TY - JOUR
T1 - Converging Stereotactic Radiotherapy Using Kilovoltage X-Rays
T2 - Experimental Irradiation of Normal Rabbit Lung and Dose-Volume Analysis With Monte Carlo Simulation
AU - Kawase, Takatsugu
AU - Kunieda, Etsuo
AU - Deloar, Hossain M.
AU - Tsunoo, Takanori
AU - Seki, Satoshi
AU - Oku, Yohei
AU - Saitoh, Hidetoshi
AU - Saito, Kimiaki
AU - Ogawa, Eileen N.
AU - Ishizaka, Akitoshi
AU - Kameyama, Kaori
AU - Kubo, Atsushi
N1 - Funding Information:
This work was presented in part at the 5th Japan–US Cancer Therapy Symposium and the 5th S. Takahashi Memorial Joint Symposium, Sept 7–9, 2007, Sendai, Japan. The authors are most grateful for the financial support received from CREST, Japan Science and Technology Agency, Tokyo, Japan.
PY - 2009/10/1
Y1 - 2009/10/1
N2 - Purpose: To validate the feasibility of developing a radiotherapy unit with kilovoltage X-rays through actual irradiation of live rabbit lungs, and to explore the practical issues anticipated in future clinical application to humans through Monte Carlo dose simulation. Methods and Materials: A converging stereotactic irradiation unit was developed, consisting of a modified diagnostic computed tomography (CT) scanner. A tiny cylindrical volume in 13 normal rabbit lungs was individually irradiated with single fractional absorbed doses of 15, 30, 45, and 60 Gy. Observational CT scanning of the whole lung was performed every 2 weeks for 30 weeks after irradiation. After 30 weeks, histopathologic specimens of the lungs were examined. Dose distribution was simulated using the Monte Carlo method, and dose-volume histograms were calculated according to the data. A trial estimation of the effect of respiratory movement on dose distribution was made. Results: A localized hypodense change and subsequent reticular opacity around the planning target volume (PTV) were observed in CT images of rabbit lungs. Dose-volume histograms of the PTVs and organs at risk showed a focused dose distribution to the target and sufficient dose lowering in the organs at risk. Our estimate of the dose distribution, taking respiratory movement into account, revealed dose reduction in the PTV. Conclusions: A converging stereotactic irradiation unit using kilovoltage X-rays was able to generate a focused radiobiologic reaction in rabbit lungs. Dose-volume histogram analysis and estimated sagittal dose distribution, considering respiratory movement, clarified the characteristics of the irradiation received from this type of unit.
AB - Purpose: To validate the feasibility of developing a radiotherapy unit with kilovoltage X-rays through actual irradiation of live rabbit lungs, and to explore the practical issues anticipated in future clinical application to humans through Monte Carlo dose simulation. Methods and Materials: A converging stereotactic irradiation unit was developed, consisting of a modified diagnostic computed tomography (CT) scanner. A tiny cylindrical volume in 13 normal rabbit lungs was individually irradiated with single fractional absorbed doses of 15, 30, 45, and 60 Gy. Observational CT scanning of the whole lung was performed every 2 weeks for 30 weeks after irradiation. After 30 weeks, histopathologic specimens of the lungs were examined. Dose distribution was simulated using the Monte Carlo method, and dose-volume histograms were calculated according to the data. A trial estimation of the effect of respiratory movement on dose distribution was made. Results: A localized hypodense change and subsequent reticular opacity around the planning target volume (PTV) were observed in CT images of rabbit lungs. Dose-volume histograms of the PTVs and organs at risk showed a focused dose distribution to the target and sufficient dose lowering in the organs at risk. Our estimate of the dose distribution, taking respiratory movement into account, revealed dose reduction in the PTV. Conclusions: A converging stereotactic irradiation unit using kilovoltage X-rays was able to generate a focused radiobiologic reaction in rabbit lungs. Dose-volume histogram analysis and estimated sagittal dose distribution, considering respiratory movement, clarified the characteristics of the irradiation received from this type of unit.
KW - Animal experimentation
KW - Clinical application
KW - Radiation injury
KW - Radiotherapy unit
KW - Respiratory movement
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U2 - 10.1016/j.ijrobp.2009.01.085
DO - 10.1016/j.ijrobp.2009.01.085
M3 - Article
C2 - 19735870
AN - SCOPUS:69549133642
SN - 0360-3016
VL - 75
SP - 468
EP - 474
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
IS - 2
ER -
