Considerations on Absorbed Dose Estimates Based on Different .BETA.-Dose Point Kernels in Internal Dosimetry.

• UCHIDA Isao

  Department of Radiation Protection

• YAMADA Yasuhiko

  Department of Nuclear Medicine

• OKIGAKI Shigeyasu

  Department of Physics, Cancer Insitute

• OYAMADA Hiyoshimaru

  Anzai Medical Co., Ltd

• ITO Akira

  Department of Physics, Cancer Insitute

• YAMASHITA Takashi

  Department of Radiotherapy, Cancer Institute Hospital

Bibliographic Information

Other Title

• 異なったβ‐Ｄｏｓｅ　Ｐｏｉｎｔ　Ｋｅｒｎｅｌに基づく吸収線量評価に関する検討
• コトナッタ ベータ Dose Point Kernel ニ モトズク キュウシ

Abstract

In radiotherapy with radiopharmaceuticals, more accurate estimates of the three-dimensional (3-D) distribution of absorbed dose is important in specifying the activity to be administered to patients to deliver a prescribed absorbed dose to target volumes without exceeding the toxicity limit of normal tissues in the body. A calculation algorithm for the purpose has already been developed by the authors. An accurate 3-D distribution of absorbed dose based on the algorithm is given by convolution of the 3-D dose matrix for a unit cubic voxel containing unit cumulated activity, which is obtained by transforming a dose point kernel into a 3-D cubic dose matrix, with the 3-D cumulated activity distribution given by the same voxel size. However, beta-dose point kernels affecting accurate estimates of the 3-D absorbed dose distribution have been different among the investigators. The purpose of this study is to elucidate how different beta-dose point kernels in water influence on the estimates of the absorbed dose distribution due to the dose point kernel convolution method by the authors.<BR>Computer simulations were performed using the MIRD thyroid and lung phantoms under assumption of uniform activity distribution of ³²P. Using beta-dose point kernels derived from Monte Carlo simulations (EGS-4 or ACCEPT computer code), the differences among their point kernels gave little differences for the mean and maximum absorbed dose estimates for the MIRD phantoms used.<BR>In the estimates of mean and maximum absorbed doses calculated using different cubic voxel sizes (4×4×4mm and 8×8×8mm) for the MIRD thyroid phantom, the maximum absorbed doses for the 4×4×4mm-voxel were estimated approximately 7% greater than the cases of the 8×8×8mm-voxel. They were found in every beta-dose point kernel used in this study. On the other hand, the percentage difference of the mean absorbed doses in the both voxel sizes for each beta-dose point kernel was less than approximately 0.6%.

Journal

• RADIOISOTOPES

  RADIOISOTOPES 44 (10), 687-692, 1995

  Japan Radioisotope Association

Keywords

• internal dosimetry
• beta-dose point kernel
• dose point kernel convolution method
• three-dimensional absorbed dose distribution
• MIRD phantom
• phosphorus-32

Details

• CRID: 1390001204154551808
• NII Article ID: 130004382721
• NII Article ID: 10002391847
• NII Book ID: AN00351589
• DOI: 10.3769/radioisotopes.44.10_687
• ISSN: 18844111
• ISSN: 00338303
• NDL BIB ID: 3645911
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I3645911
• Web Site: http://www.jstage.jst.go.jp/article/radioisotopes1952/44/10/44_10_687/_pdf
• Web Site: https://search.jamas.or.jp/link/ui/1996120550
• Text Lang: ja
• Data Source:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• Abstract License Flag: Disallowed