PMID- 27806615
OWN - NLM
STAT- MEDLINE
DCOM- 20170316
LR  - 20170316
IS  - 2473-4209 (Electronic)
IS  - 0094-2405 (Linking)
VI  - 43
IP  - 11
DP  - 2016 Nov
TI  - A volume-equivalent spherical necrosis-tumor-normal liver model for estimating 
      absorbed dose in yttrium-90 microsphere therapy.
PG  - 6082
AB  - PURPOSE: Primary hepatocellular carcinoma and metastatic liver tumors are highly 
      malignant tumors in Asia. The incidence of fatal liver cancer is also increasing 
      in the United States. The aim of this study was to establish a spherical tumor 
      model and determine its accuracy in predicting the absorbed dose in yttrium-90 
      (Y-90) microsphere therapy for liver cancer. METHODS: Liver morphology can be 
      approximated by a spherical model comprising three concentric regions 
      representing necrotic, tumor, and normal liver tissues. The volumes of these 
      three regions represent those in the actual liver. A spherical tumor model was 
      proposed to calculate the absorbed fractions in the spherical tumor, necrotic, 
      and normal tissue regions. The THORplan treatment planning system and Monte Carlo 
      N-particle extended codes were used for this spherical tumor model. Using the 
      volume-equivalent method, a spherical tumor model was created to calculate the 
      total absorbed fraction [under different tumor-to-healthy-liver ratios (TLRs)]. 
      The patient-specific model (THORplan) results were used to verify the spherical 
      tumor model results. RESULTS: The results for both the Y-90 spectrum and the Y-90 
      mean energy indicated that the absorbed fraction was a function of the tumor 
      radius and mass. The absorbed fraction increased with tumor radius. The total 
      absorbed fractions calculated using the spherical tumor model for necrotic, liver 
      tumor, and normal liver tissues were in good agreement with the THORplan results, 
      with differences of less than 3% for TLRs of 2-5. The results for the effect of 
      TLR indicate that for the same tumor configuration, the total absorbed fraction 
      decreased with increasing TLR; for the same shell tumor thickness and TLR, the 
      total absorbed fraction was approximately constant; and for tumors with the same 
      radius, the total fraction absorbed by the tumor increased with the shell 
      thickness. CONCLUSIONS: The results from spherical tumor models with different 
      tumor-to-healthy-liver ratios were highly consistent with the reference results 
      (THORplan). These findings indicate that a spherical tumor model can provide good 
      estimates of Y-90 doses in microsphere therapy and can be considered a first 
      approximation for dose estimation in Y-90 microsphere therapy.
FAU - Wu, Chin-Hui
AU  - Wu CH
AD  - Medical Physics and Radiation Measurements Laboratory, Department of Biomedical 
      Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan 
      112, Republic of China and Department of Medical Imaging and Radiological 
      Sciences, Tzu-Chi University of Science and Technology, Hualien, Taiwan 970, 
      Republic of China.
FAU - Liao, Yi-Jen
AU  - Liao YJ
AD  - School of Medical Laboratory Science and Biotechnology, College of Medical 
      Science and Technology, Taipei Medical University, Taipei, Taiwan 110, Republic 
      of China.
FAU - Lin, Tzung-Yi
AU  - Lin TY
AD  - Institute of Nuclear Engineering and Science, National Tsing Hua University, 
      Hsinchu, Taiwan 300, Republic of China.
FAU - Chen, Yu-Cheng
AU  - Chen YC
AD  - Department of Biomedical Imaging and Radiological Science, China Medical 
      University, Taichung, Taiwan 404, Republic of China.
FAU - Sun, Shung-Shung
AU  - Sun SS
AD  - Department of Biomedical Imaging and Radiological Science, China Medical 
      University, Taichung, Taiwan 404, Republic of China.
FAU - Liu, Yen-Wan Hsueh
AU  - Liu YH
AD  - Institute of Nuclear Engineering and Science, National Tsing Hua University, 
      Hsinchu, Taiwan 300, Republic of China.
FAU - Hsu, Shih-Ming
AU  - Hsu SM
AD  - Medical Physics and Radiation Measurements Laboratory, Department of Biomedical 
      Imaging and Radiological Sciences, National Yang-Ming University, Taipei, Taiwan 
      112, Republic of China; Department of Biomedical Imaging and Radiological 
      Sciences, National Yang-Ming University, Taipei, Taiwan 112, Republic of China; 
      and Biophotonics and Molecular Imaging Research Center, National Yang-Ming 
      University, Taipei, Taiwan 112, Republic of China.
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Med Phys
JT  - Medical physics
JID - 0425746
RN  - 0 (Yttrium Radioisotopes)
SB  - IM
MH  - *Absorption, Radiation
MH  - Beta Particles/therapeutic use
MH  - Humans
MH  - Liver Neoplasms/*pathology/*radiotherapy
MH  - *Microspheres
MH  - Necrosis/radiotherapy
MH  - *Patient-Specific Modeling
MH  - Tumor Burden/drug effects/*radiation effects
MH  - Yttrium Radioisotopes/chemistry/*therapeutic use
EDAT- 2016/11/04 06:00
MHDA- 2017/03/17 06:00
CRDT- 2016/11/04 06:00
PHST- 2016/11/04 06:00 [pubmed]
PHST- 2017/03/17 06:00 [medline]
PHST- 2016/11/04 06:00 [entrez]
AID - 10.1118/1.4965044 [doi]
PST - ppublish
SO  - Med Phys. 2016 Nov;43(11):6082. doi: 10.1118/1.4965044.