Radiation practice patterns among United States radiation oncologists for postmastectomy breast reconstruction and oncoplastic breast reduction

doi:10.1016/j.prro.2014.04.002

Practical Radiation Oncology

Volume 4, Issue 6, November–December 2014, Pages 466-471

https://doi.org/10.1016/j.prro.2014.04.002 Get rights and content

Abstract

Background

For patients requiring radiation therapy following mastectomy or breast reconstruction, there often exist much heterogeneity among practitioners with respect to radiation technique.

Methods and materials

A 14-question survey was sent nationwide to 1000 active email addresses from the American Society for Radiation Oncology member directory; 271 radiation oncologists completed the survey.

Results

A total of 75.2% of respondents indicate that they do not routinely deflate the ipsilateral tissue expander (TE) prior to radiation, while 11.5% do routinely deflate (P ≤ .01); 52.2% indicate that they typically use bolus when treating their patients with TEs following mastectomy, 36.7% do not, and 11.1% on a case by case basis (P ≤ .01). Of respondents indicating bolus utilization, 32.8% use a bolus of 0.5 cm every other day; 31.4% indicate a bolus of 0.5 cm every day until tolerated; 20.4% use a bolus of 1 cm every other day; 5.8% indicate a bolus of 1 cm every day until tolerated; and 9.5% indicate a customized bolus approach (P ≤ .01). A total of 22.9% of respondents deliver boost to all patients with TE while 42.9% deliver boost only to select patients, and 33.5% indicate no utilization of boost (P ≤ .01). A total of 33.1% indicate that collaborating surgeons routinely place clips at the lumpectomy cavity at the time of breast reduction or complex tissue rearrangement, while 38.3% indicate that clips are occasionally placed, and 28.6% stated clips are not routinely placed (P = .15); 38.7% of respondents routinely deliver a boost for patients undergoing breast reduction only if clips have been placed in the tumor cavity, while 34.6% indicate that a boost is used regardless of clip placement.

Conclusions

Radiation treatments with tissue expanders have become common practice, but details of radiation treatment vary widely. Radiation oncologist and breast surgeons should continue to work to optimize radiation techniques and allow proper localization for radiation boost.

Introduction

According to the National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) database, an estimated 226,870 women will be diagnosed with breast cancer in the United States in 2012, with more than 17% of these cases resulting in death (SEER).¹ With improvements in early detection as well as the effectiveness of treatment options, the rates of cancer deaths have steadily decreased over the past 2 decades (SEER).² With an increase in survivorship, issues relating to quality of life and reconstructive options have modified the context of disease. Recent analyses have found that since 2005 the rate of mastectomy is increasing across all age groups, particularly for women less than 50 years old and greater than 70 years old³; just between 2009 and 2010, the rates of breast reconstructive procedures increased by 8%.⁴

Breast tissue expanders (TEs) are a commonly utilized reconstruction technique following mastectomy. This technique can be achieved in either a 1-stage or 2-stage reconstructive process. The 1-stage technique is performed as collaboration between the breast surgeon and plastic surgeon. It involves placement of an expandable tissue expander, which is gradually filled over time with saline through an internal valve. Once ideal size is achieved, the internal valve of the expander may be closed and this expander will stand as the patient’s new permanent implant. In the 2-stage reconstructive process a saline-filled tissue expander is placed at the time of surgery and then gradually filled to achieve a desired size. Once ideal size is achieved, a second surgery is performed, exchanging the saline tissue expander for a permanent implant. The permanent implant can be inserted after all adjuvant treatments have been completed. This 2-stage “intermediate” approach has grown in favor, particularly for early-stage breast cancer patients with an uncertain requirement of postmastectomy radiation therapy.⁵

If a patient requires radiation therapy following mastectomy, there is much variability among practitioners with respect to radiation technique. Some of the variables specific to radiation are whether or not to keep the TE inflated or deflated during radiation therapy, delivery of a boost dose in the presence of a TE, utilization of bolus, thickness of bolus material used, and frequency of placement of bolus material. These variables may have effects on the desired dose distribution of radiation therapy, postoperative healing, and psychologic recovery of the patient.

We created a short clinical questionnaire focusing on the practice patterns for breast cancer reconstruction and radiation therapy. This survey was sent nationwide to radiation oncologists.

Section snippets

Methods and materials

A 14-question survey was created with question topics ranging from practice type, practice size, TE use, timing of reconstruction surgery, postmastectomy (PM) radiation boost, and bolus. This survey was created via SurveyMonkey (https://www.surveymonkey.com/). The survey was sent via email to over 1000 active email addresses of breast cancer specialists (physicians, physicists, nurses, and technicians) obtained from the American Society for Radiation Oncology member directory, who self-claimed

Results

Of the 1535 emails (collective of physicians, technicians, physicists, and nurses gathered from the member directory of the American Society for Radiation Oncology that self-claimed that they treat breast cancer patients), we received a total of 271 (17.6%) responses from radiation oncologists that fully completed survey responses. Responses were received from physicians throughout the country, establishing a representation from the United States (US) and District of Columbia. Fifty-nine

Discussion

We observed in this analysis that nearly all radiation oncologists participating in the survey (95.9%) treat patients with TEs after mastectomy. This technique dates back to 1982, when Radovan⁶ proposed a gradual method of tissue expansion to replace skin loss. Since then, this technique has evolved the methods of reconstruction in postmastectomy patients.

The use of tissue expansion in the context of adjunctive therapies has provided an alternative to autogenous reconstruction with acceptable

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Cited by (31)

Randomized clinical trial of tissue equivalent bolus prescription in postmastectomy radiotherapy stratified by skin involvement status
2023, Clinical and Translational Radiation Oncology
To assess the impact and optimize the prescription of tissue-equivalent bolus in postmastectomy radiotherapy (PMRT), we compared the use of different bolus regimens tailored by skin involvement status.
Patients with breast cancer who required PMRT were recruited (NCT01925651) and classified into two groups: standard-risk (SR, without skin involvement) and high-risk (HR, with skin involvement). SR was randomized between no bolus or 5 mm-bolus on alternate days and HR between 5 mm-bolus on alternate days or daily. Conventional fractionation (50.4 Gy; 1.8 Gy/daily) was used. Acute skin toxicity was evaluated blindly and the radiodermatitis-specific toxicity index [rads-TI] calculated. Subsequently, patients were followed up to assess oncologic outcomes, focusing on chest wall (CW) local control.
Fifty-eight patients were enrolled (34 SR and 24 HR). Baseline characteristics were similar between arms within the same risk group. Overall, maximal radiodermatitis rates were 29.4 % (G2) and 15.7 % (G3). In the SR group, no difference existed in G2 radiodermatitis incidence between the subgroups (p = 0.70) and no G3 events occurred. In the HR group, incidences of G2 (100 % vs 44.5 %, p = 0.01) and G3 radiodermatitis (70 % vs 11.1 %, p = 0.02) were higher with daily bolus. After adjusting for confounders, the daily bolus had a higher incidence of G2 (p = 0.03), G3 radiodermatitis (p = 0.04), and worse rads-TI (p < 0.01). After a median follow-up of 6.2 years, the 5-year local control was 95.8 % (95 %CI: 88.2 %–100 %) in the SR and 91.7 % (95 %CI: 77.3 %–100 %) in the HR groups. Per risk group, there was no difference in local control between the SR (p = 0.90) or the HR bolus regimens (p = 0.70).
Daily 5 mm bolus prescription significantly increased the overall toxicity burden. In this preliminary study, within the same risk group, no detriment in CW local control was detected with less intense bolus regimens (SR: no bolus; HR: alternate-days bolus). Additionally, the rads-TI was able to distinguish overall radiodermatitis burden.
The Effect of Bolus on Local Control for Patients Treated With Mastectomy and Radiation Therapy
2021, International Journal of Radiation Oncology Biology Physics
Citation Excerpt :
An international survey study of bolus use in 2004 reported that North Americans (82%) and Australasians (65%) were more likely to always use bolus than Europeans (31%).6 Surveys from the past decade report that bolus was used routinely for 36% of chest wall and 16% of reconstruction cases in Europe, whereas bolus was used for 55% of chest wall and 52% of reconstruction cases in North America.7-10 This trans-Atlantic difference of opinion is reflected in the difference between the breast atlases of the Radiation Therapy Oncology Group (RTOG), which includes skin in its chest wall clinical target volume (CTV), and the European Society for Therapeutic Radiology and Oncology (ESTRO), which excludes the ventral 5 mm of skin and subcutaneous tissue from the chest wall CTV.11-13
Bolus use during postmastectomy radiation therapy doubles the risk of grade 2 and 3 skin toxicity. Despite its unknown benefit, bolus is often prescribed during postmastectomy radiation therapy for patients without skin involvement.
For women with breast cancer receiving photon 3-dimensional conformal radiation therapy, bolus was used routinely for chest walls but was omitted for breast reconstructions by about half of radiation oncologists from 2007 to 2011. Eligible patients had newly diagnosed invasive breast cancers without skin involvement (pT1-4a, any-N, M0) treated with adjuvant or neoadjuvant radiation therapy. For the bolus and no-bolus groups, we compared the cumulative incidence of local recurrence (LR) and locoregional recurrence (LRR) with distant recurrence and death as competing risks and breast cancer mortality (BCM). Multivariable analysis of LR and BCM included stage, subtype, lymphovascular invasion, grade, margin status, beam energy, bolus use, hormone therapy, chemotherapy, and reconstruction.
Systemic therapy was used for 98% of the 1887 patients. The bolus group had 1569 patients and the no-bolus group had 318 patients. Bolus was used in 51% (281/550) of patients treated with reconstruction and 96% (1288/1337) of patients treated without reconstruction. The 10-year outcomes (95% confidence interval) in patients treated with and without bolus were, respectively: LR 1.9% (1.3-2.7) versus 0.9% (0.3-2.6), LRR 3.1% (2.3-4.0) versus 3.2% (1.6-5.5), and BCM 19.4% (17.3-21.6) versus 18.3% (13.9-23.2). On multivariable analysis, bolus use was not associated with better LR (hazard ratio = 1.4 [0.3-6.4]) or BCM (hazard ratio = 0.8 [0.5-1.2]).
For patients treated with mastectomy, radiation therapy, and modern systemic therapy, the cumulative incidence of LR was low, with or without bolus. Because bolus use increases toxicity and does not reduce LR or BCM, it should no longer be used routinely for patients without skin involvement who receive systemic therapy.
Impact of radiation dose on complications among women with breast cancer who underwent breast reconstruction and post-mastectomy radiotherapy: A multi-institutional validation study
2021, Breast
Citation Excerpt :
In the current study, boost RT was performed generally in patients with positive or close margins upon institutional preferences. Overall 15.6% of the patients received boost RT, which is a fairly small percentage compared to a US survey in 2014, in which 66.5% of responders answered that they would prescribe boost RT [25]. Recently, Naoum et al. [26] investigated the impact of the addition of chest wall boost RT on breast reconstruction morbidity.
Emerging data suggest that higher radiation doses in post-mastectomy radiotherapy may be associated with an increased risk of reconstruction complications. This study aimed to validate previous findings regarding the impact of radiation dose on complications among women with breast cancer using a multi-center dataset.
Fifteen institutions participated, and women with breast cancer who received radiotherapy after either autologous or prosthetic breast reconstruction were included. The primary endpoint was major post-radiation therapy complications requiring re-operation for explantation, flap failure, or bleeding control.
In total, 314 patients were included. Radiotherapy was performed using both conventional fractionation and hypofractionation in various schedules. The range of the radiation therapy dose in Equivalent Dose in 2 Gy fractions (EQD2; α/β = 3.5) varied from 43.4 to 71.0 Gy (median dose: 48.6 Gy). Boost radiation therapy was administered to 49 patients. Major post-radiation therapy complications were observed in 24 (7.6%) patients. In multivariate analysis, an increasing EQD2 per Gy (odds ratio [OR]: 1.58, 95% confidence interval [CI]: 1.26–1.98; p < 0.001), current smoking status (OR: 25.48, 95% CI: 1.56–415.65; p = 0.023), and prosthetic breast reconstruction (OR: 9.28, 95% CI: 1.84–46.70; p = 0.007) were independently associated with an increased risk of major complications.
A dose-response relationship between radiation dose and the risk of complications was validated in this multi-center dataset. In this context, we hypothesize that the use of hypofractionated radiotherapy (40 Gy in 15 fractions) may improve breast reconstruction outcomes. Our multi-center prospective observational study (NCT03523078) is underway to further validate this hypothesis.
Radiotherapy After Skin-Sparing Mastectomy and Implant-Based Breast Reconstruction
2019, Clinical Breast Cancer
Citation Excerpt :
When used, generally a 0.5-cm bolus is reported to be placed on the RB during the entire treatment. Similarly, Thomas et al39 reported the rate of using bolus in patients with breast reconstruction as approximately 50% in the United States with different schemes such as 0.5 cm every other day, 0.5 cm every day as tolerated, 1 cm every other day, and 1 cm every day as tolerated. It is a fact that bolus use increases the rate of acute skin complications and in patients with IBR it can also impair cosmetic outcomes.
We evaluated the cosmetic results of radiotherapy (RT) after implant-based reconstruction (IBR).
We retrospectively evaluated 170 patients with 171 breast cancers treated between December 2004 and January 2016 in 2 university hospitals. RT fields were reconstructed breast (RB) only in 24 (14%), and RB and regional lymphatics in 147 (86%) breasts, respectively. All but 1 patient received a total 50 Gy with conventional fractionation. All patients received systemic chemotherapy. One hundred thirty-eight (81%) patients received hormonal therapy; 118 tamoxifen and 20 aromatase inhibitor.
Median follow-up time was 46.8 months (range, 1-163 months). The 5-year disease-free and overall survival rate was 83% and 93%, respectively. Cosmetic results were considered excellent in 111 (65%), fair in 46 (27%), and bad in 14 (8%) RB by patients. Thirty-four (20%) RB had restorative surgery; because of surgeons’ preference because of implant natural life time span in 5, and contracture, fibrosis, deformation, or dislocation of the implant, or cellulitis in the remaining. Statistically significant adverse factors in univariate analysis for impaired cosmetic outcome were bolus use on the RB, lymphatic irradiation, and volume that received at least 110% of the prescribed dose being > 1%. The use of bolus material was the only prognostic factor for deterioration of the cosmetic result in multivariate analysis.
RT after IBR yields acceptable cosmetic results. Although only 111 (65%) of RBs were considered to have excellent cosmetic results, only a small percentage of patients needed reoperation because of bad cosmetic outcome.
The Impact of Chest Wall Boost on Reconstruction Complications and Local Control in Patients Treated for Breast Cancer
2019, International Journal of Radiation Oncology Biology Physics
Citation Excerpt :
Patients with breast cancer who are undergoing PMRT typically receive radiation doses between 50 and 50.4 Gy in 1.8- to 2-Gy fractions daily, 5 days per week.20 Adding CWB to the mastectomy scar or chest wall for at least a total dose of 60 to 60.4 Gy remains debatable among radiation oncologists.15,16 The rationale for boost is extrapolated from clinical evidence of improved local tumor control with a boost to the lumpectomy cavity in a breast-conserving management setting.21
Giving an additional radiation dose to the incision or chest wall has been a practice, but it has never been studied in a randomized setting, and it might lead to inferior cosmetic outcomes. This study aims to evaluate whether delivery of a chest wall boost (CWB) to the mastectomy scar or chest wall is independently associated with reconstruction complications and to assess its disease control efficacy in the setting of breast reconstruction.
We conducted a retrospective chart review of 746 patients with breast cancer who underwent mastectomy, breast reconstruction, and PMRT; all underwent treatment at our institution during 1997 to 2016. Various reconstruction techniques were used among this cohort including autologous reconstruction, single-stage direct-to-implant reconstruction, and 2-stage tissue expander implant. Cohorts were divided by administration of CWB. The primary objective was comparing the rate of reconstruction complications including skin necrosis, fat necrosis and infection between groups. Subgroup analysis for patients with implant-based reconstruction was performed to evaluate the effect of CWB on implant-related complications such as capsular contracture, implant exposure, and implant failure. The secondary objective was comparison of the cumulative incidence of local failure between groups overall and within clinically high-risk subgroups.
The median follow-up was 5.2 years. Most clinicopathologic features were well balanced between the 379 (51%) patients who received CWB and the 367 (49%) who did not. On multivariate analysis, CWB was significantly associated with infection, skin necrosis, and implant exposure. For implant reconstruction patients, CWB independently increased risks of implant failure. CWB administration was not associated with local tumor control benefits, even in high-risk subgroups.
Our findings suggest that omission of chest wall boost in postmastectomy radiation improves breast reconstruction outcomes without compromising local tumor control.
Outcomes in Patients Treated with Post-mastectomy Chest Wall Radiotherapy without the Routine Use of Bolus
2018, Clinical Oncology
The use of bolus in post-mastectomy radiotherapy (PMRT) varies significantly between institutions. We report on chest wall recurrence and acute toxicity rates for PMRT patients treated with selective use of bolus.
We analysed PMRT patients who received adjuvant chest wall radiotherapy for invasive breast cancer between 2004 and 2009. Patient, tumour and cancer outcomes were collected from a prospective database, with additional radiotherapy and acute toxicity details supplemented retrospectively. Chest wall bolus was reserved for patients considered at high risk of local recurrence.
There were 314 patients suitable for analysis: 52 received bolus, 262 did not. The mean age was 53.2 years. The median follow-up was 4.2 years. The most common T stage was T2 (37%), followed by T3/T4 (33%). There were 229 patients (73%) who had N+ disease; 213 (68%) patients had grade 3 cancer. Oestrogen receptor was positive in 176 (56%) cases, progesterone receptor was positive in 134 (43%) and HER2 receptor was positive in 24 (8%). Lymphovascular space invasion was present in 146 patients (46%), dermal invasion in 30 patients (10%) and positive margin in 14 patients (4%). The 4 year chest wall recurrence rate was 14% (95% confidence interval 5.4–26.8%) in the bolus group and only 3.5% (95% confidence interval 1.6–6.4%) in the non-bolus group. On univariate analysis, use of bolus was associated with a significant difference in chest wall recurrence (hazard ratio 3.09; 1.15–8.33; P = 0.025). However, when taking into account margin status, this significance was lost (hazard ratio = 2.45; 95% confidence interval 0.80–7.50, P = 0.12). There was a higher rate of acute grade 2 skin toxicity in patients receiving bolus compared with those without, 40% versus 21% (P = 0.01).
The selective use of bolus resulted in a small risk of chest wall recurrence rates for low-risk patients. This suggests that the routine use of bolus in PMRT patients may be unnecessary.

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: Conflicts of interest: None.

¹: Co-first authors.

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Original ReportRadiation practice patterns among United States radiation oncologists for postmastectomy breast reconstruction and oncoplastic breast reduction

Abstract

Background

Methods and materials

Results

Conclusions

Introduction

Section snippets

Methods and materials

Results

Discussion

Clin Breast Cancer

Pract Radiat Oncol

Int J Radiat Oncol Biol Phys

Radiother Oncol

Int J Radiat Oncol Biol Phys

Int J Radiat Oncol Biol Phys

Cancer Facts & Figs

SEER Stat Fact Sheets: Breast

Increasing mastectomy rates among all age groups for early stage breast cancer: A 10-year study of surgical choice

Breast J

American Society of Plastic Surgeons Report of the 2010 Plastic Surgery Statistics

Original Report
Radiation practice patterns among United States radiation oncologists for postmastectomy breast reconstruction and oncoplastic breast reduction