Tumor dosimetry in radioimmunotherapy: Methods of calculation for beta particles

Journal Article · Mon Mar 01 04:00:00 EST 1993 · Medical Physics; (United States)

DOI:https://doi.org/10.1118/1.597048· OSTI ID:6650446

Leichner, P K ^[1]; Kwok, C S ^[2]

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1. University of Nebraska Medical Center, Department of Radiology, Omaha, Nebraska 68198-1045 (United States)
2. Hamilton Regional Cancer Centre, Ontario Cancer Treatment and Research Foundation and McMaster University, Hamilton, Ontario (Canada)

Calculational methods of beta-particle dosimetry in radioimmunotherapy (RIT) are reviewed for clinical and experimental studies and computer modeling of tumors. In clinical studies, absorbed-dose estimates are usually based on the [ital in]-[ital vivo] quantitation of the activity in tumors from gamma camera images. Because of the limited spatial resolution of gamma cameras, clinical dosimetry is necessarily limited to the macroscopic level (macrodosimetry) and the MIRD formalism for absorbed-dose calculations is appropriate. In experimental RIT, tumor dimensions are often comparable to or smaller than the beta-particle range of commonly used radionuclides (for example, [sup 131]I, [sup 67]Cu, [sup 186]Re, [sup 188]Re, [sup 90]Y) and deviations from the equilibrium dose must be taken into account in absorbed-dose calculations. Additionally, if small tumors are growing rapidly at the time of RIT, the effects of tumor growth will need to be included in absorbed-dose estimates. In computer modeling of absorbed-dose distributions, analytical, numerical, and Monte Carlo methods have been used to investigate the consequences of uniform and nonuniform activity distributions and the effects of inhomogeneous media. Measurements and calculations of the local absorbed dose at the multicellular level have shown that variations in this dose are large. Knowledge of the absorbed dose is essential for any form of radiotherapy. Therefore, it is important that clinical, experimental, and theoretical investigations continue to provide information on tumor dosimetry that is necessary for a better understanding of the radiobiological effects of RIT.

• DOE Contract Number: FG02-91ER61195
• OSTI ID: 6650446
• Journal Information: Medical Physics; (United States), Journal Name: Medical Physics; (United States) Vol. 20:2; ISSN 0094-2405; ISSN MPHYA6
• Country of Publication: United States
• Language: English

Related Subjects

560101* -- Biomedical Sciences
Applied Studies-- Radiation Effects-- Dosimetry & Monitoring-- (1992-)
61 RADIATION PROTECTION AND DOSIMETRY
BETA DECAY RADIOISOTOPES
BETA DOSIMETRY
CALCULATION METHODS
DISEASES
DOSIMETRY
IMMUNOLOGY
IMMUNOTHERAPY
ISOTOPES
MEDICINE
MONTE CARLO METHOD
NEOPLASMS
NUCLEAR MEDICINE
RADIATION DOSE DISTRIBUTIONS
RADIOIMMUNOLOGY
RADIOIMMUNOTHERAPY
RADIOISOTOPES
RADIOLOGY
RADIOTHERAPY
SPATIAL DOSE DISTRIBUTIONS
THERAPY