Radioimmunotherapy treatment planning based on radiation absorbed dose or patient size

Journal Article · Wed May 01 04:00:00 EDT 1996 · Journal of Nuclear Medicine

OSTI ID:447729

Eary, J F; Krohn, K A; Press, O W ^[1]

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1. Univ. of Washington, Seattle, WA (United States)

Several approaches have been used to plan treatment doses for patients undergoing radioimmunotherapy. Investigators often use fixed doses, or doses based on patient size (mCi/kg or mCi/m{sup 2}). Our treatment protocols for lymphoma and leukemia involved calculation of tissue radiation absorbed dose based on images from a trace labeled infusion of antibody prior to treatment. In a recent analysis of patients treated in the Phase I and II dose escalation trial for treatment of non-Hodgkin`s lymphoma with I-131 anti-CD20 antibody (B1), we investigated the relationship between our dosimetry based treatment and dose based on patient size. Tissue radiation dose for several normal organs and for tumors were plotted versus the mCi administered per kg or m{sup 2} of the patient to evaluate the relationship between the two treatment approaches. These graphs showed correlation coefficients ranging from 0.021 to 0.684, demonstrating the variability in antibody catabolism between patients. This means that fixed doses or administrations based on patient size do not deliver consistent radiation doses to normal organs or tumors. This finding was extrapolated to show that toxicity from doses based on patient size di not correlate with treatment dose; those based on calculated rad/organ did. Phase I clinical trials using treatment doses based on patient size where there are likely to be variations in patient antibody catabolism will result in confounding toxicities at apparently similar mCi dose levels. Use of pre-treatment scans for treatment dose planning are worth the additional effort by normalizing the normal tissue toxicity.

• OSTI ID: 447729
• Report Number(s): CONF-960659--
• Journal Information: Journal of Nuclear Medicine, Journal Name: Journal of Nuclear Medicine Journal Issue: Suppl.5 Vol. 37; ISSN 0161-5505; ISSN JNMEAQ
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
ANIMAL TISSUES
DOSIMETRY
IMAGES
IODINE 131
PATIENTS
TOXICITY