Radiation Therapy Planning Techniques in Reducing Damage to Normal Tissue in Women Undergoing Breast-Conserving Surgery for Ductal Carcinoma of the Breast

Radiation Therapy Planning Techniques in Reducing Damage to Normal Tissue in Women Undergoing Breast-Conserving Surgery for Ductal Carcinoma of the Breast

WILL MULTIFUNCTIONAL MAGNETIC RESONANCE TECHNIQUES, DETAILED HISTOPATHOLOGICAL ANALYSIS AND PRONE TREATMENT POSITION IMPROVE ACCURACY OF TARGET VOLUME LOCALISATION & DEFINITION AND REDUCE EXPOSURE OF NORMAL TISSUES IN BREAST RADIOTHERAPY?

RATIONALE: Diagnostic procedures, such as multifunctional magnetic resonance imaging and CT scans, may help reduce normal tissue damage in patients undergoing radiation therapy for cancer. PURPOSE: This clinical trial is studying how well radiation therapy planning techniques work in reducing damage to normal tissue in women undergoing breast-conserving surgery for ductal breast carcinoma.

OBJECTIVES: To improve precision of tumor bed localization and definition of clinical target volume, and to reduce normal tissue irradiation in women undergoing partial breast or breast boost radiotherapy. To test whether post-operative MRI improves the precision of tumor bed delineation after wide-local excision in comparison with the current standard CT scan/clip method. To determine the impact of tumor position within the excision specimen upon the localization of clinical target volume in relation to the tumor bed. To compare theoretical non-target tissue exposure from partial breast irradiation planned in the supine and prone (face-down) positions. OUTLINE: Patients undergo planned breast-conservation surgery and placement of titanium clips to the four radial, the deep, and superficial margins of the excision cavity (for localization of tumor bed). Within 2 weeks after surgery, patients undergo supine radiotherapy-planning CT scan as standard analysis. Patients then undergo a radiotherapy-planning CT scan in the prone position. Patients complete a linear analogue questionnaire after both scans designed to assess patient comfort and anxiety in each position. Patients then undergo multifunctional MRI (including dynamic contrast-enhancement MRI and diffusion-weighted MRI) of the ipsilateral breast in the prone position (≥ 3 weeks after surgery). If suspicious lesions ≥ 5 mm are found on MRI, patients are referred for a second-look ultrasound with biopsy (if lesion visible on ultrasound); where suspicious lesions are seen only on MRI, patients undergo MRI-guided biopsy. Lesions < 5 mm are included in the whole-breast radiotherapy treatment.

ductal breast carcinoma in situ, invasive ductal breast carcinoma, breast cancer in situ, stage I breast cancer, stage II breast cancer, stage IIIA breast cancer

Difference in lung NTDmean (biologically weighted [normalized] mean of total dose to lung normalized to 2 Gy fractions) in supine vs prone positions

Closeness of agreement between clinical target volumes (CTVs) defined using uniform margin vs those defined using knowledge of all excision margins

Difference in NTDmean to ipsilateral non-planning target volume (PTV) breast tissue, chest wall muscle, and heart

DISEASE CHARACTERISTICS: Planning to undergo breast-conserving surgery (BCS)* for unifocal ductal carcinoma in situ (DCIS) or grade 1-2 invasive ductal carcinoma (IDC) of the breast NOTE: *Patients who have underwent BCS and have titanium clips placed according to this protocol are eligible for this study. No T4d or multifocal disease (as defined on mammography or ultrasound) No G3 disease Hormone receptor status not specified PATIENT CHARACTERISTICS: Inclusion criteria: Female Menopausal status not specified Exclusion criteria: Cup size DD or greater Ferromagnetic implants (exclude participation in MRI) Claustrophobia (exclude participation in MRI) Gadolinium allergy PRIOR CONCURRENT THERAPY: No prior surgery to ipsilateral breast No prior neoadjuvant chemotherapy