Treating recurrent metastatic breast cancer to the skin with proton therapy

Proton therapy offers unique physical properties that make it an excellent choice for treating metastatic breast cancer, particularly when recurrent disease occurs near previously irradiated tissues. This case study demonstrates the dosimetric benefits of proton therapy in patients with metastatic breast cancer to the skin. The case consists of one patient with 5 separate areas treated with Pencil Beam Scanning (PBS) proton therapy over a period of 2 years using Monte Carlo calculation and robust optimization. The results demonstrate that proton therapy effectively spared healthy tissues while delivering the prescribed dose to the tumor. This case demonstrates the feasibility of developing effective radiation plans for skin metastases using proton therapy, highlighting its dosimetric advantages and minimal impact on nearby organs.