Prone Whole-Breast Irradiation Using Three-Dimensional Conformal Radiotherapy in Women Undergoing Breast Conservation for Early Disease Yields High Rates of Excellent to Good Cosmetic Outcomes in Patients With Large and/or Pendulous Breasts

Abstract

Purpose To report our institution’s experience using prone positioning for three-dimensional conformal radiotherapy (3D-CRT) to deliver post-lumpectomy whole breast irradiation (WBI) in a cohort of women with large and/or pendulous breasts, to determine the rate of acute and late toxicities and, more specifically, cosmetic outcomes. We hypothesized that using 3D-CRT for WBI in the prone position would reduce or eliminate patient and breast size as negative prognostic indicators for toxicities associated with WBI. Methods and Materials From 1998 to 2006, 110 cases were treated with prone WBI using 3D-CRT. The lumpectomy, breast target volumes, heart, and lung were contoured on all computed tomography scans. A dose of 45–50 Gy was prescribed to the breast volume using standard fractionation schemes. The planning goals were ≥95% of prescription to 95% of the breast volume, and 100% of boost dose to 95% of lumpectomy planning target volume. Toxicities and cosmesis were prospectively scored using the Common Terminology Criteria for Adverse Effects Version 3.0 and the Harvard Scale. The median follow-up was 40 months. Results The median body mass index (BMI) was 33.6 kg/m2, and median breast volume was 1396 cm3. The worst toxicity encountered during radiation was Grade 3 dermatitis in 5% of our patient population. Moist desquamation occurred in 16% of patients, with only 2% of patients with moist desquamation outside the inframammary/axillary folds. Eleven percent of patients had Grade ≥2 late toxicities, including Grade 3 induration/fibrosis in 2%. Excellent to good cosmesis was achieved in 89%. Higher BMI was associated with moist desquamation and breast pain, but BMI and breast volume did not impact fibrosis or excellent to good cosmesis. Conclusion In patients with higher BMI and/or large–pendulous breasts, delivering prone WBI using 3D-CRT results in favorable toxicity profiles and high excellent to good cosmesis rates. Higher BMI was associated with moist desquamation, but prone positioning removed BMI and breast size as factors for poorer cosmetic outcomes. This series adds to the growing literature demonstrating that prone WBI may be advantageous in select patients.

Does an integrated boost increase acute toxicity in prone hypofractionated breast irradiation? A randomized controlled trial

“…grade 2-3 late toxicity was reported in 4.4% (skin) and 13.7% (subcutaneous tissues) of patients. These rates are comparable with those reported by Bergom et al (14) in 110 patients with large or pendulous breasts: 11% of patients had grade 2 late toxicities, including grade 3 induration/ fibrosis in 2%. The largest patient cohort was presented in the study by the group at the New York School of Medicine, who treated about 400 patients with prone WBI, including an integrated boost (15).…”

“…The photographs were scored by 2 medical students and 1 radiation oncologist in training. Still, the cosmetic outcome is in line with published prone (14,15) and supine data (25,27), and the most obvious explanation is that the differences are not perceived as worse cosmetic outcome when scored subjectively. Although Cardoso et al (28) reported a fair concordance between the BCCT.core software and a subjective evaluation using the Harvard scale, in our data set the software scored significantly worse than the 3 observers, both on the photograph with the arms down (PZ.007) and on the photograph with the arms up (P<.001).…”

“…A small Asian study reporting on 21 patients with relatively pendulous breasts reported no grade 2 late toxicities (23). Excellent-to-good cosmesis after prone WBI is achieved in about 80% to 90% of patients (14,15). Chronic toxicity and cosmesis seem to compare favorably with the supine results (24)(25)(26).…”

Heart dose reduction by prone deep inspiration breath hold in left-sided breast irradiation

“…kV imaging was consecutively taken to evaluate the positioning in DIBH. Multiple breath hold CBCT has been described in lung carcinoma [33] and is a potentially more accurate setup verification procedure. Interruption of the CBCT gantry rotation is, to our knowledge, not possible with our Elekta XVI software.…”

A new three-dimensional conformal radiotherapy (3DCRT) technique for large breast and/or high body mass index patients: evaluation of a novel fields assessment aimed to reduce extra–target-tissue irradiation

“…29,30 Even though prone set-up is considered a reasonable option for large breasted patients, it, however, requires patients' compliance and some older patients may not be able to maintain the position. Additionally, in our series 63.0% of patients had a BMI .30% and 94.3% had a BMI .25.…”