Postmastectomy intensity modulated radiation therapy following immediate expander-implant reconstruction.

BACKGROUND/PURPOSE: To evaluate radiation plans of patients undergoing mastectomy with immediate expander-implant reconstruction followed by postmastectomy radiation therapy (PMRT).

MATERIALS/METHODS: We identified 41 patients from June 2004 to May 2007 who underwent mastectomy, immediate expander-implant reconstruction, and PMRT with intensity-modulated radiation therapy. We assessed chest wall (CW) coverage and volume of heart and lung irradiated.

RESULTS: In 73% of patients, all CW borders were adequately covered, and in 22%, all but 1 border were adequately covered. The total lung V(20) was<20% in 39/41 patients. The mean lung V(20) was 13% (range, 3-23%), and the mean heart D(mean) was 2.81 Gy (range, 0.53-9.60 Gy). In patients with left-sided lesions without internal mammary nodes (IMNs) treatment (n=22), the mean lung V(20) was 12.6% and the mean heart D(mean) was 3.90 Gy, and in the patient with IMN treatment, the lung V(20) was 18% and heart D(mean) was 8.04 Gy. For right-sided lesions without IMN treatment (n=12), the mean lung V(20) was 12.4% and the mean heart D(mean) was 0.90 Gy, and in patients with IMN treatment (n=6), these numbers were 17.8% and 1.76 Gy. At a median follow-up of 29 months, the 30-month actuarial local control was 97%.

CONCLUSIONS: In women undergoing immediate expander-implant reconstruction, PMRT can achieve excellent local control with acceptable heart and lung doses. These results can be achieved even when the IMN are being treated, although doses to the heart and lungs will be higher.