Dosimetry Model for Radioactivity Localized to Intestinal Mucosa

Journal Article · Wed Jun 30 04:00:00 EDT 2004 · Cancer Biotherapy & Radiopharmaceuticals

DOI:https://doi.org/10.1089/1084978041425043· OSTI ID:15020866

Fisher, Darrell R; Rajon, Didier; Breitz, Hazel B; Goris, Michael L; Bolch, Wesley E; Knox, Susan J

This paper provides a new model for calculating radiation absorbed dose to the full thickness of the small and large intestinal walls, and to the mucosal layers. The model was used to estimate the intestinal radiation doses from yttrium-90-labeled-DOTA-biotin binding to NR-LU-10-streptavidin in patients. We selected model parameters from published data and observations and used the model to calculate energy absorbed fractions using the EGS4 radiation transport code. We determined the cumulated 90Y activity in the small and large intestines of patients from gamma camera images and calculated absorbed doses to the mucosal layer and to the whole intestinal wall. The mean absorbed dose to the wall of the small intestine was 16.2 mGy/MBq (60 cGy/mCi) administered from 90Y localized in the mucosa and 70 mGy/MBq (260 cGy/mCi) to the mucosal layer within the wall. Doses to the large intestinal wall and to the mucosa of the large intestine were lower than those for small intestine by a factor of about 2.5. These doses are greater by factors of about 5 to 6 than those that would have been calculated using the standard MIRD models that assume the intestinal activity is in the bowel contents. The specific uptake of radiopharmaceuticals in mucosal tissues may lead to dose-related intestinal toxicities. Tissue dosimetry at the sub-organ level is useful for better understanding intestinal tract radiotoxicity and associated dose-response relationships.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 15020866
• Report Number(s): PNWD-SA-6420
• Journal Information: Cancer Biotherapy & Radiopharmaceuticals, Journal Name: Cancer Biotherapy & Radiopharmaceuticals Journal Issue: 3 Vol. 19
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
DOSE-RESPONSE RELATIONSHIPS
DOSIMETRY
GAMMA CAMERAS
LARGE INTESTINE
MUCOUS MEMBRANES
PATIENTS
RADIATION DOSES
RADIATION TRANSPORT
RADIATIONS
RADIOACTIVITY
RADIOPHARMACEUTICALS
SMALL INTESTINE
THICKNESS
dosimetry
MIRD
intestinal tract
intestinal mucosa
monoclonal antibodies
radiation effects
yttrium-90