Quantitative bremsstrahlung imaging of yttrium-90 using a Wiener filter

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · Medical Physics; (United States)

DOI:https://doi.org/10.1118/1.597198· OSTI ID:7199390

Shen, S; DeNardo, G L; DeNardo, S J ^[1]

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1. Radiodiagnosis and Therapy, University of California Davis Medical Center, Sacramento, California 95816 (United States)

Yttrium-90 ([sup 90]Y), a pure beta emitter, is an attractive radionuclide for radioimmunotherapy of cancer. Therapeutic management requires quantitative imaging to measure the pharmacokinetics of the radionuclide in the patient for radiation dosimetric calculations. The bremsstrahlung emissions can be utilized to acquire an image of beta sources using a gamma camera. Quantitation of [sup 90]Y by bremsstrahlung imaging is difficult because of poor image quality that results from septal penetration and scatter secondary to the broad bremsstrahlung energies. In this work, quantitative methods for bremsstrahlung imaging of [sup 90]Y sources that involved the use of (a) a Wiener filter to deconvolve the septal penetration and scatter while suppressing image noise, and (b) the geometric mean of the conjugate view (GM) and effective point source (EPS) methods to quantify activities were investigated. An abdominal phantom was prepared with [sup 90]Y activities in the liver, spleen, tumors, and background volumes that were similar to those observed in patient studies. A twofold improvement in resolution recovery for full width at tenth maximum of the line spread function at 11 cm depth in water was achieved using Wiener restoration. Definition of the organ and tumor edges was greatly enhanced and cross talk between adjacent sources was suppressed after Wiener restoration. These improvements in image quality led to more accurate estimation of organ and tumor activities. Using the optimum attenuation correction method for GM and EPS quantitation of filtered bremsstrahlung images, estimates of individual activities ([le]17% error) and cumulated activities ([le]8% error) in all of the sources were accurate except for a tumor of 2 cm diameter. The results of this study provide the basis for a method to quantify beta source distribution and demonstrate the potential use of bremsstrahlung imaging in clinical settings.

• DOE Contract Number: FG03-84ER60233
• OSTI ID: 7199390
• Journal Information: Medical Physics; (United States), Journal Name: Medical Physics; (United States) Vol. 21:9; ISSN 0094-2405; ISSN MPHYA6
• Country of Publication: United States
• Language: English

Related Subjects

550604* -- Medicine-- Unsealed Radionuclides in Therapy-- (1980-)
62 RADIOLOGY AND NUCLEAR MEDICINE
BETA DECAY RADIOISOTOPES
BETA DOSIMETRY
BETA-MINUS DECAY RADIOISOTOPES
BREMSSTRAHLUNG
CAMERAS
DAYS LIVING RADIOISOTOPES
DOSES
DOSIMETRY
ELECTROMAGNETIC RADIATION
FUNCTIONS
GAMMA CAMERAS
HOURS LIVING RADIOISOTOPES
IMAGE PROCESSING
IMPLANTS
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MEDICINE
MOCKUP
NUCLEAR MEDICINE
NUCLEI
ODD-ODD NUCLEI
PHANTOMS
PROCESSING
RADIATION DOSES
RADIATION SOURCE IMPLANTS
RADIATION SOURCES
RADIATIONS
RADIOISOTOPES
RADIOLOGY
RADIOTHERAPY
STRUCTURAL MODELS
THERAPY
TRANSFER FUNCTIONS
YTTRIUM 90
YTTRIUM ISOTOPES