify any difference between X-ray and proton treatment methodologies.
Time frame: 8 years
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