Distribution patterns of lymphatic metastases: influence of axillary lymph node dissection
PH-0600
Abstract
Distribution patterns of lymphatic metastases: influence of axillary lymph node dissection
Authors: SCHLEIBINGER|, Christina Anna Maria(1)*[christina.schleibinger@gmx.net];Borm|, Kai Joachim(1);Voppichler|, Julia(1);Düsberg|, Mathias(1);Oechsner|, Markus(1);Combs|, Stephanie Elisabeth(1);Duma|, Marciana-Nona(1,2);
(1)Klinikum rechts der Isar, Department of Radiation Oncology- Technical University of Munich TUM- Ismaninger Str. 22, Munich, Germany;(2)University Hospital of the Friedrich-Schiller University, Department of Radiotherapy and Radiation Oncology- Bachstraße 18, Jena, Germany;
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Purpose or Objective
In 2018, a study on the distribution patterns of PET positive lymph node metastases (LNM) in breast cancer patients (Borm KJ et al., IJROBP 2018) was published. Therein, LNM of patients with recurrent breast cancer were analysed. The aim of the current study was to assess whether the pattern of lymph node recurrences differs between patients with prior axillary lymph node dissection (ALND) vs. no prior ALND.
Material and Methods
171 patients with recurrent breast cancer out of 235 patients comprised in the original study were included in the current study. A detailed analysis of the medical records was performed in order to record the treatment prior to diagnosis of the LNM. Furthermore, information about the primary tumor of the patients (e.g. stage, grading, biology) was collected. Reliable and comprehensive data could be collected for 134 of 171 patients. The LNM were allocated to two different groups: ALND vs. no ALND. The LNM in each group were compared with regard to the distribution pattern and size of the LNM and the presence of distant metastases. Color-coded heatmaps marking hotspots of LNM in a CT-template were created (figure 1).
Results
The ALND group consisted of 131 LNM (63 patients), the no ALND group of 136 LNM (58 patients). Most patients had distant metastases at the time of the recurrence (ALND 63,49%; no ALND 75,86%). The average number of LNM per patient was 2,08 for group ALND and 2,34 for group no ALND. In both groups, LNM occurred mainly in Level I (ALND n=40: 30,53%; no ALND n= 79: 58,09%) and the supraclavicular region (ALND n=27: 20,61%; no ALND n=26: 19,12%). LNM in Level II, III and the internal mammary region occurred more often after ALND (Level II: ALND n=16: 12,21%; no ALND n=10: 7,35% ; Level III: ALND n=22: 16,79%; no ALND n=10: 7,35%; internal mammary region: ALND n=20: 15,27%; no ALND n=10: 7,35%). Figure 1 depicts hotspots of LNM of group ALND (a) compared to LNM of group no ALND (b).
Conclusion
LNM occur with different frequencies in all axillary levels. The patients that underwent axillary dissection had less LNM in L I than the patients that did not undergo ALND. Further, the ALND patients had LNM in Level II, III and the internal mammary region more often. The current atlas reveals areas where LNM need to be expected after ALND. These areas need special consideration during regional node irradiation in the primary situation after ALND.