Reproducibility of radiation dosimetry assessed in a phantom and in 20 patients by planar imaging studies
- Univ. of California, at Davis, Sacramento, CA (United States); and others
Reproducible and accurate radiation dosimetry is important for assessment of the efficacy and toxicity of radionuclide therapy. Planar imaging methods were used and the region of interest for the whole body, organs or tumors was manually defined by the operator based on the visual boundary. The number of counts were converted to activity using a reference standard. MIRD formalism and the standard man assumption were used to derive radiation dose. Intra- and inter-operator (3 operators) reproducibility were evaluated in an abdominal phantom and in 20 patients. Operator`s skill was also examined for a trainee and 2 experienced operators. Reproducibility scores were expressed as the intraclass correlation coefficient (ICC) based on one way analysis of variance inter-operator ICC for activities in the phantom were 0.98 for organs and 0.96 for tumors. Radiation doses and biological half-lives were assessed for whole body, liver, spleen, lungs, kidneys, and tumors in patients for Cu-67, I-131 and In-111. Inter-operator ICC for radiation doses were 0.98 for whole body, 0.96 for liver, and 0.94 for spleen, but inter-operator ICC was slightly lover for kidneys (0.91) and lungs (0.86) where an aliquot method was used because of overlapping tissues. For well defined tumors of {ge} 3 cm in diameter, the inter-operator and intra-operator ICC were 0.90 and 0.96, respectively. In all cases, the intra-operator ICC was higher than inter-operator ICC. Although the differences in inter-operator ICC were not significant for the 3 radionuclides, intra-operator ICC for Cu-67 were better than those for I-131 reflecting better image quality for Cu-67. This study revealed that inter- and intra-operator reproducibility were quite good for all tissues after a training period of 80 hours using this method.
- DOE Contract Number:
- FG03-84ER60233
- OSTI ID:
- 441610
- Report Number(s):
- CONF-950603--; CNN: Grant NCI CA47829
- Journal Information:
- Journal of Nuclear Medicine, Journal Name: Journal of Nuclear Medicine Journal Issue: Suppl.5 Vol. 36; ISSN 0161-5505; ISSN JNMEAQ
- Country of Publication:
- United States
- Language:
- English
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