Erschienen in:
24.08.2018 | Original Article
Dose variability in different lymph node levels during locoregional breast cancer irradiation: the impact of deep-inspiration breath hold
verfasst von:
Montserrat Pazos, Alba Fiorentino, Aurélie Gaasch, Stephan Schönecker, Daniel Reitz, Christian Heinz, Maximilian Niyazi, Marciana-Nona Duma, Filippo Alongi, Claus Belka, Dr. med. Stefanie Corradini
Erschienen in:
Strahlentherapie und Onkologie
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Ausgabe 1/2019
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Abstract
Purpose
Aim of the present analysis was to evaluate the movement and dose variability of the different lymph node levels of node-positive breast cancer patients during adjuvant radiotherapy (RT) with regional nodal irradiation (RNI) in deep-inspiration breath hold (DIBH).
Methods
Thirty-five consecutive node-positive breast cancer patients treated from October 2016 to February 2018 receiving postoperative RT of the breast or chest wall including RNI of the supra-/infraclavicular lymph node levels (corresponding to levels IV, III, Rotter LN (interpectoral), and some parts of level II) were analyzed. To evaluate the lymph node level movement, a center of volume (COV) was obtained for each lymph node level for free-breathing (FB) and DIBH plans. Geometric shifts and dose differences between FB and DIBH were analyzed.
Results
A significant movement of the COV in anterior (y) and cranial (z) dimensions was observed for lymph node levels I–II and Rotter lymph nodes (p < 0.001) due to DIBH. Only minor changes in the lateral dimension (x axis) were observed, without reaching significance for levels III, IV, and internal mammary. There was a significant difference in the mean dose of level I (DIBH vs. FB: 38.2 Gy/41.3 Gy, p < 0.001) and level II (DIBH vs. FB: 45.9 Gy/47.2 Gy, p < 0.001), while there was no significant difference in level III (p = 0.298), level IV (p = 0.476), or internal mammary nodes (p = 0.471).
Conclusion
A significant movement of the axillary lymph node levels was observed during DIBH in anterior and cranial directions for node-positive breast cancer patients in comparison to FB. The movement leads to a significant dose reduction in level I and level II.