To boost or not to boost: Decreasing radiation therapy in conservative breast cancer treatment when “inked” tumor resection margins are pathologically free of cancer

Abstract A retrospective study was performed to compare local treatment approaches for 108 treated breasts in 105 patients with Stage I or II breast cancer. Six cases with intraductal carcinoma have shown no evidence of recurrence. The other 102 cases had invasive cancer. In 54 treated breasts in 53 patients, the treatment approach involved surgical resection of the primary tumor, pathological determination of tumor-free “inked” specimen margins and 5000 cGy to the whole breast. Local radiation therapy (RT) boosts to the primary site were not given. This approach produced a 100% local control rate (mean follow-up of 38 months). In 28 treated breasts in 27 patients, the treatment approach involved tumor excision without evaluation of specimen margins followed by RT which included a local boost by either interstitial Iridium-192 implant or electron beam. This approach yielded an actuarial local control rate of 87% at 48 months (mean follow-up of 47 months). The difference in local control rate between the two groups was statistically significant ( p