Prone Whole-breast Irradiation Research Articles

SP-0563: Prone whole-breast irradiation: are the benefits overshadowed by the challenges?

SP-0563: Prone whole-breast irradiation: are the benefits overshadowed by the challenges?

Multimodal Imaging for Clinical Target Volume Definition in Prone Whole-Breast Irradiation: A Single Institution Experience

Aim: The aim was identification of reference structures for breast clinical target volume (CTV) in prone position, throughout image fusion process. Materials & methods: We analyzed breast glandular tissue distribution in 20 diagnostic MRIs, referring to structures reported in ESTRO guidelines for supine irradiation. The volume containing breast glandular tissue in all cases was defined as MRI prone CTV (MRIpCTV). Then in ten subsequent patients planned for prone irradiation, MRI and computed tomography (CT) simulation was acquired. MRIpCTV was defined followed by our findings and transferred to CT for definitive delineation. Results: MRIpCTV was defined by the caudal edge of clavicular head, 3 mm above inframammary fold, by the medial thoracic artery, by a plane passing through the lateral surface of pectoralis muscles, by the anterior surface of pectoralis muscles and 3 mm from the skin. Deformed CTV was consistent with anatomy on CT; the limits chosen for MRIpCTV fit adequately also for CT. Conclusion: Prone irradiation is an alternative set up for selected cases, so the sample is very small. However, our suggestions could be of aid in defining prone CTV. The good consistency between MRI and CT seems to confirm that MRI may be unnecessary in routine practice.

Increasing Use of Post Lumpectomy Radiation Therapy for Ductal Carcinoma In Situ of the Breast in the United States

Purpose/Objective(s): Our institution has used 3-dimensional conformal radiation therapy (3DCRT) to deliver whole breast irradiation (WBI) in the prone position since 1998 in order to address technical difficulties associated with treating large, pendulous breasts and/or large body habitus, and/or in patients with left-sided cancers to decrease radiation received by the heart. The goal of this study was to review our updated experience using prone breast WBI to determine whether the recurrence rates and survival patterns are acceptable in this set of patients. Materials/Methods: From 1998-2013, 397 women treated with breast conserving surgery underwent WBI in the prone position using 3DCRT. Patients were treated with a median of 50 Gy to the breast volume +/a boost of 10 Gy to the lumpectomy planning target volume. All patients had >12 month follow-up. Results: Median follow-up was 43.6 mo. The median age was 59 (27-91); 67% were post-menopausal. Median BMI was 32.4 (18.6-64.6). Tumors were Tis-19.8%, T1-61.5%, T2-17.2%, T3-1.5%, and 3.3% had positive axillary nodes. Eight (2%) patients were diagnosed with an ipsilateral breast tumor (5-yr recurrence rateZ1.9%). Mean time to recurrence was 57.5 mo (19-127 mo). The original tumors were DCIS (2), infiltrating lobular (3), and invasive ductal (3). Focal DCIS margin was <2mm in 3 patients. The original tumor location and location of recurrence respectively was: lower outer quadrant (LOQ)-failed in UOQ, UIQ-failed in UIQ (2), central-failed central, UOQ-failed UOQ, LOQ-failed LOQ, UOQfailed LIQ, and UOQ-failed in skin and with distant metastases. Ipsilateral disease free survival was 97.6% at 5 yr. Distant metastasis free survival was 98.4% at 5 yr. Overall survival was 95.5% at 5 yr. Conclusion: In patients with large pendulous breasts, increased BMI and/ or left-sided tumors, delivering WBI in the prone position using 3DCRT results in recurrence rates and failure patterns similar to those anticipated using supine WBI. This series adds to the growing literature demonstrating prone WBI provides local control rates comparable to supine WBI with minimal toxicity to organs at risk. Author Disclosure: H. Saeed: None. H. Cheng: None. T.R. Kelly: None. J.A. Bovi: None. J.R. White: None. C. Bergom: None. A.D. Currey: None. J. Wilson: None.

Toxicity and Cosmetic Outcome After Breast Conservation and Prone Whole-Breast Irradiation Using Three-Dimensional Conformal Radiation Therapy

Toxicity and Cosmetic Outcome After Breast Conservation and Prone Whole-Breast Irradiation Using Three-Dimensional Conformal Radiation Therapy

Incidental dose to coronary arteries is higher in prone than in supine whole breast irradiation

Sparing of normal lung is best achieved in prone whole breast irradiation (WBI). However, exposure of the heart and coronary arteries might increase due to anterior movement of the heart in prone WBI. Treatment plans of 46patients with large breasts irradiated for mammary cancer after breast-conserving surgery were retrospectively analyzed. The average treated breast volume of right-sided breasts (n = 33) was 1,804ccm and 1,500ccm for left-sided breasts (n = 13). The majority had invasive cancer (96 %) of which 61 % were pT1 and 39 % pT2 tumors. All patients received radiation therapy to the breast only. For three-dimensional (3D) treatment planning, all patients underwent a noncontrast-enhanced CT in the supine position with a wingboard and a second CT in the prone position using a prone breastboard. Nontarget volumes of the lung, heart, and coronary arteries were contoured. A total dose of 50.4Gy was prescribed to the breast only. Differences were calculated for each patient and compared using the Wilcoxon signed-rank test. Treatment of left-sided breasts resulted in similar average mean heart doses in prone versus supine WBI (4.16 vs. 4.01Gy; p = 0.70). The left anterior descending artery (LAD) had significantly higher dose exposure in left versus right WBI independent of position. Prone WBI always resulted in significantly higher exposures of the right circumflex artery (RCA) and LAD as compared to supine WBI. In left WBI, the mean LADprone was 33.5Gy vs. LADsupine of 25.6Gy (p = 0.0051). The V20prone of the LAD was 73.6 % vs. V20supine 50.4 % (p = 0.0006). The heart dose is not different between supine and prone WBI. However, in left WBI the incidental dose to the LAD with clinically relevant doses can be significantly higher in prone WBI. This is discussed controversially in the literature as it might depend on contouring and treatment techniques. We recommend contouring of LAD if patients are treated in prone WBI and evaluation of alternative treatment techniques for optimal sparing of coronary arteries.

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

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. 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. The median body mass index (BMI) was 33.6 kg/m(2), and median breast volume was 1396 cm(3). 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. 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.

Failure Patterns after 3D Conformal Radiotherapy for Whole Breast Irradiation in the Prone Position

Prone whole breast irradiation (WBI) has shown promise in reducing radiation-related toxicities in patients with large, pendulous breasts undergoing breast conserving therapy. However, there has been concern that volume of irradiated breast in the prone position is insufficient and may lead to more frequent treatment failures. Our institution has used CT volume based 3D conformal radiation therapy (3DCRT) to deliver prone WBI for large, pendulous breasts and/or large body habitus and has demonstrated favorable toxicity profiles and cosmetic outcomes.

Accelerated Whole Breast Irradiation With Intensity-Modulated Radiotherapy to the Prone Breast

Whole breast irradiation (WBI) is the standard of care for patients with early-stage breast cancer who opt for breast conservation. After a randomized trial demonstrated equivalent cosmesis and disease control with accelerated WBI (AWBI), our institution began to offer AWBI to appropriate patients. The aim of this study was to examine our unique experience with AWBI using prone positioning and simplified intensity-modulated radiotherapy (IMRT) planning with a sequential boost to the tumor bed. We identified 356 patients who had been treated with prone WBI using IMRT in our department between January 2004 and December 2006. Of these, 128 (36%) patients had received AWBI (representing 131 treated breasts), consisting of 16 daily fractions of 265 cGy to a total dose of 4,240 cGy followed by a conventionally fractionated boost. Patients who opted for AWBI were similar demographically to the patients undergoing conventional WBI. In the AWBI cohort, 83% of the patients had Stage T1 disease and 22% had nodal involvement (N1). The tumors were estrogen receptor-positive, progesterone receptor-positive and Her-2/Neu-amplified in 82%, 69%, and 11%, respectively. The median duration of AWBI plus a boost was 29 days, and no patient required a toxicity-related treatment break. No Grade 3 or greater acute toxicity developed. At a median follow-up of 18 months, one ipsilateral breast recurrence developed that was salvaged with mastectomy and immediate reconstruction. AWBI to the prone breast using simplified IMRT with a sequential boost offers women requiring breast-only adjuvant radiotherapy an abbreviated treatment with early tumor control and cosmesis comparable to that with standard fractionation.