Safety and Efficacy of IMPT or IMRT for Breast Cancer

The Safety and Efficacy of IMPT or IMRT for Breast Cancer: A Prospective Observational Study

The purpose of this trial is to compare the toxicities and efficacy of intensity-modulated proton therapy (IMPT) and intensity-modulated radiation therapy (IMRT) for breast cancer patients indicated for radiotherapy including preoperative radiotherapy, postoperative radiotherapy, or definitive radiotherapy. IMPT or IMRT will be administered to the whole breast, chest wall, and/or regional lymph nodes. A boost dose will be delivered in patients with high-risk area, at the discretion of the radiation oncologist. Eligible breast cancer patients will be followed for at least 5 years to assess acute and late radiation induced toxicities, loco-regional recurrence, overall survival, distant metastasis, and quality of life.

Eligible breast cancer patients will receive either preoperative, postoperative, or definitive radiotherapy based on the MDT's recommendation. Patients with indications for treatment will receive either the IMPT or IMRT technique. The specific technique will be chosen based on the benefits of IMPT, patient preference, and reimbursement policies after discussion between the doctor and the patient. The primary endpoint is the occurrence of any acute radiation-induced toxicities of grade ≥2. Patients will be monitored for at least five years to evaluate acute and late radiation-induced toxicities, loco-regional recurrence, overall survival, distant metastasis, and quality of life.

Inclusion Criteria

• Aged ≥18 years old
• Karnofsky Performance Status (KPS) score ≥70
• Histologically confirmed breast cancer with indications for preoperative radiotherapy, postoperative radiotherapy, or definitive radiotherapy as determined by the treating physician.
• ER (estrogen-receptor), PR (progesterone-receptor), HER2 (human epidermal growth factor receptor 2), and Ki67 testing must be performed on the primary breast tumor.
• Women of child-bearing potential must agree to use adequate contraception starting 1 month before study treatment and throughout the duration of study participation.
• Ability to understand and willingness to participate in the research and sign the informed consent form.

Exclusion Criteria

• Pregnant or lactating women.
• Severe non-neoplastic medical comorbidities that may interfere with treatment or study participation.
• Active collagen vascular disease or other autoimmune disorders that could significantly increase the risk of radiation toxicity.
• Patients with contraindications to undergoing IMPT or IMRT, such as severe claustrophobia that cannot be managed or inability to remain immobilized during treatment.