ISSN:
1619-7089
Keywords:
Positron emission tomography
;
Antibody
;
Iodine-124
;
Glioma
;
Microdosimetry
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract We present a method to assess quantitatively the immunological characteristics of tumours using radiolabelled monoclonal antibody and positron emission tomography (PET) to improve dosimetry for radioimunotherapy. This method is illustrated with a glioma patient who was injected with 96.2 MBq of iodine-124 labelled 3F8, a murine antibody (IgG3) specific against the ganglioside GD2. Serial PET scans and plasma samples were taken over 11 days. A three-compartment model was used to estimate the plasma to tumour transfer constant (K 1), the tumour to plasma transfer constant k 2, the association and dissociation constants (k 3, k 4) of antibody binding, and the binding potential. Tumour radioactivity peaked at 18 h at 0.0045% ID/g. The kinetic parameters were estimated to be: K 1 = 0.048 ml h−1 g−1, k 2 = 0.16 h−1, k 3 = 0.03 h−1, k 4 = 0.015 h−1 and BP = 2.25. Based on these kinetic parameters, the amount of tumour-bound radiolabelled monoclonal antibody was calculated. This method permits estimates of both macrodosimetry and microdosimetry at the cellular level based on in vivo non-invasive measurement.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00208998
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