摘要:

A method is described for obtainingSvalues between a tumor and its host organ for use with the MIRD formalism. It applies the point‐source specific absorbed fractions for an infinite water medium, tabulated by Berger, to a rectangular solid of arbitrary dimensions which contains a rectangular tumor of arbitrary dimensions. Contributions from pairs of source and target volume elements are summed for theSvalues between the tumor and itself, between the remaining healthy host organ and itself, and between the tumor and the remaining healthy host organ, with the reciprocity theorem assumed for the last. This method labeledmtumor, is interfaced with the widely usedmirdoseprogram which incorporates the MIRD formalism. An example is calculated.

ISSN:0269-3127    

DOI:10.1118/1.596732

出版商:American Association of Physicists in Medicine    

年代:1998

数据来源: WILEY

摘要:

The tables of the mean restricted collision mass stopping power ratios for water, polystyrene and acrylic relative to air given in the AAPM TG‐21 protocol have been fitted to an expression with 20 coefficients using the depth in the phantom and the mean incident electron energy as two independent variables. Using these expressions, the calculated values agree with the tabulated values within +0.5% in 85% of the cases and within ±1.0% in 95% of the cases. For each of the four cylindrical chamber inner diameters, given in the protocol, the electron fluence correctionPreplhas been fitted to an expression with four coefficients using the mean electron energy at depthzas an independent variable.

ISSN:0269-3127    

DOI:10.1118/1.596745

出版商:American Association of Physicists in Medicine    

年代:1998

数据来源: WILEY

摘要:

This study reports on a spectral monitoring method in which (1) a small source fixed to the camera is used, (2) a narrow, offset window is set on the side of the photopeak, and (3) variations in count rate are measured to assess energy shifts in the vicinity of the source. For one camera model, the count rate drops from 100% to 76% over a rotation of 180°, implying a local energy shift of 1.4 keV. Also looked for are local count‐rate variations with rotation for (1) wide‐symmetric, (2) 20%‐symmetric, and (3) 10%‐asymmetric windows. The last is in limited use to partially compensate for Compton scattering. The effects of background and time stability are assessed.

ISSN:0269-3127    

DOI:10.1118/1.596660

出版商:American Association of Physicists in Medicine    

年代:1998

数据来源: WILEY

ISSN:0269-3127    

DOI:10.1002/j.2473-4209.1991.tb36341.x

出版商:American Association of Physicists in Medicine    

年代:1998

数据来源: WILEY

ISSN:0269-3127    

DOI:10.1002/j.2473-4209.1991.tb36342.x

出版商:American Association of Physicists in Medicine    

年代:1998

数据来源: WILEY

ISSN:0269-3127    

DOI:10.1002/j.2473-4209.1991.tb36343.x

出版商:American Association of Physicists in Medicine    

年代:1998

数据来源: WILEY

ISSN:0269-3127    

DOI:10.1002/j.2473-4209.1991.tb36344.x

出版商:American Association of Physicists in Medicine    

年代:1998

数据来源: WILEY

ISSN:0269-3127    

DOI:10.1002/j.2473-4209.1991.tb36345.x

出版商:American Association of Physicists in Medicine    

年代:1998

数据来源: WILEY