Marc Faraggi

Arterial wall uptake of fluorodeoxyglucose on PET imaging in stable cancer disease patients indicates higher risk for cardiovascular events

BackgroundWe aimed to evaluate the additional information of 18 fluorodeoxyglucose (FDG) arterial uptake with respect to other conventional cardiovascular risk factors and arterial calcifications in patients with stable cancer.Methods and ResultsWe compared the rate of cardiovascular events in 2 groups of patients with (n=45) and without (n=56) enhanced arterial 18FDG uptake, matched for the main clinical parameters. The extent and intensity of 18FDG uptake were quantified. A calcification index was also determined. About one third of the selected patients had a history of cardiovascular events and thus could be defined as “vulnerable patients.” Old cardiovascular events (>6 months before or after positron emission tomography [PET]) and recent cardiovascular events (<6 months before or after PET) were significantly more frequent in the high-FDG uptake group than in the low-FDG uptake group (48% vs 15%, respectively [P=.0006], and 30% vs 1.8%, respectively [P=.0002]). The extent of 18FDG arterial uptake was the unique factor significantly related to the occurrence of a recent event by either logistic regression or discriminant analysis (P=.004 for all). Conversely, calcium index was the single factor related to old events (P=.004 and P=.002, respectively).ConclusionsExtensive arterial 18FDG uptake might be an indicator of an evolving atherosclerotic process and should be mentioned in PET/computed tomography reports.

Whole body [18F]fluorodeoxyglucose positron emission tomography imaging for the diagnosis of pacemaker or implantable cardioverter defibrillator infection: a preliminary prospective study

We studied the potential use of [(18) F]fluorodeoxyglucose ((18) F-FDG) whole body positron emission tomography (PET)-computed tomography for the diagnosis of device infection and extension of infection. Twenty-one patients with suspected device infection were prospectively included and compared with 14 controls free of infection. (18) F-FDG uptake on the box and on the leads was visually and quantitatively interpreted (using the maximal standard uptake value). The final diagnosis was obtained either from bacteriological data after device culture (n = 11) or by a 6-month follow-up according to modified Dukes criteria (n = 10). Ten patients finally showed infection on bacteriological study (n = 8) or during follow-up (n = 2). Sensitivity, specificity, positive predictive value and negative predictive value were, respectively, 80%, 100%, 100% and 84.6% on patient-based analysis (presence or absence of infection). They were 100%, 100%, 100% and 100% for boxes, but only 60%, 100%, 100% and 73% for leads. Quantitative analysis could be useful for boxes but not for leads, for which the presence of a mild hot spot was the best criterion of infection. The four false negatives on leads received antibiotics for longer than the six true positives (20 ± 7.2 vs. 3.2 ± 2.3 days, p <0.01). Although the study was not designed for this purpose, management could have been modified by PET results in six of 21 patients. (18) F-FDG PET imaging may be useful for the diagnosis of device infection, and could impact on clinical management. Interpretation of negative cases should be performed with caution if patients have received antibiotics.

Diagnostic contribution of positron emission tomography with [18F]fluorodeoxyglucose for invasive fungal infections

Optimal staging and evaluation of residual lesions of invasive fungal infections (IFIs) are major challenges in the immunocompromised host. Preliminary data have suggested that [¹⁸F]fluorodeoxyglucose ([¹⁸F]FDG) uptake may be observed in the course of active invasive fungal infections. The aim of this study was to assess the role of positron emission tomography with [¹⁸F]FDG ([¹⁸F]FDG-PET) in the diagnosis and staging of IFI. A prospective monocentric study evaluating [¹⁸F]FDG-PET in 30 consecutive adults and children with European Organization for Research and Treatment of Cancer/Mycoses Study Group probable or proven IFI was performed. Twenty males and ten females (median age, 45 years (range 6-7 years)) were enrolled. Twenty-six were immunocompromised, as follows: haematological malignancy (18) with allogeneic stem cell transplantation (16/18), solid tumour (three), solid organ transplantation (two), diabetes mellitus (two) and cystic fibrosis (one). IFIs were acute invasive aspergillosis (ten), chronic disseminated candidiasis (ten), zygomycosis (two), black grains eumycetoma (two), pulmonary Histoplasma capsulatum var. capsulatum histoplasmosis (two), and Phomopsis sp. osteoarthritis, Scedosporium apiospermum and Candida krusei spondylodiscitis, and acute pulmonary coccidioidomycosis in one case each. An increased uptake of [¹⁸F]FDG was observed in all areas previously identified by computed tomography and/or magnetic resonance imaging to be involved by IFI. In 4/10 chronic disseminated candidiasis cases, [¹⁸F]FDG-PET revealed small splenic abscesses that were unapparent on the corresponding computed tomography scan. [¹⁸F]FDG uptake disappeared after 6 months of antifungal therapy in three patients with chronic disseminated candidiasis for whom the [¹⁸F]FDG-PET was performed to assess the evolution of the disease. [¹⁸F]FDG-PET could potentially be useful for the initial diagnosis and staging of IFI. Whether or not [¹⁸F]FDG-PET might be useful for assessing the optimal duration of IFI therapy should now be assessed in a specific prospective study.

Role of technetium 99m methoxyisobutylisonitrile single photon emission tomography in the evaluation of thrombolysis in acute myocardial infarction before and after admission to hospital

To investigate initial perfusion status in acute myocardial infarction, methoxyisobutylisonitrile (MIBI) was administered by the rescue physicians. Thirty-nine patients received the radiopharmaceutical at home or upon arrival at the hospital. Diagnosis was confirmed in 30 patients, and 19 emergency thrombolyses were performed. Initial single photon emission tomography (SPET) analysis was constantly abnormal in confirmed myocardial infarction sometimes before direct electrocardiographic signs. MIBI-SPET was normal in non-coronary syndromes. MIBI uptake improved after thrombolysis (P < 0.001) but also after heparin therapy (P < 0.05). SPET improvement demonstrated myocardial salvage earlier than wall motion studies. MIBI administration at the patients home allowed very early perfusion imaging when thrombolysis was performed at home. MIBI-SPET has the potential use of comparing thrombolytic agents or at home versus in hospital thrombolysis.

Lower-Limb Drainage Mapping for Lymphedema Risk Reduction After Pelvic Lymphadenectomy for Endometrial Cancer

OBJECTIVES Pelvic lymphadenectomy is associated with a significant risk of lower-limb lymphedema. In this proof-of-concept study, we evaluated the feasibility of identifying the lower-limb drainage nodes (LLDNs) during pelvic lymphadenectomy for endometrial cancer. Secondary objectives were to map lower-limb drainage and to assess the diagnostic value of our mapping technique. METHODS This prospective study included patients with endometrial cancer requiring pelvic lymphadenectomy, without neoadjuvant radiotherapy or chemotherapy and without history of lower-limb surgery. A radiopharmaceutical was injected into both feet on the day before surgery. LLDNs were identified using preoperative lymphoscintigraphy and intraoperative isotopic probe detection, then removed before complete pelvic lymphadenectomy. LLDNs and pelvic lymphadenectomy specimens underwent separate histological analysis. RESULTS Of the 12 patients with early-stage endometrial cancer, 10 underwent preoperative lymphoscintigraphy, which consistently identified inguinal, femoral, and pelvic LLDNs (detection rate: 100%). The intraoperative detection rate was 83% (10/12). Median number of hot nodes per patient was 5 nodes (range: 3-7) on the right and 3 nodes (range: 2-6) on the left. Of 107 LLDNs, 106 were in the external iliac area, including 38 in the lateral group and 45 in the intermediate and medial groups. None of the patients had node metastases at any site. No early complications related to the technique occurred. CONCLUSION Our mapping technique appears feasible, safe, and associated with a high LLDN identification rate. LLDN mapping may allow the preservation of LLDNs, thereby decreasing the risk of lower-limb lymphedema and improving quality of life.

Tecnica e risultati del prelievo del linfonodo sentinella nei cancri del collo e del corpo dell’utero

La biopsia del linfonodo sentinella e una metodica diagnostica che permette il prelievo linfonodale mirato delle prime stazioni linfonodali di un tumore, rappresentativo dei linfonodi a valle. Questa tecnica si sviluppa da una decina di anni nei cancri dell’utero, per i quali lo status linfonodale e un fattore prognostico principale. I suoi obiettivi principali sono di ridurre la morbilita degli svuotamenti completi, di individuare dei territori di drenaggio inattesi e, anche, di realizzare un’ultrastadiazione linfonodale. La tecnica di rilevamento combinata, con coloranti e isotopi, e quella che apporta i migliori risultati in termini di tasso di individuazione. I dati della letteratura sulla biopsia del linfonodo sentinella nei cancri del collo precoci hanno dimostrato ampiamente la sua fattibilita. I tassi di individuazione sono molto buoni, come anche il suo valore diagnostico. La tecnica permette di realizzare un’ultrastadiazione linfonodale evidenziando delle micrometastasi. Il prelievo del linfonodo sentinella e realizzabile anche nei cancri dell’endometrio, con, tuttavia, dei tassi di individuazione e di falsi negativi molto variabili secondo le casistiche, influenzati soprattutto dalla via di iniezione. Se l’iniezione intratumorale, realizzata soprattutto mediante isteroscopia, e quella che permette di evidenziare meglio il vero drenaggio linfatico del tumore, la sua attuazione e, tuttavia, assai poco riproducibile.

Técnica y resultados de la biopsia del ganglio centinela en los cánceres del cuello y del cuerpo uterinos

La biopsia del ganglio centinela es un metodo diagnostico que permite la extirpacion dirigida de las primeras invasiones ganglionares de un tumor, una muestra que es representativa de los ganglios subsiguientes. Esta tecnica se esta desarrollando desde hace unos 10 anos con relacion a los canceres del utero, en los cuales el estado ganglionar es un factor pronostico principal. Sus objetivos principales son limitar la morbilidad de los vaciamientos ganglionares completos, detectar territorios de drenaje inesperados y efectuar una ultraestadificacion ganglionar. La tecnica de deteccion combinada, por tincion e isotopica, produce los mejores resultados en cuanto a indices de deteccion. Los datos de las publicaciones sobre la biopsia precoz del ganglio centinela en los canceres del cuello uterino confirman ampliamente la utilidad de esta practica. Los indices de deteccion y el valor diagnostico son muy buenos. La tecnica hace posible una ultraestadificacion ganglionar para demostrar micrometastasis. La biopsia del ganglio centinela tambien es factible en los canceres de endometrio, pero los indices de deteccion y de falsos negativos varian mucho segun las series, principalmente en relacion con la via de inyeccion. Aunque la inyeccion intratumoral por histeroscopia es la que permite demostrar mejor el verdadero drenaje linfatico del tumor, su realizacion es bastante poco reproducible.