Pharmacokinetics and dosimetry of iodine-125-IUdR in the treatment of colorectal cancer metastic to liver

Journal Article · Mon Apr 01 04:00:00 EST 1996 · Journal of Nuclear Medicine

OSTI ID:381023

Daghighian, F; Humm, J L; Macapinlac, H A ^[1]

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1. Memorial Sloan-Kettering Cancer Center, New York, NY (United States); and others

The radiotoxicity of {sup 125}I is highly sensitive to the site of decay relative to nuclear DNA. This paper describes a new approach, based upon pharmacokinetic clearance of radioactivity from the tumor, with which to quantify the fraction of [{sup 125}I]IUdR incorporated within the DNA of tumor cells. Patients were inject with [{sup 125}I]IUdR through the hepatic artery. Iodine-131-IUdR was used as a tracer for imaging and quantitation. Both confentional are DNA-level dosimetry were performed. We calculated that if 15% of the tumor cells were in S phase at the time of injection, there would be 250 decays of {sup 125}I in the DNA per tumor cell after an infusion of 5 mCi [{sup 125}I]IUdR. According to in vitro data based on 5 x 10{sup 8} cells per g tumor, 99% of these cells in S phase would be killed. The estimate of cell inactivation is strongly dependent on the number of cells per gram and the fraction of cells in S phase at the time of injection, which indicates that repeat injections would be necessary to achieve a therapeutic effect. 21 refs., 1 fig., 4 tabs.

• DOE Contract Number: FG02-86ER60407
• OSTI ID: 381023
• Journal Information: Journal of Nuclear Medicine, Journal Name: Journal of Nuclear Medicine Journal Issue: Suppl.4 Vol. 37; ISSN 0161-5505; ISSN JNMEAQ
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
CELL KILLING
DEOXYURIDINE
DNA
DOSIMETRY
INJECTION
IODINE 125
IODINE 131
LABELLED COMPOUNDS
LIVER
PATIENTS
RADIOTHERAPY
TRACER TECHNIQUES
TUMOR CELLS
UPTAKE