Dynamic 18F-FET PET/CT to differentiate recurrent primary brain tumor and brain metastases from radiation necrosis after single-session robotic radiosurgery

Winna Lim; Gueliz Acker; Juliane Hardt; Markus Kufeld; Anne Kluge; Winfried Brenner; Alfredo Conti; Volker Budach; Peter Vajkoczy; Carolin Senger; Vikas Prasad

doi:10.1016/j.ctarc.2022.100583

Dynamic ¹⁸F-FET PET/CT to differentiate recurrent primary brain tumor and brain metastases from radiation necrosis after single-session robotic radiosurgery

Cancer Treat Res Commun. 2022:32:100583. doi: 10.1016/j.ctarc.2022.100583. Epub 2022 Jun 3.

Authors

Winna Lim¹, Gueliz Acker², Juliane Hardt³, Markus Kufeld⁴, Anne Kluge⁵, Winfried Brenner⁶, Alfredo Conti⁷, Volker Budach⁵, Peter Vajkoczy⁸, Carolin Senger⁵, Vikas Prasad⁹

Affiliations

¹ Department of Radiology, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, Berlin 13353, Germany.
² Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, Berlin 10117, Germany; Charité CyberKnife Center, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, Berlin 13353, Germany; BIH Academy, Clinician Scientist Program, Berlin Institute of Health at Charité - Universitätsmedizin Berlin, Charitéplatz 1, Berlin 10117, Germany.
³ Department of Biometry, Epidemiology and Information Processing, WHO Collaborating Center for Research and Training for Health in the Human-Animal-Environment Interface, University of Veterinary Medicine (Foundation) Hannover (TiHo), Buenteweg 2, Hanover 30559, Germany; Institute of Biometry and Clinical Epidemiology, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Germany; Medical Information Management, Faculty of Information and Communication, University of Applied Sciences Hannover, Germany.
⁴ Charité CyberKnife Center, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, Berlin 13353, Germany; European Radiosurgery Center Munich, Max Lebsche-Platz 31, Munich 81377, Germany; Department of Radiation Oncology, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, Berlin 13353, Germany.
⁵ Charité CyberKnife Center, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, Berlin 13353, Germany; Department of Radiation Oncology, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, Berlin 13353, Germany.
⁶ Department of Nuclear Medicine, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, Berlin 13353, Germany.
⁷ Department of Biomedical Science and Neuromotor Sciences DIBINEM, Alma Mater Studiorum - Università di Bologna, Dipartimento di Scienze Biomediche e Neuromotorie (DIBINEM), Via Altura 3, 40139 29 Bologna (BO), Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna, Via Altura 3, Bologna (BO) 40139, Italy.
⁸ Department of Neurosurgery, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Charitéplatz 1, Berlin 10117, Germany; Charité CyberKnife Center, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, Berlin 13353, Germany.
⁹ Department of Nuclear Medicine, Charité - Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Augustenburger Platz 1, Berlin 13353, Germany; Department of Nuclear Medicine, University Hospital of Ulm, Ulm 89070, Germany. Electronic address: vikas.prasad@uniklinik-ulm.de.

PMID: 35688103
DOI: 10.1016/j.ctarc.2022.100583

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.

Keywords: (18)F-FET-PET/CT; Amino acid PET; Cyberknife; Dynamic (18)F-FET-PET/CT; Radiation necrosis; Robotic radiosurgery.

MeSH terms

Brain Neoplasms* / diagnostic imaging
Brain Neoplasms* / radiotherapy
Brain Neoplasms* / secondary
Brain Neoplasms* / surgery
Fluorine Radioisotopes
Humans
Necrosis / diagnostic imaging
Necrosis / etiology
Positron Emission Tomography Computed Tomography
Positron-Emission Tomography
Radiation Injuries* / diagnostic imaging
Radiation Injuries* / etiology
Radiosurgery* / adverse effects
Retrospective Studies
Robotic Surgical Procedures* / adverse effects
Tyrosine

Substances

Fluorine Radioisotopes
Tyrosine