[Evaluation of PET-CT : product safety, clinical usefulness, reimbursement in Germany and the USA]. / Bewertung der PET-CT : Produktsicherheit, klinischer Nutzen, Erstattung im deutschen und US-amerikanischen Gesundheitssystem.

Since 1994, PET - and later PET-CT - have gained significant clinical importance. Since 2002, PET-CT systems (PET + multislice CT) are available. The combination of high sensitivity PET images fused with high resolution CT images has gained widespread clinical acceptance for diagnosis, staging and re-staging as well as prediction of response to chemotherapy in oncology. Besides oncology, there are clear indications in diseases of the heart and the brain. The development of new systems in mainly based on multislice CT (64 slice). Radiopharmacology is advancing quickly, especially in the fields of oncology and neurological disorders. However, the limited reimbursement in Germany hampers this development.

(13)N-ammonia myocardial perfusion imaging with a PET/CT scanner: impact on clinical decision making and cost-effectiveness.

PURPOSE: The purpose of the study is to determine the impact of 13N-ammonia positron emission tomography (PET) myocardial perfusion imaging (MPI) on clinical decision making and its cost-effectiveness. MATERIALS AND METHODS: One hundred consecutive patients (28 women, 72 men; mean age 60.9 +/- 12.0 years; range 24-85 years) underwent 13N-ammonia PET scanning (and computed tomography, used only for attenuation correction) to assess myocardial perfusion in patients with known (n = 79) or suspected (n = 8) coronary artery disease (CAD), or for suspected small-vessel disease (SVD; n = 13). Before PET, the referring physician was asked to determine patient treatment if PET would not be available. Four weeks later, PET patient management was reassessed for each patient individually. RESULTS: Before PET management strategies would have been: diagnostic angiography (62 of 100 patients), diagnostic angiography and percutaneous coronary intervention (PCI; 6 of 100), coronary artery bypass grafting (CABG; 3 of 100), transplantation (1 of 100), or conservative medical treatment (28 of 100). After PET scanning, treatment strategies were altered in 78 patients leading to: diagnostic angiography (0 of 100), PCI (20 of 100), CABG (3 of 100), transplantation (1 of 100), or conservative medical treatment (76 of 100). Patient management followed the recommendations of PET findings in 97% of the cases. Cost-effectiveness analysis revealed lower costs of 206/patient as a result of PET scanning. CONCLUSION: In a population with a high prevalence of known CAD, PET is cost-effective and has an important impact on patient management.

Cost-effectiveness analysis of subtraction scintigraphy in patients with acute lower gastrointestinal tract hemorrhage.

UNLABELLED: (99m)Tc-labeled red blood cell scintigraphy is a powerful detection and localization tool that may be confounded by false-positive and false-negative findings. Subtraction scintigraphy has been used in the evaluation of acute lower gastrointestinal tract hemorrhage (LGIH) to reduce the impact of interpretive confounders. The aim of this investigation was to evaluate the cost-effectiveness of the addition of subtraction scintigraphy in the evaluation of patients with acute LGIH. METHODS: The clinical phase of this research was a retrospective clinical study with a repeated-measures design including randomized control and experimental groups. A total of 49 patient studies were included in the sample. Studies were randomized and interpreted by 4 independent physicians. Decision-tree analysis was used to model direct costs and the potential risks of procedures for 2 diagnostic strategies for patients with acute LGIH: conventional scintigraphy alone and conventional scintigraphy combined with subtraction scintigraphy. The transition probabilities (or branching fraction at each decision node) for scintigraphy were based on the clinical results of this investigation. All other transition probabilities were derived from previously cited data. RESULTS: Combining subtraction techniques with conventional scintigraphy reduced the overall costs of procedures for patients with acute LGIH by $74 per patient and reduced deaths by 17.6% and complications by 15.7%. For conventional scintigraphy alone, 8.8% of patients presenting for scintigraphic evaluation of acute LGIH would undergo unnecessary angiograms, and 2.8% would have unnecessary surgery. These figures were reduced to just 5.4% and 1.8%, respectively, with the addition of subtraction scintigraphy. CONCLUSION: The use of subtraction scintigraphy as an adjunct to conventional scintigraphy for patients with acute LGIH may provide both cost and outcome benefits.

Primary hyperparathyroidism: higher success rate of first surgery after preoperative Tc-99m sestamibi-I-123 subtraction scanning.

PURPOSE: To evaluate the usefulness and cost-effectiveness of routine preoperative technetium-99m sestamibi-iodine-123 subtraction scanning in patients with parathyroid gland disease. MATERIALS AND METHODS: Tc-99m sestamibi-I-123 subtraction scanning was performed in 65 patients with primary hyperparathyroidism who were referred for evaluation before first surgery. RESULTS: Focal tracer uptake was detected in the mediastinum in two patients who then underwent primary sternotomy; a parathyroid adenoma, anterior to the ascending aorta, was resected in each case. In a third patient, imaging showed tracer uptake above the thyroid gland; this patient underwent resection of an undescended parathyroid adenoma located in the sheath of the right carotid artery. Initial surgery was curative in all patients. Preoperative subtraction scans depicted 56 of 59 (95%) solitary adenomas. Four patients had hyperplasia; two had double adenoma. Imaging findings indicated multiple parathyroid involvement in five of these patients and facilitated location of 12 of 15 (80%) enlarged glands. Four adenomas and two hyperplastic glands that weighed less than 100 mg were detected. The positive predictive value for any suspected location was 96%. Average surgery time was reduced from 120 to 90 minutes. CONCLUSION: Preoperative subtraction scanning is useful in planning parathyroid surgery and appears to be cost-effective.

Three-dimensional computed tomographic angiography in the preoperative evaluation of cerebrovascular lesions.

Although three-dimensional computed tomographic angiography was developed as a screening tool for use in patients with suspected cerebrovascular disease, this imaging modality has also proven to be of value in surgical planning for patients with large or unusual vascular lesions of the brain. The three-dimensional images generated by this technique yield valuable information regarding the size and configuration of intracranial aneurysms and vascular malformations, the presence and extent of intra-aneurysmal thrombus, the relationship of the vascular lesion to other cerebrovascular or skeletal structures, aneurysm wall thickness, and the presence and orientation of an aneurysm neck. The use of three-dimensional computed tomographic angiography in representative cases of patients with large or unusual cerebrovascular lesions is presented. It has been our experience that this imaging modality displays anatomical information that is not readily available from standard, intra-arterial angiography, provides better detail for surgical planning than magnetic resonance angiography, and is less expensive than either of these other imaging modalities.

Localization of parathyroid lesions: blind study for surgeons.

Success in the treatment of primary hyperparathyroidism rest in the accurate localization and removal of the diseased gland or glands. Computerized tomography and nuclear imaging scans are being used to localize abnormal parathyroid tissue. In the present study, fifteen consecutive patients undergoing surgery for primary hyperparathyroidism were all subjected to these ancillary studies. Results were not revealed to the operating team. In all instances an adenoma was localized during neck exploration. CT Scan failed to localize 73% of the affected glands. Nuclear scans missed almost fifty percent of the parathyroid adenomas. The low yield of these ancillary localizing tests makes them unnecessary in the routine evaluation of patients undergoing surgery for primary hyperparathyroidism.

Localization of parathyroid lesions: blind study for surgeons

Success in the treatment of primary hyperparathyroidism rest in the accurate localization and removal of the diseased gland or glands. Computerized tomography and nuclear imaging scans are being used to localize abnormal parathyroid tissue. In the present study, fifteen consecutive patients undergoing surgery for primary hyperparathyroidism were all subjected to these ancillary studies. Results were not revealed to the operating team. In all instances an adenoma was localized during neck exploration. CT Scan failed to localize 73% of the affected glands. Nuclear scans missed almost fifty percent of the parathyroid adenomas. The low yield of these ancillary localizing tests makes them unnecessary in the routine evaluation of patients undergoing surgery for primary hyperparathyroidism

Imaging of the digital arteries: digital subtraction angiography versus conventional arteriography.

A retrospective study of 95 patients was undertaken to compare digital subtraction angiography (DSA) and conventional arteriography of the hand. Eighty patients had conventional angiography and 15 had DSA. In comparison with conventional angiography, DSA is more cost-efficient and facilitates outpatient angiography. It provides images as acceptable as those of conventional angiography. We conclude that intra-arterial DSA is now the procedure of choice for angiographic mapping of the digital arteries.

Digital subtraction angiography (DSA). Work load and financial implications for a neuroradiology department.

A four year study has been undertaken into the effects on the workload and cost implications of the introduction of digital subtraction angiography (DSA) in a large United Kingdom teaching hospital. The increase in workload has been entirely due to the ability to perform intravenous angiography. DSA is cheaper than conventional angiography if more than 210 cases are undertaken each year. This difference is accounted for by the reduced use of X-ray film. However, intravenous angiography is more expensive because of the use of large volumes of nonionic medium.

A prospective analysis of the accuracy and cost-effectiveness of digital subtraction angiography for living-related renal donor evaluation.

From 1982 to 1984, we conducted a prospective study to evaluate the usefulness of i.v. renal digital subtraction angiography (DSA) for living-related donor (LRD) evaluation. Twenty-eight LRDs were evaluated with the traditional approach of intravenous pyelography (IVP) and standard catheter arteriography (SCA) (group 1). During the same period, 33 LRDs underwent renal DSA and IVP from a single i.v. contrast injection (group 2). If renal arterial imaging with DSA was considered satisfactory, no further radiographic studies were done (group 2-A, n = 23). If renal arterial imaging with DSA was not satisfactory, SCA was then obtained (group 2-B, n = 10). DSA alone accurately defined the number and location of renal arteries in 21 of 23 patients from group 2-A, and in 5 of 10 patients from group 2-B. The major limitation of DSA was in patients with multiple renal arteries; accurate imaging was obtained in only 7 of these 13 patients (54%). In group 2 overall, preoperative renal imaging was not accurate in 2 of 33 patients (6%); in both cases, an unsuspected polar artery was found at nephrectomy. The mean cost per patient of all radiographic renal imaging studies was $953.00 for group 2 and $1721.00 for group 1. These data suggest that the approach of preferentially evaluating LRDs with DSA-IVP, and obtaining SCA only if DSA yields poor visualization, is more cost-effective but not as accurate as the traditional policy of obtaining SCA and IVP in all cases.

Digital angiography in pulmonary embolism.

Pulmonary digital subtraction angiography was diagnostic in 98.3 per cent of patients with possible acute pulmonary embolism. The procedure was well tolerated even in severely ill patients. A large image intensifier made simultaneous imaging of both lungs possible, reducing the number of contrast injections necessary. Small volumes of low iso-osmolar concentration of modern contrast media were used. There was no need for catheterization of the pulmonary artery. Theoretical considerations and our limited experience indicate that this will reduce the number of complications compared with conventional pulmonary angiography. The procedure is rapidly performed and the diagnostic accuracy high. This makes digital subtraction angiography cost effective. Digital pulmonary angiography can be recommended as the primary diagnostic method in most patients with possible pulmonary embolism.

Intraarterial digital subtraction arteriographic evaluation of extremity tumors: comparison with conventional arteriography.

Conventional arteriography and intraarterial digital subtraction arteriography (IADSA) were compared in 36 patients with primary bone or soft-tissue tumors of the extremities. The sensitivity of IADSA was at least equal to conventional arteriography for demonstrating normal or abnormal major arteries and feeding arteries, equal to or superior for depicting tumor stains or draining veins, but slightly inferior for revealing minute tumor vessels. An increase of the matrix size from 256 X 256 to 512 X 512 improved these sensitivities. IADSA with 15% diatrizoate contrast material eliminated the contrast material-induced pain in all patients. With a computer-controlled iris setting, an average of 5 minutes of procedure time and 1.7 R of radiation (0.44 mC kg) per examination could be saved. IADSA reduced the cost of an examination by an average of $67. The results indicate that IADSA was diagnostic in all instances and can replace conventional arteriography for the evaluation of extremity tumors.

Intraarterial digital subtraction imaging cost considerations.

In an attempt to quantitate the cost-effectiveness of digital arterial imaging, we compared our real costs for angiographic procedures during a 6-month period with the costs for digital arteriographic imaging after the procedure was well established and accepted by both radiologists and clinicians. This study based on 400 angiograms per year, revealed that use of a digital angiographic unit resulted in an 82% reduction in film costs, a 25% reduction in staffing costs, a 19% reduction in the time required per examination, and a 30% reduction in the time required per run. Thirteen percent more runs were performed with the digital unit because it was more convenient and had a limited field of view. Overall operating cost savings were 43%. If amortized additional capital costs are included, there is a 12% reduction in overall costs. The digital imaging unit provides an immediate cost savings, with no appreciable loss of diagnostic quality. In addition, patient comfort, and perhaps safety, are improved.

Renal artery digital-subtraction angiography. An outpatient investigation for renovascular hypertension.

The adequacy and convenience of the digital-subtraction angiographic procedure by means of a Diasonics DF100 as an investigation in renovascular disease were assessed over a nine-month period in 82 sequential renal artery studies, of which 76 were carried out in patients referred for the investigation of hypertension. Contrast medium was injected as a bolus by way of a centrally placed venous catheter, or a small (5 French size or smaller) arterial catheter. Patients tolerated the procedure well, and were fully mobile within 10 minutes to one hour (venous injection) and within two hours (arterial injection) after the procedure. Of the 82 studies, nine were judged as inadequate. All technical failures occurred with the venous injection technique. Of the 76 patients with hypertension, the main renal artery was judged as normal in 61. Renal artery lesions were demonstrated in 15 studies (13 patients). Renal vein renin studies, and the clinical or postoperative course supported the diagnosis of renovascular hypertension in 11 of these. Digital-subtraction angiography of the renal artery is a useful investigation in suspected renovascular hypertension. Its major advantage over conventional angiography is that it can be performed on an outpatient basis.

Impact of digital subtraction angiography on carotid evaluation.

Impact of digital subtraction angiography by intravenous injection (DSAV) was examined in a private neurology clinic. In the evaluation of threatened stroke, advent of DSAV was associated with reduced use of both traditional noninvasive tests (from 100% of patients to 36%), and conventional arteriograms (from 29% to 4%). Less compelling indications were often prescreened with noninvasive tests; more compelling symptoms usually had initial DSAV. Conventional arteriograms were done for compelling indications and negative or inadequate DSAV. The average cost of evaluation was increased slightly in patients treated medically and reduced greatly in those having surgery. While cost and convenience might support such utilization, issues of quality of evaluation require consideration.