Intraoperative Radiotherapy for Korean Patients With Breast Cancer

A Phase II Trial Investigating Acute Local Toxicities of Intraoperative Radiotherapy as a Boost Dose in Korean Breast Cancer Patients Undergoing Breast Conserving Surgery

The purpose of this study is to evaluate acute local toxicity of IORT at the dose of 20 Gy for the replacement of boost-external beam radiotherapy in Korean women who are candidates for breast-conserving treatment.

Local toxicity checklist

• Hematoma needing surgical evacuation
• Seroma needing more than three aspirations
• Skin breakdown or delayed wound healing
• Any complication needing surgical intervention
• Radiation Therapy Oncology Group (RTOG version 2.0) toxicity grade 3 or 4 for dermatitis, telangiectasia, pain in irradiated field, or other.
• Any complication of RTOG toxicity grade more than 2

Inclusion Criteria:

• Histologically confirmed and newly diagnosed non-metastatic operable primary breast cancer
• Primary tumor <5cm, measured by ultrasonography - N0-3 (any N if resectable) and no evidence of distant metastasis (M) (isolated supraclavicular node involvement allowed)
• Age ≥18-years women with good performance status (ECOG 0-1)
• No breast operation is allowed except diagnostic biopsy
• Women with ductal carcinoma in situ diagnosed by preoperative biopsy are allowed

Exclusion Criteria:

• Pregnancy or unwillingness to use a reliable contraceptive method in women of child-bearing potential.

• Patients who received prior chemotherapy or radiotherapy for breast cancer

• Patients who have history of cancer other than in situ uterine cervix cancer or non-melanoma skin cancer

• The depth of tumor from skin measured by ultrasonography is less than 1cm.

• Contraindications to breast conservative surgery

  • Multicentric breast cancer (tumors in more than one quadrant)
  • Diffuse malignant appearing microcalcification
  • Prior therapeutic radiation to the breast region
  • Small breast, which is not possible to achieve clear margins in relation to a cosmetically acceptable result
  • History of collagen vascular disease, such as active scleroderma and active lupus

• Postoperative exclusion

  • Patients who require re-excision due to positive resection margin
  • The depth of cavity from skin after lumpectomy is less than 0.5cm