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Item does not contain fulltext, PURPOSE: The purpose of this study is to evaluate the efficacy of (18)F-FDG-PET as first-line diagnostic investigation, prior to performing a direct laryngoscopy with biopsy under general anesthesia, in patients suspected of recurrent laryngeal carcinoma after radiotherapy. PATIENTS AND METHODS: 150 patients suspected of recurrent T2-4 laryngeal carcinoma at least two months after prior (chemo)radiotherapy with curative intent for resectable disease were randomized to direct laryngoscopy (CWU: conventional workup strategy) or to (18)F-FDG-PET only followed by direct laryngoscopy if PET was assessed 'positive' or 'equivocal' (PWU: PET based workup strategy), to compare the effectiveness of these strategies. Primary endpoint was the number of indications for direct laryngoscopies classified as unnecessary based on absence of recurrence, both on direct laryngoscopy and on six month follow up. Safety endpoints comprised resectability of recurrent lesions and completeness of surgical margins following salvage laryngectomy. RESULTS: Intention-to-treat analyses were performed on all randomized patients (CWU: n=74, PWU: n=76). Tumor recurrence was similar in both groups: 45 patients (30%; 21 CWU, 24 PWU) within six months. In 53 patients in the CWU arm (72%, 95% CI: 60-81) unnecessary direct laryngoscopies were performed compared to 22 in the PWU arm (29%, 95% CI: 19-40) (p<0.0001). The percentage of salvage laryngectomies (resectability) and positive surgical margins were similar between CWU and PWU (81%, 63% respectively, p=0.17, and 29%, 7%, respectively, p=0.20). The prevalence of the combination of local unresectability and positive margins is in the CWU group 24% and in the PWU group 8%. No difference (p=0.32) in disease specific survival between both groups was found. CONCLUSION: In patients with suspected laryngeal carcinoma after radiotherapy, PET as the first diagnostic procedure can reduce the need for direct laryngoscopy by more than 50% without jeopardizing qua

Background: The separate value of endoscopic ultrasonography (EUS), multidetector computed tomography (CT), and 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in the optimal sequence in staging esophageal cancer has not been investigated adequately. Methods: The staging records of 216 consecutive operable patients with esophageal cancer were reviewed blindly. Different staging st

Item does not contain fulltext, PURPOSE: The purpose of this study is to evaluate the efficacy of (18)F-FDG-PET as first-line diagnostic investigation, prior to performing a direct laryngoscopy with biopsy under general anesthesia, in patients suspected of recurrent laryngeal carcinoma after radiotherapy. PATIENTS AND METHODS: 150 patients suspected of recurrent T2-4 laryngeal carcinoma at least two months after prior (chemo)radiotherapy with curative intent for resectable disease were randomized to direct laryngoscopy (CWU: conventional workup strategy) or to (18)F-FDG-PET only followed by direct laryngoscopy if PET was assessed 'positive' or 'equivocal' (PWU: PET based workup strategy), to compare the effectiveness of these strategies. Primary endpoint was the number of indications for direct laryngoscopies classified as unnecessary based on absence of recurrence, both on direct laryngoscopy and on six month follow up. Safety endpoints comprised resectability of recurrent lesions and completeness of surgical margins following salvage laryngectomy. RESULTS: Intention-to-treat analyses were performed on all randomized patients (CWU: n=74, PWU: n=76). Tumor recurrence was similar in both groups: 45 patients (30%; 21 CWU, 24 PWU) within six months. In 53 patients in the CWU arm (72%, 95% CI: 60-81) unnecessary direct laryngoscopies were performed compared to 22 in the PWU arm (29%, 95% CI: 19-40) (p<0.0001). The percentage of salvage laryngectomies (resectability) and positive surgical margins were similar between CWU and PWU (81%, 63% respectively, p=0.17, and 29%, 7%, respectively, p=0.20). The prevalence of the combination of local unresectability and positive margins is in the CWU group 24% and in the PWU group 8%. No difference (p=0.32) in disease specific survival between both groups was found. CONCLUSION: In patients with suspected laryngeal carcinoma after radiotherapy, PET as the first diagnostic procedure can reduce the need for direct laryngoscopy by more than 50% without jeopardizing qua

Item does not contain fulltext, The purpose of these guidelines is to assist physicians in recommending, performing, interpreting and reporting the results of FDG PET/CT for oncological imaging of adult patients. PET is a quantitative imaging technique and therefore requires a common quality control (QC)/quality assurance (QA) procedure to maintain the accuracy and precision of quantitation. Repeatability and reproducibility are two essential requirements for any quantitative measurement and/or imaging biomarker. Repeatability relates to the uncertainty in obtaining the same result in the same patient when he or she is examined more than once on the same system. However, imaging biomarkers should also have adequate reproducibility, i.e. the ability to yield the same result in the same patient when that patient would have been examined on different systems and at different imaging sites. Adequate repeatability and reproducibility are essential for the clinical management of patients and the use of FDG PET/CT within multicentre trials. A common standardized imaging procedure will help promote the appropriate use of FDG PET/CT imaging and increase the value of publications and, therefore, their contribution to evidence-based medicine. Moreover, consistency in numerical values between platforms and institutes that acquire the data will potentially enhance the role of semiquantitative and quantitative image interpretation. Precision and accuracy are additionally important as FDG PET/CT is used to evaluate tumour response as well as for diagnosis, prognosis and staging. Therefore both the previous and these new guidelines specifically aim to achieve standardized uptake value harmonization in multicentre settings.

Item does not contain fulltext, The purpose of these guidelines is to assist physicians in recommending, performing, interpreting and reporting the results of FDG PET/CT for oncological imaging of adult patients. PET is a quantitative imaging technique and therefore requires a common quality control (QC)/quality assurance (QA) procedure to maintain the accuracy and precision of quantitation. Repeatability and reproducibility are two essential requirements for any quantitative measurement and/or imaging biomarker. Repeatability relates to the uncertainty in obtaining the same result in the same patient when he or she is examined more than once on the same system. However, imaging biomarkers should also have adequate reproducibility, i.e. the ability to yield the same result in the same patient when that patient would have been examined on different systems and at different imaging sites. Adequate repeatability and reproducibility are essential for the clinical management of patients and the use of FDG PET/CT within multicentre trials. A common standardized imaging procedure will help promote the appropriate use of FDG PET/CT imaging and increase the value of publications and, therefore, their contribution to evidence-based medicine. Moreover, consistency in numerical values between platforms and institutes that acquire the data will potentially enhance the role of semiquantitative and quantitative image interpretation. Precision and accuracy are additionally important as FDG PET/CT is used to evaluate tumour response as well as for diagnosis, prognosis and staging. Therefore both the previous and these new guidelines specifically aim to achieve standardized uptake value harmonization in multicentre settings.

Background: The separate value of endoscopic ultrasonography (EUS), multidetector computed tomography (CT), and18F-fluorodeoxyglucose positron emission tomography (FDG-PET) in the optimal sequence in staging esophageal cancer has not been investigated adequately. Methods: The staging records of 216 consecutive operable patients with esophageal cancer were reviewed blindly. Different staging strategies were analyzed, and the likelihood ratio (LR) of each module was calculated conditionally on individual patient characteristics. A logistic regression approach was used to determine the most favorable staging strategy. Results: Initial EUS results were not significantly related to the LRs of initial CT and FDG-PET results. The positive LR (LR+) of EUS-fine-needle aspiration (FNA) was 4, irrespective of CT and FDG-PET outcomes. The LR+ of FDG-PET varied from 13 (negative CT) to 6 (positive CT). The LR+ of CT ranged from 3-4 (negative FDG-PET) to 2-3 (positive FDG-PET). Age, histology, and tumor length had no significant impact on the LRs of the three diagnostic tests. Conclusions: This study argues in favor of PET/CT rather than EUS as a predictor of curative resectability in esophageal cancer. EUS does not correspond with either CT or FDG-PET. LRs of FDG-PET were substantially different between subgroups of negative and positive CT results and vice versa.

1 november 2010, Contains fulltext : 87934.pdf (publisher's version ) (Closed access), OBJECTIVE: [F-18]-Fluorodeoxyglucose-positron emission tomography (FDG-PET) is used increasingly in the work-up to surgery for patients with potentially resectable colorectal liver metastases. This study evaluates the clinical effectiveness, impact on health care resources and cost-effectiveness of adding FDG-PET to the diagnostic algorithm alongside a randomized clinical trial from a health care perspective. METHODS: In a randomized clinical trial, the net monetary benefit (NMB) of FDG-PET added to conventional diagnostic work-up (CWU) was determined in patients with colorectal liver metastases. Seventy-five patients were included in each arm. Change in clinical management, futile laparotomies, preoperative findings and all relevant health care consumption were prospectively documented during 3 years. To assess health-related quality of life European Quality of Life-5 Dimensions was administered at the time of randomization, 3 and 6 weeks postoperatively, and every 3 months postoperatively for 3 years. Quality-adjusted life years (QALYs) were calculated based on European Quality of Life-5 Dimensions outcomes. RESULTS: In adding FDG-PET, diagnostic performance increased and futile laparotomies were reduced by 38%. Both health-related quality of life and QALYs showed no significant difference between the CWU and PET groups. For CWU and PET groups costs were euro 92,836 and euro 81,776, respectively, accumulated in 3 years after randomization. NMB ranged from euro 1004 to euro 11,060 depending on the monetary value given to a QALY. When costs for chemotherapy were disregarded, costs amounted to euro 15,874 for CWU and euro 18,664 for PET group. CONCLUSION: Additional costs of FDG-PET in the diagnostic work-up of patients with potentially resectable colorectal liver metastases were compensated by a reduction in futile laparotomies. The NMB analysis showed savings over a relevant range of willingness to pay for a QALY.

1 januari 2010, Contains fulltext : 88624.pdf (publisher's version ) (Closed access), The aim of this guideline is to provide a minimum standard for the acquisition and interpretation of PET and PET/CT scans with [18F]-fluorodeoxyglucose (FDG). This guideline will therefore address general information about[18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) and is provided to help the physician and physicist to assist to carrying out,interpret, and document quantitative FDG PET/CT examinations,but will concentrate on the optimisation of diagnostic quality and quantitative information.

01 november 2010, Contains fulltext : 87934.pdf (publisher's version ) (Closed access), OBJECTIVE: [F-18]-Fluorodeoxyglucose-positron emission tomography (FDG-PET) is used increasingly in the work-up to surgery for patients with potentially resectable colorectal liver metastases. This study evaluates the clinical effectiveness, impact on health care resources and cost-effectiveness of adding FDG-PET to the diagnostic algorithm alongside a randomized clinical trial from a health care perspective. METHODS: In a randomized clinical trial, the net monetary benefit (NMB) of FDG-PET added to conventional diagnostic work-up (CWU) was determined in patients with colorectal liver metastases. Seventy-five patients were included in each arm. Change in clinical management, futile laparotomies, preoperative findings and all relevant health care consumption were prospectively documented during 3 years. To assess health-related quality of life European Quality of Life-5 Dimensions was administered at the time of randomization, 3 and 6 weeks postoperatively, and every 3 months postoperatively for 3 years. Quality-adjusted life years (QALYs) were calculated based on European Quality of Life-5 Dimensions outcomes. RESULTS: In adding FDG-PET, diagnostic performance increased and futile laparotomies were reduced by 38%. Both health-related quality of life and QALYs showed no significant difference between the CWU and PET groups. For CWU and PET groups costs were euro 92,836 and euro 81,776, respectively, accumulated in 3 years after randomization. NMB ranged from euro 1004 to euro 11,060 depending on the monetary value given to a QALY. When costs for chemotherapy were disregarded, costs amounted to euro 15,874 for CWU and euro 18,664 for PET group. CONCLUSION: Additional costs of FDG-PET in the diagnostic work-up of patients with potentially resectable colorectal liver metastases were compensated by a reduction in futile laparotomies. The NMB analysis showed savings over a relevant range of willingness to pay for a QALY.

01 januari 2010, Contains fulltext : 88624.pdf (publisher's version ) (Closed access), The aim of this guideline is to provide a minimum standard for the acquisition and interpretation of PET and PET/CT scans with [18F]-fluorodeoxyglucose (FDG). This guideline will therefore address general information about[18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) and is provided to help the physician and physicist to assist to carrying out,interpret, and document quantitative FDG PET/CT examinations,but will concentrate on the optimisation of diagnostic quality and quantitative information.

01 januari 2010, Contains fulltext : 88624.pdf (publisher's version ) (Closed access), The aim of this guideline is to provide a minimum standard for the acquisition and interpretation of PET and PET/CT scans with [18F]-fluorodeoxyglucose (FDG). This guideline will therefore address general information about[18F]-fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET/CT) and is provided to help the physician and physicist to assist to carrying out,interpret, and document quantitative FDG PET/CT examinations,but will concentrate on the optimisation of diagnostic quality and quantitative information.

01 november 2010, Contains fulltext : 87934.pdf (publisher's version ) (Closed access), OBJECTIVE: [F-18]-Fluorodeoxyglucose-positron emission tomography (FDG-PET) is used increasingly in the work-up to surgery for patients with potentially resectable colorectal liver metastases. This study evaluates the clinical effectiveness, impact on health care resources and cost-effectiveness of adding FDG-PET to the diagnostic algorithm alongside a randomized clinical trial from a health care perspective. METHODS: In a randomized clinical trial, the net monetary benefit (NMB) of FDG-PET added to conventional diagnostic work-up (CWU) was determined in patients with colorectal liver metastases. Seventy-five patients were included in each arm. Change in clinical management, futile laparotomies, preoperative findings and all relevant health care consumption were prospectively documented during 3 years. To assess health-related quality of life European Quality of Life-5 Dimensions was administered at the time of randomization, 3 and 6 weeks postoperatively, and every 3 months postoperatively for 3 years. Quality-adjusted life years (QALYs) were calculated based on European Quality of Life-5 Dimensions outcomes. RESULTS: In adding FDG-PET, diagnostic performance increased and futile laparotomies were reduced by 38%. Both health-related quality of life and QALYs showed no significant difference between the CWU and PET groups. For CWU and PET groups costs were euro 92,836 and euro 81,776, respectively, accumulated in 3 years after randomization. NMB ranged from euro 1004 to euro 11,060 depending on the monetary value given to a QALY. When costs for chemotherapy were disregarded, costs amounted to euro 15,874 for CWU and euro 18,664 for PET group. CONCLUSION: Additional costs of FDG-PET in the diagnostic work-up of patients with potentially resectable colorectal liver metastases were compensated by a reduction in futile laparotomies. The NMB analysis showed savings over a relevant range of willingness to pay for a QALY.

Contains fulltext : 80310.pdf (publisher's version ) (Closed access), With the increasing possibilities for surgical treatment of colorectal liver metastases, careful selection of patients who may benefit from surgical treatment becomes critical. The addition of PET to (18)F-FDG may significantly improve conventional staging by CT. Up to now, definitive evidence that the addition of (18)F-FDG PET to conventional staging leads to superior clinical results and improved clinical management in these patients has been lacking. In this randomized controlled trial in patients with colorectal liver metastases, we investigated whether the addition of (18)F-FDG PET is beneficial and reduces the number of futile laparotomies. METHODS: A total of 150 patients with colorectal liver metastases selected for surgical treatment by imaging with CT were randomly assigned to CT only (n = 75) or CT plus (18)F-FDG PET (n = 75). Patients were followed up for at least 3 y. The primary outcome measure was futile laparotomy, defined as any laparotomy that did not result in complete tumor treatment, that revealed benign disease, or that did not result in a disease-free survival period longer than 6 mo. RESULTS: Patient and tumor characteristics were similar for both groups. The number of futile laparotomies was 34 (45%) in the control arm without (18)F-FDG PET and 21 (28%) in the experimental arm with (18)F-FDG PET; the relative risk reduction was 38% (95% confidence interval, 4%-60%, P = 0.042). CONCLUSION: The number of futile laparotomies was reduced from 45% to 28%; thus, the addition of (18)F-FDG PET to the work-up for surgical resection of colorectal liver metastases prevents unnecessary surgery in 1 of 6 patients.

Contains fulltext : 80310.pdf (publisher's version ) (Closed access), With the increasing possibilities for surgical treatment of colorectal liver metastases, careful selection of patients who may benefit from surgical treatment becomes critical. The addition of PET to (18)F-FDG may significantly improve conventional staging by CT. Up to now, definitive evidence that the addition of (18)F-FDG PET to conventional staging leads to superior clinical results and improved clinical management in these patients has been lacking. In this randomized controlled trial in patients with colorectal liver metastases, we investigated whether the addition of (18)F-FDG PET is beneficial and reduces the number of futile laparotomies. METHODS: A total of 150 patients with colorectal liver metastases selected for surgical treatment by imaging with CT were randomly assigned to CT only (n = 75) or CT plus (18)F-FDG PET (n = 75). Patients were followed up for at least 3 y. The primary outcome measure was futile laparotomy, defined as any laparotomy that did not result in complete tumor treatment, that revealed benign disease, or that did not result in a disease-free survival period longer than 6 mo. RESULTS: Patient and tumor characteristics were similar for both groups. The number of futile laparotomies was 34 (45%) in the control arm without (18)F-FDG PET and 21 (28%) in the experimental arm with (18)F-FDG PET; the relative risk reduction was 38% (95% confidence interval, 4%-60%, P = 0.042). CONCLUSION: The number of futile laparotomies was reduced from 45% to 28%; thus, the addition of (18)F-FDG PET to the work-up for surgical resection of colorectal liver metastases prevents unnecessary surgery in 1 of 6 patients.

Contains fulltext : 80310.pdf (publisher's version ) (Closed access), With the increasing possibilities for surgical treatment of colorectal liver metastases, careful selection of patients who may benefit from surgical treatment becomes critical. The addition of PET to (18)F-FDG may significantly improve conventional staging by CT. Up to now, definitive evidence that the addition of (18)F-FDG PET to conventional staging leads to superior clinical results and improved clinical management in these patients has been lacking. In this randomized controlled trial in patients with colorectal liver metastases, we investigated whether the addition of (18)F-FDG PET is beneficial and reduces the number of futile laparotomies. METHODS: A total of 150 patients with colorectal liver metastases selected for surgical treatment by imaging with CT were randomly assigned to CT only (n = 75) or CT plus (18)F-FDG PET (n = 75). Patients were followed up for at least 3 y. The primary outcome measure was futile laparotomy, defined as any laparotomy that did not result in complete tumor treatment, that revealed benign disease, or that did not result in a disease-free survival period longer than 6 mo. RESULTS: Patient and tumor characteristics were similar for both groups. The number of futile laparotomies was 34 (45%) in the control arm without (18)F-FDG PET and 21 (28%) in the experimental arm with (18)F-FDG PET; the relative risk reduction was 38% (95% confidence interval, 4%-60%, P = 0.042). CONCLUSION: The number of futile laparotomies was reduced from 45% to 28%; thus, the addition of (18)F-FDG PET to the work-up for surgical resection of colorectal liver metastases prevents unnecessary surgery in 1 of 6 patients.

Contains fulltext : 70810.pdf (publisher's version ) (Closed access), INTRODUCTION: Several studies have shown the usefulness of positron emission tomography (PET) quantification using standardised uptake values (SUV) for diagnosis and staging, prognosis and response monitoring. Many factors affect SUV, such as patient preparation procedures, scan acquisition, image reconstruction and data analysis settings, and the variability in methodology across centres prohibits exchange of SUV data. Therefore, standardisation of 2-[(18)F] fluoro-2-deoxy-D-glucose (FDG) PET whole body procedures is required in multi-centre trials. METHODS: A protocol for standardisation of quantitative FDG whole body PET studies in the Netherlands (NL) was defined. This protocol is based on standardisation of: (1) patient preparation; (2) matching of scan statistics by prescribing dosage as function of patient weight, scan time per bed position, percentage of bed overlap and image acquisition mode (2D or 3D); (3) matching of image resolution by prescribing reconstruction settings for each type of scanner; (4) matching of data analysis procedure by defining volume of interest methods and SUV calculations and; (5) finally, a multi-centre QC procedure is defined using a 20-cm diameter phantom for verification of scanner calibration and the NEMA NU 2 2001 Image Quality phantom for verification of activity concentration recoveries (i.e., verification of image resolution and reconstruction convergence). DISCUSSION: This paper describes a protocol for standardization of quantitative FDG whole body multi-centre PET studies. CONCLUSION: The protocol was successfully implemented in the Netherlands and has been approved by the Netherlands Society of Nuclear Medicine.

Contains fulltext : 71067.pdf (publisher's version ) (Closed access), BACKGROUND AND PURPOSE: The aim of the study was to define the added value of whole body FDG-PET in screening for distant metastases in patients with head and neck squamous cell carcinoma and risk factors. MATERIALS AND METHODS: In a multi-center prospective study between 1998 and 2003, 145 consecutive HNSCC patients with risk factors for distant metastases underwent chest CT and whole body FDG-PET for screening of distant metastases. The data of 92 evaluable patients who developed distant metastases or who had a follow-up of at least 12 months were analyzed. Besides their performance in clinical practice, the operational characteristics of PET and CT using ROC analyses were investigated. RESULTS: Pretreatment screening identified distant metastases in 19 patients (21%). FDG-PET had a higher sensitivity (53% vs. 37%) and positive predictive value (80% vs. 75%) than CT. The combination of CT and FDG-PET had the highest sensitivity (63%). The ROC analyses of the five point ordinal scales revealed that the "area under the curve" (AUC) of FDG-PET was significantly higher as compared to CT. CONCLUSION: In HNSCC patients with risk factors, pretreatment screening for distant metastases by chest CT is improved by FDG-PET.

Contains fulltext : 70883.pdf (publisher's version ) (Open Access), BACKGROUND: Surgical resection is the preferred treatment of potentially curable esophageal cancer. To improve long term patient outcome, many institutes apply neoadjuvant chemoradiotherapy. In a large proportion of patients no response to chemoradiotherapy is achieved. These patients suffer from toxic and ineffective neoadjuvant treatment, while appropriate surgical therapy is delayed. For this reason a diagnostic test that allows for accurate prediction of tumor response early during chemoradiotherapy is of crucial importance. CT-scan and endoscopic ultrasound have limited accuracy in predicting histopathologic tumor response. Data suggest that metabolic changes in tumor tissue as measured by FDG-PET predict response better. This study aims to compare FDG-PET and CT-scan for the early prediction of non-response to preoperative chemoradiotherapy in patients with potentially curable esophageal cancer. METHODS/DESIGN: Prognostic accuracy study, embedded in a randomized multicenter Dutch trial comparing neoadjuvant chemoradiotherapy for 5 weeks followed by surgery versus surgery alone for esophageal cancer. This prognostic accuracy study is performed only in the neoadjuvant arm of the randomized trial. In 6 centers, 150 consecutive patients will be included over a 3 year period. FDG-PET and CT-scan will be performed before and 2 weeks after the start of the chemoradiotherapy. All patients complete the 5 weeks regimen of neoadjuvant chemoradiotherapy, regardless the test results. Pathological examination of the surgical resection specimen will be used as reference standard. Responders are defined as patients with < 10% viable residual tumor cells (Mandard-score).Difference in accuracy (area under ROC curve) and negative predictive value between FDG-PET and CT-scan are primary endpoints. Furthermore, an economic evaluation will be performed, comparing survival and costs associated with the use of FDG-PET (or CT-scan) to predict tumor response with survival and

Contains fulltext : 70883.pdf (publisher's version ) (Open Access), BACKGROUND: Surgical resection is the preferred treatment of potentially curable esophageal cancer. To improve long term patient outcome, many institutes apply neoadjuvant chemoradiotherapy. In a large proportion of patients no response to chemoradiotherapy is achieved. These patients suffer from toxic and ineffective neoadjuvant treatment, while appropriate surgical therapy is delayed. For this reason a diagnostic test that allows for accurate prediction of tumor response early during chemoradiotherapy is of crucial importance. CT-scan and endoscopic ultrasound have limited accuracy in predicting histopathologic tumor response. Data suggest that metabolic changes in tumor tissue as measured by FDG-PET predict response better. This study aims to compare FDG-PET and CT-scan for the early prediction of non-response to preoperative chemoradiotherapy in patients with potentially curable esophageal cancer. METHODS/DESIGN: Prognostic accuracy study, embedded in a randomized multicenter Dutch trial comparing neoadjuvant chemoradiotherapy for 5 weeks followed by surgery versus surgery alone for esophageal cancer. This prognostic accuracy study is performed only in the neoadjuvant arm of the randomized trial. In 6 centers, 150 consecutive patients will be included over a 3 year period. FDG-PET and CT-scan will be performed before and 2 weeks after the start of the chemoradiotherapy. All patients complete the 5 weeks regimen of neoadjuvant chemoradiotherapy, regardless the test results. Pathological examination of the surgical resection specimen will be used as reference standard. Responders are defined as patients with < 10% viable residual tumor cells (Mandard-score).Difference in accuracy (area under ROC curve) and negative predictive value between FDG-PET and CT-scan are primary endpoints. Furthermore, an economic evaluation will be performed, comparing survival and costs associated with the use of FDG-PET (or CT-scan) to predict tumor response with survival and

Contains fulltext : 70810.pdf (publisher's version ) (Closed access), INTRODUCTION: Several studies have shown the usefulness of positron emission tomography (PET) quantification using standardised uptake values (SUV) for diagnosis and staging, prognosis and response monitoring. Many factors affect SUV, such as patient preparation procedures, scan acquisition, image reconstruction and data analysis settings, and the variability in methodology across centres prohibits exchange of SUV data. Therefore, standardisation of 2-[(18)F] fluoro-2-deoxy-D-glucose (FDG) PET whole body procedures is required in multi-centre trials. METHODS: A protocol for standardisation of quantitative FDG whole body PET studies in the Netherlands (NL) was defined. This protocol is based on standardisation of: (1) patient preparation; (2) matching of scan statistics by prescribing dosage as function of patient weight, scan time per bed position, percentage of bed overlap and image acquisition mode (2D or 3D); (3) matching of image resolution by prescribing reconstruction settings for each type of scanner; (4) matching of data analysis procedure by defining volume of interest methods and SUV calculations and; (5) finally, a multi-centre QC procedure is defined using a 20-cm diameter phantom for verification of scanner calibration and the NEMA NU 2 2001 Image Quality phantom for verification of activity concentration recoveries (i.e., verification of image resolution and reconstruction convergence). DISCUSSION: This paper describes a protocol for standardization of quantitative FDG whole body multi-centre PET studies. CONCLUSION: The protocol was successfully implemented in the Netherlands and has been approved by the Netherlands Society of Nuclear Medicine.

Contains fulltext : 71067.pdf (publisher's version ) (Closed access), BACKGROUND AND PURPOSE: The aim of the study was to define the added value of whole body FDG-PET in screening for distant metastases in patients with head and neck squamous cell carcinoma and risk factors. MATERIALS AND METHODS: In a multi-center prospective study between 1998 and 2003, 145 consecutive HNSCC patients with risk factors for distant metastases underwent chest CT and whole body FDG-PET for screening of distant metastases. The data of 92 evaluable patients who developed distant metastases or who had a follow-up of at least 12 months were analyzed. Besides their performance in clinical practice, the operational characteristics of PET and CT using ROC analyses were investigated. RESULTS: Pretreatment screening identified distant metastases in 19 patients (21%). FDG-PET had a higher sensitivity (53% vs. 37%) and positive predictive value (80% vs. 75%) than CT. The combination of CT and FDG-PET had the highest sensitivity (63%). The ROC analyses of the five point ordinal scales revealed that the "area under the curve" (AUC) of FDG-PET was significantly higher as compared to CT. CONCLUSION: In HNSCC patients with risk factors, pretreatment screening for distant metastases by chest CT is improved by FDG-PET.

Contains fulltext : 70883.pdf (publisher's version ) (Open Access), BACKGROUND: Surgical resection is the preferred treatment of potentially curable esophageal cancer. To improve long term patient outcome, many institutes apply neoadjuvant chemoradiotherapy. In a large proportion of patients no response to chemoradiotherapy is achieved. These patients suffer from toxic and ineffective neoadjuvant treatment, while appropriate surgical therapy is delayed. For this reason a diagnostic test that allows for accurate prediction of tumor response early during chemoradiotherapy is of crucial importance. CT-scan and endoscopic ultrasound have limited accuracy in predicting histopathologic tumor response. Data suggest that metabolic changes in tumor tissue as measured by FDG-PET predict response better. This study aims to compare FDG-PET and CT-scan for the early prediction of non-response to preoperative chemoradiotherapy in patients with potentially curable esophageal cancer. METHODS/DESIGN: Prognostic accuracy study, embedded in a randomized multicenter Dutch trial comparing neoadjuvant chemoradiotherapy for 5 weeks followed by surgery versus surgery alone for esophageal cancer. This prognostic accuracy study is performed only in the neoadjuvant arm of the randomized trial. In 6 centers, 150 consecutive patients will be included over a 3 year period. FDG-PET and CT-scan will be performed before and 2 weeks after the start of the chemoradiotherapy. All patients complete the 5 weeks regimen of neoadjuvant chemoradiotherapy, regardless the test results. Pathological examination of the surgical resection specimen will be used as reference standard. Responders are defined as patients with < 10% viable residual tumor cells (Mandard-score).Difference in accuracy (area under ROC curve) and negative predictive value between FDG-PET and CT-scan are primary endpoints. Furthermore, an economic evaluation will be performed, comparing survival and costs associated with the use of FDG-PET (or CT-scan) to predict tumor response with survival and

Contains fulltext : 70810.pdf (publisher's version ) (Closed access), INTRODUCTION: Several studies have shown the usefulness of positron emission tomography (PET) quantification using standardised uptake values (SUV) for diagnosis and staging, prognosis and response monitoring. Many factors affect SUV, such as patient preparation procedures, scan acquisition, image reconstruction and data analysis settings, and the variability in methodology across centres prohibits exchange of SUV data. Therefore, standardisation of 2-[(18)F] fluoro-2-deoxy-D-glucose (FDG) PET whole body procedures is required in multi-centre trials. METHODS: A protocol for standardisation of quantitative FDG whole body PET studies in the Netherlands (NL) was defined. This protocol is based on standardisation of: (1) patient preparation; (2) matching of scan statistics by prescribing dosage as function of patient weight, scan time per bed position, percentage of bed overlap and image acquisition mode (2D or 3D); (3) matching of image resolution by prescribing reconstruction settings for each type of scanner; (4) matching of data analysis procedure by defining volume of interest methods and SUV calculations and; (5) finally, a multi-centre QC procedure is defined using a 20-cm diameter phantom for verification of scanner calibration and the NEMA NU 2 2001 Image Quality phantom for verification of activity concentration recoveries (i.e., verification of image resolution and reconstruction convergence). DISCUSSION: This paper describes a protocol for standardization of quantitative FDG whole body multi-centre PET studies. CONCLUSION: The protocol was successfully implemented in the Netherlands and has been approved by the Netherlands Society of Nuclear Medicine.

Contains fulltext : 71067.pdf (publisher's version ) (Closed access), BACKGROUND AND PURPOSE: The aim of the study was to define the added value of whole body FDG-PET in screening for distant metastases in patients with head and neck squamous cell carcinoma and risk factors. MATERIALS AND METHODS: In a multi-center prospective study between 1998 and 2003, 145 consecutive HNSCC patients with risk factors for distant metastases underwent chest CT and whole body FDG-PET for screening of distant metastases. The data of 92 evaluable patients who developed distant metastases or who had a follow-up of at least 12 months were analyzed. Besides their performance in clinical practice, the operational characteristics of PET and CT using ROC analyses were investigated. RESULTS: Pretreatment screening identified distant metastases in 19 patients (21%). FDG-PET had a higher sensitivity (53% vs. 37%) and positive predictive value (80% vs. 75%) than CT. The combination of CT and FDG-PET had the highest sensitivity (63%). The ROC analyses of the five point ordinal scales revealed that the "area under the curve" (AUC) of FDG-PET was significantly higher as compared to CT. CONCLUSION: In HNSCC patients with risk factors, pretreatment screening for distant metastases by chest CT is improved by FDG-PET.

Contains fulltext : 70883.pdf (publisher's version ) (Open Access), BACKGROUND: Surgical resection is the preferred treatment of potentially curable esophageal cancer. To improve long term patient outcome, many institutes apply neoadjuvant chemoradiotherapy. In a large proportion of patients no response to chemoradiotherapy is achieved. These patients suffer from toxic and ineffective neoadjuvant treatment, while appropriate surgical therapy is delayed. For this reason a diagnostic test that allows for accurate prediction of tumor response early during chemoradiotherapy is of crucial importance. CT-scan and endoscopic ultrasound have limited accuracy in predicting histopathologic tumor response. Data suggest that metabolic changes in tumor tissue as measured by FDG-PET predict response better. This study aims to compare FDG-PET and CT-scan for the early prediction of non-response to preoperative chemoradiotherapy in patients with potentially curable esophageal cancer. METHODS/DESIGN: Prognostic accuracy study, embedded in a randomized multicenter Dutch trial comparing neoadjuvant chemoradiotherapy for 5 weeks followed by surgery versus surgery alone for esophageal cancer. This prognostic accuracy study is performed only in the neoadjuvant arm of the randomized trial. In 6 centers, 150 consecutive patients will be included over a 3 year period. FDG-PET and CT-scan will be performed before and 2 weeks after the start of the chemoradiotherapy. All patients complete the 5 weeks regimen of neoadjuvant chemoradiotherapy, regardless the test results. Pathological examination of the surgical resection specimen will be used as reference standard. Responders are defined as patients with < 10% viable residual tumor cells (Mandard-score).Difference in accuracy (area under ROC curve) and negative predictive value between FDG-PET and CT-scan are primary endpoints. Furthermore, an economic evaluation will be performed, comparing survival and costs associated with the use of FDG-PET (or CT-scan) to predict tumor response with survival and

Contains fulltext : 52887.pdf (publisher's version ) (Closed access), PURPOSE: Standardised uptake values (SUVs) depend on acquisition, reconstruction and region of interest (ROI) parameters. SUV quantification in multi-centre trials therefore requires standardisation of acquisition and analysis protocols. However, standardisation is difficult owing to the use of different scanners, image reconstruction and data analysis software. In this study we evaluated whether SUVs, obtained at three different institutes, may be directly compared after calibration and correction for inter-institute differences. METHODS: First, an anthropomorphic thorax phantom containing variously sized spheres and activities, simulating tumours, was scanned and processed in each institute to evaluate differences in scanner calibration. Secondly, effects of image reconstruction and ROI method on recovery coefficients were studied. Next, SUVs were derived for tumours in 23 subjects. Of these 23 patients, four and ten were scanned in two institutes on an HR+ PET scanner and nine were scanned in one institute on an ECAT EXACT PET scanner. All phantom and clinical data were reconstructed using iterative reconstruction with various iterations, with both measured (MAC) and segmented attenuation correction (SAC) and at various image resolutions. Activity concentrations (AC) or SUVs were derived using various ROI isocontours. RESULTS: Phantom data revealed differences in SUV quantification of up to 30%. After application-specific calibration, recovery coefficients obtained in each institute were equal to within 15%. Varying the ROI isocontour value resulted in a predictable change in SUV (or AC) for both phantom and clinical data. Variation of image resolution resulted in a predictable change in SUV quantification for large spheres/tumours (>5 cc) only. For smaller tumours (<2 cc), differences of up to 40% were found between high (7 mm) and low (10 mm) resolution images. Similar differences occurred when data were reconstructed with a small number of iterations. Finally

Contains fulltext : 53274.pdf (publisher's version ) (Closed access), The aim of this prospective study was to evaluate the value of (18)F-FDG PET for the assessment of chemotherapy response in patients with non-small cell lung cancer. Furthermore, part of the objective of this study was to compare 2 methods to quantify changes in glucose metabolism. METHODS: In 51 patients, dynamic (18)F-FDG PET was performed before and at 5-8 wk into treatment. Simplified methods to measure glucose metabolism (standardized uptake value [SUV]) and quantitative measures (metabolic rate of glucose [MR(Glu)]), derived from Patlak analysis, were evaluated. The overall survival and progression-free survival with respect to MR(Glu) and SUV were calculated using Kaplan-Meier estimates. Fractional changes in tumor glucose use were stratified by the median value and also the predefined EORTC (European Organization for Research and Treatment of Cancer) metabolic response criteria, and criteria applying cutoff levels similar to those of RECIST (Response Evaluation Criteria in Solid Tumors) were evaluated. RESULTS: When stratifying at the median value of DeltaMR(Glu) and DeltaSUV, the difference in overall survival (P = 0.017 for DeltaMR(Glu), P = 0.018 for DeltaSUV) and progression-free survival (P = 0.002 for DeltaMR(Glu), P = 0.0009 for DeltaSUV) was highly significant. When applying the predefined criteria for metabolic response, the cutoff levels as also used for size measurement (RECIST) showed significant differences for DeltaSUV between response categories in progression-free survival (P = 0.0003) as well as overall survival (P = 0.027). CONCLUSION: The degree of chemotherapy-induced changes in tumor glucose metabolism as determined by (18)F-FDG PET is highly predictive for patient outcome, stratifying patients into groups with widely differing overall survival and progression-free survival probabilities. The use of (18)F-FDG PET for therapy monitoring seems clinically feasible, because simplified methods to measure tumor glucose use (SUV) are sufficient

Contains fulltext : 53268.pdf (publisher's version ) (Closed access), INTRODUCTION: Standard uptake value (SUV) is a quantitative measure for the preferential uptake of a radiopharmaceutical in a tumor compared with the homogeneous distribution in the body. SUV can be based on the maximal value of one pixel (SUVmax) or on the mean value in a region outlined by isodensity contours. The prognostic value of different SUVs in non-small cell lung cancer (NSCLC) is not established. We evaluated this value for SUVmax, SUV70%, and SUV50% among patients with resectable NSCLC. METHODS: All consecutive patients with resectable NSCLC who underwent an attenuation-corrected whole-body fluorine-18 fluorodeoxyglucose positron emission tomography scan from two university hospitals were selected. By adjusting the isocontour in the region of interest on the scan, SUVmax, SUV70%, and SUV50% of the primary tumor were calculated. RESULTS: Sixty-six patients (50 male, median age 63 years) were included. Of the tumors, 16 were pathological stage IA, 23 were IB, 4 were IIA, 14 were IIB, and 9 were IIIA. Median (range) values for SUVmax, SUV70%, and SUV50% were 6.4 (1.6-19.1), 5.1 (1.0-15.7), and 4.0 (0.9-13.4), respectively. SUVs were associated with survival. Analysis of residuals of SUVmax as a continuous variable in a Cox's proportional hazard model for survival suggested no cutoff point and no indication of time-dependency. Patients with a SUV higher than the median value had a worse survival than patients with a SUV lower than median (hazard ratios for SUVmax, SUV70%, and SUV50% all were 2.9; p = 0.02). CONCLUSIONS: SUVmax, SUV70%, and SUV50% measured with fluorine-18 fluorodeoxyglucose positron emission tomography have a similar prognostic value, and no "natural" cutoff point for SUVmax in resectable NSCLC was identified.

Contains fulltext : 52887.pdf (publisher's version ) (Closed access), PURPOSE: Standardised uptake values (SUVs) depend on acquisition, reconstruction and region of interest (ROI) parameters. SUV quantification in multi-centre trials therefore requires standardisation of acquisition and analysis protocols. However, standardisation is difficult owing to the use of different scanners, image reconstruction and data analysis software. In this study we evaluated whether SUVs, obtained at three different institutes, may be directly compared after calibration and correction for inter-institute differences. METHODS: First, an anthropomorphic thorax phantom containing variously sized spheres and activities, simulating tumours, was scanned and processed in each institute to evaluate differences in scanner calibration. Secondly, effects of image reconstruction and ROI method on recovery coefficients were studied. Next, SUVs were derived for tumours in 23 subjects. Of these 23 patients, four and ten were scanned in two institutes on an HR+ PET scanner and nine were scanned in one institute on an ECAT EXACT PET scanner. All phantom and clinical data were reconstructed using iterative reconstruction with various iterations, with both measured (MAC) and segmented attenuation correction (SAC) and at various image resolutions. Activity concentrations (AC) or SUVs were derived using various ROI isocontours. RESULTS: Phantom data revealed differences in SUV quantification of up to 30%. After application-specific calibration, recovery coefficients obtained in each institute were equal to within 15%. Varying the ROI isocontour value resulted in a predictable change in SUV (or AC) for both phantom and clinical data. Variation of image resolution resulted in a predictable change in SUV quantification for large spheres/tumours (>5 cc) only. For smaller tumours (<2 cc), differences of up to 40% were found between high (7 mm) and low (10 mm) resolution images. Similar differences occurred when data were reconstructed with a small number of iterations. Finally

Contains fulltext : 53274.pdf (publisher's version ) (Closed access), The aim of this prospective study was to evaluate the value of (18)F-FDG PET for the assessment of chemotherapy response in patients with non-small cell lung cancer. Furthermore, part of the objective of this study was to compare 2 methods to quantify changes in glucose metabolism. METHODS: In 51 patients, dynamic (18)F-FDG PET was performed before and at 5-8 wk into treatment. Simplified methods to measure glucose metabolism (standardized uptake value [SUV]) and quantitative measures (metabolic rate of glucose [MR(Glu)]), derived from Patlak analysis, were evaluated. The overall survival and progression-free survival with respect to MR(Glu) and SUV were calculated using Kaplan-Meier estimates. Fractional changes in tumor glucose use were stratified by the median value and also the predefined EORTC (European Organization for Research and Treatment of Cancer) metabolic response criteria, and criteria applying cutoff levels similar to those of RECIST (Response Evaluation Criteria in Solid Tumors) were evaluated. RESULTS: When stratifying at the median value of DeltaMR(Glu) and DeltaSUV, the difference in overall survival (P = 0.017 for DeltaMR(Glu), P = 0.018 for DeltaSUV) and progression-free survival (P = 0.002 for DeltaMR(Glu), P = 0.0009 for DeltaSUV) was highly significant. When applying the predefined criteria for metabolic response, the cutoff levels as also used for size measurement (RECIST) showed significant differences for DeltaSUV between response categories in progression-free survival (P = 0.0003) as well as overall survival (P = 0.027). CONCLUSION: The degree of chemotherapy-induced changes in tumor glucose metabolism as determined by (18)F-FDG PET is highly predictive for patient outcome, stratifying patients into groups with widely differing overall survival and progression-free survival probabilities. The use of (18)F-FDG PET for therapy monitoring seems clinically feasible, because simplified methods to measure tumor glucose use (SUV) are sufficient

Contains fulltext : 53268.pdf (publisher's version ) (Closed access), INTRODUCTION: Standard uptake value (SUV) is a quantitative measure for the preferential uptake of a radiopharmaceutical in a tumor compared with the homogeneous distribution in the body. SUV can be based on the maximal value of one pixel (SUVmax) or on the mean value in a region outlined by isodensity contours. The prognostic value of different SUVs in non-small cell lung cancer (NSCLC) is not established. We evaluated this value for SUVmax, SUV70%, and SUV50% among patients with resectable NSCLC. METHODS: All consecutive patients with resectable NSCLC who underwent an attenuation-corrected whole-body fluorine-18 fluorodeoxyglucose positron emission tomography scan from two university hospitals were selected. By adjusting the isocontour in the region of interest on the scan, SUVmax, SUV70%, and SUV50% of the primary tumor were calculated. RESULTS: Sixty-six patients (50 male, median age 63 years) were included. Of the tumors, 16 were pathological stage IA, 23 were IB, 4 were IIA, 14 were IIB, and 9 were IIIA. Median (range) values for SUVmax, SUV70%, and SUV50% were 6.4 (1.6-19.1), 5.1 (1.0-15.7), and 4.0 (0.9-13.4), respectively. SUVs were associated with survival. Analysis of residuals of SUVmax as a continuous variable in a Cox's proportional hazard model for survival suggested no cutoff point and no indication of time-dependency. Patients with a SUV higher than the median value had a worse survival than patients with a SUV lower than median (hazard ratios for SUVmax, SUV70%, and SUV50% all were 2.9; p = 0.02). CONCLUSIONS: SUVmax, SUV70%, and SUV50% measured with fluorine-18 fluorodeoxyglucose positron emission tomography have a similar prognostic value, and no "natural" cutoff point for SUVmax in resectable NSCLC was identified.

Contains fulltext : 53274.pdf (publisher's version ) (Closed access), The aim of this prospective study was to evaluate the value of (18)F-FDG PET for the assessment of chemotherapy response in patients with non-small cell lung cancer. Furthermore, part of the objective of this study was to compare 2 methods to quantify changes in glucose metabolism. METHODS: In 51 patients, dynamic (18)F-FDG PET was performed before and at 5-8 wk into treatment. Simplified methods to measure glucose metabolism (standardized uptake value [SUV]) and quantitative measures (metabolic rate of glucose [MR(Glu)]), derived from Patlak analysis, were evaluated. The overall survival and progression-free survival with respect to MR(Glu) and SUV were calculated using Kaplan-Meier estimates. Fractional changes in tumor glucose use were stratified by the median value and also the predefined EORTC (European Organization for Research and Treatment of Cancer) metabolic response criteria, and criteria applying cutoff levels similar to those of RECIST (Response Evaluation Criteria in Solid Tumors) were evaluated. RESULTS: When stratifying at the median value of DeltaMR(Glu) and DeltaSUV, the difference in overall survival (P = 0.017 for DeltaMR(Glu), P = 0.018 for DeltaSUV) and progression-free survival (P = 0.002 for DeltaMR(Glu), P = 0.0009 for DeltaSUV) was highly significant. When applying the predefined criteria for metabolic response, the cutoff levels as also used for size measurement (RECIST) showed significant differences for DeltaSUV between response categories in progression-free survival (P = 0.0003) as well as overall survival (P = 0.027). CONCLUSION: The degree of chemotherapy-induced changes in tumor glucose metabolism as determined by (18)F-FDG PET is highly predictive for patient outcome, stratifying patients into groups with widely differing overall survival and progression-free survival probabilities. The use of (18)F-FDG PET for therapy monitoring seems clinically feasible, because simplified methods to measure tumor glucose use (SUV) are sufficient

Contains fulltext : 53268.pdf (publisher's version ) (Closed access), INTRODUCTION: Standard uptake value (SUV) is a quantitative measure for the preferential uptake of a radiopharmaceutical in a tumor compared with the homogeneous distribution in the body. SUV can be based on the maximal value of one pixel (SUVmax) or on the mean value in a region outlined by isodensity contours. The prognostic value of different SUVs in non-small cell lung cancer (NSCLC) is not established. We evaluated this value for SUVmax, SUV70%, and SUV50% among patients with resectable NSCLC. METHODS: All consecutive patients with resectable NSCLC who underwent an attenuation-corrected whole-body fluorine-18 fluorodeoxyglucose positron emission tomography scan from two university hospitals were selected. By adjusting the isocontour in the region of interest on the scan, SUVmax, SUV70%, and SUV50% of the primary tumor were calculated. RESULTS: Sixty-six patients (50 male, median age 63 years) were included. Of the tumors, 16 were pathological stage IA, 23 were IB, 4 were IIA, 14 were IIB, and 9 were IIIA. Median (range) values for SUVmax, SUV70%, and SUV50% were 6.4 (1.6-19.1), 5.1 (1.0-15.7), and 4.0 (0.9-13.4), respectively. SUVs were associated with survival. Analysis of residuals of SUVmax as a continuous variable in a Cox's proportional hazard model for survival suggested no cutoff point and no indication of time-dependency. Patients with a SUV higher than the median value had a worse survival than patients with a SUV lower than median (hazard ratios for SUVmax, SUV70%, and SUV50% all were 2.9; p = 0.02). CONCLUSIONS: SUVmax, SUV70%, and SUV50% measured with fluorine-18 fluorodeoxyglucose positron emission tomography have a similar prognostic value, and no "natural" cutoff point for SUVmax in resectable NSCLC was identified.

Contains fulltext : 52887.pdf (publisher's version ) (Closed access), PURPOSE: Standardised uptake values (SUVs) depend on acquisition, reconstruction and region of interest (ROI) parameters. SUV quantification in multi-centre trials therefore requires standardisation of acquisition and analysis protocols. However, standardisation is difficult owing to the use of different scanners, image reconstruction and data analysis software. In this study we evaluated whether SUVs, obtained at three different institutes, may be directly compared after calibration and correction for inter-institute differences. METHODS: First, an anthropomorphic thorax phantom containing variously sized spheres and activities, simulating tumours, was scanned and processed in each institute to evaluate differences in scanner calibration. Secondly, effects of image reconstruction and ROI method on recovery coefficients were studied. Next, SUVs were derived for tumours in 23 subjects. Of these 23 patients, four and ten were scanned in two institutes on an HR+ PET scanner and nine were scanned in one institute on an ECAT EXACT PET scanner. All phantom and clinical data were reconstructed using iterative reconstruction with various iterations, with both measured (MAC) and segmented attenuation correction (SAC) and at various image resolutions. Activity concentrations (AC) or SUVs were derived using various ROI isocontours. RESULTS: Phantom data revealed differences in SUV quantification of up to 30%. After application-specific calibration, recovery coefficients obtained in each institute were equal to within 15%. Varying the ROI isocontour value resulted in a predictable change in SUV (or AC) for both phantom and clinical data. Variation of image resolution resulted in a predictable change in SUV quantification for large spheres/tumours (>5 cc) only. For smaller tumours (<2 cc), differences of up to 40% were found between high (7 mm) and low (10 mm) resolution images. Similar differences occurred when data were reconstructed with a small number of iterations. Finally

Voor Friesland Foods (het voormalige Friese Vlag) vormt water een essentieel onderdeel van het productieproces. Het bedrijf wil op haar productielocaties het (afval)waterverbruik terugdringen zonder daarbij concessies te doen aan de productveiligheid en -kwaliteit. Deze waterbesparing moet via brongerichte maatregelen worden gerealiseerd. Op de productielocatie in Marum wordt het afvalwater gezuiverd in een laag belaste actiefslibinstallatie die door eigen personeel wordt beheerd. De afgelopen jaren heeft men in Marum zich ingespannen om zonder ingrijpende aanpassingen van de zuiveringsinstallatie tegen verantwoorde kosten te voldoen aan de nieuwe lokale eisen voor fosfaat- en stikstofverwijdering. De uiteindelijke oplossing wijkt af van hetgeen gangbaar is

Contains fulltext : 50520.pdf (publisher's version ) (Closed access), The use of dynamic (18)F-FDG PET to determine changes in tumor metabolism requires tumor and plasma time-activity curves. Because arterial sampling is invasive and laborious, our aim was to validate noninvasive image-derived input functions (IDIFs). METHODS: We obtained 136 dynamic (18)F-FDG PET scans of 76 oncologic patients. IDIFs were determined using volumes of interest over the left ventricle, ascending aorta, and abdominal aorta. The tumor metabolic rate of glucose (MRGlu) was determined with the Patlak analysis, using arterial plasma time-activity curves and IDIFs. RESULTS: MRGlu using all 3 IDIFs showed a high correlation with MRGlu based on arterial sampling. Comparability between the measures was also high, with the intraclass correlation coefficient being 0.98 (95% confidence interval, 0.97-0.99) for the ascending aorta IDIF, 0.94 (0.92-0.96) for the left ventricle IDIF, and 0.96 (0.93-0.98) for the abdominal aorta IDIF. CONCLUSION: The use of IDIFs is accurate and simple and represents a clinically viable alternative to arterial blood sampling.

Contains fulltext : 50520.pdf (publisher's version ) (Closed access), The use of dynamic (18)F-FDG PET to determine changes in tumor metabolism requires tumor and plasma time-activity curves. Because arterial sampling is invasive and laborious, our aim was to validate noninvasive image-derived input functions (IDIFs). METHODS: We obtained 136 dynamic (18)F-FDG PET scans of 76 oncologic patients. IDIFs were determined using volumes of interest over the left ventricle, ascending aorta, and abdominal aorta. The tumor metabolic rate of glucose (MRGlu) was determined with the Patlak analysis, using arterial plasma time-activity curves and IDIFs. RESULTS: MRGlu using all 3 IDIFs showed a high correlation with MRGlu based on arterial sampling. Comparability between the measures was also high, with the intraclass correlation coefficient being 0.98 (95% confidence interval, 0.97-0.99) for the ascending aorta IDIF, 0.94 (0.92-0.96) for the left ventricle IDIF, and 0.96 (0.93-0.98) for the abdominal aorta IDIF. CONCLUSION: The use of IDIFs is accurate and simple and represents a clinically viable alternative to arterial blood sampling.

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Item does not contain fulltext, Parkinson's disease (PD) is a common neurodegenerative disorder that produces progressive disability despite symptomatic treatment. Several strategies, including stereotaxic brain lesions, deep brain stimulation, transplants of dopamine cells and administration of neurotrophic factors, have been proposed to improve efficacy and to counteract the progression of the disease. We here report the effects of repetitive intracerebral infusion of basic fibroblast growth factor (bFGF) and glial-derived neurotrophic factor, up to I year, in Cynomolgus monkeys with long standing asymmetric parkinsonism produced by unilateral intracarotid injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The treatment with neurotrophic factors was initiated when the parkinsonian deficits were stable, 6 months after the administration of MPTP. The evaluation of the response to the neurotrophic factors was performed by blind observers using: clinical scales that measured global motor deficit, motor ability in both hands, apomorphine-induced rotation, determination of the levels of monoamine metabolites in cerebrospinal fluid, and 6-F18-fluoro-L-DOPA (F-DOPA) uptake in the striatum and histology. Both factors, but bFGF more so, improve motor behavior, dopamine metabolism, striatal F-DOPA uptake, and the number of dopamine neurons. The procedure is well tolerated and provides a strong background for efficacy and safety of this treatment in patients with PD.

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Item does not contain fulltext, Parkinson's disease (PD) is a common neurodegenerative disorder that produces progressive disability despite symptomatic treatment. Several strategies, including stereotaxic brain lesions, deep brain stimulation, transplants of dopamine cells and administration of neurotrophic factors, have been proposed to improve efficacy and to counteract the progression of the disease. We here report the effects of repetitive intracerebral infusion of basic fibroblast growth factor (bFGF) and glial-derived neurotrophic factor, up to I year, in Cynomolgus monkeys with long standing asymmetric parkinsonism produced by unilateral intracarotid injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The treatment with neurotrophic factors was initiated when the parkinsonian deficits were stable, 6 months after the administration of MPTP. The evaluation of the response to the neurotrophic factors was performed by blind observers using: clinical scales that measured global motor deficit, motor ability in both hands, apomorphine-induced rotation, determination of the levels of monoamine metabolites in cerebrospinal fluid, and 6-F18-fluoro-L-DOPA (F-DOPA) uptake in the striatum and histology. Both factors, but bFGF more so, improve motor behavior, dopamine metabolism, striatal F-DOPA uptake, and the number of dopamine neurons. The procedure is well tolerated and provides a strong background for efficacy and safety of this treatment in patients with PD.

Item does not contain fulltext, Parkinson's disease (PD) is a common neurodegenerative disorder that produces progressive disability despite symptomatic treatment. Several strategies, including stereotaxic brain lesions, deep brain stimulation, transplants of dopamine cells and administration of neurotrophic factors, have been proposed to improve efficacy and to counteract the progression of the disease. We here report the effects of repetitive intracerebral infusion of basic fibroblast growth factor (bFGF) and glial-derived neurotrophic factor, up to I year, in Cynomolgus monkeys with long standing asymmetric parkinsonism produced by unilateral intracarotid injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The treatment with neurotrophic factors was initiated when the parkinsonian deficits were stable, 6 months after the administration of MPTP. The evaluation of the response to the neurotrophic factors was performed by blind observers using: clinical scales that measured global motor deficit, motor ability in both hands, apomorphine-induced rotation, determination of the levels of monoamine metabolites in cerebrospinal fluid, and 6-F18-fluoro-L-DOPA (F-DOPA) uptake in the striatum and histology. Both factors, but bFGF more so, improve motor behavior, dopamine metabolism, striatal F-DOPA uptake, and the number of dopamine neurons. The procedure is well tolerated and provides a strong background for efficacy and safety of this treatment in patients with PD.

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