Impact of Postoperative Radiation Therapy on Postmastectomy Breast Reconstruction
Abramson Cancer Center of the University of Pennsylvania
Last Modified: November 1, 2007
Presenter: L.C. Keiler
Presenter's Affiliation: University Hospital of Cleveland, Cleveland, OH
Type of Session: Scientific
- Despite improvements in early-detection of breast cancer, many patients still present with disease requiring surgical intervention with mastectomy.
- Post-mastectomy radiation treatment (PMRT) is recommended for adequate local control and improved overall survival in patients with T3 – T4 classification tumors, as well as those with advanced nodal disease and/ or involvement of the skin or chest wall.
- As surgical approaches have improved, many patients have the option to undergo immediate breast reconstruction at the time of mastectomy. Reconstructions are most commonly performed with either an autologous tissue flap using either the transverse rectum abdominal muscle (TRAM) or the latissimus dorsi (LD), or a permanent implant (PI). Preceding PI placement, use of tissue expanders (TE) is generally necessary.
- Many patients undergoing PMRT require radiation after breast reconstruction is complete, and little data exists regarding the cosmetic effects and rates of complication when radiation is delivered to the reconstructed breast.
- This observational study was carried out in order to assess the treatment complications and impact on cosmesis from PMRT delivered after breast reconstruction, and to compare these issues with different types of reconstruction utilized.
- Between 1988 and 2006, 73 women were treated with PMRT after breast reconstruction at the University Hospital of Cleveland, and were considered in this study. Radiation records for these patients were retrospectively reviewed.
- Information regarding comorbid conditions, systemic treatment, reconstruction method, and radiotherapy techniques were recorded and correlated with acute radiation toxicity and other complications, including fat necrosis, lymphedema, telangiectasias, and revision of reconstruction.
- Cosmetic outcomes were recorded based on the Harvard/ RTOG criteria of excellent/ good/ fair/ poor.
- Complication rates were estimated using the Kaplan-Meier methodology. Differences in cosmesis were assessed using Fishers Exact Test, and Cox multivariate regression models were used to determine independent predictors of complications.
- Median follow-up was 46 months (range 4 months – 11 years).
- Median patient age was 47 years (range 24 – 79 years).
- Reconstruction was performed at the time of mastectomy in 71 patients, and delayed for more than a year in 2 patients.
- Reconstruction was performed with TRAM flap in 37 patients, TE in 25 patients, LD flap in 4 patients, and combination of TE and LD in 7 patients.
- Pre- and post-PMRT cosmesis did not differ significantly between reconstruction types.
- All patients were treated with PMRT following reconstruction, with opposed tangent fields to a median dose of 50.4 Gray (Gy) (range 6 – 56 Gy). An en face electron boost (range 8 – 16 Gy) was delivered to 13 patients. A third, supraclavicular field, was utilized for 64 patients (median dose 64 Gy), and a posterior-axillary boost to 19 (median dose 48 Gy).
- PMRT dose, radiation energy, use of boost, use of supraclavicular field, and use of posterior-axillary boost were not associated with cosmesis scores or revision rates.
- Bolus of 1 cm or ½ cm was applied to the chest wall every other day for 40 patients, and use of bolus was not correlated with cosmesis score or revision rate.
- Median time from reconstruction to PMRT was 7.6 months (range 2 months – 14 years), and time to reconstruction was not correlated with cosmesis score or revision rate.
- Revisions of breast reconstruction were performed for 9 patients before beginning PMRT. Of these, 3 had infection, 3 had skin necrosis, 3 had capsular contracture, and 1 had poor cosmesis.
- Revisions of breast reconstruction were performed for 13 patients after completion of PMRT. Of these, 2 had infection, 1 had skin necrosis, 1 had implant leakage, and 9 had poor cosmesis.
- TRAM was less likely than TE to require revision after PMRT (9% versus 35%, p = 0.016) and overall (16% versus 48%, p = 0.006).
- Chemotherapy was delivered to 85% of patients considered in this study.
- A trend towards more reconstruction revisions was observed in patients receiving chemotherapy (34% versus 9%, p = 0.1).
- Patients who received chemotherapy had worse cosmesis before PMRT, which persisted after PMRT, with 80% of patients who did not receive chemotherapy having good or excellent cosmesis scores after PMRT versus 76% who did, and 80% of patients who did not receive chemotherapy having excellent cosmesis scores after PMRT versus 15% who did (p = 0.037).
- Pre-PMRT cosmesis scores were excellent for 27% of patients, good for 44%, fair for 17%, and poor for 13%.
- Post-PMRT cosmesis scores were excellent for 22%, good for 54%, fair for 13%, and poor for 11%.
- No single agent or regimen was correlated with cosmetic outcome.
- Hypertension, diabetes, alcohol use, and smoking were not correlated with cosmesis scores or revision rates.
- All patients experienced acute radiation toxicity during PMRT, including erythema in 100%, and dry or moist desquamation in 16%. These side effects during PMRT did not affect cosmesis or revision rate.
- After PMRT, 16 patients developed fat necrosis, 7 developed telangiectasias, and 8 developed lymphedema.
- Patients with TRAM reconstruction were more likely to develop fat necrosis, which developed in 38% of these patients (p = 0.0004).
- Fat necrosis, lymphedema, and telangiectasias did not reflect post-PMRT cosmesis scores or predict for revision.
- The authors conclude that PMRT is well-tolerated, with 75% of patients undergoing reconstruction before PMRT having good or excellent cosmetic outcomes.
- They note that neither acute PMRT toxicity nor fat necrosis predicted for cosmetic outcome or need for future revision, but that TE reconstruction was more likely than TRAM to require future surgical revision. They observe that patients with TRAM reconstruction were more likely to experience fat necrosis, but that this did not affect cosmesis.
- This observational study is an attempt to answer a patient-centered question that is encountered in clinical settings not infrequently.
- Despite improved early detection rates, PMRT is still indicated for improved local control and overall survival in a large proportion of women treated for breast cancer. As is true in any medical decision making process, the decision to recommend PMRT is based on an assessment of risks versus benefits associated with undergoing this treatment.
- To patients who have undergone recent mastectomy and reconstruction, both potential need for further surgery and potential cosmetic impact are important priorities during consideration of PMRT.
- Based on the results of this study, most women who undergo PMRT after breast reconstruction have good or excellent cosmetic results at the completion of treatment.
- Radiation techniques used did not appear to affect cosmetic outcome or need for revision in this population of patients, nor did time between reconstruction and PMRT. This information should be useful to radiation oncologists as PMRT is planned for patients following reconstruction.
- Although cosmetic outcomes were similar with different reconstruction types, patients with TE reconstruction were more likely to require revisions than those who had TRAM reconstruction.
- Additionally, patients who received chemotherapy were more likely to require revision, and were less likely to have good or excellent cosmetic results. This may be due to impact of chemotherapy itself, but may also reflect that patients with worse breast cancers and perhaps more extensive axillary surgical treatment had both worse cosmetic outcomes and required chemotherapy.
- Although this study is largely observational and considers a modestly-sized population of patients, it does offer physicians and patients useful information when PMRT is being considered and planned. Patients may be advised that need for revision of reconstruction may be slightly higher for patients who undergo reconstruction with TE versus those who have a TRAM flap reconstruction, and that need for chemotherapy may impact ultimate cosmetic outcome; however, other factors, including radiation technique, time to radiation, acute radiation toxicity, and associated patient co-morbidities do not appear to affect cosmetic or reconstructive outcomes. This data demonstrates that patients and physicians should make treatment decisions for the most part independently of the details of reconstruction, as the majority of patients do achieve good or excellent cosmetic results following PMRT after breast reconstruction.
Partially funded by an unrestricted educational grant from Bristol-Myers Squibb.