@article{LimAckerHardtetal.2022,
  author    = {Winna Lim and Gueliz Acker and Juliane Hardt and Markus Kufeld and Anne Kluge and Winfried Brenner and Alfredo Conti and Volker Budach and Peter Vajkoczy and Carolin Senger and Vikas Prasad},
  title     = {Dynamic 18F-FET PET/CT to differentiate recurrent primary brain tumor and brain metastases from radiation necrosis after single-session robotic radiosurgery},
  series   = {Cancer Treatment and Research Communications},
  volume    = {32},
  issn      = {2468-2942},
  doi       = {10.25968/opus-2434},
  url       = {http://nbn-resolving.de/urn:nbn:de:bsz:960-opus4-24347},
  year      = {2022},
  abstract  = {Objective Cyberknife robotic radiosurgery (RRS) provides single-session high-dose radiotherapy of brain tumors with a steep dose gradient and precise real-time image-guided motion correction. Although RRS appears to cause more radiation necrosis (RN), the radiometabolic changes after RRS have not been fully clarified. 18F-FET-PET/CT is used to differentiate recurrent tumor (RT) from RN after radiosurgery when MRI findings are indecisive. We explored the usefulness of dynamic parameters derived from 18F-FET PET in differentiating RT from RN after Cyberknife treatment in a single-center study population. Methods We retrospectively identified brain tumor patients with static and dynamic 18F-FET-PET/CT for suspected RN after Cyberknife. Static (tumor-to-background ratio) and dynamic PET parameters (time-activity curve, time-to-peak) were quantified. Analyses were performed for all lesions taken together (TOTAL) and for brain metastases only (METS). Diagnostic accuracy of PET parameters (using mean tumor-to-background ratio >1.95 and time-to-peak of 20 min for RT as cut-offs) and their respective improvement of diagnostic probability were analyzed. Results Fourteen patients with 28 brain tumors were included in quantitative analysis. Time-activity curves alone provided the highest sensitivities (TOTAL: 95\%, METS: 100\%) at the cost of specificity (TOTAL: 50\%, METS: 57\%). Combined mean tumor-to-background ratio and time-activity curve had the highest specificities (TOTAL: 63\%, METS: 71\%) and led to the highest increase in diagnosis probability of up to 16\% p. – versus 5\% p. when only static parameters were used. Conclusions This preliminary study shows that combined dynamic and static 18F-FET PET/CT parameters can be used in differentiating RT from RN after RRS.},
  language  = {en}
}