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The investigation of 32 P wire for catheter‐based endovascular irradiation
Author(s) -
Xu Zhigang,
Reinstein L. E.,
Yang Guozhen,
Pai S.,
Gluckman G.,
Almond P. R.
Publication year - 1997
Publication title -
medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.473
H-Index - 180
eISSN - 2473-4209
pISSN - 0094-2405
DOI - 10.1118/1.597944
Subject(s) - materials science , dose rate , nuclear medicine , percentage depth dose curve , irradiation , homogeneity (statistics) , biomedical engineering , dosimetry , physics , ionization chamber , mathematics , medicine , ion , medical physics , statistics , quantum mechanics , nuclear physics , ionization
The dose distribution from a32 P source has been measured and calculated in order to evaluate its application in endovascular irradiation. The source dimension was 27 mm in length and 0.3 mm in diameter and was embedded in the end of a Ni–Ti wire. Dose measurements were performed using radiochromic film in several specially designed tissue equivalent phantoms. Loevinger's point dose kernel was used for the calculation. The approximate dose rate at a radial distance of 1.5 mm from the center of the source was found to be 6.75 cGy/s per GBq (0.25 cGy/s per mCi), which allows the delivery of a therapeutic dose in a short time interval with a satisfactory homogeneity without stepping the source. However, the dose rate falls off almost exponentially along the radial distance. Therefore it may not be suitable for treating large diameter vessel from a centrally located source. The effect of a curved32 P wire source on the radial dose distribution was also investigated. The results showed that for a maximum bend of 180° the dose rate was increased by as much as 20% along the inner radial distance but decreased by as much as 20% along the outer radial distance compared to the dose along a straight wire. However, for curvatures normally encountered in a clinical situation, the dose rate was changed less than 5%.