This patient had been treated by radical prostatectomy for adenocarcinoma. Fifteen years later, he was referred to us due to occult biochemical recurrence (PSA = 1.56 ng/mL). Fluoride (18F) PET/CT and then fluorocholine (18F) (FCH) PET/CT were performed. On fluoride (18F) PET/CT, only one focus in the left iliac crest was suspicious but the biopsy of an osteoblastic anomaly had been performed 5 months before, with a negative result. On FCH PET/CT, a diffuse and intense uptake of bone marrow was noted, as well as a focus corresponding to a right external iliac lymph node, which had already been visualised on the previous FCH PET/CT and prompted endoscopic resection of three lymph nodes, which proved to be non-malignant. The osteomedullary uptake was attributed to a very recent treatment by pegfilgrastim, a recombinant human granulocyte colony stimulating factor (G-CSF). It was concluded that the recurrence was electively located in this lymphatic basin and IMRT was performed which led to a fourfold reduction in PSA serum levels. This observation illustrates the risk, never mentioned yet, of false-positive results concerning osteomedullary cancer spread, in case of treatment by G-CSF. It also confirms the role of FCH PET/CT in case of occult recurrence of prostate cancer, including verification of resection of a suspicious lymph node detected on a previous FCH PET/CT, and its capacity to guide IMRT. (C) 2012 Elsevier Masson SAS. All rights reserved.

The aim of this study was to determine whether early acquisition of F-fluorodihydroxyphenylalanine (F-FDOPA) PET/CT could improve the detection of medullary thyroid cancer (MTC). We retrospectively compared early (median time: 15 min) and delayed (median time: 94 min) acquisitions, positive on at least one of the two phases, in 15 dual-phase F-FDOPA PET/CT examinations performed on 14 patients referred for initial staging (one examination), suspected recurrence (eight examinations) or restaging of MTC (six examinations). Among the 14 true-positive (TP) examinations, more lesions (51 vs. 43) or more intense uptake (mean SUVmax=4 vs. 2.4, P<0.05) was observed on early versus delayed phases, regardless of the anatomical site of disease (lymph node, liver or bone). The only false-positive case, a reactive lymph node, was visible only on the delayed acquisition. Early acquisition appeared to be more appropriate in the detection of MTC lesions compared with acquisition at 60 min or later.

AIMThe aim of this paper was to compare the diagnostic performance of positron emission tomography/computed tomography (PET/CT) with fluorocholine (18F) (FCH) or fluoride(18F) (FNa) for the detection of bone metastasis in patients with prostate cancer complaining from osteoarticular pain, taking into account whether they were referred for initial staging or recurrence localization. The initial hypothesis was that FCH site-based specificity would be superior to that of F Na, with no loss in sensitivity.METHODSForty-two patients were enrolled in this prospective study, underwent both PET/CTs and were then followed-up for at least 6 months. The standard of truth (SOT) about the presence/absence and location of bone metastasis could be determined in 40 patients, by 2 independent medical assessors, blinded to the results of both PET/CTs. The comparison was performed according to the guideline of the European Medicines Agency, i.e. based on the results of blind reading with SOT as reference.RESULTSBone extension was present in 22 patients and absent in 18. Patient-based performance for FCH vs. FNa was 91% vs. 91% for sensitivity, 89% vs. 83% for specificity and 90% vs. 88% for accuracy (no significant difference). Of 360 skeletal sites, 68 were malignant and 292 non-invaded. There was no significant difference in site-based performance in the group of patients referred at initial staging, but in the group of patients referred for suspicion of recurrence, FCH was significantly more specific than FNa (96% vs. 91%, P=0.033 with Obuchowski's correction) while sensitivity was the same, 89%.CONCLUSIONBoth radiopharmaceuticals, based on a very different metabolic approach, showed good diagnostic performance. If FCH is available, it should be preferred in patients after initial treatment.

The utility of preoperative scintigraphy in case of secondary hyperparathyroidism is questioned by some authors. Obviously, an imaging modality that will detect all hyperplastic glands, including the ectopic ones, would be of interest in those patients at high risk for surgery. However, scintigraphy has a limited detection rate in some patients. We investigated whether one of the following parameters would identify a subgroup of patients in whom the detection rate would be optimal: age, gender, hemodialysis and duration since its onset, and plasma levels of parathyrin (PTH).Methods. - Retrospective series of 38 patients referred for preoperative parathyroid scintigraphy due to secondary hyperparathyroidism who then underwent parathyroidectomy. Scintigraphy was performed 20 min and then 3 h after injection of 8 MBq/kg of sestamibi (Tc-99m) with a previous ingestion of 0.1 MBq/kg iodine-123, 3 h before.Result. - No significant correlation was observed between the number of glands detected on scintigraphy (and confirmed by postoperative histology) and plasma PTH levels (r = -0.17). A weak positive correlation (r= +0.34) was noted in the group of six non-hemodialysed patients. No significant relationship between this number of detected glands and a clinical parameter was observed.Conclusion. - In our experience, these parameters do not permit to select, among patients with secondary hyperparathyroidism and scheduled for parathyroidectomy, those who will better benefit from parathyroid scintigraphy. (C) 2010 Elsevier Masson SAS. All rights reserved.

Case report. - A patient was referred to fluorocholine (18F) PET/CT to restage a biological recurrence of his prostate cancer. There was a doubt on local and lymph node recurrence on MRI.Result. - PET/CT showed several pelvic foci evocative of local and lymph node recurrence, more extensive than the MRI anomaly without bone lesion; this recurrence was treated by hormone therapy. But FCH PET/CT also revealed a left cerebral focus. Cerebral MRI was therefore performed which confirmed an anomaly evocative of a grade II brain lesion.Conclusion. - This observation illustrates the fact that, in case of prostate cancer, a whole-body imaging, including the skull, is useful, even when foci are detected in the pelvis. Several types of cancer take-up fluorocholine (18F): in case of a visceral distant focus in a patient with prostate cancer, the hypothesis of a second primary cancer should be considered. (C) 2010 Elsevier Masson SAS. All rights reserved.

Purpose. To evaluate the impact of FDG PET/CT on the management of patients referred for the staging and/or the follow-up of anal carcinoma, and PET/CT on patient management.Patients and methods. We included patients referred to our department for anal carcinoma whose therapeutic management was evaluable thanks to follow-up data during at least 6 months.Results. Data of 44 patients were analysed: 22 had PET/CT for initial staging and 36 during follow-up. PET/CT had impact in nine patients out of 44 (20%) and it was relevant in eight of them.Conclusion. FDG PET/CT is an accurate imaging modality in anal cancer, its impact on patient management is more obvious when persistence or recurrence of disease is suspected. (C) 2009 Elsevier Masson SAS. Tous droits reserves.

Fluorodeoxyglucose (F-18) or FDG, the radioactive glucose analogue which is the reference radiopharmaceutical in oncologic PET, is not well suited for the detection of prostate cancer metastases the glucose metabolism of which is usually only slightly enhanced. Fluoride (18F) accumulates into the cortical bone, rapidly and intensely in reaction to a bony metastasis. In 2008, it has been granted a marketing authorisation in France, including imaging bone metastasis of prostate cancer. We report original clinical cases to illustrate its diagnostic performance. Whole-body MRI is developing and can also detect bone metastases. Recently diffusion-weighted MRI (DWI) has been proposed to increase the detection rate of metastases of the axial skeleton, which are largely predominant in prostate cancer. Using either hybrid PET/CT or MRI requires mobilising equipments, which are less available and more expensive than the gamma-cameras for classical bone scintigraphy, in the aim to achieve superior diagnostic performance. A clinical study protocol (STIC) has just been accepted for public funding. It aims to assess the impact on patient management of the discovery of the first macroscopic bony metastasis and the efficacy of diagnostic strategies including those innovations, individually and in association. In case of prostate cancer with a high risk of metastasis, but without any proven bone metastasis and no typical pattern on bone scintigraphy, fluoride (F-18) PET/CT will be performed as well as whole-body MRI. Histopathology and/or data of a 6-month follow-up will be the standard of truth to evaluate the adequacy of impact on patient management and the benefit / cost ratio of those examinations. With this prospective national study, we hope to demonstrate in the real world a clinical role for this radiopharmaceutical, which was proposed several decades ago, but benefits from a renewed interest thanks to the development of PET/CT imaging. (C) 2009 Elsevier Masson SAS. All rights reserved.

Le traitement initial des cancers différenciés de la thyroïde (CTD) consiste en une thyroïdectomie totale suivie, dans de nombreux cas, par l’administration d’iode 131. Ce traitement postopératoire a trois buts : (i) détruire les reliquats thyroïdiens normaux pour faciliter la surveillance ultérieure en augmentant la spécificité du dosage de thyroglobuline ; (ii) effectuer une scintigraphie corps entier 2 à 7 jours après la prise de l’iode 131 pour permettre un bilan d’extension complet et s’assurer de l’absence de maladie résiduelle ; (iii) traiter d’éventuels résidus tumoraux, ce qui permet de diminuer les rechutes cliniques et d’améliorer la survie. Chez les patients à très faible risque, il est recommandé de ne pas administrer d’iode 131. Dans le groupe intermédiaire, il a été montré par deux études prospectives multicentriques randomisées (ESTIMABL et HILO) qu’une activité de 1,1 GBq (30 mCi) administrée après thyroid stimulating hormon recombinante humaine (TSHrh) était adaptée. La désescalade thérapeutique se poursuit dans le cadre d’un autre essai prospectif randomisé (ESTIMABL 2) comparant une activité de 30 mCi après injection de TSHrh à une simple surveillance. Chez les patients à risque élevé de rechute ou avec maladie résiduelle, il est recommandé d’administrer une forte activité d’iode 131. En cas de métastases à distance, l’iode radioactif permet d’obtenir une guérison chez 1/3 des patients. En absence de guérison, les patients sont dits réfractaires à l’iode 131 et peuvent, dans certains cas, bénéficier de traitements par inhibiteurs de tyrosine kinase.Initial treatment of differentiated thyroid cancer is based on a total thyroidectomy and in many cases on the administration of radioactive iodine. Following total thyroidectomy, radioactive iodine is given, based on the primary tumor characteristics. In case of a very low-risk of recurrence it is recommended not to give radioactive treatment. In case of intermediate risk patients, two randomized prospective studies (ESTIMABL and HILO) have shown that an activity of 1.1 GBq (30 mCi) given after recombinant human thyroid stimulating hormon (rhTSH) was adequate. A further step is taken towards less treatment has now been undertaken with the ESTIMABL2 study, a prospective randomized study comparing a treatment with 1.1 GBq (30 mCi) of radioactive iodine treatment to follow-up without ablation. In case of high-risk patients or in case of persistent disease a high activity of radioactive iodine is given after TSH stimulation. In case of distant metastases, cure is obtained with radioactive iodine in 1/3 of the patients. In the absence of cure, patients are classified as refratory to radioactive iodine and may benefit from tyrosine kinase inhibitors.

Bien que la TEP/TDM au FDG soit un examen extrêmement sensible et performant pour nombre de cancers, le FDG n’est pas un traceur spécifique et il peut se révéler peu sensible dans certaines pathologies néoplasiques, le plus souvent très bien différenciées ou lentement évolutives. Il existe donc un intérêt de plus en plus important pour la mise au point de radiopharmaceutiques spécifiques, complémentaires du FDG. Nous rapportons quelques exemples de l’utilité clinique, démontrée ou potentielle de ces radiopharmaceutiques dans plusieurs types de pathologie tumorale.

Ga-68 is a positron emitter, obtained from a Ge-68/Ga-68 generator, which can be used to label peptides of clinical interest. DOTATOC is a tracer of high affinity for the type 2 somatostatin receptors and is used for imaging of tumours which are expressing them, including endocrine tumours. We report on the case of a patient with a history of small bowel carcinoid tumour with hepatic metastases, treated by somatostatin analogues, in whom somatostatin receptor scintigraphy showed three liver foci and DOTATOC-(Ga-68) PET/CT highlighted much more liver lesions. Two recent studies emphasised on the superiority of DOTATOC- (Ga-68) PET over somatostatin receptor scintigraphy, and its complementarity with CT, especially for the diagnosis of bone metastases. DOTATOC-(Ga-68) PET/CT, which associates the specificity of somatostatin receptor scintigraphic detection with the spatial resolution of PET and the anatomical precision of CT, seems to be promised to a brilliant future, the more so as it offers many advantages to the patient: a shorter waiting time, one single image acquisition and a satisfying dosimetry. (C) 2008 Published by Elsevier Masson SAS.