Theodore Edward Yaeger MD, Presenter: Nothing to Disclose

TITLE: Solid Modulated Accelerated Radiotherapy (SMART) for Early Stage Breast Cancer Conservation Purpose: Partial breast irradiation is being studied as an alternative to whole breast irradiation for early stage disease. Presently there are three common methods utilized: Multi-catheter brachytherapy, single catheter brachytherapy and external beam limited volume radiation. This presentation is to introduce a modification to standard tangent-beam techniques. We describe a technique of intensity modulating radiation therapy (IMRT) that allows partial breast irradiation to the seroma with conventional whole breast prophylaxis. This technique concurrently treats the whole breast and the lumpectomy seroma cavity with a shortened course using beam modulation (SMART). Materials and Methods: Patients with stage 0 (Tis), 1 (T1), or early 2 (T2) breast cancers (N0, M0) were planned for both conventional tangent to boost and intensity modulation radiation therapy. Patient plans that developed improved dose homogeneity were then treated with IMRT. Patients without any advantage from IMRT were treated conventionally (half-beam blocked tangents fields followed by seroma boost). The populations were compared for treatment tolerance and outcomes. Results: During 2.5 years of operation at a rural outreach radiation center 33 patients were seen for breast conservation. Beam modulation techniques were introduced after the first year to offer IMRT as a treatment option. Subsequently 22 patients were evaluated and 17 were offered IMRT. Five patients had no improvement in their plans and were treated conventionally. All 33 patients were judged for treatment tolerance and local control. To date, no patient with either technique has experience a local cancer failure. However, nearly 50% of patients treated with conventional tangent fields required treatment for skin reactions while only one in the IMRT group developed a minor erythema, gone after one week. No patient in the IMRT group developed breast edema. All conventional-treated patients had edema of various magnitudes, symptomatic in larger breast volumes. Both groups had similar demographics, stage distributions, and prescribed total doses. In addition to skin sparing, beam modulation IMRT also allowed a more uniform dose distrunution to the whole breast volume and a greater gradient to the seroma volume. Conclusions: Solid Modulated Accelerated Radiation Therapy (SMART) is a useful form of IMRT delivery that yields similar tumor control probabilities to conventional therapy. Especially for larger volume patients it significantly enhances patient treatment tolerances and improves cosmetic outcomes. Thus far, it has shown to be a shortened-course, non-invasive cosmetic alternative for low nodal risk early stage breast cancer patients.

Yaeger, T, Solid Modulated Accelerated Radiotherapy (SMART) for Early Stage Breast Cancer Conservation.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8500037.html