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    Home > Research & Grants > Grants Program > Research Grants > Research Grants Awarded > Abstract
    Awarded Grants
    Intensity Modulated Radiotherapy for Treatment of Breast Cancer Patients in Prone Position

    Scientific Abstract:
    Background: For large, pendulous, breasts, the current standard external beam radiotherapy (RT) either in supine or in prone position is dosimetrically, technically and social-economically problematic. Objective/Hypothesis: This project is to develop, technically and clinically, the new methodology for breast irradiation in prone position using intensity modulated RT (IMRT). We hypothesize that the proposed development is advantageous in dosimetry and effectiveness over the existing RT technology. Specific Aims: (1) Determine treatment margin and IMRT mothods for breast irradiation in prone position; and (2) conduct clinical trials to determine the feasibility of using the newly-developed IMRT methods to reduce treatment time. Study Design: Patient 4D CT and online electronic portal images will be used to assess respiratory motion and setup error in prone position. The obtained information will be used to determine the margin required for partial breast irradiation. The fixed-gantry IMRT will be used for partial breast irradiation in prone position using the margins determined. The TomoTherapy IMRT will be used for whole breast irradiation plus a boost to the lumpectomy site with or without the irradiation of regional lymph nodes. Carefully selected 20 patients will be enrolled in the clinical study to determine the feasibility and patient tolerance of IMRT simultaneous integrated boost in prone position for reducing treatment time by one week, and another 20 patients will be enrolled in the clinical trial to determine the feasibility of accelerated partial breast radiation using IMRT in prone position. Potential Outcomes and Benefits of the Research: The proposed study contains many novel aspects in technology and methodology. Sucessfully completion of this project will remove the existing technical difficulties for irradiating large breasts. It will provide dosimetric, technical and clinical possibility for accelerated full or partial breast irradiation in selected women with early stage breast cancer, thereby reducing treatment time. The proposed study has great potential to improve local control and cosmetic outcome, to reduce the cost for patient care and/or to improve life quality of breast cancer patients. Patients with large, pendulous, breasts will benefit the most from this study.

    Lay Abstract:
    A series of randomized studies have demonstrated that the treatment of early stage breast cancer with breast conserving surgery plus radiotherapy yields excellent local control with limited toxicity. Both external beam radiotherapy (EBRT) and/or brachytherapy are currently used. However, for large, pendulous, breasts, the current standard radiotherapy (EBRT) either in supine or in prone position is dosimetrically and technically problematic. Irradiation in supine position can lead to significant dose inhomogeneity and unacceptable volume of the heart and/or the lung in the irradiated field, resulting in increased acute toxicity and inferior cosmetic outcome. The prone position techniques used by far have some limitations, including the inability of delivering radiation to regional lymph nodes, inability to deliver partial breast irradiation due to unknown treatment margin, inability to deliver electron boost, and inadequate irradiation of chest wall. In addition, the long treatment time (normally 5-7 weeks) of the current standard of care using EBRT may discourage some women from choosing conservative treatment over mastectomy. To address these problems, we propose to develop new methodology for breast irradiation using intensity modulated radiotherapy (IMRT) for patients setup in prone position. We will first develop methodology for full and partial breast irradiation using two forms of IMRT, fixed-gantry and rotational (TomoTherapy) IMRT, for prone setup. Then, we will conduct clinical studies to demonstrate the advantages of the newly developed technology and feasibility of using thistechnology to reduce treatment time. Successfully completion of this project will remove the existing technical difficulties for irradiating large breasts. It will provide dosimetric, technical and clinical possibility for accelerated full or partial breast irradiation in selected women with early stage breast cancer, thereby reducing treatment time. The proposed study has great potential to improve local control and cosmetic outcome, to reduce the cost for patient care and/or to improve life quality of breast cancer patients. Patients with large, pendulous, breasts will benefit the most from this study.