TY - JOUR
T1 - Radiation dose distributions in normal tissue adjacent to tumors containing 131I or 90Y
T2 - The potential for toxicity
AU - Sparks, Richard B.
AU - Crowe, Eric A.
AU - Wong, Franklin C.
AU - Toohey, Richard E.
AU - Siegel, Jeffry A.
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2002
Y1 - 2002
N2 - Given the relatively large tumor-absorbed doses reported for patients receiving radionuclide therapy, particularly radioimmunotherapy, and the relatively long pathlength of the nonpenetrating emissions of some radionuclides being used for these therapies, there exists the possibility of large absorbed doses to tissues adjacent to, surrounded by, or surrounding these tumors. Because tumors can occur adjacent to critical organs or tissues, such as arteries, nerves, pericardium, and the walls of the organs of the gastrointestinal tract, large absorbed doses to these normal tissues can lead to acute complications. Methods: In this study, the Monte Carlo radiation transport code MCNP4b was used to simulate the deposition of energy from emissions of 2 radionuclides of interest, 131I and 90Y, to assess the possible magnitude of the absorbed doses in tissues adjacent to tumors. Mathematic models were constructed to simulate situations that might occur, such as tumor wrapped around a small cylinder (e.g., a nerve or artery), tumor against a tissue (e.g., the pericardium or wall of any gastro-intestinal tract organ), and tumor surrounded by any soft tissue. Tumor masses of 10, 20, and 40 g were used in each model. Depth dose distributions were calculated using Monte Carlo simulations of the radiation transport in these geometric models. Results: For tissues close to tumors containing 90Y, the absorbed dose ranged from 24% of the absorbed dose in the tumor, for the case of tissues 1 mm from the tumor, to 103% of the absorbed dose in the tumor, for the case of small structures such as nerves or arteries surrounded by tumor. For tissues close to tumors containing 131I, the absorbed dose ranged from 4% of the absorbed dose in the tumor, for the case of tissues 1 mm from the tumor, to 46% of the absorbed dose in the tumor, for the case of small structures such as nerves or arteries surrounded by tumor. Conclusion: This study showed that when absorbed doses to tumors are large, the absorbed dose to adjacent tissues can also be large, potentially causing unexpected toxicities.
AB - Given the relatively large tumor-absorbed doses reported for patients receiving radionuclide therapy, particularly radioimmunotherapy, and the relatively long pathlength of the nonpenetrating emissions of some radionuclides being used for these therapies, there exists the possibility of large absorbed doses to tissues adjacent to, surrounded by, or surrounding these tumors. Because tumors can occur adjacent to critical organs or tissues, such as arteries, nerves, pericardium, and the walls of the organs of the gastrointestinal tract, large absorbed doses to these normal tissues can lead to acute complications. Methods: In this study, the Monte Carlo radiation transport code MCNP4b was used to simulate the deposition of energy from emissions of 2 radionuclides of interest, 131I and 90Y, to assess the possible magnitude of the absorbed doses in tissues adjacent to tumors. Mathematic models were constructed to simulate situations that might occur, such as tumor wrapped around a small cylinder (e.g., a nerve or artery), tumor against a tissue (e.g., the pericardium or wall of any gastro-intestinal tract organ), and tumor surrounded by any soft tissue. Tumor masses of 10, 20, and 40 g were used in each model. Depth dose distributions were calculated using Monte Carlo simulations of the radiation transport in these geometric models. Results: For tissues close to tumors containing 90Y, the absorbed dose ranged from 24% of the absorbed dose in the tumor, for the case of tissues 1 mm from the tumor, to 103% of the absorbed dose in the tumor, for the case of small structures such as nerves or arteries surrounded by tumor. For tissues close to tumors containing 131I, the absorbed dose ranged from 4% of the absorbed dose in the tumor, for the case of tissues 1 mm from the tumor, to 46% of the absorbed dose in the tumor, for the case of small structures such as nerves or arteries surrounded by tumor. Conclusion: This study showed that when absorbed doses to tumors are large, the absorbed dose to adjacent tissues can also be large, potentially causing unexpected toxicities.
KW - Absorbed-dose profile
KW - Dosimetry
KW - Radioimmunotherapy
KW - Tissue toxicity
KW - Tumors
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M3 - Article
C2 - 12163638
AN - SCOPUS:0036327871
SN - 0161-5505
VL - 43
SP - 1110
EP - 1114
JO - Journal of Nuclear Medicine
JF - Journal of Nuclear Medicine
IS - 8
ER -