Search

Purpose: Standardized added metabolic activity (SAM) is a PET parameter for assessing the total metabolic load of malignant processes, avoiding partial volume effects and lesion segmentation. The potential role of this parameter in the assessment of response to chemotherapy and bevacizumab was tested in patients with metastatic colorectal cancer with potentially resectable liver metastases (mCRC). Methods: F-FDG PET/CT was performed in 18 mCRC patients with liver metastases before treatment and after five cycles of FOLFOX/FOLFIRI and bevacizumab. Of the 18 patients, 16 subsequently underwent resection of liver metastases. Baseline and follow-up SUV, and SAM as well as reduction in SUV (∆SUV) and SAM (∆SAM) of all liver metastases were correlated with morphological response, and progression-free and overall survival (PFS and OS). Results: A significant reduction in metabolic activity of the liver metastases was seen after chemotherapy with a median ∆SUV of 25.3 % and ∆SAM of 94.5 % ( p = 0.033 and 0.003). Median baseline SUV and SAM values were significantly different between morphological responders and nonresponders (3.8 vs. 7.2, p = 0.021; and 34 vs. 211, p = 0.002, respectively), but neither baseline PET parameters nor morphological response was correlated with PFS or OS. Follow-up SUV and SAM as well as ∆SAM were found to be prognostic factors. The median PFS and OS in the patient group with a high follow-up SUV were 10.4 months and 32 months, compared to a median PFS of 14.7 months and a median OS which had not been reached in the group with a low follow-up SUV ( p = 0.01 and 0.003, respectively). The patient group with a high follow-up SAM and a low ∆SAM had a median PFS and OS of 9.4 months and 32 months, whereas the other group had a median PFS of 14.7 months and a median OS which had not been reached ( p = 0.002 for both PFS and OS). Conclusion: F-FDG PET imaging is a useful tool to assess treatment response and predict clinical outcome in patients with mCRC who undergo chemotherapy before liver metastasectomy. Follow-up SUV, follow-up SAM and ∆SAM were found to be significant prognostic factors for PFS and OS. [ABSTRACT FROM AUTHOR]

Purpose. The aim of the study was to determine the accuracy of non-rigid nine-parameter image registrations based on 153Gd transmission computed tomography (TCT) images as compared with those based on 99mTc-ethyl cysteinate dimer (ECI)) images and to assess whether normalised mutual information (NMI) or count difference (CD) should he used. Methods. TCT and ECD data were acquired in 25 randomly selected patients. Emission images were registered to an ECD template with a CD cost function. The same registration parameters were applied to the transmission images to create a TCT template. All TCT images were registered to the TCT template and the same registration parameters were applied to the ECD images. The procedure was repeated with NMI as cost function. Accuracy of both ECD-based and TCT-based registrations was assessed by comparing the normalisation parameter values and regional activities in the spatially normalised ECD images, using a mixed-model analysis of variance (ANOVA). Scheffé post hoc tests were performed. Results. No significant differences were found between ECD/CD, ECD/NMI and TCT/CD, suggesting that ECD registration can he done with either CD or NMI, and that TCT registration using CD is equally as accurate as ECD registration. The accuracy of TCT registration with NMI was lower, with discrepancies occurring in the frontal inferior region and the cerebellum. The analysis of normalisation parameters indicated that z-scaling is underestimated and yz-rotation overestimated with TCT/NMI registration. Conclusion. We conclude that ECD registrations with CD or NMI are as accurate as TCT registrations with CD and that TCT registrations with NMI should he avoided. [ABSTRACT FROM AUTHOR]

The least invasive of all surgical weightlowering procedures is the adjustable laparoscopic gastric banding (ALGB) technique. A rare complication (0.9%-1.8% of patients) but one that may require surgical revision is leakage of the gastric banding device. This paper reports on the usefulness of technetium-99m scintigraphy for the assessment of gastric band leaks as compared with radiography. Between March 1997 and October 2001, 23 obese patients (20 women and 3 men; mean age 35 years; range 23-60 years; mean body mass index before gastric banding procedure, 39.2 kg/m²; range 29.3-52.1 kg/m²) were referred for exclusion of gastric banding leakage by means of radiography and [sup 99m]Tc-pertechnetate scintigraphy. Both procedures were performed on the same day in all patients. Two patients underwent both procedures, respectively two and three times. A total of 27 radiographic and scintigraphic examinations were performed. Radiographs were judged positive for leakage when escape of contrast agent through a defect in the gastric banding device was visualised or when indirect criteria, e.g. smooth passage of barium suspension through the stoma after injection of contrast agent, were present. Scintigraphic images were judged positive when tracer disappearance out of the banding device and uptake in the thyroid gland as well as enhancement of the gastric mucosa were observed 30 min and/or 3 h post injection. Overall sensitivity, specificity and accuracy for radiography and [sup 99m]TC scintigraphy were 81.8% vs 81.8%, 75% vs 100% and 77.7% vs 92.6%. Leakage from the reservoir or the connecting tube is a late complication of ALGB. The presented data suggest that [sup 99m]Tc-pertechnetate scintigraphy is more efficient than radiography in determining the presence of such leaks. [ABSTRACT FROM AUTHOR]

Introduction. Vagus nerve stimulation is a novel treatment for patients with medically refractory epilepsy, who are not candidates for conventional epilepsy surgery, or who have had such surgery without optimal outcome. To date only studies with relatively short follow-up are available. In these studies efficacy increased with time and reached a maximum after a period of 6 to 12 months. Implantation of a vagus nerve stimulator requires an important financial investment but a cost-benefit analysis has not been published. Patients and Methods. Our own experience with VNS in Gent comprises 15 patients with mean age of 29 years (range: 17–44 years) and mean duration of epilepsy of 18 years (range: 4–32 years). All patients underwent a comprehensive presurgical evaluation and were found not to be suitable candidates for resective epilepsy surgery. Mean post-implantation follow-up is 24 months (range: 7–43 months). In patients with follow-up of at least one year, efficacy of treatment in terms of seizure control and seizure severity was assessed one year before and after the implantation of a vagus nerve stimulator. Epilepsy-related direct medical costs (ERDMC) before and after the implantation were also compared. Results. A mean reduction of seizure frequency from 14 seizures/month (range: 2–40/month) to 8 seizures/month (range: 0–30/month) was achieved (Wilcoxon signed rank test n=14; p=0.0016). Five patients showed a marked seizure reduction of ≥50%; 6 became free of complex partial seizures, 3 of whom became entirely seizure free for more than 12 months; 2 patients had a worthwhile reduction of seizure frequency between 30–50%; in 2 patients seizure frequency reduction has remained practically unchanged. Seizure freedom or ≥50% seizure reduction was achieved within the first 4 months after implantation in 6/11 patients. Before the implantation, the mean yearly epilepsy-related direct medical costs per patient were estimated to be 8830US$ (n=13; range: 1879–31129US$; sd=7667); the average number of hospital admission days per year was 21 (range: 4–100; sd=25.7). In the 12 months after implantation, ERDMC had decreased to 4215US$ (range: 615–11794US$; sd=3558) (Wilcoxon signed rank test n=13; p=0.018) and the average number of admission days to 8 (range: 0–35) (Wilcoxon signed rank test n=13; p=0.023). Conclusion. VNS is an effective treatment of refractory epilepsy and remains effective during long-term follow-up. Cost-benefit analysis suggests that the cost of VNS is saved within two years following implantation. [ABSTRACT FROM AUTHOR]