Background: To evaluate whether current dose reduction strategies for the CT component of hybrid Positron Emission Tomography—Computed Tomography (PET/CT) systems could reduce patient dose with maintaining adequate i...Background: To evaluate whether current dose reduction strategies for the CT component of hybrid Positron Emission Tomography—Computed Tomography (PET/CT) systems could reduce patient dose with maintaining adequate image quality for PET/CT studies. Materials and Methods: Literature survey was initially based on the selection of keywords and years of publication to identify potentially relevant articles, then the further search was conducted on the authors and references from these articles. The abstract of each article was first appraised to decide whether the content was relevant to this research question. The articles were classified into five groups: studies on dosimetry, studies on radiation-induced diseases, studies on dose reduction methods for CT-based attenuation correction (CTAC), studies on dose reduction methods for CT localization, and studies on reducing the need for a full-dose diagnostic CT in PET/CT imaging. 58 peer-reviewed articles were selected and appraised and 29 articles were used to compose this literature review. Results: The published nuclear medicine and medical physics literature were reviewed. CT dose contributed 47% - 81% of the total effective dose of a standard PET/CT study and was associated with radiation-induced diseases. The dose reduction techniques were extracted and divided into three categories: reducing the CT dose for attenuation correction (AC) and localization, selectively localizing CT use, and reducing the need for a full-dose diagnostic CT. Conclusion: Three strategies have been demonstrated, with high potential for reducing patient dose while maintaining an adequate CT image quality, used for CTCA localization and diagnosis, respectively.展开更多
Background: The PET/CT imaging studies have two doses components the dose from the PET radiopharmaceutical and the other from the low dose CT used for PET images attenuation correction. We have one PET/CT scanner at o...Background: The PET/CT imaging studies have two doses components the dose from the PET radiopharmaceutical and the other from the low dose CT used for PET images attenuation correction. We have one PET/CT scanner at our institution a Philips Time of Flight scanner. Our local patient’s radiation protection rules requires continuous assessment of radiation doses delivered to our patients. Purposes: The objectives of this study are to develop a weight- based facility DRLs for paediatric F-18-FDG PET-CT imaging for oncology in a large tertiary hospital and to determine whether the calculated DRLs compares with internationally published DRLs. Materials & Methods: Radiation dose data and patient demographics of two-hundreds and sixteen paediatric PET-CT oncology patients imaging procedures from one large tertiary hospital were selected and analysed in order to establish a facility paediatric DRLs. Statistical analysis was performed. Results: The PET dose reference levels ranged between [62 - 525] MBq of injected activity for a range of pediatric age groups. The CTDI<sub>vol</sub> values were between 3.5 and 16.5 mGy for all age groups. Comparison with current EANM and SNMMI recommendations of patient’s dose are discussed. Conclusion: Our pediatric PET/CT reference levels are higher than the ones reported internationally with notable variations. .展开更多
Objective:To compare the differences of radiation-induced doses between 18F-FDG-PET/CT and CT/MRI-guided target delineation in nasopharyngeal carcinoma in intensity-modulated radiotherapy.Methods:A total of 31 patient...Objective:To compare the differences of radiation-induced doses between 18F-FDG-PET/CT and CT/MRI-guided target delineation in nasopharyngeal carcinoma in intensity-modulated radiotherapy.Methods:A total of 31 patients with locally advanced nasopharyngeal carcinoma receiving treatment in our hospital from December 2016 to December 2017 were studied in this research,and 18F-FDG-PET/CT and CT/MRI were used to guide the target delineation to develop an intensity-modulated radiotherapy plan(experimental group and control group).The dose differences between GTV and endangered organs in the two groups were compared.Results:Comparison of primary tumor volume:PET/CT was smaller than CT/MRI,and volumes of T3 and T4 were significantly different(P<0.001).Comparison of the two delineation plans,in terms of PGTV in Dmin,Dmean,and D95,the data of experimental group was smaller than that of the control group;in Dmax,the PGTV of the experimental group was larger than that of the control group with P<0.001 considered as a significant difference.In Dmin and Dmax,doses of experimental groups of the spinal cord were lower than those of the control group,showing a significant difference(P=0.022,0.042);In Dmean,there was no difference between the two groups.In Dmax doses of an experimental group of the brainstem and parotid gland were significantly smaller than the control group(P=0.001,0.047)while there was no difference between Dmin and Dmean.There was no difference between the two groups of Dmin,Dmean,and Dmax in the doses received by chiasm and temporal lobe.Conclusion:PET/CT guided target delineation is applied in the simultaneous dose adjustment of intensity-modulated radiation therapy in patients with advanced nasopharyngeal carcinoma.In primary lesion targets shown by MRI/CT,the tumor tissue of PET/CT concentration zone was given a higher dose with relatively smaller average dose and minimum dose in the overall tumor target area.Statistics also showed that the doses received by the spinal cord,brain stem,and parotid gland were reduced with no effect on the optic chiasm and temporal lobe.In the future,more studies should probe into the long-term effects of dose changes on lesion control and endangered organs.展开更多
文摘Background: To evaluate whether current dose reduction strategies for the CT component of hybrid Positron Emission Tomography—Computed Tomography (PET/CT) systems could reduce patient dose with maintaining adequate image quality for PET/CT studies. Materials and Methods: Literature survey was initially based on the selection of keywords and years of publication to identify potentially relevant articles, then the further search was conducted on the authors and references from these articles. The abstract of each article was first appraised to decide whether the content was relevant to this research question. The articles were classified into five groups: studies on dosimetry, studies on radiation-induced diseases, studies on dose reduction methods for CT-based attenuation correction (CTAC), studies on dose reduction methods for CT localization, and studies on reducing the need for a full-dose diagnostic CT in PET/CT imaging. 58 peer-reviewed articles were selected and appraised and 29 articles were used to compose this literature review. Results: The published nuclear medicine and medical physics literature were reviewed. CT dose contributed 47% - 81% of the total effective dose of a standard PET/CT study and was associated with radiation-induced diseases. The dose reduction techniques were extracted and divided into three categories: reducing the CT dose for attenuation correction (AC) and localization, selectively localizing CT use, and reducing the need for a full-dose diagnostic CT. Conclusion: Three strategies have been demonstrated, with high potential for reducing patient dose while maintaining an adequate CT image quality, used for CTCA localization and diagnosis, respectively.
文摘Background: The PET/CT imaging studies have two doses components the dose from the PET radiopharmaceutical and the other from the low dose CT used for PET images attenuation correction. We have one PET/CT scanner at our institution a Philips Time of Flight scanner. Our local patient’s radiation protection rules requires continuous assessment of radiation doses delivered to our patients. Purposes: The objectives of this study are to develop a weight- based facility DRLs for paediatric F-18-FDG PET-CT imaging for oncology in a large tertiary hospital and to determine whether the calculated DRLs compares with internationally published DRLs. Materials & Methods: Radiation dose data and patient demographics of two-hundreds and sixteen paediatric PET-CT oncology patients imaging procedures from one large tertiary hospital were selected and analysed in order to establish a facility paediatric DRLs. Statistical analysis was performed. Results: The PET dose reference levels ranged between [62 - 525] MBq of injected activity for a range of pediatric age groups. The CTDI<sub>vol</sub> values were between 3.5 and 16.5 mGy for all age groups. Comparison with current EANM and SNMMI recommendations of patient’s dose are discussed. Conclusion: Our pediatric PET/CT reference levels are higher than the ones reported internationally with notable variations. .
基金Scientific Research Project on Health Planning(16A200048).
文摘Objective:To compare the differences of radiation-induced doses between 18F-FDG-PET/CT and CT/MRI-guided target delineation in nasopharyngeal carcinoma in intensity-modulated radiotherapy.Methods:A total of 31 patients with locally advanced nasopharyngeal carcinoma receiving treatment in our hospital from December 2016 to December 2017 were studied in this research,and 18F-FDG-PET/CT and CT/MRI were used to guide the target delineation to develop an intensity-modulated radiotherapy plan(experimental group and control group).The dose differences between GTV and endangered organs in the two groups were compared.Results:Comparison of primary tumor volume:PET/CT was smaller than CT/MRI,and volumes of T3 and T4 were significantly different(P<0.001).Comparison of the two delineation plans,in terms of PGTV in Dmin,Dmean,and D95,the data of experimental group was smaller than that of the control group;in Dmax,the PGTV of the experimental group was larger than that of the control group with P<0.001 considered as a significant difference.In Dmin and Dmax,doses of experimental groups of the spinal cord were lower than those of the control group,showing a significant difference(P=0.022,0.042);In Dmean,there was no difference between the two groups.In Dmax doses of an experimental group of the brainstem and parotid gland were significantly smaller than the control group(P=0.001,0.047)while there was no difference between Dmin and Dmean.There was no difference between the two groups of Dmin,Dmean,and Dmax in the doses received by chiasm and temporal lobe.Conclusion:PET/CT guided target delineation is applied in the simultaneous dose adjustment of intensity-modulated radiation therapy in patients with advanced nasopharyngeal carcinoma.In primary lesion targets shown by MRI/CT,the tumor tissue of PET/CT concentration zone was given a higher dose with relatively smaller average dose and minimum dose in the overall tumor target area.Statistics also showed that the doses received by the spinal cord,brain stem,and parotid gland were reduced with no effect on the optic chiasm and temporal lobe.In the future,more studies should probe into the long-term effects of dose changes on lesion control and endangered organs.
