Radiotherapy has been shown to reduce breast-cancer specific mortality in patients at high risk for distant dissemination. It has also been shown to increase rates of non-breast cancer deaths and morbidity due to cardiovascular and pulmonary toxicity. Although treatment planning has improved significantly through the years, recent reports still demonstrate treatment-related morbidity even with 3-dimensional planned techniques. Thus, while 3D planning represents the state of the art treatment for loco-regional radiotherapy for breast cancer, further improvement is needed to continue to decrease heart and lung exposure. The ultimate goal of the proposed research is to determine whether treatment planning using intensity-modulated radiotherapy (IMRT), the "next generation" of radiation treatment delivery systems, results in less radiation exposure to the heart and lungs than the best current RT technique in women with node positive breast cancer. This proposal will test the potential clinical value of IMRT compared to the best standard 3D plan (partially wide tangent fields, PWTF) in the treatment of breast cancer. These two treatment techniques will be studied in a Phase II randomized trial using quantitative indicators of potential cardiac and lung toxicity. The preliminary data generated from this trial will be used to ultimately justify a multi-institutional comparison of the two treatment techniques with long-term clinical cardiac and pulmonary toxicity as endpoints.
1. Primary Objective 1.1 To compare the extent of new myocardial perfusion defects following breast cancer radiotherapy using the best standard 3-D radiotherapy technique, partially wide tangent fields, versus the best optimized technique. 2. Secondary Objectives 2.1 To compare changes in ejection fraction and alterations in cardiac wall motion with treatment by technique 2.2 To compare changes in lung perfusion defects and pulmonary function tests (DLCO, FEV1, and FVC) by technique 2.3 To compare rates of pericarditis and pneumonitis by technique Cardiac Endpoints: Myocardial SPECT-CT perfusion defects, ejection fraction, alterations in cardiac wall motion, per SPECT-CT (adenosine stress and rest (if necessary)) scan. Pulmonary Endpoints: Lung SPECT-CT perfusion defects per SPECT-CT scan, and changes in pulmonary function tests: DLCO, FEV1, FVC Clinical Endpoints: pericarditis and pneumonitis.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
54
All patients treated with the optimized plan will be treated to the entire target volume to 52.2 Gy in 1.74 Gy fractions, which is biologically equivalent to 50 Gy in 2 Gy fractions. This fractionation scheme will allow the boost of 10 Gy to be incorporated into the planning directive and to be delivered simultaneously with the treatment to the remaining target volume.
All patients treated using the best standard technique will receive 50 Gy in 2 Gy fractions or 50.4 Gy in 1.8 Gy fractions to the entire target volume delivering one treatment per day, five fractions per week (excluding holidays). A boost of 10 Gy to the tumor bed of an intact breast will be delivered. Patients treated to the chest wall will receive a 10Gy scar boost if mastectomy margins are positive in a patient with Stage II disease or if the patient was originally diagnosed with T3 or T4 (Stage III) disease
University of Michigan Health Systems
Ann Arbor, Michigan, United States
The Number of Participants With a Significant Increase in Perfusion Defects (PD)
To compare the extent of new myocardial perfusion defects following breast cancer radiotherapy using the best standard 3-D radiotherapy technique, partially wide tangent fields, versus the best optimized technique. Perfusion defects (PD) were assessed by comparing normalized perfusion distributions against our institution's normal polar map databases for the left anterior descending artery (LAD) using thresholds of 2.5-SD (standard deviation) and 1.5-SD below the normal mean. On the basis of interest variability, a PD increase greater than 5% or 10% was considered significant for 2.5- and 1.5-SD thresholds, respectively.
Time frame: 1 Year
Mean Percent Change in Ejection Fraction (LVEF)
To compare change in ejection fraction between treatment arms.
Time frame: baseline to approx 1 year
Number of Participants With New Lung Perfusion Defects
To compare changes in lung perfusion defects by treatment arm. Perfusion defects (PD) were assessed by comparing normalized perfusion distributions against our institution's normal polar map databases for the left anterior descending artery (LAD).
Time frame: baseline to approx 1 year
The Number of Participants That Experience Pericarditis and Pneumonitis
To compare rates of pericarditis and pneumonitis by treatment arm. Pericarditis (inflammation of the pericardium): Grade1: Asymptomatic, ECG or physical exam; changes consistent with pericarditis Grade 2: Symptomatic pericarditis Grade 3: Pericarditis with physiologic consequences Grade 4: Life-threatening Pneumonitis (inflammation of the walls of the alveoli in the lungs) Grade 1: Asymptomatic, radiographic findings only Grade 2: Symptomatic, not interfering with ADL (activities of daily living) Grade 3: Symptomatic, interfering with ADL Grade 4: Life-threatening
Time frame: approx 1 year
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