Patient-specific dosimetry using quantitative SPECT imaging and three-dimensional discrete fourier transform convolution

Journal Article · Sat Feb 01 04:00:00 EST 1997 · Journal of Nuclear Medicine

OSTI ID:460080

Akabani, G; Hawkins, W G; Eckblade, M B; Leichner, P K ^[1]

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1. Univ. of Nebraska Medical Center, Omaha, NE (United States)

The objective of this study was to develop a three-dimensional discrete Fourier transform (3D-DFT) convolution method to perform the dosimetry for {sup 131}I-labeled antibodies in soft tissues. Mathematical and physical phantoms were used to compare 3D-DFT with Monte Carlo transport (MCT) calculations based on the EGS4 code. The mathematical and physical phantoms consisted of a sphere and cylinder, respectively, containing uniform and nonuniform activity distributions. Quantitative SPECT reconstruction was carried out using the circular harmonic transform (CHT) algorithm. The radial dose profile obtained from MCT calculations and the 3D-DFT convolution method for the mathematical phantom were in close agreement. The root mean square error (RMSE) for the two methods was <0.1%, with a maximum difference <21%. Results obtained for the physical phantom gave a RMSE <0.1% and a maximum difference of <13%; isodose contours were in good agreement. SPECT data for two patients who had undergone {sup 131}I radioimmunotherapy (RIT) were used to compare absorbed-dose rates and isodose rate contours with the two methods of calculations. This yielded a RMSE <0.02% and a maximum difference of <13%. Our results showed that the 3D-DFT convolution method compared well with MCT calculations. The 3D-DFT approach is computationally much more efficient and, hence, the method of choice. This method is patient-specific and applicable to the dosimetry of soft-tissue tumors and normal organs. It can be implemented on personal computers. 22 refs., 6 figs., 2 tabs.

• DOE Contract Number: FG02-91ER61195
• OSTI ID: 460080
• Journal Information: Journal of Nuclear Medicine, Journal Name: Journal of Nuclear Medicine Journal Issue: 2 Vol. 38; 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
99 GENERAL AND MISCELLANEOUS
DOSE RATES
DOSIMETRY
IODINE 131
MONTE CARLO METHOD
PATIENTS
PHANTOMS
RADIOIMMUNOTHERAPY
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY