[show abstract][hide abstract] ABSTRACT: Among thyroid malignancies, medullary thyroid carcinoma (MTC) has some very specific features. Production and secretion of large amounts of peptides occur in malignant transformed C cells with few exceptions, leading to high serum levels of calcitonin (Ctn) and carcinoembryonic antigen (CEA), that act after thyroidectomy as tumour markers warning for the presence of persistent or metastatic MTC. The availability of those serum biomarkers with an excellent sensitivity challenges medical imaging to localise the recurrent cancer tissue, since surgery is a major therapeutic option. The aims of this article are (i) to review literature evidence about the efficacy and tolerance of radiopharmaceuticals for 3 targets of PET/CT imaging (glucose metabolism, bioamines metabolism and somatostatin receptors) and also bone scintigraphy which is recommended in the Guidelines of European Society for Medical Oncology (ESMO; (ii) to compare the availability and the costs in relation with those radiopharmaceuticals, (iii) and to discuss a possible sequence of those examinations, in order to optimise spending and to minimise the overall radiation dose. In this context of recurrent MTC suspected on rising tumour markers levels after thyroidectomy, this survey of literature confirms that FDOPA is the best radiopharmaceutical for PET/CT with significant diagnostic performance if Ctn >150pg/mL; an early image acquisition starting during the first 15 min is advised. In negative cases, FDG should be the next PET radiopharmaceutical, in particular if Ctn and CEA levels are rapidly rising, and PET with a somatostatin analogue labelled with gallium-68 when neither FDOPA nor FDG PET are conclusive. Bone scintigraphy could complement FDG-PET/CT if FDOPA is not available.
[show abstract][hide abstract] ABSTRACT: Radiopharmacists of the Nuclear Medicine department of hospital Tenon have prepared and controlled the 68Ga-labeled DOTATOC, for 4 years, as part of a clinical research study. The aim of this article is to share our experience, since this activity is not yet developed in France. Radiolabelling of DOTATOC (68Ga) requires the settling of a 68Ge/68Ga generator, which is connected to an automated PC-controlled radiopharmaceutical labelling device (Elusynth 68Ga, Iason) and comprises several steps. Performed quality controls (QC) are those commonly used for radiopharmaceuticals including: appearance, pH, radiochemical purity (RCP), radionuclide purity (PRN) and determination of the physical half-life. Bacterial endotoxins and sterility tests are systematically done. We obtained a mean value of radiolabelling yield around 45%. The results of QC are always in accordance with the specifications. The preparation failed in 7% of the 195 DOTATOC (68Ga), over the last 4 years. It is important to note that the preparation of DOTATOC (68Ga) monopolizes the radiopharmacist during 3 hours. This radiolabelling technique can be easily applied to other peptides, in order to develop other 68Ga-labelled PET tracers.
[show abstract][hide abstract] ABSTRACT: Hibernoma is a rare benign tumour of soft tissue, generally asymptomatic, usually discovered in young adults. It is a form of lipoma that originates from brown adipose tissue. Its diagnosis is based on histology, the main differential diagnoses being lipoma and liposarcoma. Its appearance on FDG PET/CT has being described only in few case reports. We report here the case of a 68-year-old patient with ENT cancer in whom an adipose tumour in the left axilla has been discovered on CT performed for staging. The diagnosis of hibernoma was suggested in the report of FDG PET/CT examination and was consistent with results of other imaging modalities. On MRI, contrast enhancement was observed after gadolinium contrast injection, which was not typical for a lipoma. On PET/CT, the FDG uptake by the adipose tumour was very intense (SUVmax = 16), which is characteristic for hibernoma that derives from brown adipose tissue. Imaging was unable to distinguish between hibernoma and liposarcoma. The diagnosis of benign mixed hibernoma-lipoma was ascertained on histopathology after complete resection of the tumour. Elements favouring hibernoma over liposarcoma are present in this observation: high avidity for FDG (SUVmax > 10) and a fluctuating intensity of uptake, SUVmax of the tumour increasing from 16 to 48 within 16 months in the presented case. A high SUVmax on FDG PET in an adipose tumour on CT seems to be more suggestive of a benign tumour, hibernoma, than of its malignant counterpart, liposarcoma.
[show abstract][hide abstract] ABSTRACT: The registration of a new PET radiopharmaceutical by medicines agencies is infrequent and it seemed interesting to follow its consequences on the prescription of alternative nuclear medicine (NM) examinations by the referring physicians. Fluorocholine (18F) (FCH) was registered in France for localisation of bone metastases of prostate cancer (PC) on April 2nd 2010.MethodsA survey of the prescription of NM examinations in patients with PC was performed at Hôpital Tenon, covering eight quarters since the registration of FCH.ResultsDuring that period of time, 721 NM examinations were performed in PC patients. Demand for FCH PET/CT grew rapidly, from 11% of the NM examinations during the first quarter to 37% during the second quarter and to 56% during the eighth quarter. The total number of NM examinations requested for PC also grew over that period. Overall, the share of FCH PET/CT was 42%, 27% for bone PET/CT with fluoride (18F) (F Na), 25% for bone scintigraphy (BS). FDG PET/CT remained limited to few cases of castrate-resistant or metastatic PC (6% of NM examinations). Examinations limited to the detection of bone metastases (F Na and BS) were predominantly demanded for initial staging while FCH was more frequently requested in case of occult recurrence, at lower PSA serum levels. Therapy monitoring and follow-up appeared to be promising settings requiring assessment; 19% of NM examinations were prescribed in this context, same proportion as restaging prior to treatment resuming.Conclusion
The introduction of FCH resulted in a rapid demand for this PET/CT examination, in particular in case of occult recurrence, with an overall increase in PC patients referred to NM imaging, of + 11% comparing the two successive years.
[show abstract][hide abstract] ABSTRACT: 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).
Medecine Nucleaire-imagerie Fonctionnelle Et Metabolique - MED NUCL. 01/2010; 34(7):388-392.
[show abstract][hide abstract] ABSTRACT: Case reportA 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.
Medecine Nucleaire-imagerie Fonctionnelle Et Metabolique - MED NUCL. 01/2010; 34(9):540-545.
[show abstract][hide abstract] ABSTRACT: Case reportIn order to stage hepatocellular carcinoma (HCC), a patient was referred to PET/CT using fluorodeoxyglucose(18F) (FDG) and, if necessary, fluorocholine(18F) (FCH). HCC was proven by biopsy of a hepatic mass discovered on CT performed for a biological recurrence of prostate cancer.
Medecine Nucleaire-imagerie Fonctionnelle Et Metabolique - MED NUCL. 01/2010; 34(7):378-382.
[show abstract][hide abstract] ABSTRACT: PurposeTo 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.
Medecine Nucleaire-imagerie Fonctionnelle Et Metabolique - MED NUCL. 01/2010; 34(2):96-102.
[show abstract][hide abstract] ABSTRACT: Dermatomyositis is an idiopathic inflammatory myopathy that may be associated with malignancies. The technique of 18-F fluorodeoxyglucose (FDG)-positron emission tomography (PET) is an important tool to investigate underlying malignancy in patients with a possible paraneoplastic syndrome. We report two consecutive patients with dermatomyositis in whom 18-F FDG-PET revealed unsuspected infections. Physicians should be aware that a positive 18-F FDG-PET is not specific for malignancy and may reveal other conditions including an infectious disorder.
Clinical and Experimental Dermatology 12/2009; 34(8):e769-71. · 1.33 Impact Factor
[show abstract][hide abstract] ABSTRACT: Fluorodeoxyglucose (18F) 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 (18F) 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.
Medecine Nucleaire-imagerie Fonctionnelle Et Metabolique - MED NUCL. 01/2009; 33(7):388-397.
[show abstract][hide abstract] ABSTRACT: Although FDG PET/CT imaging provides high sensitivity in several kinds of cancer and has many applications, it is important to recognize that FDG is not a “specific” radiotracer for imaging malignant disease and that its sensitivity is also sometimes limited (especially for well-differentiated or slow growing tumours). Highly “tumour-specific” complementary PET radiopharmaceuticals are then essential to evaluate. Some examples of the potential clinical utility of specific PET radiopharmaceuticals are reported in this issue.
Medecine Nucleaire-imagerie Fonctionnelle Et Metabolique - MED NUCL. 01/2009; 33(3):152-160.
[show abstract][hide abstract] ABSTRACT: The clinical usefulness of 2-deoxy-2-[F-18]fluoro-D-glucose-positron emission tomography (FDG-PET) in head and neck squamous cell carcinoma (HNSCC) is now well-documented. However, its sensitivity is greater than its specificity due to false-positive results in inflammatory or infectious lesions, which are frequent in this area, in particular after treatment by surgery and/or radiotherapy. O-2-fluoro-(18F)-ethyl-L-thyrosine (FET) has been reported not to be taken up by such lesions, and a preliminary study indicated that this may be clinically useful in HNSCC. We performed a prospective study to compare the diagnostic performances of FDG and FET PET/CT in the different settings of HNSCC.
Twenty-seven patients (20 men and seven women, aged 48-76, among 30 patients included) and 69 suspected cancer sites are now evaluable on basis of postsurgical histology and/or follow-up greater than 6 months; 15 patients were referred for initial staging and 12 during posttherapy follow-up, a recurrence being suspected in eight of them. FDG and FET PET/CT were performed on two different days, the patient fasting for 6 h, 1 h after injection of 5 MBq/kg of body mass of each radiopharmaceutical. Both PET/CT examinations were blind read more than 6 months after the end of inclusions in a random order for each tracer and with a time interval greater than 1 month between FDG and FET PET/CT blind readings.
Overall diagnostic performances, derived from blind reading: FDG PET/CT on a per patient basis: sensitivity 100%, specificity 71%, accuracy 93%; FDG PET/CT on a per site basis: sensitivity 95%, specificity 63%, accuracy 83%; FET PET/CT on a per patient basis: sensitivity 70%, specificity 100%, accuracy 78%; FET PET/CT on a per site basis: sensitivity 64%, specificity 100%, accuracy 78%. At site level, sensitivity was significantly greater with FDG (p<0.02) and specificity with FET (p<0.01). The statistical level of significance was not reached at patient level.
Although its good specificity was confirmed, FET did not appear to be suited as a first-line PET tracer in HNSCC imaging and cannot replace FDG for staging due to insufficient sensitivity. However, it was useful in a few selected cases to favor a wait and see attitude when a FDG+ FET- focus was discovered in patients referred for systematic FDG PET during follow-up. In contrast, second primary cancers should not be ruled out if FDG was clearly positive in the lungs or the digestive tract.
[show abstract][hide abstract] ABSTRACT: 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.
British Journal of Cancer 04/2008; 98(5):875-80. · 5.08 Impact Factor
[show abstract][hide abstract] ABSTRACT: Malignant lymphomas are lymphoproliferative disorders arising in both lymphoid tissue and non-lymphoid organ systems. Treatment rarely is surgical, and currently relies on a combination of chemotherapy and radiation therapy. The role of imaging is to determine the spread of the disease, to identify targets and to assess therapeutic response. Imaging techniques mainly use morphological criteria, and may underestimate infiltrative disease, as observed in bones. The frequent presence of residual masses after treatment usually prevents classification of patients as complete response. Over time, positron emission tomography (PET) with F18-fluorodeoxyglucose (FDG) has become a prominent part of the workup at diagnosis and during follow-up. Recently, PET has been integrated in the revised response criteria for malignant lymphoma.