Jakob Liermann1,2,3,4, Mustafa Syed1,2,3,4, Edgar Ben-Josef5, Kai Schubert1,2, Ingmar Schlampp1,2,3, Simon David Sprengel1,2,3, Jonas Ristau1,2,3, Fabian Weykamp1,2,3, Manuel Röhrich6, Stefan A Koerber1,2,3, Uwe Haberkorn6, Juergen Debus1,2,3,4,7,8, Klaus Herfarth1,2,3,4,7,8, Frederik L Giesel6, Patrick Naumann1,2,3. 1. Department of Radiation Oncology, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany. 2. Heidelberg Institute of Radiation Oncology (HIRO), Im Neuenheimer Feld 400, 69120 Heidelberg, Germany. 3. National Center for Tumor Diseases (NCT), Im Neuenheimer Feld 460, 69120 Heidelberg, Germany. 4. Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120 Heidelberg, Germany. 5. Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104, USA. 6. Department of Nuclear Medicine, Heidelberg University Hospital, Im Neuenheimer Feld 400, 69120 Heidelberg, Germany. 7. Clinical Cooperation Unit Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany. 8. German Cancer Consortium (DKTK), Partner Site Heidelberg, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
Abstract
(1) Background: A new radioactive positron emission tomography (PET) tracer uses inhibitors of fibroblast activation protein (FAPI) to visualize FAP-expressing cancer associated fibroblasts. Significant FAPI-uptake has recently been demonstrated in pancreatic cancer patients. Target volume delineation for radiation therapy still relies on often less precise conventional computed tomography (CT) imaging, especially in locally recurrent pancreatic cancer patients. The need for improvement in precise tumor detection and delineation led us to innovatively use the novel FAPI-PET/CT for radiation treatment planning. (2) Methods: Gross tumor volumes (GTVs) of seven locally recurrent pancreatic cancer cases were contoured by six radiation oncologists. In addition, FAPI-PET/CT was used to automatically delineate tumors. The interobserver variability in target definition was analyzed and FAPI-based automatic GTVs were compared to the manually defined GTVs. (3) Results: Target definition differed significantly between different radiation oncologists with mean dice similarity coefficients (DSCs) between 0.55 and 0.65. There was no significant difference between the volumes of automatic FAPI-GTVs based on the threshold of 2.0 and most of the manually contoured GTVs by radiation oncologists. (4) Conclusion: Due to its high tumor to background contrast, FAPI-PET/CT seems to be a superior imaging modality compared to the current gold standard contrast-enhanced CT in pancreatic cancer. For the first time, we demonstrate how FAPI-PET/CT could facilitate target definition and increases consistency in radiation oncology in pancreatic cancer.
(1) Background: A new radioactive positron emission tomography (PET) tracer uses inhibitors of fibroblast activation protein (FAPI) to visualize FAP-expressing cancer associated fibroblasts. Significant FAPI-uptake has recently been demonstrated in pancreatic cancerpatients. Target volume delineation for radiation therapy still relies on often less precise conventional computed tomography (CT) imaging, especially in locally recurrent pancreatic cancerpatients. The need for improvement in precise tumor detection and delineation led us to innovatively use the novel FAPI-PET/CT for radiation treatment planning. (2) Methods: Gross tumor volumes (GTVs) of seven locally recurrent pancreatic cancer cases were contoured by six radiation oncologists. In addition, FAPI-PET/CT was used to automatically delineate tumors. The interobserver variability in target definition was analyzed and FAPI-based automatic GTVs were compared to the manually defined GTVs. (3) Results: Target definition differed significantly between different radiation oncologists with mean dice similarity coefficients (DSCs) between 0.55 and 0.65. There was no significant difference between the volumes of automatic FAPI-GTVs based on the threshold of 2.0 and most of the manually contoured GTVs by radiation oncologists. (4) Conclusion: Due to its high tumor to background contrast, FAPI-PET/CT seems to be a superior imaging modality compared to the current gold standard contrast-enhanced CT in pancreatic cancer. For the first time, we demonstrate how FAPI-PET/CT could facilitate target definition and increases consistency in radiation oncology in pancreatic cancer.
Authors: Martijn A van Dam; Floris A Vuijk; Judith A Stibbe; Ruben D Houvast; Saskia A C Luelmo; Stijn Crobach; Shirin Shahbazi Feshtali; Lioe-Fee de Geus-Oei; Bert A Bonsing; Cornelis F M Sier; Peter J K Kuppen; Rutger-Jan Swijnenburg; Albert D Windhorst; Jacobus Burggraaf; Alexander L Vahrmeijer; J Sven D Mieog Journal: Cancers (Basel) Date: 2021-12-02 Impact factor: 6.639
Authors: Christopher Montemagno; Shamir Cassim; Nicolas De Leiris; Jérôme Durivault; Marc Faraggi; Gilles Pagès Journal: Int J Mol Sci Date: 2021-06-15 Impact factor: 5.923
Authors: Jakob Liermann; Patrick Naumann; Fabian Weykamp; Philipp Hoegen; Juergen Debus; Klaus Herfarth Journal: Front Oncol Date: 2021-07-14 Impact factor: 6.244