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@ARTICLE{Holzwarth:301281,
      author       = {N. Holzwarth$^*$ and Z. Rachel and J.-H. Nölke$^*$ and M.
                      Schellenberg and L. Bauer and N. Schreck$^*$ and C. J.
                      Bender$^*$ and K. K. Dreher$^*$ and S. Regnery and K.
                      Weusthof and M. Wiesenfarth$^*$ and A. Kopp-Schneider$^*$
                      and J. Debus$^*$ and A. Seitel$^*$ and S. Adeberg and L.
                      Maier-Hein$^*$ and T. Held},
      title        = {{P}hotoacoustic imaging for monitoring radiotherapy
                      treatment response in head and neck tumors.},
      journal      = {Scientific reports},
      volume       = {15},
      number       = {1},
      issn         = {2045-2322},
      address      = {[London]},
      publisher    = {Springer Nature},
      reportid     = {DKFZ-2025-00966},
      pages        = {16344},
      year         = {2025},
      note         = {#EA:E130#},
      abstract     = {Head and neck (HN) tumors are responsible for approximately
                      $4\%$ of annual new cancer cases worldwide. Besides surgery,
                      radiochemotherapy, particularly fractionated radiotherapy
                      (RT), is the gold-standard treatment modality for these
                      cancers. However, there is currently no reliable early
                      measure of success available to further personalize
                      treatment plans. This work aims to address this critical
                      bottleneck by pioneering the use of photoacoustic imaging
                      (PAI) to measure treatment response in HN cancer patients
                      undergoing RT. PAI leverages the photoacoustic effect in
                      order to non-invasively recover functional tissue properties
                      in depths of up to several centimeters. We hypothesized that
                      oxygen saturation ([Formula: see text]), hemoglobin
                      concentration, and water content, as measured by PAI, would
                      non-invasively reflect expected RT treatment effects, namely
                      reoxygenation of lymph nodes (hypothesis H1), inflammation
                      of surrounding organs (H2) and xerostomia (H3). Our study
                      with n = 30 human subjects showed notable changes in
                      [Formula: see text], hemoglobin concentration, and water
                      levels in HN tumor patients resulting from disease
                      treatment. Our data confirmed hypotheses H2 and H3, while an
                      observed decrease in [Formula: see text] over the treatment
                      course contradicted our prior assumptions (H1). A
                      comprehensive analysis based on device and tissue digital
                      twins, however, revealed that low blood volume fraction as
                      encountered in malignant nodes, can lead to particularly
                      high [Formula: see text] prediction errors, indicating that
                      the measured [Formula: see text] values cannot be trusted
                      within these regions. We conclude that our study is the
                      first to show that PAI is capable of measuring early
                      molecular changes induced by RT in human tissue
                      non-invasively. Further studies are now needed to convert
                      the potential of the new imaging technique into patient
                      benefit.},
      keywords     = {Humans / Photoacoustic Techniques: methods / Head and Neck
                      Neoplasms: radiotherapy / Head and Neck Neoplasms:
                      diagnostic imaging / Male / Female / Middle Aged / Aged /
                      Hemoglobins: metabolism / Hemoglobins: analysis / Adult /
                      Treatment Outcome / Head and neck cancer (Other) / In vivo
                      (Other) / Photoacoustic imaging (Other) / Radiotherapy
                      (Other) / Xerostomia (Other) / Hemoglobins (NLM Chemicals)},
      cin          = {E130 / C060 / E050},
      ddc          = {600},
      cid          = {I:(DE-He78)E130-20160331 / I:(DE-He78)C060-20160331 /
                      I:(DE-He78)E050-20160331},
      pnm          = {315 - Bildgebung und Radioonkologie (POF4-315)},
      pid          = {G:(DE-HGF)POF4-315},
      typ          = {PUB:(DE-HGF)16},
      pubmed       = {pmid:40348865},
      doi          = {10.1038/s41598-025-95137-0},
      url          = {https://inrepo02.dkfz.de/record/301281},
}