The valve uptake index: improving assessment of prosthetic valve endocarditis and updating [18F]FDG PET/CT(A) imaging criteria.

AIMS: Diagnosis of prosthetic valve endocarditis (PVE) by positron emission computed tomography angiography (PET/CTA) is based on visual and quantitative morpho-metabolic features. However, the fluorodeoxyglucose (FDG) uptake pattern can be sometimes visually unclear and susceptible to subjectivity. This study aimed to validate a new parameter, the valve uptake index [VUI, maximum standardized uptake value (SUVmax)-mean standardized uptake value (SUVmean)/SUVmax], designed to provide a more objective indication of the distribution of metabolic activity. Secondly, to re-evaluate the utility of traditionally used PVE imaging criteria and determine the potential value of adding the VUI in the diagnostic algorithm of PVE. METHODS AND RESULTS: Retrospective analysis of 122 patients (135 prosthetic valves) admitted for suspicion of endocarditis, with a conclusive diagnosis of definite (N = 57) or rejected (N = 65) PVE, and who had undergone a cardiac PET/CTA scan as part of the diagnostic evaluation. We measured the VUI and recorded the SUVmax, SUVratio, uptake pattern, and the presence of endocarditis-related anatomic lesions. The VUI, SUVmax, and SUVratio values were 0.54 ± 0.1 vs. 0.36 ± 0.08, 7.68 ± 3.07 vs. 3.72 ± 1.11, and 4.28 ± 1.93 vs. 2.16 ± 0.95 in the 'definite' PVE group vs. the 'rejected' group, respectively (mean ± SD; P < 0.001). A cut-off value of VUI > 0.45 showed a sensitivity, specificity, and diagnostic accuracy for PVE of 85%, 88%, and 86.7% and increased diagnostic ability for confirming endocarditis when combined with the standard diagnostic criteria. CONCLUSIONS: The VUI demonstrated good diagnostic accuracy for PVE, even increasing the diagnostic power of the traditionally used morphometabolic parameters, which also confirmed their own diagnostic performance. More research is needed to assess whether the integration of the VUI into the PVE diagnostic algorithm may clarify doubtful cases and thus improve the diagnostic yield of PET/CTA.

Assessment of pacemaker lead-related infective endocarditis with three-dimensional echocardiography and cardiac computed tomography.

Pacemaker endocarditis is rare and symptoms may be misleading. If missed, it carries significant morbidity and mortality, particularly in the elderly. Advances in multi-modality imaging in recent years have emphasised its role in clinical decision making. This case highlights the ability of multi-modality imaging techniques to individualise diagnosis, management and prognosis in patients with suspected cardiovascular implantable electronic device (CIED) endocarditis.

Single Photon Emission Tomography in the Diagnostic Assessment of Cardiac and Vascular Infectious Diseases.

Cardiac and vascular infection is an arising cause of mortality and morbidity in the adult population. Diagnosis based on culture and anatomic imaging are frequently inconclusive. Radiolabeled leucocyte scintigraphy plays a useful role in the diagnosis and management of these serious infectious conditions. In this paper, we present an update on the diagnostic performance of single- photon emission tomographic (SPECT) techniques using different radionuclides in the management of patients with cardiac and vascular infections. We performed a thorough search of recent literature on the topic. We present a discussion on the clinical utility of different SPECT tracers in cardiac and vascular infections, including infective endocarditis, cardiac implantable electronic device (CIED) infections, left ventricular assist device infection, and vascular graft infection. Radionuclide technique using SPECT tracers is a useful imaging modality in the diagnosis of cardiac infection. Among the different SPECT tracers for infection imaging, radiolabeled leucocyte scintigraphy is currently the most useful tool in the diagnosis and management of patients with suspected cardiac and vascular infection. Radiolabeled leucocyte scintigraphy has a high specificity, a result of the ability of the leucocytes to accumulate as sites of pyogenic infection but not at sites of sterile inflammation such as seen in the early post-operative period or in response to the presence of a prosthetic cardiac or vascular material. Limited experience with radiotracers for in vivo labelling of leucocytes such as 99mTc-sulesomab and 99mTc-besilesomab show acceptable diagnostic performance without the need for the tedious process of ex-vivo labeling. 67Ga scintigraphy used to be popular for cardiac and vascular infection imaging. Its use has run out of favor following the availability of more effective molecular imaging methods. SPECT techniques with radiolabeled leucocyte scintigraphy has a high diagnostic performance in the evaluation of patients with suspected cardiac or vascular infection. It is able to confirm or reject the presence of infection when results of anatomic imaging or culture remain inconclusive. Its diagnostic performance is not compromised by sterile inflammation occurring in the early post-operative period or in response to implanted prosthetic materials.

The Role of 18FDG PET/CT in the Assessment of Endocarditis, Myocarditis and Pericarditis.

Endocarditis, myocarditis and pericarditis are a heterogeneous group of phenotypic syndromes where the culprit area of inflammation is the heart. Inflammation may be determined by an infective agent, toxins, drugs or an activated immune system. Clinical manifestations can be subtle and diagnosis remains a challenge for cardiologists, requiring high level of suspicion and advanced multimodal cardiac imaging to avoid life-threatening consequences. The purpose of this review is to report the recent advances of PET/CT imaging with 18FDG in helping the management of patients affected by inflammatory heart disease. Two independent reviewers searched in PubMed articles published before or in June 2019 and final decisions on the inclusion of references were done in consensus with a third reviewer. At the end of the selection process 23/206 articles on "cardiac inflammation"; 26/235 articles on "endocarditis", "prosthetic heart valve", "pacemaker", "implantable cardiac device"; 7/103 articles on "myocarditis"; 13/330 articles on sarcoidosis" and 2/19 articles on "pericarditis" were included. Compared with the conventional methods, molecular imaging has the advantage to non-invasively and directly trace the inflammatory process, and to identify earlier the presence and the extent of intra-cardiac and extra-cardiac involvement, to enable quantification of disease activity, guide therapeutic interventions, and monitor treatment success.

Echocardiographic assessment of residuals after transvenous intracardiac lead extraction.

Detection of residual fibrotic tissue, called ghosts, after lead extraction is a new phenomenon in cardiology. This paper aims at describing the phenomenon of ghosts and determining their characteristic features. The study group consisted of 580 consecutive patients who underwent transvenous lead extraction (TLE) due to local infection, endocarditis and a superfluous lead. Each patient was clinically examined with the application of transthoracic echocardiography and transesophageal echocardiography directly before and after TLE. In the study population ghosts were detected in 110 patients (19%), and in 470 cases (81%) fibrotic tissue residuals were not found. Ghosts were most often located along the originally implanted lead's route. Longer ghosts were found after the removal of cardiac resynchronization therapy (CRT) and dual chamber pacing (DDD) devices. The local infection and infective endocarditis are associated with a larger number of ghosts revealed after the removal procedure (p = 0.006). The type of the implanted device: CRT/ICD/double chamber pacemaker/single chamber pacemaker, similar to the number of leads, did not impact on the number of the detected ghosts. The relationship between abrasions of the leads and the presence of ghosts proved significant, however (p = 0.043). TLE is associated with the presence of fibrotic tissue residuals in approx. 19% of patients. Indications for lead extraction due to local infection and endocarditis yielded significantly more cases of ghosts than in the entire patient population. The presence of abrasions is a good predictor for the presence of ghosts on the leads.

Assessment and management of infected total knee replacements.

Infection following total knee replacement surgery is a challenging and devastating complication. Clinical assessment including history, examination, radiographs, blood tests and knee aspirations helps to establish the diagnosis. Revision surgery is typically required to eradicate infection and restore function. This has traditionally been performed through two-stage revision surgery, although single-stage revision surgery is gaining popularity with comparable results in carefully selected patients. This article reviews the clinical assessment and principles of surgical management of infected total knee replacements.

Fluoroscopy- vs ultrasound-guided aspiration techniques in the management of periprosthetic joint infection: which is the best?

BACKGROUND: Fluid samples obtained from an affected joint still play a central role in the diagnosis of periprosthetic joint infection (PJI). It is the only preoperative test able to discover the causative microbiological agent. In the hip, fluid aspiration can be performed through fluoroscopy, ultrasound, or, less commonly, computed tomography. However, there is still a lack of consensus on which method is preferable in terms of efficacy and costbenefit. PURPOSES: We, therefore, asked whether (1) the benefits in terms of sensitivity and specificity and (2) the costs were comparable between fluoroscopy- and ultrasound-guided joint aspirations in a suspicious of hip PJI. METHODS: Between 2013 and 2016, 52 hip aspirations were performed on 49 patients with clinical, radiological, or serological suspicion of PJI, waiting for a revision surgery. The patients were divided in two groups: fluoroscopy- (n = 26) vs ultrasound-guided hip aspiration group (n = 26). These groups were also divided in control and infected patients. The criteria of MusculoSkeletal Infection Society (MSIS) were used, as gold standard, to define PJI. RESULTS: (1) Ultrasound-guided aspiration revealed valid sensitivity (89% vs 60%) and specificity (94% vs 81%) in comparison with fluoroscopic-guided aspiration. (2) The cost analysis was also in favor of ultrasound-guided aspiration (125.30€) than fluoroscopic-guided aspiration (343.58€). CONCLUSIONS: We concluded that ultrasound-guided hip aspiration could represent a valid, safe, and less expensive diagnostic alternative to fluoroscopic-guided aspiration in hip PJI.

What is the Accuracy of Nuclear Imaging in the Assessment of Periprosthetic Knee Infection? A Meta-analysis.

BACKGROUND: In the assessment of possible periprosthetic knee infection, various imaging modalities are used without consensus regarding the most accurate technique. QUESTIONS/PURPOSES: To perform a meta-analysis to compare the accuracy of various applied imaging modalities in the assessment of periprosthetic knee infection. METHODS: A systematic review and meta-analysis was conducted with a comprehensive search of MEDLINE and Embase® in accordance with the PRISMA and Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) recommendations to identify clinical studies in which periprosthetic knee infection was investigated with different imaging modalities. The sensitivity and specificity of each imaging technique were determined and compared with the results of microbiologic and histologic analyses, intraoperative findings, and clinical followup of more than 6 months. A total of 23 studies, published between 1990 and 2015, were included for meta-analysis, representing 1027 diagnostic images of symptomatic knee prostheses. Quality of the included studies showed low concerns regarding external validity, whereas internal validity indicated more concerns regarding the risk of bias. The most important concerns were found in the lack of uniform criteria for the diagnosis of a periprosthetic infection and the flow and timing of the included studies. Differences among techniques were tested at a probability less than 0.05 level. Where there was slight overlap of confidence intervals for two means, it is possible for the point estimates to be statistically different from one another at a probability less than 0.05. The z-test was used to statistically analyze differences in these situations. RESULTS: Bone scintigraphy was less specific than all other modalities tested (56%; 95% CI, 0.47-0.64; p < 0.001), and leukocyte scintigraphy (77%; 95% CI, 0.69-0.85) was less specific than antigranulocyte scintigraphy (95%; 95% CI, 0.88-0.98; p < 0.001) or combined leukocyte and bone marrow scintigraphy (93%; 95% CI, 0.86-0.97; p < 0.001). Fluorodeoxyglucose positron emission tomography (FDG-PET) (84%; 95% CI, 0.76-0.90) was more specific than bone scintigraphy (56%; 95% CI, 0.47-0.64; p < 0.001), and less specific than antigranulocyte scintigraphy (95%; 95% CI, 0.88-0.98; p = 0.02) and combined leukocyte and bone marrow scintigraphy (93%; 95% CI, 0.86-0.97; p < 0.001). Leukocyte scintigraphy (88%; 95% CI, 0.81-0.93; p = 0.01) and antigranulocyte scintigraphy (90%; 95% CI, 0.78-0.96; p = 0.02) were more sensitive than FGD-PET (70%; 95% CI, 0.56-0.81). However, because of broad overlapping of confidence intervals, no differences in sensitivity were observed among the other modalities, including combined bone scintigraphy (93%; 95% CI, 0.85-0.98) or combined leukocyte and bone marrow scintigraphy (80%; 95% CI, 0.66-0.91; p > 0.05 for all paired comparisons). CONCLUSIONS: Based on current evidence, antigranulocyte scintigraphy and combined leukocyte and bone marrow scintigraphy appear to be highly specific imaging modalities in confirming periprosthetic knee infection. Bone scintigraphy was a highly sensitive imaging technique but lacks the specificity needed to differentiate among various conditions that cause painful knee prostheses. FDG-PET may not be the preferred imaging modality because it is more expensive and not more effective in confirming periprosthetic knee infection. LEVEL OF EVIDENCE: Level III, diagnostic study.

The Accuracy of Imaging Techniques in the Assessment of Periprosthetic Hip Infection: A Systematic Review and Meta-Analysis.

BACKGROUND: Various imaging techniques are used for excluding or confirming periprosthetic hip infection, but there is no consensus regarding the most accurate technique. The objective of this study was to determine the accuracy of current imaging modalities in diagnosing periprosthetic hip infection. METHODS: A systematic review and meta-analysis of the literature was conducted with a comprehensive search of MEDLINE and Embase to identify clinical studies in which periprosthetic hip infection was investigated with different imaging modalities. The sensitivity and specificity of each imaging technique were determined and compared with the results of microbiological and histological analysis, intraoperative findings, and clinical follow-up of >6 months. RESULTS: A total of 31 studies, published between 1988 and 2014, were included for meta-analysis, representing 1,753 hip prostheses. Quality assessment of the included studies identified low concerns with regard to external validity but more concerns with regard to internal validity including risk of bias (>50% of studies had insufficient information). No meta-analysis was performed for radiography, ultrasonography, computed tomography, and magnetic resonance imaging because of insufficient available clinical data. The pooled sensitivity and specificity were 88% (95% confidence interval [CI], 81% to 94%) and 92% (95% CI, 88% to 96%), respectively, for leukocyte scintigraphy; 86% (95% CI, 80% to 90%) and 93% (95% CI, 90% to 95%) for fluorodeoxyglucose positron emission tomography (FDG PET); 69% (95% CI, 58% to 79%) and 96% (95% CI, 93% to 98%) for combined leukocyte and bone marrow scintigraphy; 84% (95% CI, 70% to 93%) and 75% (95% CI, 66% to 82%) for antigranulocyte scintigraphy; and 80% (95% CI, 72% to 86%) and 69% (95% CI, 64% to 73%) for bone scintigraphy. CONCLUSIONS: Of the currently used imaging techniques, leukocyte scintigraphy has satisfactory accuracy in confirming or excluding periprosthetic hip infection. Although not significantly different, combined leukocyte and bone marrow scintigraphy was the most specific imaging technique. FDG PET has an appropriate accuracy in confirming or excluding periprosthetic hip infection, but may not yet be the preferred imaging modality because of limited availability and relatively higher cost. LEVEL OF EVIDENCE: Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Assessment of the diagnostic accuracy of 18F-FDG PET/CT in prosthetic infective endocarditis and cardiac implantable electronic device infection: comparison of different interpretation criteria.

PURPOSE: The diagnosis of prosthetic valve (PV) infective endocarditis (IE) and infection of cardiac implantable electronic devices (CIEDs) remains challenging. The aim of this study was to assess the usefulness of 18F-FDG PET/CT in these patients and analyse the interpretation criteria. METHODS: We included 41 patients suspected of having IE by the Duke criteria who underwent 18F-FDG PET/CT. The criteria applied for classifying the findings as positive/negative for IE were: (a) visual analysis of only PET images with attenuation-correction (AC PET images); (b) visual analysis of both AC PET images and PET images without AC (NAC PET images); (c) qualitative analysis of NAC PET images; and (d) semiquantitative analysis of AC PET images. 18F-FDG PET/CT was considered positive for IE independently of the intensity and distribution of FDG uptake. The gold standard was the Duke pathological criteria (if tissue was available) or the decision of an endocarditis expert team after a minimum 4 months follow-up. RESULTS: We studied 62 areas with suspicion of IE, 28 areas (45 %) showing definite IE and 34 (55 %) showing possible IE. Visual analysis of only AC PET images showed poor diagnostic accuracy (sensitivity 20 %, specificity 57 %). Visual analysis of both AC PET and NAC PET images showed excellent sensitivity (100 %) and intermediate specificity (73 %), focal uptake being more frequently associated with IE. The accuracy of qualitative analysis of NAC PET images depended on the threshold: the maximum sensitivity, specificity and accuracy achieved were 88 %, 80 %, 84 %, respectively. In the semiquantitative analysis of AC PET images, SUVmax was higher in areas of confirmed IE than in those without IE (∆SUVmax 2.2, p < 0.001). When FDG uptake was twice that in the liver, IE was always confirmed, and SUVmax 5.5 was the optimal threshold for IE diagnosis using ROC curve analysis (area under the curve 0.71). CONCLUSION: The value of 18F-FDG PET/CT in the diagnosis of suspected IE of PVs and CIEDs is highly dependent on patient preparation and the method used for image interpretation. Based on our results, the best method is to consider a study positive for IE when FDG uptake is present in both AC PET and NAC PET images.

Outcomes of Aortic Surgery for Abdominal Aortic Graft Infections.

BACKGROUND: Literature on postoperative outcomes following aortic surgery for aortic graft infection (AGI) is limited by relatively small sample sizes, resulting in lack of national benchmarks for quality of care. We report in-hospital outcomes following abdominal aortic surgery for AGI and identify factors associated with postoperative complications using the Nationwide Inpatient Sample (NIS) database. METHODS: Patients who underwent aortic graft resection for AGI were identified from the 2002 to 2008 NIS database, a multicenter database capturing 20% of all US admissions. Multivariable logistic regression analyses were performed. RESULTS: Among 394 patients (men: 73.4%) who underwent abdominal aortic surgery for AGI, 53% of the admissions were emergent/urgent. A significant trend for decreasing number of abdominal aortic surgery for AGIs per year was observed (Pearson r correlation: -.96; P = .0006). Over the same time span, a significant correlation was also seen with decrease in open and increase in endovascular aortic aneurysm repairs in the NIS database. In-hospital rates of overall postoperative morbidity and mortality were 68.3% and 19.8%, respectively. In-hospital rates of postoperative respiratory failure, renal failure, and cardiac arrest were 35.5%, 14.2%, and 8.9%, respectively. Median length of stay was 26 days, with median hospital charges being US$184 162. On multivariable analysis, increase in age per year (odds ratio [OR] 1.07; 95% confidence interval [CI]: 1.03-1.12) was independently associated with postoperative morbidity, while higher hospital volume for this procedure was protective (OR: 0.71; 95% CI: 0.56-0.89). No preoperative factors were independently associated with postoperative mortality. CONCLUSION: Incidence of abdominal aortic surgery for AGI has progressively declined over the span of our study in association with decreased open and increased endovascular aortic aneurysm repairs. Aortic surgery for AGI is associated with very high morbidity and mortality rates along with prolonged lengths of stay and elevated hospital charges. The outcomes of operations for AGI are better in younger patients and higher volume hospitals.

SPECT/CT Assessment of Infected Intracardiac Devices With and Without Attenuation Correction.

Left ventricular assist devices (LVADs) provide the ability to maintain cardiac output and sustain life as a bridge to transplantation, definitive therapy, or a permanent decision. We present a case of LVAD drive infection that was differentiated from pump infection by the use of attenuation-corrected and non-attenuation-corrected CT, along with correlation with the planar images. Clinically, the patient was suspected of having infection; however, the clinician did not know which components of the device were involved. The patient's scan showed abnormal activity along the driveline with and without attenuation correction, whereas the pump showed abnormal activity with attenuation correction only. This finding suggested that the drive line was infected but that the activity within the pump was secondary to overcorrection of attenuation. The driveline was cultured, confirming infection.

INNOVATIVE MULTIPLANAR RECONSTRUCTION AND VOLUME-RENDERED COMPUTED TOMOGRAPHY IN THE ASSESSMENT OF SCLERAL BUCKLE-RELATED COMPLICATIONS.

PURPOSE: To describe the role of multiplanar reconstruction and three-dimensional volume-rendered imaging in the assessment of silicon-based scleral buckle (SB)-related complications. METHODS: Five eyes of five patients with SB-related complications where the history, surgical notes, and clinical examination proved inconclusive were included. Unenhanced axial orbital computed tomography images of all patients were acquired parallel to orbitomeatal line, and images were reviewed in orthogonal planes. The volume rendition of the imaged volume was evaluated in various tilts, with special reference to the spatial relationship of the band-buckle to the globe and bony orbit. All patients underwent imaging-assisted SB removal. RESULTS: Imaging assisted in in vivo localization of the obscure band or buckle in all five eyes. Band was seen as hyperdense structure encircling whole of the globe, whereas buckle was seen as segmental, broad, hyperdense structure with scleral indentation. Presence of SB was identified in three patients, and globe integrity was shown in the other two. Abnormal anterior displacement of band and buckle was demonstrated in three cases on volume-rendered imaging in relation to lateral orbital rim. Focal exuberant soft-tissue proliferation around the buckle was present in all patients, suggesting chronic inflammation and infection. Successful removal of band and buckle could be achieved, and all patients were relieved of their preoperative complaints. No complication occurred during intraoperative and postoperative period. CONCLUSION: Use of multiplanar reconstruction and three-dimensional volume-rendered computed tomography imaging played a pivotal role in surgical success.

Risk factors for 1-year mortality among patients with cardiac implantable electronic device infection undergoing transvenous lead extraction: the impact of the infection type and the presence of vegetation on survival.

AIMS: Infections of cardiac implantable electronic devices (CIEDs) are infrequent but carry significant morbidity and mortality. We aimed to assess risk factors for 1-year mortality among patients with CIED infection and to evaluate if the type of infection and the presence of vegetation affect survival. METHODS AND RESULTS: We reviewed records of all patients with infected CIEDs who underwent transvenous lead extraction at our tertiary care centre between 2002 and 2008. Patients who presented with infection involving the device pocket were classified as 'pocket infection', and those who presented with bacteraemia with or without vegetation and a pocket that looked benign were classified as 'endovascular infection' (EVI). One-year mortality was examined using the social security death index. Five hundred and two patients were identified (68.5 ± 15 years); 289 (58%) had pocket infection and 213 (42%) had EVI. One-year mortality rate was 20%. Using multivariable Cox regression model, EVI was associated with significantly higher 1-year mortality (hazard ratio 2.1, P-value 0.0008). Among patients with EVI, 100 patients had vegetation on transoesophageal echo; however, there was no difference in 1-year mortality between patients with EVI and vegetation compared with patients with EVI and no vegetation (27, 27 vs. 40, 35%; P-value 0.188). Risk factors for 1-year mortality among patients with EVI included renal failure, worse functional class, and bleeding requiring transfusion. The presence of vegetation was not associated with increased 1-year mortality. CONCLUSION: One-year mortality is higher among patients with EVI compared with patients with pocket infection; this increased mortality does not seem to be related to the presence of vegetations.

Usefulness of 18F-fluorodeoxyglucose positron emission tomography scan in the assessment of periprosthetic collections: report of 2 cases with opposite management.

Vascular prosthetic infection is a rare but serious complication of vascular surgery that requires rapid diagnosis and treatment. It is associated with high rates of amputation and death. The diagnosis is difficult when faced with a chronic nonspecific clinical presentation. We report 2 cases showing the diagnostic usefulness of positron emission tomography (PET). In 1 case, PET excluded with certainty the septic character of a periprosthetic collection fistulized with the skin by showing a periprosthetic fixation insufficient to diagnose an infection. In the other case, it confirmed the prosthetic infection in association with an evocative clinical picture by revealing a pathologic periprosthetic hyperfixation. PET scan therefore drew aside the diagnosis of prosthetic infection faced with a mild clinical and paraclinical presentation in the first case, and made it possible to pose it with certainty in the second case. This examination made it possible to save valuable time in 1 case and to elucidate the periprosthetic collection in the other case. Therefore, the rule of surgical explantation of any prosthesis with flow or periprosthetic collection is no more univocal.

The role of ultrasound in the assessment of post-operative complications following hip arthroplasty.

Hip arthroplasty is one of the most commonly performed orthopedic procedures. Clinicians can be faced with the diagnostic dilemma of the patient presenting with a painful hip following arthroplasty and satisfactory post-operative radiographs. Identifying the cause of symptoms can be challenging and ultrasound is increasingly being utilized in the evaluation of potential soft tissue complications following hip surgery. In this article, we describe the common surgical approaches used during hip arthroplasty as this can influence the nature and location of subsequent complications. A review of the literature is presented along with the imaging appearances frequently encountered when imaging this patient population.

Summary: Indications for positron­emission tomography (pet): a brief update

The purpose of this report is to provide an initial response to various questions concerning the expansion of the clinical indications for positron-emission tomography (PET) and PET-CT1 in oncology and for other types of diseases with regard to the current practice in Québec. A targeted literature review identified 28 health technology assessments and systematic reviews on this topic published between 2004 and 2010, from which information concerning PET clinical indications was extracted. These indications were placed in two categories: the initial indications (diagnostic characterization and tumour initial staging) and follow-up indications (evaluation of treatment response, disease progression, and evaluation of recurrences). In twelve cancers, initial and follow-up indications are accepted both in the literature and in Québec, with a low potential for expanding indications based on nuances or specificities that cannot be discussed in the context of this report. A potential expansion of the indications accepted in Québec was identified for six cancers, for two of which there is an international consensus, namely, glioma for the initial indications and gastrointestinal stromal tumours for both initial and follow-up indications. The other indications are the subject of debate because of a lack of interpretable evidence (kidney cancer for the initial indications and pancreatic cancer for the follow-up indications); emerging, thanks to the large number of recent studies (thyroid cancer for the initial indications); or included in another category (unspecified brain cancer placed together with glioma). With regard to non-oncological indications, only chronic osteomyelitis and prosthesis-related infections could constitute new, emerging indications. As for the utility of PET in planning radiotherapy treatments, this question could not be resolved because of a lack of evidence. This is an emerging and mainly experimental field, and there is presently no systematic review of the available data. The current research mainly concerns technical issues specific to each cancer. The Unité d'évaluation des technologies et des modes d'intervention en santé (UETMIS) at the Centre hospitalier universitaire de Québec (CHUQ) is analyzing now the literature on this new technological application and its potential use in Québec. In conclusion, the range of new or expanded indications for PET in relation to those currently accepted in Québec remains fairly limited. However, PET is a rapidly evolving technology, and its combined use with other technologies such as magnetic resonance imaging, is opening development prospects for new clinical applications. Following an agreement with the Ministère de la Santé et des Services sociaux, it was agreed that the most concerned professional associations with PET would be consulted to check if the results of this update on the indications accurately reflect the current state of knowledge and their application in Québec clinical practice. The minutes of the meetings are presented in Appendix E, and the main points are summarized in Section 5.

Assessment of subacute inflammatory and proliferative response to coronary stenting in a porcine model by local gene expression studies and histomorphometry.

The aim of the study was to analyse inflammatory and proliferative response early after coronary stenting by angiography, histomorphometry and local gene expression analysis using quantitative rt-PCR. Therefore, eight German domestic pigs underwent stenting of the left coronary artery. Selective coronary angiography was performed after 14 days. Explanted coronary arteries were examined histomorphometrically after methacrylate-embedding. Snap-frozen samples were examined for local gene expression of TGF-beta, TNF-alpha, GM-CSF, VEGF, PDGF and Fas Ligand (FasL) by real-time quantitative rt-PCR normalized to the housekeeping gene GAPDH and compared to unstented coronary arteries. All stented coronaries were patent with only little neointima formation. The median vessel diameter was 2.55 mm (range 2.43-2.68 mm). Histopathology revealed little inflammatory response limited to the tissue surrounding the stent struts; luminal area ranged from 84% to 91%. Compared to unstented control arteries, no significant differences in local gene expression were detected for VEGF, PDGF, TGF-beta, TNF-alpha and GM-CSF. Expression of FasL was upregulated as little as 1.7-fold (p=0.01). We conclude that, in native coronary arteries, no significant upregulation of investigated genes regulating vascular remodelling, inflammation or fibrogenesis was demonstrated 14 days after stenting. Whether upregulation of FasL as a marker gene of apoptosis is transient and biological significant requires further investigation.

Assessment of patient selection criteria for treatment of the infected hip arthroplasty.

In a group of 37 infected hip arthroplasties (36 patients) treated consecutively between January 1997 and October 1999, the feasibility of published patient selection criteria for direct exchange arthroplasty was tested. These criteria include the requirement of a healthy patient with good soft tissues, minimal femoral bone loss, and an organism identified preoperatively as an antibiotic sensitive gram-positive organism. After assignment of the selection criteria, only four patients (four hips) (11%) were deemed potential candidates for a direct exchange procedure. Infected arthroplasties excluded from a primary exchange included 14 patients (15 hips) with gram-negative or methicillin-resistant gram-positive organisms obtained from preoperative joint aspirations, 10 patients (10 hips) with moderate or severe femoral bone loss, four patients (four hips) who required a proximal femoral osteotomy for component removal, two patients (two hips) with poor health status, and two patients (two hips) with poor soft tissues. Because of the increasing emergence of antibiotic-resistant bacteria and an increased prevalence of revision arthroplasties with associated bone loss, the feasibility of published selection criteria for direct exchange are limited. A philosophy of delayed reconstruction for the treatment of the infected hip arthroplasty seems most appropriate in the current era of patient treatment.

[Radionuclide scan with TC-99m-tin colloid in the evaluation of orthopedic implant infections]. / Gammagrafía con 99mTc-coloide de estaño en la valoración de la infección de los implantes ortopédicos.

We have studied 26 patients (32-77 years old, 16 females) with suspicion of joint arthroplasty infection: 11 total hip replacements, 12 total knee replacements and 3 osteosinthesys. A bone scintigraphy with MDP-99mTc, a scintigraphy with HMPAO-WBC and a scintigraphy with 99mTc-stannous colloid were made in all patients. The final diagnostic was based in joint cultures and clinic and radiologic evolution of the patients. The earliest phase of the bone scintigraphy was positive in 18 patients. The later phase was positive in all them. The WBC was positive in 20 out of 26 patients. The bone marrow scintigraphy showed a congruent pattern with WBC in 18 patients (17 infected and 1 without infection). The other ones (8 patients) showed an incongruent pattern (7 with infection and 1 without it). The results show that the bone marrow scintigraphy with 99mTc-stannous colloid improves the accuracy of the diagnostic of bone prosthesis infection and should be included into the diagnosis protocol of this disease.