Anne-Sophie Pirson

Role of PET in the Initial Staging of Cutaneous Malignant Melanoma: Systematic Review

PURPOSE To calculate summary estimates of the diagnostic performance of fluorine 18 fluorodeoxyglucose (FDG) positron emission tomographic (PET) imaging in the initial staging of cutaneous malignant melanoma (CMM), following the new American Joint Committee on Cancer (AJCC) staging classification on per-patient and per-lesion bases. MATERIALS AND METHODS MEDLINE, EMBASE, Web of Science, and Cochrane Database of Systematic Reviews databases, and reference lists of reviews and included papers were searched, without any language restrictions, for relevant articles published before March 2007. Two reviewers independently assessed study eligibility and methodologic quality by using the quality assessment of diagnostic accuracy studies checklist. A pooled random effect was estimated and a fixed coefficient regression model was used to explore the existing heterogeneity. RESULTS Twenty-eight studies involving 2905 patients met the inclusion criteria. The pooled estimates of FDG PET for the detection of metastasis in the initial staging of CMM were sensitivity, 83% (95% confidence interval [CI]: 81%, 84%); specificity, 85% (95% CI: 83%, 87%); positive likelihood ratio (LR), 4.56 (95% CI: 3.12, 6.64); negative LR, 0.27 (95% CI: 0.18, 0.40); and diagnostic odds ratio, 19.8 (95% CI: 10.8, 36.4). Results from eight studies suggested that FDG PET was associated with 33% disease management changes (range, 15%-64%). CONCLUSION There is good preliminary evidence that FDG PET is useful for the initial staging of patients with CMM, especially as adjunctive role in AJCC stages III and IV, to help detect deep soft-tissue, lymph node, and visceral metastases. FDG PET-computed tomographic imaging seemed to be more precise than PET alone, as suggested by four eligible studies. Further evaluation by using a well-designed prospective study, with clinical outcome-focused measures and cost effectiveness analysis, is needed to clarify the appropriate role of FDG PET in CMM staging. SUPPLEMENTAL MATERIAL http://radiology.rsnajnls.org/cgi/content/full/249/3/836/DC1.

Cost-effectiveness analysis of FDG PET-CT in the management of pulmonary metastases from malignant melanoma.

Abstract Objectives. Most guidelines consider FDG PET-CT to detect occult extra-pulmonary disease prior to lung metastasectomy. A cost-effectiveness analysis, using a Markov model over a 10 year period, was performed to compare two different surveillance programs, either PET-CT or whole-body CT, in patients with suspected pulmonary metastasised melanoma. Methods. Data from published studies provided probabilities for the model. Complication and care costs were obtained from standardised administrative databases from 19 hospitals identified by DRG codes (reported in 2009 Euros). For the cost calculation of PET-CT we performed a microcosting analysis. All costs and benefits were yearly discounted at respectively 3% and 1.5%. Outcomes included life-months gained (LMG) and the number of futile surgeries avoided. Cost-effectiveness ratios were in Euros per LMG. Univariate and probabilistic sensitivity analyses addressed uncertainty in all model parameters. Results. The PET-CT strategy provided 86.29 LMG (95% CI: 81.50–90.88 LMG) at a discounted cost of €3 974 (95% CI: €1 339–12 303), while the conventional strategy provided 86.08 LMG (95% CI: 81.37–90.68 LMG) at a discounted cost of €5 022 (95% CI: €1 378–16 018). This PET-CT strategy resulted in a net saving of €1 048 with a gain of 0.2 LMG. Based on PET-CT findings, 20% of futile surgeries could be avoided. Conclusion. Integrating PET-CT in the management of patients with high risk MM appears to be less costly and more accurate by avoiding futile thoracotomies in one of five patients as well as by providing a small survival benefit at 10 years.

Activity-based costing evaluation of a [18F]-fludeoxyglucose positron emission tomography study

OBJECTIVE The aim of the study is to use the activity-based costing approach to give a better insight in the actual cost structure of a positron emission tomography procedure (FDG-PET) by defining the constituting components and by simulating the impact of possible resource or practice changes. METHODS The cost data were obtained from the hospital administration, personnel and vendor interviews as well as from structured questionnaires. A process map separates the process in 16 patient- and non-patient-related activities, to which the detailed cost data are related. One-way sensitivity analyses shows to which degree of uncertainty the different parameters affect the individual cost and evaluate the impact of possible resource or practice changes like the acquisition of a hybrid PET/CT device, the patient throughput or the sales price of a 370MBq (18)F-FDG patient dose. RESULTS The PET centre spends 73% of time in clinical activities and the resting time after injection of the tracer (42%) is the single largest departmental cost element. The tracer cost and the operational time have the most influence on cost per procedure. The analysis shows a total cost per FDG-PET ranging from 859 Euro for a BGO PET camera to 1142 Euro for a 16 slices PET-CT system, with a distribution of the resource costs in decreasing order: materials (44%), equipment (24%), wage (16%), space (6%) and hospital overhead (10%). CONCLUSIONS The cost of FDG-PET is mainly influenced by the cost of the radiopharmaceutical. Therefore, the latter rather than the operational time should be reduced in order to improve its cost-effectiveness.

FDG PET utility in paraneoplastic sweet syndrome.

We describe a 43-year-old woman who presented a sudden onset of fever and migratory arthralgias. Physical examination revealed tender, well-demarcated erythematous papules and plaques, consistent with a Sweet syndrome. After developing systemic symptoms with hepatomegaly, a liver biopsy and FDG PET imaging demonstrated the presence of an aggressive and extended non-Hodgkin T-cell lymphoma. This case highlights the usefulness of FDG PET imaging for the screening of this paraneoplastic symdrome.

The diagnostic accuracy of (18)F-FDG PET in cutaneous malignant melanoma

Dear Sir, We read with great interest the meta-analysis by JiménezRequena et al. published in the February 2010 issue concerning the diagnostic performance of F-FDG PET in cutaneous malignant melanoma [1]. In agreement with a 2-year-old meta-analysis published in Radiology [2], the authors found that F-FDG PET is not adequate for regional node staging, but could be useful in the detection of distant metastases. However, we would like to point out some methodological flaws, which could have resulted in potentially incomplete or misleading conclusions. Although their meta-regression analysis showed that the year of publication was the variable that most influenced the diagnostic odds ratio, the authors included studies only up to January 2006, but eight studies, with the largest numbers of patients, have been published since then [3–10]. Some of these investigated the accuracy of F-FDG PET/ CT, which is the current state of the art in nuclear medicine. In addition to better patient comfort due to the one-step acquisition, the seamless integration of anatomic (CT) and metabolic (PET) images results in an increased accuracy with a pooled sensitivity and specificity of 92% and 91%, respectively [7, 8, 10]. As health technology assessment supports evidence-based decision making in imaging policy and practice, meta-analyses should include the most recent studies in which use the state of the art imaging protocols have been used. In the era of evidence-based medicine, with systematic reviews as its cornerstone, quality assessment is as important in diagnostic accuracy studies as it is in any other review. The methodological quality criteria used by Jiménez-Requena et al. were well designed, but were modified from previously developed criteria, and English language articles were considered for potential inclusion in their study. Such an approach could be biased by preconceived ideas and hamper the updating of diagnostic meta-analyses. The QUADAS tool, which is a systematically developed evidenced-based tool for the assessment of diagnostic accuracy studies, has been developed for facilitating comparison among meta-analyses. We therefore also emphasize the need to design high-quality prospective studies for assessing new diagnostic imaging technologies [11–13]. Our last comments deal with the endpoints chosen by the authors, which are not easily transposable to the clinical setting. As stressed in the introduction, the American Joint Cancer Classification (AJCC) is routinely used for prognostic issues. The AJCC staging system divides tumours into four main stages based upon tumour thickness and ulceration of the primary tumour (stages I and II), the presence of clinical occult or apparent regional lymphatic metastases (stage III) and the presence of visceral or nonvisceral metastases (stage IV). As staging work-up and follow-up guidelines are usually based on this classification, a comparison with these clinicopathological endpoints would be more meaningful clinically [14]. The search for homogeneity in primary studies using multiple endpoints (patients, lesions, areas and scans) usually delays An authors reply to this letter is available at http://dx.doi.org/10.1007/ s00259-010-1476-3.

Bladder hernia simulating metastatic lesion on FDG PET study.

Abstract:A 67-year-old man with a cerebral metastasis underwent an FDG PET study to search for the primary tumor. Colonic adenocarcinoma without liver metastases was found. An unsuspected inguinal focus, simulating a metastasis, was urinary activity in a vesical hernia. Vesical hernias are not so un

Additional value of I-123 MIBG SPECT in neuroblastoma.

A 4-year-old boy with fever and abdominal pain was found to have left basal hypoventilation on physical examination. Chest x-ray showed a homogeneous density of the lower left lung. Corresponding computed tomography demonstrated a left adrenal mass extending to the chest with calcifications on contrast enhancement. I-123 MIBG was performed for tumor characterization and the histology revealed a neuroblastoma.

Refractory thyroid carcinoma: which systemic treatment to use?

The incidence of thyroid cancer has increased markedly in recent decades, but has been stable in terms of mortality rates. For the most part, these cancers are treated with surgery, which may or may not be followed by radioactive iodine depending on the tumor subtype. Still, many of these cancers will recur and may be treated with radioactive iodine or another surgery. It is unclear what treatment is best for cases of locally advanced or metastatic thyroid cancer that are refractory to radioactive iodine. Chemotherapy has a very low response rate. However, in the past few years, several systemic therapies, primarily targeted, have emerged to improve the overall survival of these patients. Alternative treatments are also of interest, namely peptide receptor radionuclide therapy or immunotherapy.

Unusual ventilation-perfusion scans in the follow-up of two lung transplant patients.

Airway anastomotic stenosis after lung transplantation is a potential cause of early morbidity and mortality, especially after double lung transplantation. A 55-year-old woman and a 63-year-old man were referred for ventilation-perfusion scans [Kr-81 and Tc-99m macroaggregated albumin (MAA)] for routine assessment 3 months after having benefited from a bilateral lung transplantation The unilateral absence of ventilation in each case suggested main bronchial obstruction. In the former patient, the bronchoscopy was inconsistent with the lung scan findings, showing only an incomplete stenosis secondary to an aspergillosis fibrin lesion. A worsening of the obstruction in the supine position was thus suspected and confirmed by improved ventilation in the upright position. In the latter case, the before and after ventilation-perfusion scans showed the benefits of dilatation treatment of the stenotic bronchial anastomosis. These cases illustrate the benefit of ventilation-perfusion scans in the detection of airway anastomotic stenosis after lung transplantation, even in non-, or poorly symptomatic patients, and their usefulness in the evaluation of the response to treatment.

Acute renal failure as the first presenting sign of non-Hodgkin’s lymphoma

Acute renal failure is rarely the first manifestation of non-Hodgkin’s lymphoma [1, 2, 3]. Here we report the case of a 29-year-old man with acute renal failure due to bilateral lymphomatous infiltration by non-Hodgkin’s high-grade lymphoma, diffuse large B-cell type, as demonstrated by a percutaneous biopsy of the kidney. The figure shows the maximum intensity projection of the coronal images of an initial FDG-PET scan (A) and an FDG-PET scan performed after four cycles of R-ACVBP chemotherapy (B). At initial staging, markedly increased uptake was noted in the enlarged kidneys as well as in the spleen and cervical, axillary and mediastinal lymph nodes. After 4 months of treatment the renal clearance and the follow-up FDG-PET appearance had normalised.