Partial Breast IrradiationRAD 1802: Pilot Trial of Five Fraction Stereotactic Body Radiotherapy for Early Stage Breast Cancer Patients Eligible for Post-Operative Accelerated Partial Breast Irradiation (APBI)

This study will enroll patients that have a confirmed histology of early stage breast cancer. The patient will undergo a lumpectomy and will then receive partial breast 5 fractions stereotactic body radiation therapy at a dose of 6 gy for 5 fractions for treatment. Patients will be followed for 36 total months with specific follow-ups at 3, 6, 9, 12, 18, 24, and 36 months.

Stereotactic body radiation therapy (SBRT) has gained favor in the treatment of select central nervous system, lung, and abdominal malignancies due to its ability to deliver highly conformal doses of radiotherapy while using sharp dose gradients to deliver comparatively lower doses to the surrounding normal tissue. Utilization of SBRT is more labor intensive than conventional fractionation and requires precise immobilization and localization techniques with daily image guidance with direct physician and physicist oversight for all treatments. While more labor intensive and often utilizing more advanced technologies, SBRT allows the advantage of reducing setup margins compared to conventionally fractionated treatment while being able to shorten overall treatment times due to the ability to safely dose escalate high risk areas