Experimental measurements of dosimetric parameters on the transverse axis of a new 125I source.
Med Phys
; 27(6): 1275-80, 2000 Jun.
Article
en En
| MEDLINE
| ID: mdl-10902556
ABSTRACT
Permanent prostate implant using 125I or 103Pd sources is a common treatment choice in the management of early prostate cancer. As sources of new designs are developed and marketed for application in permanent prostate implants, it is of paramount importance that their dosimetric characteristics are carefully determined, in order to maintain a high accuracy of patient treatment. This report presents the results of experimental measurements of the dosimetric parameters performed for a newly available 125I seed source, the model MED3631-A/M source (IoGold), manufactured by North American Scientific, Inc. The measurements were performed in a large scanning water phantom, using a diode detector. The positioning of the source and the diode detector was achieved by a computer-controlled positioning mechanism in the scanning water phantom. The dose rate constant in water for the new 125I source was measured in comparison with an existing 125I source of similar design and verified using thermoluminescent dosimetry (TLD) measurement. The radial dose function values for the source were measured using the diode detector. The measurement technique and the results are compared with the dose distribution parameters for the 125I sources discussed in the AAPM TG43 report and elsewhere [Med. Phys. 26, 570-573 (1999)]. For the dose rate constant in water of the new source, it is recommended that a value of 0.950 cGy/U-hr be used based on the NIST 1985 air-kerma strength calibration standard, or 1.060 cGy/U-hr based on the 1999 NIST air-kerma strength standard. The measured radial dose function values for the MED3631-A/M source agree closely with those of the model 6702 source. It is therefore recommended that the radial dose function values for the model 6702 125I source, as recommended by the AAPM TG43 report, be adopted for the new source as well.
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Bases de datos:
MEDLINE
Métodos Terapéuticos y Terapias MTCI:
Terapias_biologicas
/
Hidroterapia
Asunto principal:
Neoplasias de la Próstata
/
Planificación de la Radioterapia Asistida por Computador
/
Braquiterapia
/
Radioisótopos de Yodo
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Med Phys
Año:
2000
Tipo del documento:
Article
País de afiliación:
Estados Unidos