Dynamic O-(2-18F-fluoroethyl)-L-tyrosine positron emission tomography differentiates brain metastasis recurrence from radiation injury after radiotherapy

Garry Ceccon; Philipp Lohmann; Gabriele Stoffels; Natalie Judov; Christian P Filss; Marion Rapp; Elena Bauer; Christina Hamisch; Maximilian I Ruge; Martin Kocher; Klaus Kuchelmeister; Bernd Sellhaus; Michael Sabel; Gereon R Fink; Nadim J Shah; Karl-Josef Langen; Norbert Galldiks

doi:10.1093/neuonc/now149

Dynamic O-(2-18F-fluoroethyl)-L-tyrosine positron emission tomography differentiates brain metastasis recurrence from radiation injury after radiotherapy

Neuro Oncol. 2017 Feb 1;19(2):281-288. doi: 10.1093/neuonc/now149.

Authors

Garry Ceccon¹, Philipp Lohmann², Gabriele Stoffels², Natalie Judov², Christian P Filss^{2

3}, Marion Rapp⁴, Elena Bauer¹, Christina Hamisch⁵, Maximilian I Ruge⁶, Martin Kocher⁷, Klaus Kuchelmeister⁸, Bernd Sellhaus⁹, Michael Sabel⁴, Gereon R Fink^{1

2}, Nadim J Shah^{2

3

10}, Karl-Josef Langen^{2

9

11}, Norbert Galldiks^{1

2

12}

Affiliations

¹ Department of Neurology, University of Cologne, Cologne, Germany.
² Institute of Neuroscience and Medicine, Research Center Jülich, Jülich, Germany.
³ Department of Neurology, University of Aachen, Aachen, Germany.
⁴ Department of Neurosurgery, University of Düsseldorf, Düsseldorf, Germany.
⁵ Department of Neurosurgery, University of Cologne, Cologne, Germany.
⁶ Department of Stereotaxy and Functional Neurosurgery, University of Cologne, Cologne, Germany.
⁷ Department of Radiation Oncology, University of Cologne, Cologne, Germany.
⁸ Department of Neuropathology, University of Bonn, Bonn, Germany.
⁹ Department of Neuropathology, University of Aachen, Aachen, Germany.
¹⁰ Jülich-Aachen Research Alliance (JARA) - Section JARA-Brain, Jülich and Aachen, Germany.
¹¹ Department of Nuclear Medicine, University of Aachen, Aachen, Germany.
¹² Center of Integrated Oncology (CIO), University of Cologne, Cologne, Germany.

Abstract

Background: The aim of this study was to investigate the potential of dynamic O-(2-[18F]fluoroethyl)-L-tyrosine (18F-FET) PET for differentiating local recurrent brain metastasis from radiation injury after radiotherapy since contrast-enhanced MRI often remains inconclusive.

Methods: Sixty-two patients (mean age, 55 ± 11 y) with single or multiple contrast-enhancing brain lesions (n = 76) on MRI after radiotherapy of brain metastases (predominantly stereotactic radiosurgery) were investigated with dynamic 18F-FET PET. Maximum and mean tumor-to-brain ratios (TBRmax, TBRmean) of 18F-FET uptake were determined (20-40 min postinjection) as well as tracer uptake kinetics (ie, time-to-peak and slope of time-activity curves). Diagnoses were confirmed histologically (34%; 26 lesions in 25 patients) or by clinical follow-up (66%; 50 lesions in 37 patients). Diagnostic accuracies of PET parameters for the correct identification of recurrent brain metastasis were evaluated by receiver-operating-characteristic analyses or the chi-square test.

Results: TBRs were significantly higher in recurrent metastases (n = 36) than in radiation injuries (n = 40) (TBRmax 3.3 ± 1.0 vs 2.2 ± 0.4, P < .001; TBRmean 2.2 ± 0.4 vs 1.7 ± 0.3, P < .001). The highest accuracy (88%) for diagnosing local recurrent metastasis could be obtained with TBRs in combination with the slope of time-activity curves (P < .001).

Conclusions: The results of this study confirm previous preliminary observations that the combined evaluation of the TBRs of 18F-FET uptake and the slope of time-activity curves can differentiate local brain metastasis recurrence from radiation-induced changes with high accuracy. 18F-FET PET may thus contribute significantly to the management of patients with brain metastases.

Keywords: FET PET; kinetic analysis; radiation-induced changes; radionecrosis; stereotactic radiosurgery.

MeSH terms

Adolescent
Adult
Aged
Brain Neoplasms / diagnostic imaging*
Brain Neoplasms / metabolism
Brain Neoplasms / secondary*
Diagnosis, Differential
Disease Progression
Female
Follow-Up Studies
Humans
Male
Middle Aged
Neoplasm Recurrence, Local / diagnostic imaging*
Neoplasm Recurrence, Local / metabolism
Neoplasm Recurrence, Local / pathology
Neoplasm Staging
Positron-Emission Tomography / methods*
Prognosis
Radiation Injuries / diagnostic imaging*
Radiation Injuries / etiology
Radiation Injuries / metabolism
Radiopharmaceuticals / metabolism
Radiotherapy / adverse effects*
Tyrosine / analogs & derivatives*
Tyrosine / metabolism
Young Adult

Substances

O-(2-fluoroethyl)tyrosine
Radiopharmaceuticals
Tyrosine