Trial Information

Geometric Reproducibility of the Lumpectomy Cavity Using a Breast Cup Immobilization Device II

Breast conserving therapy (BCT) has become the standard of care for treating early-stage
breast cancers based on six prospective randomized trials with 20 years of follow-up data
(Fisher). During lumpectomy, the surgeon removes the tumor and a surrounding rim of normal
tissue (margin), leaving surgical clips to help designate the resection bed. Radiation
treatment is directed at the whole breast for 5 1/2 weeks and is generally followed by a 1-2
week boost directed at the lumpectomy site plus a margin of normal breast tissue. The
benefit of adding the tumor bed boost, (TBB) has been shown in two studies to decrease local
failures [Romestaig; Bartelink].

Studies have evaluated the role of radiation following lumpectomy in very select groups
which have not been able to define a group who do not benefit from the addition of
radiotherapy. In the group of patients who received surgery alone, 85% of the breast
recurrences occurred in the tumor bed. Due to these two facts, radiotherapy directed only
at the tumor bed has been evaluated. Treating this smaller tumor volume has allowed higher
doses of radiation to be delivered safely shortening the treatment course from 6-7 weeks to
one week.