EP-1012 FREE BREATHING GATING IS SUPERIOR TO PRONE POSITION FOR WHOLE BREAST RADIOTHERAPY

200 Background: Recent randomized evidence has demonstrated low rates of axillary nodal failure in patients with one to two positive lymph nodes who receive local therapy with sentinel lymph node biopsy and simple tangential radiotherapy alone. Decreasing utilization of complete axillary nodal dissections has potential implications for radiotherapy treatment delivery design. We sought to compare the inadvertent coverage of the axillary lymph nodal regions between supine versus prone position for whole breast radiotherapy using simple tangent fields. Methods: Twenty patients with breast cancer who had previously received whole breast radiotherapy with simple tangent fields were randomly selected. Patients were selected such that 10 patients had received treatment in the supine position and 10 patients in the prone position. Axillary lymph node levels I-III were contoured by a single physician according to the RTOG breast contouring atlas. The previously generated radiotherapy plans, each to deliver a prescribed dose between 42.56 and 50Gy, were dosimetrically compared to assess differences in coverage of the nodal volumes. Results: In both positions, dose to each of the axillary nodal regions was low. For level I, the volume receiving 95% of the prescribed dose (V95) was 34.7% for supine positioning and 1.6% for prone positioning. All other analyzed volumes, specifically V25 (71.5% vs 32.6%), V50 (63.3% vs 28.2%), and V75 (57.6% vs 24.1%), were 50% greater for supine compared to prone positioning. Level II coverage was less with V95 of 6% and 0.1% respectively. Similarly V25 (32.8% vs 5.7%), V50 (25.7% vs 3.8%), and V75 (20.3% vs 2.1%) were less compared to level one and greater in the supine position. Level III coverage was less than 10% for both positions at all measured volumes of V95, V75, V50, and V25. Conclusions: Delivery of radiotherapy using simple tangents inadequately covers all axillary nodal levels. Coverage is greater in the supine position with very little inadvertent coverage in the prone position. The risk of nodal recurrence should be carefully considered when deciding to use a simple tangential field design. Additional factors such as dose to the lung and heart should also be considered for positioning.

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Korean First Prospective Phase II Study, Feasibility of Prone Position in Postoperative Whole Breast Radiotherapy: A Dosimetric Comparison

Cancer Research and Treatment ◽

10.4143/crt.2018.423 ◽

2019 ◽

Vol 51 (4) ◽

pp. 1370-1379 ◽

Cited By ~ 1

Author(s):

Yoonsun Chung ◽

Jeong Il Yu ◽

Won Park ◽

Doo Ho Choi

Keyword(s):

Prone Position ◽

Phase Ii ◽

Phase Ii Study ◽

Breast Radiotherapy ◽

Dosimetric Comparison ◽

Whole Breast Radiotherapy ◽

Prospective Phase

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Breath Hold Breast Radiotherapy In The Era of Precision Medicine: Appropriate Selection for Left Descending Artery Sparing

10.21203/rs.3.rs-127934/v1 ◽

2020 ◽

Author(s):

Edy Ippolito ◽

Carlo Greco ◽

Maristella Marrocco ◽

Silvia Gentile ◽

Serena Palizza ◽

...

Keyword(s):

Breast Cancer ◽

Minimum Distance ◽

Free Breathing ◽

Left Breast ◽

Breath Hold ◽

Operating Characteristics ◽

Breast Radiotherapy ◽

Heart Volume ◽

Deep Inspiration Breath Hold ◽

Whole Breast Radiotherapy

Abstract Background and purpose To identify anatomical and/or preplanning characteristics correlated with left descending artery (LAD) dose and therefore provide guidance in the selection of patients with left-breast cancer that could benefit the most from the use of deep inspiration breath hold radiotherapy (DIBH-RT). Materials and methods We retrospectively identified patients with left-sided breast cancer who underwent whole breast radiotherapy in DIBH and extracted data from treatment plans in free-breathing (FB) and DIBH. The following anatomical parameters were obtained from the planning CTs in FB: lung volume, heart volume, breast separation, minimum distance from LAD to tangent open field. Receiving operating characteristics was also performed to define the cut-off point of parameters to use in LAD dosimetry prediction. Areas under the curve (AUCs) were calculated for all variables. Post-test probability has been calculated to evaluate advantage for parameters combination. Results One hundred ninety-seven patients were identified. The strongest predictor at FB CT scan of LAD maximum dose > 10 Gy and a LAD mean dose > 4 Gy was the minimum distance of LAD from tangent open fields. Adding consecutively other preplanning anatomic parameters, the positive predictive value (PPV) to identify patients at risk of higher dose to LAD was > 90%. Conclusions The dosimetric benefit of DIBH is valid for all patients and DIBH should be preferred for all left sided patients; however we can identify a subgroup of patients who benefit the least from DIBH. This is the group with favorable anatomy: limited breast separation, well expanded lungs, LAD distant from open tangent fields.

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Prone versus supine free-breathing for right-sided whole breast radiotherapy

Scientific Reports ◽

10.1038/s41598-021-04385-3 ◽

2022 ◽

Vol 12 (1) ◽

Author(s):

Odile Fargier-Bochaton ◽

Xinzhuo Wang ◽

Giovanna Dipasquale ◽

Mohamed Laouiti ◽

Melpomeni Kountouri ◽

...

Keyword(s):

Free Breathing ◽

September 11 ◽

Breast Cancer Patients ◽

Lung Dose ◽

Breast Radiotherapy ◽

Tumor Bed ◽

Whole Breast Radiotherapy ◽

The Mean ◽

The Right ◽

Robust Linear Regression

AbstractProne setup has been advocated to improve organ sparing in whole breast radiotherapy without impairing breast coverage. We evaluate the dosimetric advantage of prone setup for the right breast and look for predictors of the gain. Right breast cancer patients treated in 2010–2013 who had a dual supine and prone planning were retrospectively identified. A penalty score was computed from the mean absolute dose deviation to heart, lungs, breasts, and tumor bed for each patient's supine and prone plan. Dosimetric advantage of prone was assessed by the reduction of penalty score from supine to prone. The effect of patients' characteristics on the reduction of penalty was analyzed using robust linear regression. A total of 146 patients with right breast dual plans were identified. Prone compared to supine reduced the penalty score in 119 patients (81.5%). Lung doses were reduced by 70.8%, from 4.8 Gy supine to 1.4 Gy prone. Among patient's characteristics, the only significant predictors were the breast volumes, but no cutoff could identify when prone would be less advantageous than supine. Prone was associated with a dosimetric advantage in most patients. It sets a benchmark of achievable lung dose reduction.Trial registration: ClinicalTrials.gov NCT02237469, HUGProne, September 11, 2014, retrospectively registered.

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Is prone free breathing better than supine deep inspiration breath-hold for left whole-breast radiotherapy? A dosimetric analysis

Strahlentherapie und Onkologie ◽

10.1007/s00066-020-01731-8 ◽

2021 ◽

Author(s):

Xinzhuo Wang ◽

Odile Fargier-Bochaton ◽

Giovanna Dipasquale ◽

Mohamed Laouiti ◽

Melpomeni Kountouri ◽

...

Keyword(s):

Breast Cancer ◽

Cancer Patients ◽

Free Breathing ◽

Breath Hold ◽

Deep Inspiration ◽

Breast Cancer Patients ◽

Breast Radiotherapy ◽

Deep Inspiration Breath Hold ◽

Number Of Patients ◽

Whole Breast Radiotherapy

Abstract Purpose The advantage of prone setup compared with supine for left-breast radiotherapy is controversial. We evaluate the dosimetric gain of prone setup and aim to identify predictors of the gain. Methods Left-sided breast cancer patients who had dual computed tomography (CT) planning in prone free breathing (FB) and supine deep inspiration breath-hold (DiBH) were retrospectively identified. Radiation doses to heart, lungs, breasts, and tumor bed were evaluated using the recently developed mean absolute dose deviation (MADD). MADD measures how widely the dose delivered to a structure deviates from a reference dose specified for the structure. A penalty score was computed for every treatment plan as a weighted sum of the MADDs normalized to the breast prescribed dose. Changes in penalty scores when switching from supine to prone were assessed by paired t-tests and by the number of patients with a reduction of the penalty score (i.e., gain). Robust linear regression and fractional polynomials were used to correlate patients’ characteristics and their respective penalty scores. Results Among 116 patients identified with dual CT planning, the prone setup, compared with supine, was associated with a dosimetric gain in 72 (62.1%, 95% CI: 52.6–70.9%). The most significant predictors of a gain with the prone setup were the breast depth prone/supine ratio (>1.6), breast depth difference (>31 mm), prone breast depth (>77 mm), and breast volume (>282 mL). Conclusion Prone compared with supine DiBH was associated with a dosimetric gain in 62.1% of our left-sided breast cancer patients. High pendulousness and moderately large breast predicted for the gain.

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