Study on Single Fraction Breast Brachytherapy for Breast Cancer

Inclusion Criteria

• Female patients diagnosed with Ductal Carcinoma in Situ (DCIS) or invasive breast cancer.
• Aged between 40 and 85 at the time of diagnosis.
• Have had a lumpectomy with no remaining cancer cells at the edges of the removed tissue.
• Tumor size must be Tis, T1, or T2, with T2 tumors being 3 cm or smaller.
• If the tumor is HER2-positive, the patient should be planning to receive or have already received HER2-targeted therapy.
• For invasive breast cancer, a procedure to check lymph nodes under the arm must be done, unless certain criteria are met.
• Patients aged 70 or older with specific tumor characteristics may not need lymph node checks.
• Patients aged 50-69 with certain tumor characteristics may avoid lymph node checks at the surgeon's discretion.
• Must be able to start brachytherapy within 12 weeks after surgery or chemotherapy.
• Must understand and agree to sign a consent form.

Exclusion Criteria

• Pregnant or breastfeeding women.
• Have active connective tissue diseases.
• Have Paget's disease of the breast.
• Have had breast cancer or DCIS before the current diagnosis.
• Have had previous radiation therapy to the breast or chest.
• Have multiple tumors in different areas of the breast.
• Have cancer in both breasts at the same time.
• Have surgical margins that cannot be assessed or are positive for cancer.
• Have received chemotherapy before surgery.
• Have a surgical cavity that cannot be clearly defined or is not suitable for the implant.
• Have medical, psychological, or social conditions that may increase risk or affect adherence to the study.