Prone Breast Irradiation for Pendulous Breasts

Study Overview
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Brief Summary
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We hypothesize that for large pendulous breasts, breast irradiation in supine and prone position are equivalent with regard to coverage of the PTV, but with a better dose homogeneity in prone position and a smaller radiation exposure of lung and heart.The purpose of this study is to compare the 3-D dose distribution in PTV(Planning Target Volume) and normal tissues in prone position versus supine position.

Detailed Description
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Local excision followed by adjuvant radiotherapy has become standard treatment for women with early-stage breast cancer. Adjuvant radiotherapy may encounter technical difficulties in patients with pendulous breasts when treated in supine position. Based upon literature and our own preliminary experiences, we hypothesize that for large pendulous breasts, breast irradiation in supine and prone position are equivalent with regard to coverage of the PTV, but with a better dose homogeneity in prone position and a smaller radiation exposure of lung and heart. However, no quantitative data are yet available to test this hypothesis. Therefore, the aim of our study is to compare the 3-D dose distribution in PTV and normal tissues in prone position versus supine position. For treatment in prone-position an in-house developed device, the mammaboard was used.

Official Title
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Mamma Board Project: Prone Breast Irradiation for Pendulous Breasts

Conditions
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Breast Cancer

Intervention / Treatment
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* Device: Mamma board


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients should have had breast-conserving surgery for breast cancer or DCIS (Ductal Carcinoma in Situ) No indication for radiotherapy of regional nodes Large, pendulous breasts (bra size D and over) Exclusion Criteria: Regional radiotherapy is indicated Unable to lie in prone position

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Mamma board<br>use of the mamma board during radiotherapy | Device: Mamma board<br>* use of mamma board during radiotherapy<br>* Other names: radiation, prone breast, mammaboard;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dose Homogeneity 1: PTV | Quantitatively compare the 3 D dose distribution in the PTV (Planning Target Volume) and normal tissues in prone position versus supine position | 1 day after treatment planning | 
| Dose Homogeneity 2: V105% and V107% | Quantitatively compare the 3 D dose distribution in the PTV (Planning Target Volume) in prone position versus supine position | 1 day after treatment planning | 
| Dose Homogeneity 3: V95 % | PTV coverage (% of PTV < 95% of prescribed dose) in prone position versus supine position | 1 day after treatment planning | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| PTV Coverage in Organs at Risk: MLD (Gy) | Doses in organs at risk: lung MLD (Mean Lung Dose) | during treatment planning | 
| PTV Coverage in Organs at Risk: Heart V30 | Doses in organs at risk: heart V30: the volumes (%) of the heart that received >= 30Gy | during treatment planning | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Breast cancer, Breast conserving surgery, Radiotherapy, Pendulous breasts