Phase II Protocol of Proton Therapy for Partial Breast Irradiation in Early Stage Breast Cancer
Current standard of care for early stage breast cancer is mastectomy or breast conserving
therapy with whole breast irradiation following lumpectomy. However, studies of breast
cancer recurrence have demonstrated the majority of tumors to recur in or adjacent to the
original tumor site. The question has thus been raised as to whether radiation to the whole
breast is necessary or justified. Limiting radiation to the area of the original tumor may
reduce acute and long-term skin and organ toxicities while making radiation therapy more
convenient and less expensive. Several clinical trials are underway comparing partial breast
irradiation (PBI) to whole breast irradiation. Numerous centers are offering partial breast
irradiation outside of clinical trials as well, despite the lack of long-term safety and
efficacy data on PBI.
Available PBI methods include brachytherapy, in which catheters or balloons are surgically
inserted to deliver radiation therapy to the lumpectomy cavity, and conventional external
beam radiation therapy, or EBRT. External beam photon therapy is attractive for its
non-invasive nature and ability to deliver a more homogenous dose distribution compared to
brachytherapy, however it also delivers a greater radiation dose to surrounding normal
breast tissue.Proton therapy has the capacity to provide the same advantages as photon EBRT
while minimizing dose to normal surrounding tissue. Clinical data on PBI with protons is
minimal, however, leaving many questions unanswered. The impetus behind this protocol is to
address these gaps by further investigating the feasibility, safety, and efficacy of proton
therapy for partial breast irradiation.
Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment
To assess events of freedom from ipsilateral breast recurrence occurrences in patients receiving partial breast proton radiation therapy limited to the region of the tumor.
Freedom from failure (FFF): The events for FFF will be the first ipsilateral breast cancer recurrence. It is expected that less than 3% of patients will experience an ipsilateral breast cancer recurrence (FFF ≥ 97%). A recurrence rate of ≥ 15% (FFF ≤ 85%) is considered unacceptable. Therefore, the null hypothesis is the FFF of ipsilateral breast cancer recurrence is 85% or lower and the alternative hypothesis is that FFF of ipsilateral breast cancer is 97% or higher.
At 3 years
Andrew Chang, MD
Proton Collaborative Group
United States: Institutional Review Board
|ProCure Proton Therapy Center||Warrenville, Illinois 60555|
|ProCure Proton Therapy Center||Oklahoma City, Oklahoma 73142|