Objective To evaluate the feasibility of using a low concentration of contrast medium （Visipaque 270 mgl/mL）, low tube voltage, and an advanced image reconstruction algorithm in head and neck computed tomography ang...Objective To evaluate the feasibility of using a low concentration of contrast medium （Visipaque 270 mgl/mL）, low tube voltage, and an advanced image reconstruction algorithm in head and neck computed tomography angiography （CTA）. Methods Forty patients （22 men and 18 women; average age 48.7 ± 14.25 years; average body mass index 23.9 ± 3.7 kg/m^2） undergoing CTA for suspected vascular diseases were randomly assigned into two groups. Group A （n = 20） was administered 370 mgl/mL contrast medium, and group B （n = 20） was administered 270 mgl/mL contrast medium. Both groups were administered at a rate of 4.8 mL/s and an injection volume of 0.8 mL/kg. Images of group A were obtained with 120 kVp and filtered back projection （FBP） reconstruction, whereas images of group B were obtained with 80 kVp and 80% adaptive iterative statistical reconstruction algorithm （ASiR）. The CT values and standard deviations of intracranial arteries and image noise on the corona radiata were measured to calculate the contrast-to-noise ratio （CNR） and signal-to-noise ratio （SNR）. The beam-hardening artifacts （BHAs） around the skull base were calculated. Two readers evaluated the image quality with volume rendered images using scores from 1 to 5. The values between the two groups were statistically compared. Results The mean CT value of the intracranial arteries in group B was significantly higher than that in group A （P 〈 0.001）. The CNR and SNR values in group B were also statistically higher than those in group A （P 〈 0.001）. Image noise and BHAs were not significantly different between the two groups. The image quality score of VR images of in group B was significantly higher than that in group A （P = 0.001）. However, the quality scores of axial enhancement images in group B became significantly smaller than those in group A （P〈 0.001）. The CT dose index volume and dose-length product were decreased by 63.8% and 64%, respectively, in group B （P 〈 0.001 for both）. Conclusion Visipaque combined with 80 kVp and 80% ASiR provided similar image quality in intracranial CTA with 64% radiation dose reduction compared with the use of lopamidol, 120 kVp, and FBP reconstruc-tion.展开更多
Objective：To clarify the prognostic value of post-treatment 18F-fluorodeoxyglucose （FDG） positron emission tomography （PET）/computed tomography （CT） in patients with advanced head and neck squamous cell carcino...Objective：To clarify the prognostic value of post-treatment 18F-fluorodeoxyglucose （FDG） positron emission tomography （PET）/computed tomography （CT） in patients with advanced head and neck squamous cell carcinoma （HNSCC） after combined intra-arterial chemotherapy and radiotherapy （IACR）.Methods：Thirty-six patients with HNSCC who underwent IACR were recruited.The period from the end of IACR to the last post-treatment 18F-FDG PET/CT examination was 8-12 weeks.Both patient-based and lesion-based analyses were used to evaluate the PET/CT images.For lesion-based analysis,36 regions （12 lesions of recurrences and 24 scars at primary sites） were selected.The Kaplan-Meier method was used to assess the overall survival （OS） stratified by 18F-FDG uptake or visual interpretation results.Results：Twelve patients with recurrence were identified by six months after IACR.The sensitivity and specificity in the patient-based analysis were 67％ （8/12） and 88％ （21/24）,respectively.The mean OS was estimated to be 12.1 months （95％ CI,6.3-18.0 months） for the higher maximum standardized uptake value （SUVmax） group （n=7） and 44.6 months （95％ CI,39.9-49.3 months） for the lower SUVmax group （n=29）.OS in the higher SUVmax group （cut-off point,6.1） or positive visual interpretation group was significantly shorter than that in the lower SUVmax or negative visual interpretation group （P＜0.001 and P＜0.05,respectively）.Conclusions：The SUVmax and visual interpretation of HNSCC on post-IACR 18F-FDG PET/CT can provide prognostic survival estimates.展开更多
Positron emission tomography/Computer tomography (PET/CT) is a multimodality imaging diagnostic technique that analyzes the uptake and retention of different radiopharmaceuticals by cells providing metabolic informati...Positron emission tomography/Computer tomography (PET/CT) is a multimodality imaging diagnostic technique that analyzes the uptake and retention of different radiopharmaceuticals by cells providing metabolic information on biochemical processes. PET/CT has been used for radiotherapy planning, providing useful information to the Radio-oncologist about the localization, size and metabolic activity of tumor lesions. In this paper, we show advantages of the 18F-FDG PET/CT respect to simple CT imaging for target volume delineation in patients with diagnosis of Squamous Head and Neck Carcinoma that has been scheduled to undergo a hypofractionated radiotherapy treatment. On ten studied patients, the target volume defined from PET/CT images was less extensive than those defined from simple CT images. In six patients the target volume was significantly less extensive and in two of them a new lymph node disease was reported, re-staging and corresponding target volume was also delineated with less extensive margins from PET/CT images. A greater accuracy in delineating the volumes and improving the distribution of doses in the planning of the radiant treatment in these patients was possible, allowing a high precision in the delivery of the prescribed dose to the target volume diminishing the maximum dose to the adjacent healthy tissues. In conclusion we show that the use of 18F-FDG PET/CT was superior than the simple CT as the primary modality of imaging for hypofractioned radiotherapy treatment planning in patients with Squamous Head and Neck Carcinoma.展开更多
Cancer of the head and neck is often devastating and the morbidity associated with its treatment is substantial. Positron Emission Tomography-Computed Tomography (PET-CT) combines the power of biological / molecular i...Cancer of the head and neck is often devastating and the morbidity associated with its treatment is substantial. Positron Emission Tomography-Computed Tomography (PET-CT) combines the power of biological / molecular imaging with the anatomic detail of CT in order to provide a very sensitive and specific imaging tool for the evaluation of head and neck pathology. PET can aid the clinician in establishing diagnosis, staging, (It has been shown to be more accurate than CT), assessing, prognosis and determining response to therapy. Lymphoma, melanoma, multiple myeloma, leukemia, salivary gland tumors, odontogenic carcinomas, soft tissue sarcomas, thyroid, parathyroid, lacrimal gland and bone / cartilage tumors are some of the entities where PET-CT may be useful. (Tumors of salivary glands and of odontogenic tissue are particularly difficult to diagnose due to the relative infrequency when compared with other tumors and the extremely vast histologic variation).It is important to note that carcinoma metastasis, is the most common malignancy found within the mandibular bone. PET-CT and skeletal scintigraphy are both very sensitive and specific in these types of patients.展开更多
文摘Objective To evaluate the feasibility of using a low concentration of contrast medium （Visipaque 270 mgl/mL）, low tube voltage, and an advanced image reconstruction algorithm in head and neck computed tomography angiography （CTA）. Methods Forty patients （22 men and 18 women; average age 48.7 ± 14.25 years; average body mass index 23.9 ± 3.7 kg/m^2） undergoing CTA for suspected vascular diseases were randomly assigned into two groups. Group A （n = 20） was administered 370 mgl/mL contrast medium, and group B （n = 20） was administered 270 mgl/mL contrast medium. Both groups were administered at a rate of 4.8 mL/s and an injection volume of 0.8 mL/kg. Images of group A were obtained with 120 kVp and filtered back projection （FBP） reconstruction, whereas images of group B were obtained with 80 kVp and 80% adaptive iterative statistical reconstruction algorithm （ASiR）. The CT values and standard deviations of intracranial arteries and image noise on the corona radiata were measured to calculate the contrast-to-noise ratio （CNR） and signal-to-noise ratio （SNR）. The beam-hardening artifacts （BHAs） around the skull base were calculated. Two readers evaluated the image quality with volume rendered images using scores from 1 to 5. The values between the two groups were statistically compared. Results The mean CT value of the intracranial arteries in group B was significantly higher than that in group A （P 〈 0.001）. The CNR and SNR values in group B were also statistically higher than those in group A （P 〈 0.001）. Image noise and BHAs were not significantly different between the two groups. The image quality score of VR images of in group B was significantly higher than that in group A （P = 0.001）. However, the quality scores of axial enhancement images in group B became significantly smaller than those in group A （P〈 0.001）. The CT dose index volume and dose-length product were decreased by 63.8% and 64%, respectively, in group B （P 〈 0.001 for both）. Conclusion Visipaque combined with 80 kVp and 80% ASiR provided similar image quality in intracranial CTA with 64% radiation dose reduction compared with the use of lopamidol, 120 kVp, and FBP reconstruc-tion.
文摘Objective：To clarify the prognostic value of post-treatment 18F-fluorodeoxyglucose （FDG） positron emission tomography （PET）/computed tomography （CT） in patients with advanced head and neck squamous cell carcinoma （HNSCC） after combined intra-arterial chemotherapy and radiotherapy （IACR）.Methods：Thirty-six patients with HNSCC who underwent IACR were recruited.The period from the end of IACR to the last post-treatment 18F-FDG PET/CT examination was 8-12 weeks.Both patient-based and lesion-based analyses were used to evaluate the PET/CT images.For lesion-based analysis,36 regions （12 lesions of recurrences and 24 scars at primary sites） were selected.The Kaplan-Meier method was used to assess the overall survival （OS） stratified by 18F-FDG uptake or visual interpretation results.Results：Twelve patients with recurrence were identified by six months after IACR.The sensitivity and specificity in the patient-based analysis were 67％ （8/12） and 88％ （21/24）,respectively.The mean OS was estimated to be 12.1 months （95％ CI,6.3-18.0 months） for the higher maximum standardized uptake value （SUVmax） group （n=7） and 44.6 months （95％ CI,39.9-49.3 months） for the lower SUVmax group （n=29）.OS in the higher SUVmax group （cut-off point,6.1） or positive visual interpretation group was significantly shorter than that in the lower SUVmax or negative visual interpretation group （P＜0.001 and P＜0.05,respectively）.Conclusions：The SUVmax and visual interpretation of HNSCC on post-IACR 18F-FDG PET/CT can provide prognostic survival estimates.
文摘Positron emission tomography/Computer tomography (PET/CT) is a multimodality imaging diagnostic technique that analyzes the uptake and retention of different radiopharmaceuticals by cells providing metabolic information on biochemical processes. PET/CT has been used for radiotherapy planning, providing useful information to the Radio-oncologist about the localization, size and metabolic activity of tumor lesions. In this paper, we show advantages of the 18F-FDG PET/CT respect to simple CT imaging for target volume delineation in patients with diagnosis of Squamous Head and Neck Carcinoma that has been scheduled to undergo a hypofractionated radiotherapy treatment. On ten studied patients, the target volume defined from PET/CT images was less extensive than those defined from simple CT images. In six patients the target volume was significantly less extensive and in two of them a new lymph node disease was reported, re-staging and corresponding target volume was also delineated with less extensive margins from PET/CT images. A greater accuracy in delineating the volumes and improving the distribution of doses in the planning of the radiant treatment in these patients was possible, allowing a high precision in the delivery of the prescribed dose to the target volume diminishing the maximum dose to the adjacent healthy tissues. In conclusion we show that the use of 18F-FDG PET/CT was superior than the simple CT as the primary modality of imaging for hypofractioned radiotherapy treatment planning in patients with Squamous Head and Neck Carcinoma.
文摘Cancer of the head and neck is often devastating and the morbidity associated with its treatment is substantial. Positron Emission Tomography-Computed Tomography (PET-CT) combines the power of biological / molecular imaging with the anatomic detail of CT in order to provide a very sensitive and specific imaging tool for the evaluation of head and neck pathology. PET can aid the clinician in establishing diagnosis, staging, (It has been shown to be more accurate than CT), assessing, prognosis and determining response to therapy. Lymphoma, melanoma, multiple myeloma, leukemia, salivary gland tumors, odontogenic carcinomas, soft tissue sarcomas, thyroid, parathyroid, lacrimal gland and bone / cartilage tumors are some of the entities where PET-CT may be useful. (Tumors of salivary glands and of odontogenic tissue are particularly difficult to diagnose due to the relative infrequency when compared with other tumors and the extremely vast histologic variation).It is important to note that carcinoma metastasis, is the most common malignancy found within the mandibular bone. PET-CT and skeletal scintigraphy are both very sensitive and specific in these types of patients.
