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The effect of erythropoietin stimulation on bone marrow uptake of FDG has been well documented. Similar metabolic activation of bone marrow with (18)F-fluorocholine (FCH) has not been previously reported. FCH PET/CT was performed in a patient with biochemical recurrent prostate cancer who was receiving erythropoietin for hemochromatosis. Diffuse skeletal uptake of FCH was seen. (18)F-Fluoride PET/CT performed the following day demonstrates multiple abnormal focal bone metastases. Generalized skeletal uptake of FCH results in poor contrast between the metastases compared to noninvolved bone. The metabolic activation of bone marrow by erythropoietin could result in false-negative FCH results for detecting bone metastases.

Objectives To assess the clinical performance of fluorodeoxyglucose positron emission tomography (FDG PET) using either a coincidence (CDET) gamma camera or PET equipment with Nal crystals for the detection of recurrencesof colorectal cancer. Methods From July 1997 to December 1999, 290 examinations were performed in 244 patients using a CDET gamma camera (2-dimensional system with 19 mm thick crystals). Additionally, from January 2000 to July 2002, 354 examinations were performed in 303 patients using PET (3-dimensional system with Nal crystals). Results Four hundred and seventy-three of the 644 examinations performed were evaluable on the basis of histological data (202 examinations) or more than 6 months of follow-up (273 examinations). The performances of the two systems were equivalent on a patient basis (sensitivity, specificity and accuracy of dedicated PET was 92%, 84% and 90%, respectively; and sensitivity, specificity and accuracy of CDET was 90%, 94% and 91%, respectively). On a site basis, a highly significant reduction in sensitivity was observed for lesions ≤ 10 mm vs. > 10 mm with both PET and the CDET gamma camera, but no difference was observed between PET and CDET according to the size of the lesions. Conclusion For detection of recurrent colorectal carcinoma, a 2-D coincidence gamma camera with 19 mm thick crystals and optimized acquisition and reconstruction parameters provides similar results in terms of accuracy, both per patient and per site, to those of an Nal PET camera.

Small cell lung carcinomas (SCLC) express neuroendocrine markers, and dihydroxyphenylalanine (DOPA) is known to accumulate in neuroendocrine tumours. This study was performed with the aim of evaluating the uptake of 3,4-dihydroxy-6-(18)F-fluoro-phenylalanine ([(18)F]FDOPA) by SCLC, based on comparison with the results of fluorine-18 fluorodeoxyglucose ([(18)F]FDG) positron emission tomography (PET) and standard imaging procedures. [(18)F]FDG PET and [(18)F]FDOPA PET were performed on four patients with newly diagnosed SCLC. There was agreement between the results of [(18)F]FDOPA PET and [(18)F]FDG PET in four tumoural sites out of 11, whereas [(18)F]FDG PET and standard imaging procedures were in full agreement. A semi-quantitative analysis based on standardised uptake values (SUVs) was performed in order to compare [(18)F]FDG and [(18)F]FDOPA tumour uptake. The median [(18)F]FDG SUV(max) was 5.9 (with a 95% confidence interval from 4.4 to 9.2), while the median [(18)F]FDOPA SUV(max) was 1.9 (with a 95% confidence interval from 1.6 to 3.8). The difference between [(18)F]FDG SUV(max) and [(18)F]FDOPA SUV(max) was significant ( P0.01). [(18)F]FDOPA PET appeared less sensitive than [(18)F]FDG PET and standard imaging procedures in the staging of SCLC. No clear relation between [(18)F]FDOPA uptake and positivity of neuroendocrine markers on immunohistochemistry emerged from these preliminary results; however, since [(18)F]FDOPA uptake may reflect better differentiation of the tumour, and possibly a better prognosis, this point warrants clarification in a larger study.

This prospective study was performed to evaluate the ability of a dual-head gamma camera with fluorine-18 fluorodeoxyglucose coincidence detection emission tomography (FDG-CDET) to detect primary tumor and cervical lymph nodes in head and neck squamous cell carcinoma (HNSCC), and to show the response of the carcinoma to chemotherapy. The findings were compared with those of physical examination, computed tomography (CT), and histopathology, before treatment in 61 patients, and after induction chemotherapy in 34 of them. Before treatment, the primary was detected in 93%, 79%, and 95% of cases on panendoscopy, CT, and FDG-CDET, respectively. After chemotherapy, 34 patients were evaluable for response of the primary tumor. Surgical resection was performed in 23 of them: agreement with histopathologic results for response to treatment was 74%, 69%, and 78% for panendoscopy, CT, and FDG-CDET, respectively. No surgical resection was performed in 11 of the 34 patients, but biopsies were performed before radiotherapy, and their rates of agreement with histopathologic results for response to treatment were 75%, 75%, and 67% on panendoscopy, CT, and FDG-CDET, respectively. For cervical lymph nodes, 245 sites were resected in 41 patients, and FDG-CDET appeared competitive with CT in detecting metastatic neck disease, especially after neoadjuvant chemotherapy; the accuracy was 93%. These results demonstrated the ability of FDG-CDET to detect primary tumors and cervical lymph nodes in HNSCC and to show its response to chemotherapy, as compared to the ability of CT and panendoscopy. It may be a complementary tool to evaluate residual disease after induction chemotherapy, although higher sensitivity would be required for FDG-CDET to be considered as a staging modality.

Introduction Les tumeurs neuro-endocrines (TNE) sont relativement rares, mais pratiquement toutes sont explorees en medecine nucleaire. La TEP/TDM a la 18F-Fdopa est disponible depuis une decennie et plus recemment le 68Ga-edotreotide ou Dotatoc ligand des recepteurs de la somatostatine. Cependant, les donnees manquent concernant le debit de dose emis par le patient lorsqu’il quitte le service apres un examen par TEP ; or la radioprotection du public, des proches des patients et de l’environnement est un sujet de preoccupation. Materiels et methodes Nous avons realise des mesures de debit de dose apres examen par TEP/TDM 68Ga-Dotatoc ou 18F-Fdopa chez des patients consecutifs adresses a notre centre pour suspicion ou stadification de TNE. Les mesures ont ete effectuees quand ils s’appretaient a quitter le service, en utilisant un radiametre Target Identifinder de la societe ARIES. Apres miction, les mesures du debit de dose a 1 m (en μSv/h) ont ete realisees chaque fois en regard du sternum (pour evaluer la zone « thorax ») et en regard de la vessie (pour evaluer la zone « pelvis »). Nous avons utilise l’analyse de variance pour comparer les debits de dose entre ces deux radiopharmaceutiques et un test- t apparie pour comparer les valeurs en regard des deux zones anatomiques. Resultats Les mesures ont eu lieu pendant une periode de 3 mois, chez 68 patients au total, 53 fois (29 hommes et 24 femmes) apres injection de 68Ga-Dotatoc et 15 fois (6 hommes et 9 femmes) de 18F-Fdopa. Il n’existait pas de difference significative concernant les caracteristiques demographiques des patients de ces deux groupes. La mediane de l’activite administree etait 122 MBq pour 68Ga-Dotatoc et 198 MBq pour 18F-Fdopa. La mediane des delais entre injection et mesure etait 87 min pour 68Ga-Dotatoc et 117 min pour 18F-Fdopa. Le debit de dose de tous les patients etait inferieur a 20 μSv/h. Les moyennes des debits de dose (en μSv/h) face au sternum et a la vessie etaient, respectivement, 4,8 et 5,1 pour 68Ga-Dotatoc et 9,5 et 10,1 pour 18F-Fdopa. Le debit de dose etait en moyenne significativement plus eleve en regard du « pelvis » que du « thorax ». Discussion Le debit de dose a 1 m des patients quittant le service apres avoir beneficie d’un examen TEP 68Ga-Dotatoc ou 18F-Fdopa pour TNE est suffisamment faible pour ne pas poser de probleme de radioprotection ni de necessiter une quelconque restriction dans le transport du patient.

Nodular lymphocyte predominant Hodgkin disease (NLPHL) differs clearly from classical Hodgkin lymphoma (cHL) by clinical presentation and more favorable outcome. Patients often present with early stage IA or IIA. Extranodal disease and B-symptoms are uncommon. Histologically, NLPHL is characterized by the presence of atypical "lymphocyte predominant cells" (LP cells) or "pop-corn" cells in a non-neoplastic and reactionnal nodular background of small mature B-lymphocytes. LP cells are negative for CD30 and positive for CD20, BCL6 and EMA (in half of the cases). FDG-PET plays an important role in evaluation of cHL and NLPHL for staging, therapy assessment and relapse. Historically, patients with NLPHL have been treated like patients with cHL, but their very favorable prognosis and the risk of late complications of chemotherapy and/or radiotherapy have led to a de-escalation in recent years. Patients with early stage could be treated by surgical adenectomy alone or associated with not intensive chemotherapy. Currently, there is no consensus regarding to the optimal treatment of patients with advanced stage. Rituximab used as monotherapy or in association with chemotherapy has achieved complete or partial responses. The outcome of NLPHL is singular by the frequent occurrence of late relapses and the risk of transformation into aggressive B lymphoma justifying an extended follow-up. Further prospective studies are needed to optimize treatment of these advanced and recurrent forms.

Resume Bien que les cancers gynecologiques restent actuellement en dehors de l’AMM du 〚18F〛-fluoro-2-desoxyglucose (FDG) en France, de nombreuses etudes y montrent un interet potentiel pour la TEP, un nouvel examen d’imagerie derive de la scintigraphie, permettant la detection du FDG ou des molecules similaires a l’aide soit d’une machine dediee soit d’une gamma-camera « hybride » (TEDC). Les indications de la TEP au FDG dans les cancers du sein, de l’ovaire ou du col uterin sont passees en revue selon les diverses phases du diagnostic : examen systematique, caracterisation d’une masse, bilan d’extension, efficacite de la chimiotherapie et recherche de recidive. En regroupant les resultats publies, l’exactitude de l’examen TEP est estimee avec precision dans plusieurs indications : caracterisation d’une tumeur mammaire (598/696 = 86 %), extension ganglionnaire d’un cancer du sein (525/602 = 87 %), recidive de cancer du sein (114/127 = 90 %), caracterisation d’une masse annexielle (130/176 = 78 %), recidive de cancer de l’ovaire (152/172 = 88 %), extension ganglionnaire d’un cancer du col uterin (98/103 = 95 %). Nous rapportons ensuite des donnees originales concernant les performances diagnostiques de la TEDC : chez 44 patientes suspectes de recidive du cancer du sein, la sensibilite de la FDG-TEDC etait de 94 %, la specificite de 82 % et l’exactitude de 91 % ; chez 18 patientes suspectes de recidive de cancer ovarien la sensibilite, la specificite et l’exactitude etaient de 100 %. Les examens TEP au FDG effectues par notre equipe en l’an 2000 ont abouti, selon 63 questionnaires retournes, a un changement de stade dans 48 % des cancers du sein, 36 % des cancers de l’ovaire et 43 % des cancers du col uterin et surtout a une modification therapeutique dans 69 %, 64 % et 60 % des cas respectivement, contre 50 % pour l’ensemble des cancers, sans difference significative entre TEP dediee et TEDC.

The presence of somatostatin receptors on human renal cell carcinomas in surgically removed kidneys has been demonstrated by autoradiography. The aim of this study was to detect to in vivo presence of somatostatin receptors in primary renal tumours and their possible metastases before surgery, using 111In-pentreotide scintigraphy. 201Tl was used as a sensitive tumour-seeking agent with blood flow-dependent uptake. Fifteen patients were imaged before surgical removal of the renal tumour. Thirteen tumours were malignant. The large tumours (more than 4 cm in diameter) did not accumulate 111In-pentreotide or 201Tl. In contrast, the single small tumour accumulated both tracers. A scalp skin metastasis was demonstrated in one patient by 201Tl and 111In-pentreotide uptake. In one case, known lung metastases were visualized with both 201Tl and 111In-pentreotide, but the lung metastases of another three patients as well as one case of epidural metastasis were not identified. In one patient with a photopaenic lesion, positive labelling of the surgically removed tumour was demonstrated by in vitro autoradiography. Somatostatin receptor scintigraphy with 111In-pentreotide appears to have little value for the detection of metastases in patients with renal cell carcinoma, as some metastases (especially those of the lungs) were missed. The absence of 111In-pentreotide uptake by large primary tumours is an interesting finding, suggesting inaccessibility of these very large tumours to drugs.

The aim of this review is to give an overview of FDG PET/CT applications in children and adolescents with lymphoma. Today, FDG PET is used for tailoring treatment intensity in children with Hodgkin lymphoma within the framework of international treatment optimisation protocols. In contrast, the role of this method in children with Non-Hodgkin lymphoma is not well defined. This paper overviews clinical appearance and metabolic behaviour of the most frequent lymphoma subtypes in childhood. The main focus of the review is to summarise knowledge about the role of FDG PET/CT for initial staging and early response assessment.

Congenital hyperinsulinism (HI) is an inappropriate insulin secretion by the pancreatic β-cells secondary to various genetic disorders. The incidence is estimated at 1/50, 000 live births, but it may be as high as 1/2, 500 in countries with substantial consanguinity. Recurrent episodes of hyperinsulinemic hypoglycemia may expose to high risk of brain damage. Hypoglycemias are diagnosed because of seizures, a faint, or any other neurological symptom, in the neonatal period or later, usually within the first two years of life. After the neonatal period, the patient can present the typical clinical features of a hypoglycemia: pallor, sweat and tachycardia. HI is a heterogeneous disorder with two main clinically indistinguishable histopathological lesions: diffuse and focal. Atypical lesions are under characterization. Recessive ABCC8 mutations (encoding SUR1, subunit of a potassium channel) and, more rarely, recessive KCNJ11 (encoding Kir6.2, subunit of the same potassium channel) mutations, are responsible for most severe diazoxide-unresponsive HI. Focal HI, also diazoxide-unresponsive, is due to the combination of a paternally-inherited ABCC8 or KCNJ11 mutation and a paternal isodisomy of the 11p15 region, which is specific to the islets cells within the focal lesion. Genetics and 18F-fluoro-L-DOPA positron emission tomography (PET) help to diagnose diffuse or focal forms of HI. Hypoglycemias must be rapidly and intensively treated to prevent severe and irreversible brain damage. This includes a glucose load and/or a glucagon injection, at the time of hypoglycemia, to correct it. Then a treatment to prevent the recurrence of hypoglycemia must be set, which may include frequent and glucose-enriched feeding, diazoxide and octreotide. When medical and dietary therapies are ineffective, or when a focal HI is suspected, surgical treatment is required. Focal HI may be definitively cured when the partial pancreatectomy removes the whole lesion. By contrast, the long-term outcome of diffuse HI after subtotal pancreatectomy is characterized by a high risk of diabetes, but the time of its onset is hardly predictable.

The aim of this study was to compare the effectiveness of a hand-held preoperative compact imager (POCI) camera with conventional lymphoscintigraphy using a γ-camera for sentinel lymph node (SLN) detection in breast cancer.The main objective was to demonstrate the noninferiority of the POCI relative to conventional lymphoscintigraphy and to compare the number of SLNs detected by the 2 imaging devices. Our study, a clinical prospective, double-blind, noninferiority study, planned to include 200 patients with early breast cancer and started in January 2006. A standard SLN protocol (4 periareolar injections of 37 MBq of (99m)Tc-nanocolloids, 2 h before lymphoscintigraphy) was performed preoperatively using a conventional γ-camera and then the POCI camera. Scans were obtained by 2 different nuclear medicine physicians unaware of each other's results. The day after, in the operating room, the surgeon, after receiving the previous results, used the counting probe for surgical SLN biopsy. The number and localization of axillary SLNs obtained by lymphoscintigraphy and the POCI and the duration of the whole procedure were determined.Among the 162 patients included, 138 were evaluable. The POCI detected more SLNs than did lymphoscintigraphy in 50 patients (36%), the same number of in 54 patients (39%), and fewer SLNs in 34 patients (25%), representing 84 (61%) discordant pairs. The noninferiority of preoperative compact imaging of axillary SLNs numbers was found to be statistically significant (95% confidence interval, 30%-52%, P = 0.025) using the McNemar test. The duration of acquisition was shorter using the POCI (10 min in 84% [n = 117] of patients; mean, 7.5 ± 3.3 min) than lymphoscintigraphy (13% [n = 18] of patients; mean, 15.7 ± 3.4 min), with P0.001 using the McNemar test for paired proportions.Preoperative compact imaging using a hand-held camera was able to predict the number and localization of breast cancer SLNs and was not inferior to conventional lymphoscintigraphy in this study. Further studies will determine whether preoperative compact imaging could replace lymphoscintigraphy, especially in surgical centers without an on-site nuclear medicine department.

The purpose of the study was to assess the diagnostic performance of positron emission tomography/computed tomography and fluorodeoxyglucose (18F) (FDG PET/CT) for the staging and the follow-up of anal carcinoma, and to evaluate the impact of FDG PET/CT on patient management.Patients with anal carcinoma were referred to our department from October 2004 until July 2008. The diagnostic performance was evaluated on a perexamination basis and on a per-site basis, together with impact of PET/CT on patient management. The standard of truth was histology when available and, in all cases, follow-up data during at least 6 months.Fifty-eight FDG PET/CT performed in 44 patients were analysed—22 for initial staging and 36 during follow-up. The detection rate of non-excised tumours on initial examination was 93%. During post-treatment follow-up, FDG PET/CT had, on a per-examination basis, sensitivity for the detection of persistent or recurrent disease of 93% and specificity of 81%, and on a per-site basis, 86% and 97%, respectively. Its negative predictive value was 94% on a per-examination basis and 98% on a per-site basis. FDG PET/CT had an impact on management in nine patients out of 44 (20%), which was relevant in eight of them (89%).FDG PET/CT is an accurate imaging modality in anal cancer. It has an interesting added value during post-treatment follow-up, especially when persistence or recurrence of disease is suspected. Further studies are needed to evaluate whether surveillance by means of FDG PET/CT might have a positive impact on overall survival.

Aim Bronchioloalveolar (BAC) cancer is a source of false-negative F-fluorodeoxyglucose (FDG) PET/computed tomography (CT) results. A few studies reported better diagnostic performances with PET tracers of lipid metabolism, C-choline, or C-acetate, for the detection of well-differentiated adenocarcinoma or BAC. F-fluorocholine (FCH) is a lipid analogue for PET imaging, with advantages in terms of logistics and image resolution. We carried out this prospective pilot study to evaluate whether FCH PET/CT could detect lung cancer with a BAC component and could be more sensitive than FDG in this aim. Methods Fifteen patients with a lung nodule or lesion suspected for BAC on CT and/or with a history of BAC had PET/CT 60-90 min after 5 MBq FDG/kg body mass and, on a separate day, 10-20 min after 4 MBq FCH/kg body mass. The standard of truth was histology and a 6-month follow-up. Results Nine patients (12 lesions) presented BAC or adenocarcinoma with BAC features, two patients presented adenocarcinoma without BAC features (five lesions) and four patients presented benign lesions (15 non-malignant sites). For both FCH and FDG, patient-based sensitivity was 78% for detecting cancer with a BAC component and 82% for detecting malignancy. Site-based sensitivity for detecting malignancy was 76 and 75% for detecting cancer with BAC features, for both radiopharmaceuticals. Specificity was similar for FCH and FDG (site-based 93 vs. 81%, NS). In these early-stage cancers, only one adrenal metastasis was observed that took up FCH and FDG. Conclusion In this population of patients with ground-glass opacities selected on CT suggestive of BAC or with a history of BAC and a recent lung anomaly on CT, FCH detected all malignant lesions with at least a 2.0 cm short axis. However, FDG had similar performance.

We assessed the potential benefits of including systematic 18fluorodeoxyglucose positron emission tomography (FDG-PET) for detecting tumour recurrence in a prospective randomised trial. Patients (N=130) who had undergone curative therapy were randomised to undergo either conventional (Con) or FDG-PET procedures during follow-up. The two groups were matched at baseline. Recurrence was confirmed histologically. 'Intention-to-treat' analysis revealed a recurrence in 46 patients (25 in the FDG-PET group, and 21 in the Con group; P=0.50), whereas per protocol analysis revealed a recurrence in 44 out of 125 patients (23 and 21, respectively; P=0.60). In another three cases, PET revealed unexpected tumours (one gastric GIST, two primary pulmonary cancers). Three false-positive cases of FDG-PET led to no beneficial procedures (two laparoscopies and one liver MRI that were normal). We failed to identify peritoneal carcinomatosis in two of the patients undergoing FDG-PET. The overall time in detecting a recurrence from the baseline was not significantly different in the two groups. However, recurrences were detected after a shorter time (12.1 vs 15.4 months; P=0.01) in the PET group, in which recurrences were also more frequently (10 vs two patients) cured by surgery (R0). Regular FDG-PET monitoring in the follow up of colorectal cancer patients may permit the earlier detection of recurrence, and influence therapy strategies.

Dear Sir, We read with great interest the “EANM procedure guidelines for brain tumour imaging using labelled amino acid analogues” that were published in the November issue of the Eur J Nucl Med Mol Imaging [1]. The publication of an EANM guideline is a professional event of major importance, and the present most valuable work is based on an extensive survey of the literature. However, we would suggest that 6-fluoro-(F)-L-3,4dihydroxyphenylalanine (FDOPA) needs to be included in the limited guideline list of radiopharmaceuticals. FDOPA is clearly a “labelled amino acid analogue” and is currently registered in France for brain tumour imaging, while the three other radiopharmaceuticals that are listed in the guideline [iodomethyltyrosine-(I) or IMT, methionine(C) or MET or fluoroethylthyrosine-(F) or FET] have no marketing authorisation. We would like to briefly summarise the published data that support the use of FDOPA PET in brain tumours and thus favour a limited revision of the guidelines. The first description of imaging of a brain tumour with FDOPA PET was a case report by Heiss in 1996 [2]. A 57year-old woman suffering from a minor movement disorder of the left arm and hand was referred for FDOPA PET. The FDOPA PET study not only proved asymmetrically reduced dopamine uptake in the putamen, but also revealed pathologically increased FDOPA accumulation in the right frontal lobe. Further PET examinations demonstrated increased MET uptake and low glucose metabolism in this right frontal region. Histology confirmed the diagnosis of a grade 2 oligo-astrocytoma. In 2003, Becherer et al. [3] reported on the performance of FDOPA PET in this setting, in comparison with MET, in series of 20 patients with known supratentorial brain lesions. The diagnoses were 18 primary brain tumours, one metastasis and one non-neoplastic cerebral lesion. MET and FDOPA images matched in all patients and showed all lesions as hot spots with higher uptake than in the contralateral brain. Standardised uptake value ratios for the tumour to the contralateral side (mean±SD) were similar for MET and FDOPA: 2.05±0.91 vs 2.04±0.53. The benign lesion, which biopsy revealed to be focal demyelination, was false positive, showing increased uptake of both MET and FDOPA. Recently, Chen et al. [4] compared the diagnostic performance of FDOPA PET and FDG PET in 30 patients with brain tumours: seven at diagnosis and 23 in whom recurrence was suspected. Visual analysis, considering as malignant any focus with an intensity greater than that of background, revealed a greater sensitivity for FDOPA (22/23=96% vs.14/23=61% for FDG), with an identical specificity: 3/7=43%. In fact, this low specificity was due to three cases with post-irradiation necrotic areas that faintly took up FDOPA to a much lesser extent than viable tumour tissue but that nevertheless had to be considered false positive results at visual analysis. To solve this problem, the authors proposed use of the tumour/striatum activity ratio, with a cut-off value of 0.75. The validity of this proposal was tested in another series of 51 patients including 47 with Eur J Nucl Med Mol Imaging (2007) 34:1131–1132 DOI 10.1007/s00259-007-0400-y

In digestive oncology, the most frequent indication for FDG PET, in our experience and as reported in the literature, is the localisation of recurrent colorectal cancer. This molecular imaging method has also been shown to be clinically useful in various other settings, especially for preoperative staging, for colorectal, esophageal, gastric, pancreatic, hepatic and biliary cancers. We also report on current PET practice in two particular cancers: hepatocellular carcinoma, for which other tracers, including fluoromethylcholine-(18F), are being currently evaluated, and gastrointestinal endocrine tumours, which are included in the recent French marketing authorisation of fluoroDOPA-(18F) and which are also potential targets for radiolabelled somatostatin analogues for PET imaging.

Prospectively evaluate the impact of fluorodeoxyglucose-fluorine-18 positron emission tomography (FDG-PET) in the management of recurrence of advanced head and neck squamous cell carcinoma during the first year after treatment.Seventy patients were followed-up every 6 to 8 weeks during the first year after initial combined curative therapy. FDG-PET, together with conventional imaging and endoscopy were performed systematically at 1 year (group A) or prompted earlier in case of clinically suspicious recurrence (group B). The referring physician evaluated the impact of FDG-PET on the patient's management. Another clinician checked the pertinence of decisions.FDG-PET had a therapeutic impact in 8 of 43 group A patients and in 16 of 27 group B patients; the overall rate was 34%. This change was pertinent in 5 of 8 and 14 of 16 cases, respectively. Overall pertinence rate of decisions was 90% versus 70% without FDG-PET.FDG-PET had a significant overall therapeutic impact; the induced decisions were either pertinent or just led to "futile" noninvasive examinations. Systematic FDG-PET had a significantly lesser impact in comparison with FDG-PET motivated by clinical suspicion.

In prostate cancer, use of FDG, the radiopharmaceutical currently most widely used in oncology, is limited to the most aggressive cancers and, in the absence of another tracer, to attempting to localise occult recurrences detected biochemically (elevated PSA serum levels). Four other PET tracers are currently suggested in various situations of prostate cancer development: for guiding biopsies, for diagnosis and staging of the primary cancer and of local or metastatic recurrences, especially in bone, and for localizing occult biochemical recurrence. This article is illustrated by cases summarising our experience with fluoromethylcholine-(18F) and PET/CT. They cover a wide spectrum of clinical settings: localisation of intraprostatic neoplastic lesions, initial staging, monitoring treatment by ultrasound, detection of occult recurrences and characterisation of images on conventional imaging modalities, which are questionable or difficult to interpret.

We compared (18)F-fluorocholine hybrid positron emission tomography/X-ray computed tomography (FCH-PET/CT) with ultrasonography (US) and scintigraphy in patients with hyperparathyroidism and discordant, or equivocal results of US and (123)I/(99m)Tc-sesta-methoxyisobutylisonitrile (sestaMIBI) dual-phase parathyroid scintigraphy. FCH-PET/CT was performed in 17 patients with primary (n = 11) lithium induced (n = 1) or secondary hyperparathyroidism (1 dialyzed, 4 renal-transplanted).The reference standard was based on results of surgical exploration and histopathological examination. The results of imaging modalities were evaluated, on site and by masked reading, on per-patient and per-lesion bases.In a first approach, equivocal images/foci were considered as negative. On a per-patient level, the sensitivity was for US 38%, for scintigraphy 69% by open and 94% by masked reading, and for FCH-PET/CT 88% by open and 94% by masked reading. On a per-lesion level, sensitivity was for US 42%, for scintigraphy 58% by open and 83% by masked reading, and for FCH-PET/CT 88% by open and 96% by masked reading. One ectopic adenoma was missed by the 3 imaging modalities. Considering equivocal images/foci as positive increased the accuracy of the open reading of scintigraphy or of FCH-PET/CT, but not of US. FCH-PET/CT was significantly superior to US in all approaches, whereas it was more sensitive than scintigraphy only for open reading considering equivocal images/foci as negative (P = 0.04). FCH uptake was more intense in adenomas than in hyperplastic parathyroid glands. Thyroid lesions were suspected in 9 patients. They may induce false-positive results as in one case of oncocytic thyroid adenoma, or false-negative results as in one case of intrathyroidal parathyroid adenoma. Thyroid cancer (4 cases) can be visualized with FCH as with (99m)Tc-sestaMIBI, but the intensity of uptake was moderate, similar to that of parathyroid hyperplasia.This pilot study confirmed that FCH-PET/CT is an adequate imaging tool in patients with primary or secondary hyperparathyroidism, since both adenomas and hyperplastic parathyroid glands can be detected. The sensitivity of FCH-PET/CT was better than that of US and was not inferior to that of dual-phase dual-isotope (123)I/(99m)Tc-scintigraphy. Further studies should evaluate whether FCH could replace (99m)Tc-sestaMIBI as the functional agent for parathyroid imaging, but US would still be useful to identify thyroid lesions.

Objectifs Nous avons compare la TEP/TDM a la FCH, l’echographie (E) et la scintigraphie double isotope 123 I/ 99 mTc-sestamibi (MIBI) double phase chez des patients atteints d’hyperparathyroidie (HPT) avec resultats discordants ou equivoques de E ou de MIBI. Patients et methodes TEP/TDM debutee apres injection de 3 MBq/kg de FCH chez 17 patients avec HPT soit primaire ( n = 11), soit induite par le lithium ( n = 1), soit renale (1 dialysee, quatre greffes). L’etalon de verite etait base sur les resultats de l’exploration chirurgicale avec histologie des glandes prelevees. Les resultats d’imagerie ont ete evalues, en ouvert (O) puis en insu (I), aux niveaux patient et lesion. Resultats Dans une premiere approche, les images douteuses ont ete considerees comme negatives. Par patient, la sensibilite Se (au moins une glande parathyroide anormale detectee dans son site correct) a ete pour E de 38 %, pour MIBI 69 % en O et 94 % en I, pour FCH 88 % en O et 94 % en I. Par lesion, Se a ete pour E de 42 %, pour MIBI 58 % en O et 83 % en I, pour FCH 88 % en O et 96 % en I. Seul un adenome ectopique a ete manque par les 3 modalites d’imagerie. Considerer les images douteuses comme positives ameliore Se en O pour MIBI et FCH, mais pas E. La TEP/TDM FCH a ete significativement superieure a E dans toutes les approches, alors qu’elle etait plus sensible que MIBI seulement pour la lecture en O considerant les images douteuses comme negatives ( p = 0,04). Il y avait une tendance a une plus forte fixation de la FCH par les adenomes que par les glandes parathyroides hyperplasiques. Des lesions de la thyroide peuvent induire des resultats faux-positifs comme dans un adenome oncocytaire de la thyroide ou faux negatifs comme dans un cas d’adenome de la parathyroide intra-thyroidien. Un nodule de cancer de la thyroide (4 cas) peut etre visualise avec FCH ou avec MIBI, fixant avec une intensite moderee, analogue a l’hyperplasie d’une parathyroide. Conclusions La TEP/TDM a la FCH est adequate en imagerie de HPT primaire ou secondaire. Elle pourrait remplacer le MIBI pour l’HPT, mais l’echographie resterait utile pour signaler les lesions de la thyroide.

FDG PET can detect thyroid cancer in patients referred for exploration of a different cancer. Because of its lack of specificity, however, this modality is not indicated for examination of thyroid nodules: ultrasonography and fine needle biopsy with cytology allow histological diagnosis, which can be completed by iodine-123 scintigraphy when an autonomous nodule is suspected. No information is currently available about the utility of FDG PET in preoperative staging. In follow-up of patients undergoing thyroidectomy for adenocarcinoma, FDG PET is useful for detecting recurrence in cases where serum thyroglobulin levels rise and iodine-131 scintigraphy is negative: surgical resection may be appropriate. Nonetheless FDG PET should be performed more widely and earlier: the initial presence of foci positive for FDG is a major predictor of shorter survival, and most cancer lesions take up either iodine or FDG. In follow-up of medullary carcinoma, FDG PET detects residual tissue better than any other scintigraphic procedures, especially when serum levels of CEA (carcinoembryonic antigen) are rising rapidly. FDOPA PET seems to have better sensitivity than FDG-PET and may be useful in occult recurrence, as three case reports indicate.

FDG-PET can be successful in localizing the primary cancer when a metastasis is discovered but no primary tumor can be identified (cancer of unknown primary, or CUP) by physical examination, laboratory testing (for tumor markers, for example) or conventional imaging. The greatest number of PET studies in CUP concern secondary lesions in cervical lymph nodes, and PET is an established clinical use (highest ranking, 1A) according to the 3rd German Consensus Conference and an "option" in the French Standards, Options, and Recommendations. Success rates range from 30% to 50% in most studies using PET; a higher rate was reported recently with PET/CT. FDG-PET should be performed sufficiently early in cases of neurological paraneoplastic syndrome, because established lesions become irreversible. Identification of the antibody present helps to specify the organ and FDG-PET can then localize the lesion; together these techniques make it possible to perform curative surgery even when the primary tumor is not visible. The success rate is somewhat lower than in cases of metastasis, around 35%. The clinical utility of PET in other paraneoplastic syndromes has not yet been sufficiently studied, but these conditions are rare. It is precisely in cases with a kind of 'orphan' indication that FDG PET should be considered, as an effective "problem solver".

Normal biodistribution of FDG includes intense physiologic uptake in the brain, which consumes glucose. The high background therefore makes it difficult to detect the foci taking up glucose, which correspond to malignant lesions. FDG PET is nevertheless clinically useful for detecting high-grade gliomas, cerebral lymphomas and, in some cases, unexpected brain metastases in whole-body PET examinations. As an adjunct to CT and MRI, FDG-PET can make stereotactic radiosurgery more precise in targeting primary or secondary brain cancers and can differentiate necrotic fibrosis from viable cancer tissue during follow-up in cases of abnormal or equivocal MRI results. When available, methionine-(11C) PET delineates low grade gliomas accurately. Several fluorine (18F)-labeled radiopharmaceuticals have been proposed in this setting, with FET and FDOPA apparently the most effective. Four original clinical cases illustrating performances of FET and FDOPA PET in this setting are presented.

FDG PET is useful when cancer in the head or neck (except for tumors of the salivary glands, which cannot be characterized accurately) is diagnosed or suspected but not confirmed by biopsy. It can, for example, find evidence of suspicious lymph nodes in clinically N0 necks, detect foci suggestive of distant metastases or second cancers, and provide useful prognostic information. Because it can be very difficult to identify anatomical structures and landmarks on PET images in the head and neck region, PET/CT fusion is very helpful in this area. In early assessment of chemotherapy, the absence of a significant reduction in FDG uptake after one or two cycles predicts lack of efficacy and thus indicates the need to modify the regimen. Conversely, the disappearance of FDG foci indicates effective treatment and good prognosis but cannot rule out the persistence of any malignant tissue at the end of treatment, especially neoadjuvant. Diagnostic impact is probably greatest in monitoring for recurrence and restaging known recurrence: FDG PET should be performed - perhaps routinely - early enough that curative options are still open, but long enough after the end of treatment to avoid false positive results from inflammation. The strategy and timing of FDG PET during follow-up should be determined in more detail in the future, as should the role (if any) of fluorotyrosine (FET) PET in squamous cell carcinoma.

FDG, a radioactive glucose analog for PET imaging, requires some precautions: it should be used only in patients with glycemia7mmol/L, fasting for at least 6 h but well hydrated, and after pregnancy is ruled out. FDG-PET has many indications in oncology. Its clinical utility has been documented in some circumstances, listed as routine indications in the European Principal Characteristics Summary and the French Standards, Options, and Recommendations. The European "Points to Consider" define as a principal criterion of clinical utility the impact of the imaging results on patient management. The original results presented here evaluate the clinical impact of FDG-PET among patients at Tenon Hospital by the rate of modifications in patient' management, determined with the same questionnaire as that used in two California studies of 2044 patients. Our response rate was lower than in our previous retrospective study in 2000 (34% versus 73%), probably because a prospective evaluation requires more work by the referring physician (who had to respond to two separate letters). On the other hand, the modification rate rose significantly (54% versus 46%, p0.001), especially for colorectal cancer (58% versus 44%, p0.02). The California studies had similar response rates (31%-48%, depending on the indication). Their modification rates were also similar, although higher for lymphoma (68%), colorectal (65%) and breast (58%) cancers.

The aim of this study was to evaluate whether (18)F-fluorodihydroxyphenylalanine ((18)F-FDOPA) PET is accurate for the diagnosis and follow-up of any type of well-differentiated digestive endocrine tumor and to assess its performance compared with standard somatostatin receptor scintigraphy (SRS) using (111)In-pentetreotide.We reviewed the results of 33 evaluable (18)F-FDOPA PET and (111)In-pentetreotide SRS examinations performed between March 2002 and September 2005 in 30 patients referred for documented well-differentiated digestive endocrine tumor.The sensitivity and accuracy of (18)F-FDOPA PET were significantly better for carcinoid tumors (defined according to the World Health Organization 2000 classification) (n = 19) than for noncarcinoid tumors (n = 14)-that is, 93% versus 25% for sensitivity (P0.01) and 89% versus 36% for accuracy (P0.01), respectively. In contrast, the performances of (111)In-pentetreotide SRS did not differ according to the carcinoid or noncarcinoid type of the primary endocrine tumor-that is, 81% versus 75% for sensitivity and 79% versus 71% for accuracy, respectively. In carcinoid tumors, comparison between (18)F-FDOPA PET and (111)In-pentetreotide SRS showed that (18)F-FDOPA PET more accurately evaluated the extent of disease than (111)In-pentetreotide SRS. (111)In-Pentetreotide SRS did not reveal any additional lesions in any case. Conversely, in noncarcinoid tumors, the extent of the disease was more accurately evaluated in all cases by (111)In-pentetreotide SRS than by (18)F-FDOPA PET.This preliminary study emphasizes the importance of a precise histologic characterization of well-differentiated digestive endocrine tumor to select the best radiopharmaceutical. (18)F-FDOPA PET appears to be useful in carcinoid tumors and could become the first-line scintigraphic imaging modality for these tumors, but (111)In-pentetreotide SRS appeared to be a better first-line scintigraphic imaging modality for noncarcinoid digestive tumors.

In response to the evolution of the information-seeking behaviour of patients and concerns from health professionals regarding cancer patient information, the French National Federation of Comprehensive Cancer Centres (FNCLCC) introduced, in 1998, an information and education program dedicated to patients and relatives, the SOR SAVOIR PATIENT program (SSP). The methodology of this program adheres to established quality criteria regarding the elaboration of patient information. Cancer patient information, developed in this program, is based on clinical practice guidelines produced by the FNCLCC and the twenty French regional cancer centres, the National League against Cancer, the French Hospital Federation, the National Oncology Federation of Regional and University Hospitals, the French Oncology Federation of General Hospitals, many learned societies, as well as an active participation of patients, former patients and caregivers. The guidelines, "Standards, Options: Recommendations" (SOR) are used as primary information sources. The handbook SOR SAVOIR PATIENT Understanding positron emission tomography (PET) with [18F]-FDG in clinical oncology, integrally published in this issue of the Bulletin du Cancer, is an adapted version of the clinical practice guidelines (CPG) Standards, Options and Recommendations for positron emission tomography (PET) with [18F]-FDG in clinical oncology. The main objectives of this article are to allow persons affected by cancer and their close relatives to better understand this medical imaging technique and its implementation. This document also offers health professionals a synthetic evidence-based patient information source that should help them communicate that information during the physician-patient encounter. Positron emission tomography (PET) is a scintigraphy technique using a radiotracer, [18F]-fluorodeoxyglucose (abbreviated [18F]-FDG), administered intravenously into the patient's arm. This tracer, similar to glucose (sugar), binds to cancer cells and temporarily emits radiations that can be recorded by a special camera in the PET scanner. PET scanning can be used to obtain complementary information at different stages of the disease, whether for assessing diagnosis, treatment evolution or follow-up. By 2007, in the framework of the government plan against cancer, about seventy-five PET scanners are expected to be installed in France. Twenty-four are currently in use; a similar number is under installation. At the end of this process, all French regions should have at least one PET imaging equipment. The SOR SAVOIR PATIENT guide: Understanding positron emission tomography (PET) with [18F]-FDG in clinical oncology and the integral report of CPG SOR 2003: Standards, Options and Recommendations for positron emission tomography (PET) with [18F]-FDG in clinical oncology can be downloaded from the FNCLCC website: http:\\www.fnclcc.fr.

Background Since the introduction of sentinel node (SN) mapping in breast cancer, extra-axillary lymph node sites of breast tumor drainage are discovered in about one-quarter of cases, especially after intraparenchymal injection. In most such cases, an ipsilateral axillary SN is associated with an extra-axillary SN. Non visualization of ipsilateral axillary SN and extra-axillary SN drainage are often associated with an increased risk of axillary involvement. Case We report a case of contralateral axillary SN drainage on lymphoscintigraphy in a breast cancer patient with a history of bilateral reduction mammoplasty and no ipsilateral axillary lymph node involvement. J. Surg. Oncol. 2004;86:167–169. © 2004 Wiley-Liss, Inc.

Prognosis and management of patients with recurrent breast cancer depend on the spread of the disease. The aim of this study was to evaluate the performance of fluorine-18 fluorodeoxyglucose gamma camera positron emission tomography (FDG-GPET) in detecting breast cancer recurrence, its clinical impact and the relevance of induced changes in management. Patients (n = 134) with suspicion of recurrence either clinically or on conventional imaging (suspected recurrence: SR) or with an isolated increase in tumour marker levels (occult recurrence: OR) underwent FDG-GPET on a coincidence gamma camera. The reference standard for evaluation of accuracy, either histology (n = 26) or follow-up for 1 year (n = 49), was available in 75 (56%) patients. A questionnaire was sent to the referring clinician to evaluate the impact of FDG on management. Responses were obtained for 75 patients. Information regarding both approaches was available for 46 patients (46/134 = 34%). At the patient level, the sensitivity of FDG-GPET was 84%, significantly higher than the 63% sensitivity for conventional modalities, and the specificity was 78% versus 61%. The values for FDG-GPET were 81% and 86% respectively in the SR group and 90% and 73% respectively in the OR group, without any significant difference between these settings. The rate of change in management was 44% overall, 43% in the SR group and 45% in the OR group. Within the two groups, intermodality (major) changes were more frequent than intramodality (minor) changes. In the 46 patients for whom both approaches were available, 93% of management modifications were relevant (validated by biopsy or clinical follow-up). The results of this retrospective study show that FDG-GPET has an important role to play in patient management by confirming and evaluating the extent of recurrence or by localising occult recurrence.

The aim of this study was to assess the capacity of positron emission tomography (PET) with fluorodeoxyglucose (FDG) to determine axillary lymph node status in patients with breast cancer undergoing sentinel node (SN) biopsy.Thirty-two patients with breast cancer and clinically negative axillary nodes were recruited. All patients underwent FDG-PET before SN biopsy. After SN biopsy, all patients underwent complete axillary lymph node (ALN) dissection.The SNs were identified in all patients. Fourteen patients (43.8%) had metastatic SNs (macrometastatic in seven, micrometastatic in six, and isolated tumor cells in one). The false-negative rate of SN biopsy was 6.6% (1 in 15). FDG-PET identified lymph node metastases in 3 of the 14 patients with positive SNs. The overall sensitivity, specificity, and positive and negative predictive values of FDG-PET in the diagnosis of axillary metastasis were 20%, 100%, 100%, and 58.6%, respectively. No false-positive findings were obtained with FDG-PET.This study demonstrates the limitations of FDG-PET in the detection of ALN metastases in patients with early breast cancer. In contrast, FDG-PET seems to be a specific method for staging the axilla in breast cancer. SN biopsy can be avoided in patients with positive FDG-PET, in whom complete ALN dissection should be the primary procedure.

A 65-year-old man was treated initially for a localized rectal carcinoma in 1998. One year later, his serum carcinoembryonic antigen (CEA) level increased. Results of a colonoscopy and computed tomography (CT) of the lung were negative. Abdominal CT showed a right suprarenal mass, suggestive of a metastatic tumor. Fluorodeoxyglucose (FDG)-coincidence detection (CDET) imaging showed an isolated right suprarenal focus of uptake. Adrenalectomy confirmed the diagnosis. F-18 FDG can be used to determine whether tumors are resectable in patients with elevated CEA levels. The CT scan showed an isolated adrenal tumor, whereas FDG-CDET imaging characterized this enlargement as probably malignant with no other sites of pathologic uptake.

To evaluate positron emission tomography (PET) with (18)F-fluorodeoxyglucose (FDG) for characterizing and initial staging of pancreatic tumors and to determine its impact on therapeutic strategy.This study included 24 patients with pancreatic tumor who underwent PET before treatment. Twenty-two patients had a malignant tumor and two had a benign tumor. The PET scan was performed after intravenous injection of FDG with a gamma camera. PET findings were compared with histology of the pancreatic tumor (n=24), liver metastases (n=5), peritoneal metastases (n=5), and lymph node metastases (n=5). Absence of metastasis or lymph node involvement was determined by surgery or by CT scan, ultrasonography, magnetic resonance imaging and at least two months follow-up.The sensitivity of the PET scans to identify pancreatic carcinoma was 64% (95% confidence interval 44-84%). PET scans could not be interpreted for lymph node involvement adjacent to the tumor. For liver metastases, the PET scan was positive in 3 out of 5 patients. For peritoneal metastases, the PET scan was positive in 4 out of 5 patients but was doubtful in one. There were two false positives. Among the 4 cystic tumors, the PET scan was positive for 2 malignant tumors and negative for 2 benign tumors. Surgical strategy was modified in only one of the 24 patients on the basis of PET findings.The sensitivity of PET for the diagnosis of primary malignant pancreatic tumor was found to be low. The contribution of FDG-PET to the surgical decision appears to be limited to the detection of metastases or lymph node involvement distant from the tumor, contraindicating surgery. Nevertheless, the sensitivity of FDG-PET is lower than that of laparoscopy for peritoneal metastases. Indications for PET should be included in an evaluation of therapeutic decision making and cost analysis.

Positron emission tomography (PET) with fluorine-18 fluorodeoxyglucose (FDG) is a very useful technique for the imaging of lymphomas in the adult population. It provides unique information about the behaviour of malignant cells and contributes to more accurate staging of the illness and better assessment of response to therapy. The purpose of this study was to evaluate the usefulness of FDG PET in childhood lymphoma compared with conventional imaging methods (CIMs) and clinical data. Between July 1998 and August 2001, 42 FDG PET examinations were performed using a dedicated PET system (27 examinations) or a hybrid coincidence PET system (15 examinations) for initial tumour staging ( n=7), restaging ( n=5) or assessment of response to therapy or residual masses ( n=30) in 27 children with Hodgkin's disease (HD) ( n=20) or non-Hodgkin's lymphoma (NHL) ( n=7). FDG PET results were compared with CIM findings and clinical data. Since 2000, a standardised questionnaire for evaluation of the clinical impact of FDG PET on both staging and therapy has been sent to the 16 referring physicians and 13 have replied. In all children, FDG PET was performed without any side-effects. FDG PET was found to be very sensitive (Se=12/12) for staging and restaging of the illness, showing more lesions than CIMs, with a 50% patient upstaging rate (6/12). It was very accurate for monitoring response to therapy and for characterisation of residual masses. False-positive results were observed in two NHL patients with thymic uptake and one false-negative result was obtained in a patient whose NHL relapsed 1 month after a negative FDG PET. The questionnaire emphasised the impact of FDG PET on clinical management, which was modified on the basis of the FDG PET results in 23% of patients. As previously demonstrated in the adult population, FDG PET appeared to be a very sensitive imaging technique for staging and restaging of lymphoma in children and was very useful for monitoring the response to therapy.

To validate a computed tomography (CT) and (18)F-deoxyglucose (FDG) image fusion procedure and to evaluate its usefulness to facilitate target definition and treatment planning in three-dimensional conformal radiation therapy (3D-CRT) for non-small-cell lung cancer.Twelve patients were assessed by CT and FDG-coincidence mode dual-head gamma camera (CDET) before radiotherapy. The patients were placed in a similar position during CT and FDG-CDET. Matching was achieved by minimizing the cost function by 3D translation and rotation between four landmarks drawn on the patient's skin. Virtual simulation was performed from image fusion and estimated dose-volume histograms (DVH) were calculated.Quantitative analysis indicated that the matching error was5 mm. Fusion of anatomic and metabolic data corrected staging of lymph nodes (N) for 4 patients and staging of metastases for 1 patient. In these 5 patients, DVH revealed that the lung volume irradiated at 20 Gy (Vl(20)) was decreased by an average of 22.8%, and tumor volume irradiated at the 95% isodose (V(95)) was increased by 22% and 8% for 2 patients, respectively, and was decreased by an average of 59% for 3 patients after fusion. No difference in terms of Vl(20) and V(95) was observed for the other 7 patients.We have validated CT and FDG-CDET lung image fusion to facilitate determination of lung cancer volumes, which improved the accuracy of 3D-CRT.

Purpose: Osteonecrosis of the hyoid boneis an uncommon disease that has only been described occasionally in the literature. Materials and Methods: We report 3 cases of osteonecrosis of the hyoid bone after radiation therapy for carcinoma at various sites in the head and neck region. Results: Imaging computed tomography (CT) scans were performed for all 3 cases and did aid in the diagnosis. In 1 case, a 201thallium scintigraphy and a bone scan (99mtechnetium-diphosphonate) were performed and this confirmed the diagnosis of osteoradionecrosis. Conclusion: Osteoradionecrosis of the hyoid bone may be misdiagnosed as recurrent neoplasm. Although recurrent or persistent neoplastic disease must initially be ruled out, it is subsequently important to correctly identify osteonecrosis of the hyoid bone, because its surgical treatment is simple and the prognosis is good.

A FDG-CDET examination on a Picker gamma-camera equiped with coincidence detection and thick cristals was performed in 80 patients during the 2nd half of 1997. Sensitivity and specificity were both 100% for the detection of malignancy in primary lung tumours. Accuracy was 91% for the detection of hilar or mediastinal lymph nodes involvement vs 59% for CT; lymphangitic carcinomatosis, metastases and concomittant tumours were also successfully detected and confirmed. FDG-CDET contributed to significant management changes in 30% of the patients referred for lung abnormalities. FDG-CDET was also usefull in “occult” recurrence of colorectal cancer with an accuracy of 78% vs 42% for CT in this difficult indication; a longer follow-up is needed to be able to evaluate all the 25 patients whose management have been adequately modified in 60% of the cases. We conclude that the diagnostic performances of FDG-CDET derived from our current series cannot be distinguished from the corresponding results published with FDG-PET.

A 26-year-old man with a history of major beta-thalassemia was referred to our center for suspicion of femoral bone sepsis. He was treated 12 years ago for femoral bone sepsis that occurred after epiphysis trauma and was scheduled for further surgery. He underwent both F-18 FDG coincidence detection-emission tomography (CDET) and Tc-99m HDP bone scintigraphy in our department. As expected because of beta-thalassemia, bone scintigraphy showed both increased diffuse uptake in all metaphyses and epiphyses and elevated renal activity. FDG-CDET images showed increased diffuse uptake in the bone marrow. The pattern of FDG uptake by the bone marrow in beta-thalassemia should be recognized because of the risk of false positive results.