Diagnostic Value of 18F-FACBC PET/MRI in Brain Metastases. (14th December 2022)

• Record Type: Journal Article
• Authors: Øen, Silje Kjærnes; Johannessen, Knut; Pedersen, Lars Kjelsberg; Berntsen, Erik Magnus; Totland, Jon Andre; Johansen, Håkon; Bogsrud, Trond Velde; Solheim, Tora S.; Karlberg, Anna; Eikenes, Live
• Is Part Of: Clinical nuclear medicine. Volume 47:Number 12(2022)
• Page Start: 1030
• Page End: 1039
• Publication Date: 2022-12-14
• Subjects: brain metastases -- 18F-FACBC -- PET -- contrast enhancement -- MRI -- detection; Nuclear medicine -- Periodicals; Radioisotope scanning -- Periodicals; Nuclear Medicine -- Periodicals; 616.07575
• DOI: 10.1097/RLU.0000000000004435
• Languages: English
• ISSNs: 0363-9762

Abstract

Abstract : Purpose: The study aims to evaluate whether combined 18 F-FACBC PET/MRI could provide additional diagnostic information compared with MRI alone in brain metastases. Patients and Methods: Eighteen patients with newly diagnosed or suspected recurrence of brain metastases received dynamic 18 F-FACBC PET/MRI. Lesion detection was evaluated on PET and MRI scans in 2 groups depending on prior stereotactic radiosurgery (SRS group) or not (no-SRS group). SUVs, time-activity curves, and volumetric analyses of the lesions were performed. Results: In the no-SRS group, 29/29 brain lesions were defined as "MRI positive." With PET, 19/29 lesions were detected and had high tumor-to-background ratios (TBRs) (Dmax MR, ≥7 mm; SUVmax, 1.2–8.4; TBR, 3.9–25.9), whereas 10/29 lesions were undetected (Dmax MR, ≤8 mm; SUVmax, 0.3–1.2; TBR, 1.0–2.7). In the SRS group, 4/6 lesions were defined as "MRI positive, " whereas 2/6 lesions were defined as "MRI negative" indicative of radiation necrosis. All 6 lesions were detected with PET (Dmax MR, ≥15 mm; SUVmax, 1.4–4.2; TBR, 3.6–12.6). PET volumes correlated and were comparable in size with contrast-enhanced MRI volumes but were only partially congruent (mean DSC, 0.66). All time-activity curves had an early peak, followed by a plateau or a decreasing slope. Conclusions: 18 F-FACBC PET demonstrated uptake in brain metastases from cancer of different origins (lung, gastrointestinal tract, breast, thyroid, and malignant melanoma). However, 18 F-FACBC PET/MRI did not improve detection of brain metastases compared with MRI but might detect tumor tissue beyond contrast enhancement on MRI. 18 F-FACBC PET should be further evaluated in recurrent brain metastases.