Net fractional depth dose: a basis for a unified analytical description of FDD, TAR, TMR, and TPR

Journal Article · · Med. Phys.; (United States)

DOI:https://doi.org/10.1118/1.595581· OSTI ID:5735052

van de Geijn, J; Fraass, B A

The net fractional depth dose (NFD) is defined as the fractional depth dose (FDD) corrected for inverse square law. Analysis of its behavior as a function of depth, field size, and source-surface distance has led to an analytical description with only seven model parameters related to straightforward physical properties. The determination of the characteristic parameter values requires only seven experimentally determined FDDs. The validity of the description has been tested for beam qualities ranging from /sup 60/Co gamma rays to 18-MV x rays, using published data from several different sources as well as locally measured data sets. The small number of model parameters is attractive for computer or hand-held calculator applications. The small amount of required measured data is important in view of practical data acquisition for implementation of a computer-based dose calculation system. The generating function allows easy and accurate generation of FDD, tissue-air ratio, tissue-maximum ratio, and tissue-phantom ratio tables.

• Research Organization: National Institutes of Health, Bethesda, MD
• OSTI ID: 5735052
• Journal Information: Med. Phys.; (United States), Vol. 11:6
• Country of Publication: United States
• Language: English

Related Subjects

61 RADIATION PROTECTION AND DOSIMETRY
DEPTH DOSE DISTRIBUTIONS
MULTI-PARAMETER ANALYSIS
COBALT 60
GAMMA RADIATION
PHANTOMS
RADIOTHERAPY
X RADIATION
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
COBALT ISOTOPES
ELECTROMAGNETIC RADIATION
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MEDICINE
MINUTES LIVING RADIOISOTOPES
MOCKUP
NUCLEAR MEDICINE
NUCLEI
ODD-ODD NUCLEI
RADIATION DOSE DISTRIBUTIONS
RADIATIONS
RADIOISOTOPES
RADIOLOGY
SPATIAL DOSE DISTRIBUTIONS
STRUCTURAL MODELS
THERAPY
YEARS LIVING RADIOISOTOPES
655003* - Medical Physics- Dosimetry