The choice of IMRT for early-stage right breast cancer.

2013 ◽  
Vol 31 (26_suppl) ◽  
pp. 81-81
Author(s):  
Sophia Edwards-Bennett ◽  
Stephen Andrews ◽  
Patrick Francke ◽  
Frank Vicini
Keyword(s):  
Breast Cancer ◽  
Radiation Therapy ◽  
Chest Wall ◽  
Early Stage ◽  
Treatment Plan ◽  
Univariate Analysis ◽  
Surrogate Marker ◽  
Intensity Modulated Radiation Therapy ◽  
Skin Dose ◽  
Intensity Modulated

81 Background: The benefit of Intensity Modulated Radiation Therapy (IMRT) has been established for left breast cancer. However, IMRT is not routinely employed for right breast cancer. The purpose of this study is to (1) compare dosimetric parameters in women with early stage right breast cancer undergoing whole breast radiation therapy using 3-dimensional conformal radiation (3DCRT) versus intensity modulated radiation therapy (IMRT) (2) determine treatment planning and/or anatomical correlates for patients who may benefit from IMRT. Methods: IMRT versus 3DCRT treatment plans were compared for 20 consecutive female patients with early stage (T1-T2 N0M0 ) right breast cancer treated at our center from 1/2012 to 12/2012. The planned target volume (PTV), contoured according to the RTOG atlas guidelines, was prescribed to 46-8-50.4 Gy in 26-28 fractions with PTV coverage goal of ≥ 95 % receiving the prescription dose. Dosimetric and anatomic parameters: % right lung receiving 20 Gy (lung V20), maximum breast dose (Dmax), maximum skin dose (Dmax skin), chest wall separation (CWS) and medial gantry angle (MGA) were determined for each paired treatment plan. Wilcoxon-signed rank test was utilized to compare IMRT and 3DCRT dosimetric parameters. Univariate analysis was used to identify planning or anatomic correlates associated with favorable dosimetric outcomes. Results: The lung V20Gy for IMRT ( 10.86±2.81%) was significantly lower than for 3DCRT (12.92±3.45 %, p < 0.043). IMRT significantly reduced Dmax to 53.79 ± 2.17 Gy from 56.7 ± 2.24 Gy with 3DCRT (p 0.001). 3DCRT yielded significantly higher Dmax skin (33.47±3.21 Gy) than IMRT (24.16 ±2.65 Gy, p< 0.0001). Mean CWS and MGA were 22.4 ± 2.6 cm and 126 ± 5.1° respectively. There was a significant association between CWS and Dmax for 3DCRT (p < 0.026). Conclusions: The most significant impact of IMRT for right breast cancer was the reduction of Dmax and Dmax skin, with a more tempered advantage in the reduction of lung V20. Reduction of maximum breast and skin dose harbors clinical relevance as it relates to acute skin toxicity, long- term fibrosis and adverse cosmetic outcomes. Chest wall separation may be a potential planning surrogate marker to determine which right-sided breast cancer patients may benefit from IMRT.

Correlation Between Toxicity and Dosimetric Parameters in Patients Treated with Adjuvant Intensity-Modulated Radiation Therapy for Breast Cancer: The Results of a Prospective Study.

2020 ◽  
Author(s):  
David Pasquier ◽  
Benoit Bataille ◽  
Florence Le Tinier ◽  
Raoudha Bennadji ◽  
Hélène Langin ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Radiation Therapy ◽  
Late Onset ◽  
Univariate Analysis ◽  
Intensity Modulated Radiation Therapy ◽  
Conservative Surgery ◽  
High Dose ◽  
Total Mastectomy ◽  
Intensity Modulated ◽  
A Prospective Study

Abstract Background. In the treatment of breast cancer, intensity-modulated radiation therapy (IMRT) reportedly reduces the high-dose irradiation of at-risk organs and decreases the frequency of adverse events (AEs). Comparisons with conventional radiotherapy have shown that IMRT is associated with lower frequencies of acute and late-onset AEs. Here, we extended a prospective, observational, single-center study of the safety of IMRT to a second investigating center. Methods. Patients scheduled for adjuvant IMRT after partial or total mastectomy were given a dose of 50 Gy (25 fractions of 2 Gy over five weeks), with a simultaneous integrated boost in patients having undergone conservative surgery. Results. 300 patients were included in the study, and 288 were analyzed. The median follow-up period was 2.1 years. Most AEs were mild. The most common AEs were skin-related - mainly radiodermatitis (in 266 patients (92.4%)) and hyperpigmentation (in 178 (61.8%)). Smoking (odds ratio) [95%CI] = 2.10 [1.14–3.87]; p = 0.017), no prior chemotherapy (0.52 [0.27–0.98]; p = 0.044), and D98% for subclavicular skin (1.030 [1.001–1.061]; p = 0.045) were associated with grade ≥ 2 acute AEs. In a univariate analysis, the mean dose, (p < 0.0001), D2% (p < 0.0001), D50% (p = 0.037), D95% (p = 0.0005), D98% (p = 0.0007), V30Gy (p < 0.0001), and V45Gy (p = 0.0001) were significantly associated with grade ≥ 1 acute esophageal AEs. In a multivariate analysis, D95% for the skin (p < 0.001), D98% for the subclavicular skin and low D95% for the internal mammary lymph nodes were associated with grade ≥ 1 medium-term AEs. Conclusions. The safety profile of adjuvant IMRT after partial or total mastectomy is influenced by dosimetric parameters. Trial registration: ClinicalTrials.gov NCT02281149

scholarly journals Dosimetric effects of supine immobilization devices on the skin in intensity-modulated radiation therapy for breast cancer: a retrospective study

BMC Cancer ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ran Lv ◽  
Guangyi Yang ◽  
Yongzhi Huang ◽  
Yanhong Wang
Keyword(s):  
Breast Cancer ◽  
Radiation Therapy ◽  
Retrospective Study ◽  
Intensity Modulated Radiation Therapy ◽  
Radical Mastectomy ◽  
Planning System ◽  
Treatment Planning System ◽  
Skin Dose ◽  
Intensity Modulated ◽  
Left And Right

Abstract Background The dose perturbation effect of immobilization devices is often overlooked in intensity-modulated radiation therapy (IMRT) for breast cancer (BC). This retrospective study assessed the dosimetric effects of supine immobilization devices on the skin using a commercial treatment planning system. Methods Forty women with BC were divided into four groups according to the type of primary surgery: groups A and B included patients with left and right BC, respectively, who received 50 Gy radiotherapy in 25 fractions after radical mastectomy, while groups C and D included patients with left and right BC, respectively, who received breast-conservation surgery (BCS) and 40.05 Gy in 15 fractions as well as a tumor bed simultaneous integrated boost to 45 Gy. A 0.2-cm thick skin contour and two sets of body contours were outlined for each patient. Dose calculations were conducted for the two sets of contours using the same plan. The dose differences were assessed by comparing the dose-volume histogram parameter results and by plan subtraction. Results The supine immobilization devices for BC resulted in significantly increased skin doses, which may ultimately lead to skin toxicity. The mean dose increased by approximately 0.5 and 0.45 Gy in groups A and B after radical mastectomy and by 2.7 and 3.25 Gy in groups C and D after BCS; in groups A–D, the percentages of total normal skin volume receiving equal to or greater than 5 Gy (V5) increased by 0.54, 1.15, 2.67, and 1.94%, respectively, while the V10 increased by 1.27, 1.83, 1.36, and 2.88%; the V20 by 0.85, 1.87, 2.76, and 4.86%; the V30 by 1.3, 1.24, 10.58, and 11.91%; and the V40 by 1.29, 0.65, 10, and 10.51%. The dose encompassing the planning target volume and other organs at risk, showed little distinction between IMRT plans without and with consideration of immobilization devices. Conclusions The supine immobilization devices significantly increased the dose to the skin, especially for patients with BCS. Thus, immobilization devices should be included in the external contour to account for dose attenuation and skin dose increment. Trial registration This study does not report on interventions in human health care.

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