Publication

Radiation dosimetry of 18F-AzaFol: A first inhuman use of a folate receptor PET tracer

Journal Paper/Review - Apr 8, 2020

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Keywords
Folate receptor, FOLR1, FRalpha, FRα, 18F-Azafol, Imaging, Positron emission tomography (PET), OLINDA/
EXM, Dosimetry, Lung cancer, Choroid plexuses
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Citation
Müller J, Früh M, Siano M. Radiation dosimetry of 18F-AzaFol: A first inhuman use of a folate receptor PET tracer. EJNMMI Research 2020; 10
Type
Journal Paper/Review (English)
Journal
EJNMMI Research 2020; 10
Publication Date
Apr 8, 2020
Publisher
Springer Nature (Heidelberg)
Brief description/objective

Background: The folate receptor alpha (FRα) is an interesting target for imaging and therapy of different cancers.
We present the first in-human radiation dosimetry and radiation safety results acquired within a prospective, multicentric
trial (NCT03242993) evaluating the 18F-AzaFol (3′-aza-2′-[18F]fluorofolic acid) as the first clinically assessed PET tracer
targeting the FRα.
Material and methods: Six eligible patients presented a histologically confirmed adenocarcinoma of the lung with
measurable lesions (≥ 10mm according to RECIST 1.1). TOF-PET images were acquired at 3, 11, 18, 30, 40, 50, and 60
min after the intravenous injection of 327 MBq (range 299–399 MBq) of 18F-AzaFol to establish dosimetry. Organ
absorbed doses (AD), tumor AD, and patient effective doses (E) were assessed using the OLINDA/EXM v.2.0 software
and compared with pre-clinical results.
Results: No serious related adverse events were observed. The highest AD were in the liver, the kidneys, the urinary
bladder, and the spleen (51.9, 45.8, 39.1, and 35.4 μGy/MBq, respectively). Estimated patient and gender-averaged E
were 18.0 ± 2.6 and 19.7 ± 1.4 μSv/MBq, respectively. E in-human exceeded the value of 14.0 μSv/MBq extrapolated
from pre-clinical data. Average tumor AD was 34.8 μGy/MBq (range 13.6–60.5 μGy/MBq).
Conclusions: 18F-Azafol is a PET agent with favorable dosimetric properties and a reasonable radiation dose burden for
patients which merits further evaluation to assess its performance.