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Results: As of September 2005, there have been 36 RN relapses for an actuarial nodal control rate (NCR) of 98% at 10 years. There was no difference in NCR between those undergoing AXD (NCR = 97.4%) and those receiving RT without AXD (NCR = 97.9%). In multivariate analysis, young age, non-Caucasian race, and pathologic nodal status correlated with increased risk of nodal relapse. Of the 126 patients undergoing SNB, there was only 1 nodal recurrence. None of the 16 SN-positive patients treated with RT without AXD had nodal failure. Conclusions: In patients undergoing BCS+RT, both regional nodal irradiation and AXD (including SNB) resulted in equally high rates of regional nodal control. Nodal RT may also be an effective treatment for SN-positive patients. |
| After conservative surgery, all patients were treated with RT using tangential fields directed at the intact breast. Radiation was administered with standard techniques using 4–6 MeV linear accelerators, and appropriate wedges were used to obtain homogenous dose distribution. Patients were treated to the whole breast at a standard fractionation of 2 Gy daily to a total median dose of 48 Gy (range, 40–60 Gy), followed by electron beam boost to the tumor bed to a total median dose of 64 Gy (range, 50–72 Gy) over 5–7 weeks. Regional lymph node radiation was administered to the majority of patients using the following guidelines. Patients undergoing AXD were treated to the breast alone if pathologically they were node-negative, or to the breast and supraclavicular nodes if pathologically they were node-positive. The general policy during this time was to include the supraclavicular fossa (without axillary radiation) in all node-positive patients, including those with 1–3 positive nodes. Radiation treatment to the internal mammary nodes was highly individualized throughout this period and was added in some cases to the treatment plan. External beam radiation was administered to the supraclavicular fossa using a separate anterior beam half-blocked at the central axis. The field was angled 10–15° off of the spinal cord and extended medially from the midline and laterally to the medial border of the head of the humerus. The prescribed dose was 46 Gy specified at a depth of 3 cm. Internal mammary nodes were irradiated with alternating photons and 13 MeV electrons with a separate en face field, also to a total median dose of 46 Gy specified at a depth of 3 cm. Sometimes the internal mammary nodes were accidentally included in the tangential fields. In patients not undergoing AXD, supraclavicular and axillary nodes were irradiated, with or without an additional internal mammary field. Radiation to the supraclavicular fossa and internal mammary nodes were delivered using the treatment technique described above. Axillary lymph nodes were irradiated by extending the lateral border of the supraclavicular field laterally to include the entire humeral head and clear the entire axillary contents. A total median dose of 46 Gy at 3 cm was prescribed. A posterior axillary boost was rarely used, even in patients with multiple nodes involved or with inadequate AXDs. atients undergoing SNB were, in general, treated to tangents only if they were found to have pathologically negative SNs. SN-positive patients who did not receive completion AXD were treated with radiation to the breast and regional nodes or to “high tangents,” depending on clinical factors and physician preference. In the high tangent technique, the superior border of the tangential field was placed within 2 cm of the humeral head. This was reserved for patients whose SN was only involved microscopically. |
