Radioimmunoscintigraphy and Pretreatment Dosimetry of 131 I-Omburtamab for Planning Treatment of Leptomeningeal Disease.

Autor:	Pandit-Taskar N; Department of Radiology, Memorial Sloan Kettering Cancer Center, New York, New York; pandit-n@mkscc.org.; Department of Radiology, Weill Cornell Medical College, New York, New York., Grkovski M; Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York; and., Zanzonico PB; Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York; and., Pentlow KS; Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York; and., Modak S; Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York., Kramer K; Department of Pediatrics, Memorial Sloan Kettering Cancer Center, New York, New York., Humm JL; Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York; and.
Jazyk:	angličtina
Zdroj:	Journal of nuclear medicine : official publication, Society of Nuclear Medicine [J Nucl Med] 2023 Jun; Vol. 64 (6), pp. 946-950. Date of Electronic Publication: 2023 Feb 09.
DOI:	10.2967/jnumed.122.265131
Abstrakt:	Radiolabeled antibody treatment with 131 I-omburtamab, administered intraventricularly into the cerebrospinal fluid (CSF) space, can deliver therapeutic absorbed doses to sites of leptomeningeal disease. Assessment of distribution and radiation dosimetry is a key element in optimizing such treatments. Using a theranostic approach, we performed pretreatment 131 I-omburtamab imaging and dosimetric analysis in patients before therapy. Methods: Whole-body planar images were acquired 3 ± 1, 23 ± 2, and 47 ± 2 h after intracranioventricular administration of 75 ± 5 MBq of 131 I-omburtamab via an Ommaya reservoir. Multiple blood samples were also obtained for kinetic analysis. Separate regions of interest (ROIs) were manually drawn to include the lateral ventricles, entire spinal canal CSF space, and over the whole body. Count data in the ROIs were corrected for background and physical decay, converted to activity, and subsequently fitted to an exponential clearance function. The radiation absorbed dose was estimated to the CSF, separately to the spinal column and ventricles, and to the whole body and blood. Biodistribution of the injected radiolabeled antibody was assessed for all patients. Results: Ninety-five patients were included in the analysis. Biodistribution showed prompt localization in the ventricles and spinal CSF space with low systemic distribution, noted primarily as hepatic, renal, and bladder activity after the first day. Using ROI analysis, the effective half-lives were 13 ± 11 h (range, 5-75 h) for CSF in the spinal column, 8 ± 3 h (range, 3-17 h) for ventricles, and 41 ± 11 (range, 23-81 h) for the whole body. Mean absorbed doses were 0.63 ± 0.38 cGy/MBq (range, 0.24-2.25 cGy/MBq) for CSF in the spinal column, 1.03 ± 0.69 cGy/MBq (range, 0.27-5.15 cGy/MBq) for the ventricular CSF, and 0.45 ± 0.32 mGy/MBq (range, 0.05-1.43 mGy/MBq) for the whole body. Conclusion: Pretherapeutic imaging with 131 I-omburtamab allows assessment of biodistribution and dosimetry before the administration of therapeutic activity. Absorbed doses to the CSF compartments and whole body derived from the widely applicable serial 131 I-omburtamab planar images had acceptable agreement with previously reported data determined from serial 124 I-omburtamab PET scans. (© 2023 by the Society of Nuclear Medicine and Molecular Imaging.)
Databáze:	MEDLINE
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