[Neuroradiological investigations in mild brain injuries: state of the art and practical recommendations]. / La neuro-imagerie après traumatisme crânien léger: mise au point et recommandations pratiques.

OBJECTIVES: To clarify the contribution of each technique of neuroradiological and nuclear medicine investigations after mild brain injuries. To analyze the pathophysiological mechanisms of the lesions. To update indications for imaging techniques in the short or long term management. To define the practical recommendations. METHOD: The international databases were consulted for each neuroradiological technique; the most valuable articles were retained for study (PubMed, ). RESULTS AND DISCUSSION: Standard skull X-rays are obsolete. Craniofacial (bony windows) and brain CT-scan (parenchymal windows) is the most efficient diagnosis tool in the acute phase because of its accessibility. Brain MRI is less accessible in the emergency setting but is feasible in some centers. It is the best choice in the first weeks following mild brain injury but may be normal. Taking into account the limitations of morphological imaging, functional imaging techniques (SPECT, fMRI, PET-scan) are necessary as they may show axonal damage or brain atrophy. There is however the problem of availability. SPECT is the most accessible. Spectro-MRI is promising. In spite of progress in neuroradiological investigation methods, the neuropsychological evaluation and multi-disciplinary treatment of these patients by a skilled team remains of utmost importance.

[The therapeutic impact of PET-FDG scanning in broncho-pulmonary cancer]. / Impact thérapeutique de l'imagerie TEP-FDG en carcinologie bronchopulmonaire.

BACKGROUND: Because of the expected high performances of scintigraphic scans with [18F]-fluorodeoxyglucose (FDG) not only in diagnostics and but also in therapeutic impact, especially in thoracic oncology, there are a lot of French nuclear medicine departments which will soon be equipped with a positron emission tomograph (PET). MATERIAL AND METHODS: The Nuclear Medicine Department of the Hôpital d'Instructions des Armées du Val-de-Grâce, Paris, led a retrospective study among physicians interested in 338 FDG-PET exams performed between may 2000 and march 2002 in order to compare its own results with international literature concerning four indications for lung cancer: pulmonary nodule or mass malignancy diagnostic, lung carcinoma extension evaluation, therapeutic efficiency, recurrence suspicion. RESULTS: There seems to be no divergence, regarding limitation induced by the not exhaustive analysis of the retrospective study: more than every two FDG-PET exam highly influenced the effective therapy. CONCLUSION: That is why clinical FDG-PET has to be widely developed to investigate lung cancer.

[Positron emission tomography in clinical oncology]. / Tomographie par émission de positons en oncologie clinique.

A NEW FORM OF MEDICAL IMAGING: Positron emission tomography (PET) is used for the non-invasive in vivo visualisation of biochemical cell processes. It reveals the metabolic characteristics of neoplastic lesions and hence their identification by compensating the lack of lesion specificity of radiological techniques. VARIOUS INDICATIONS: Using the current oncology marker, 18F-fluorodeoxyglucose (FDG), excellent results with PET have been established at all stages of neoplasia, notably for the diagnosis of initial malignancy and the identification of residual lesions and early detection of relapses. Moreover, the fact that the whole of the body can be explored makes PET the tool of choice in the control of the extension and operability of cancers. With the close correlation between imaging and the metabolism of the lesions, PET is the earliest and most precise for assessing the effects of treatment. LIMITS AND PERSPECTIVES: The existence of benign inflammatory FDG binding should lead to the development of markers of other metabolisms directly linked to cell proliferation. The lack of anatomical reference points characteristic of PET does not permit the precise localisation of the lesions detected and could be corrected by combining, in a single apparatus, the PET camera and an X scan, the anatomical resolution of which is irreplaceable. This type of equipment represents the development of a new branch of medical imaging, oncological imaging.

[Interest in 18-FDG positron emission tomography in radiotherapy planning: example of lung cancer radiotherapy]. / Intérêt de la tomographie à émission de positons au 18fluoro-déoxy-glucose dans la définition des champs de radiothérapie: exemple de la radiothérapie thoracique.

18 FDG positon emission tomography provides metabolic images and allows better local and metastatic staging than radiologic methods. A best cartography of node involvement and a best delineation of the tumor zone should allow an optimal radiotherapy. Lung cancer is a good example of the interest of this new method.

[Positron emission tomography in head and neck oncology: five cases]. / La tomographie à émission de positons en oncologie ORL. Une revue à propos de 5 cas.

FDG-PET (18-fluoro-desoxyglucose positron emission tomography) is a fonctionnal imaging method based on the high rate of glycolysis in different types of cancer-cells. We report the first five cases where FDG-PET was used in France for head and neck cancers. The results were analyzed on the basis of data reported to date in the literature, leading to a proposal for rational use of this diagnostic available in only a few centers in France. For primary assessment of cervicofacial carcinomas, different imaging techniques such as CT and MRI have improved tumor staging. Although 18-FDG-PET cannot replace these techniques used to monitor size and structural changes in tumors and lymph nodes, it will be helpful in following their metabolic activity. This diagnostic tool consequently is greatly helpful for detection and post-therapeutic evaluation of head and neck carcinomas and their recurrence. 18-FDG-PET is currently under evaluation as a tool for detecting cervical lymph nodes and early assessment of response to chemotherapy.

[Value of positron-emission tomography in the post-treatment follow-up of epidermoid carcinoma of the head and neck]. / Intérêt de la tomographie par émission de positons dans le suivi post-thérapeutique des carcinomes épidermoïdes de la tête et du cou.

UNLABELLED: This study aimed at pointing out the supply of the positron emission tomography (PET) in the posttherapeutic follow-up of the head and neck squamous cell carcinomas and to determine the best period to perform this test. PATIENTS AND METHODS: Twenty patients have been included in this series, 16 men and 4 women. The PET was performed between 3 and 6 months after the end of all therapy. It systematically included radiation therapy. The results of the PET have been compared with those obtained by histology. The average distance of the follow-up of the patients after the achievement of the test was 11 months. RESULTS: They divided up according to the presence or not of an abnormal fixation on the PET imaging. Negative PETs: eight cases. Among those, a patient showed a metastatic cervical adenopathy at five months. Positive PETs: twelve cases which can be divided into three groups according to the area of the fixation. Primary site: 8 cases, 4 of which false-positive. Cervical lymph nodes: one case. Other sites: three cases. In our series PET had a sensitivity of 87% and a specificity of 67%. CONCLUSION: The PET is an original imaging as it allows a corporal metabolic study at one go. It seems to be very useful in the follow-up of patients who show a head and neck squamous cell carcinoma. The best period to perform it is the third or fourth posttherapeutic month. The high sensitivity is interesting within the context of an early detection of a residual tumour, for it allows to think of a suitable therapy quicker.

[Positron emission tomography in head and neck oncology]. / Tomographie par émission de positons en oncologie de la tête et du cou.

Defining a therapeutic strategy in oncology requires a substantial amount of imaging data provided by modern techniques. While the description of the lesions and their environment has become very precise, there remains a certain degree of uncertainty concerning tissue typing. Positron emission tomography is a scintigraphy technique which can produce quantitative images of metabolic characteristics. 18F-fluorodeoxyglucose is a tracer allowing an analysis of glucose metabolism known to be highly increased in malignant tissues. Increased uptake is an indication of malignancy with an established correlation with proliferative capacity. The only limitation of the method is the generally weak uptake observed in benign hypermetabolic inflammatory or infectious areas. All stages of the disease are concerned for head and neck cancer patients. Clinical experience to date indicates that PET can be applied most usefully to search or residual disease with a possible differentiation between post-therapeutic fibrosis and viable tumor tissue as well as the identification of early relapse. Study of early response to chemotherapy is also an interesting application. Search for extension can also be improved with this technique allowing both regional and whole body explorations. Positron emission tomography is not widely available in France at the present time so all patients cannot be examined with this technique. Positron emission tomography is an evolving technique with improvements being proposed both in the technique and in tracer elements. Further information will be available with new developments in this non-invasive exploration tool.

[Fluorodeoxyglucose (FDO) positron emission tomography (PET) in testicular germ cell tumors in adults: preliminary French clinical evaluation, development of the technique and its clinical applications]. / Tomographie à émission de positons (T.E.P.) au fluorodéoxyglucose (F.D.G.) dans les tumeurs germinales testiculaires de l'adulte: première évaluation clinique française, mise au point sur la technique et ses applications cliniques.

OBJECTIVES: Metabolic positron emission tomography (PET) is a new imaging modality for the detection of tumours, which uses fluorodeoxyglucose (FDG) to demonstrate increased carbohydrate metabolism of malignant cells. The management of testicular germ cell tumours in adults raises three clinical problems poorly resolved by conventional imaging techniques: identification of suspected recurrences in a context of elevated circulating serum markers, initial staging assessment after orchidectomy, evaluation of the response to treatment. MATERIAL AND METHODS: The authors report the data obtained in 16 patients (6 cases of seminoma and 10 cases of non seminomatous germ cell tumour [NSGCT]), investigated in the Frédéric-Joliot Department using a dedicated PET camera, 60 minutes after intravenous injection of 270 MBq of FDG. RESULTS: In 9 cases of assessment of elevated serum markers with no tumour identified by conventional examinations, PET demonstrated images likely to correspond to tumour sites in 7 patients (5 true-positives [TP] and 2 false-positives [FP] due to postoperative inflammatory changes). PET was negative in 2 out of 9 patients, in whom subsequent follow-up showed spontaneous but delayed return to normal of tumour markers. In 3 of the 4 cases of initial staging of the disease, PET excluded an extension suspected by conventional imaging and the 4th case was a FP for PET. In 3 cases of evaluation of the response to treatment, PET concluded on the absence of viable residual tumour mass, with a false-negative result in one case. CONCLUSIONS: These results are in line with those reported in the literature, which emphasize the diagnostic difficulties encountered in this disease. The significant contribution of FDG-PET should be confirmed by larger series of patients investigated by this new modality.

[Progression of stage I non-seminomatous germ cell tumors during surveillance. Role of positron emission tomography]. / Progression des tumeurs germinales non séminomateuses de stade I sous surveillance. Place de la tomographie à émission de positons.

Surveillance is one of the options proposed in the management of stage 1 non-seminomatous germ cell tumours when there is only a low risk of progression. No consensus has yet been reached concerning the modalities of this surveillance and several protocols are available, including the CCAFU protocol. The presence of recurrences in this population at low risk of progression, estimated to be 5%, accounts for the continuing research for more precise predictive factors of occult metastases. Although several studies appear to indicate a useful predictive value for some of these factors, their application in clinical practice still appears to be difficult. PET metabolic imaging (positron emission tomography) could constitute a new approach to staging of these tumours, allowing the detection of tumour sites by an increase of carbohydrate metabolism of malignant cells. However, no study is yet available to define the real place of this technique.

[Positron emission tomography in thoracic radiography]. / Apport de la tomographie par émission de positons à la radiothérapie thoracique.

The optimisation of the field of irradiation is the aim of the radiotherapist. Pet-Scan provides information revealing a better cartography of node involvement and allowing a better delineation of the tumour zone. In the follow-up of irradiated patients, PET-Scan provides information on the nature of residual lesions and a possible recurrence.

[Fluorodeoxyglucose and bronchopulmonary cancer. Initial French results with positron emission tomography]. / Fluoro-déoxy-glucose et cancer bronchopulmonaire. Les premiers résultats français en caméra à positons.

Despite recent advances, the contribution of medical imaging techniques is limited, particularly in terms of tissue characterization, in the diagnosis of pulmonary nodules and search for extension of bronchogenic cancer. The metabolic properties of the glucose analog deoxyglucose labeled with 18F1 would allow metabolic imaging. Positron emission tomography (PET) provides clinicians with quality images with an interesting sensitivity. We report the results of a feasibility study conducted in our first 17 patients. We observed 14 true positives, 1 true negative and 1 false positive and 1 false negative in patients with a malignant primary lesion. We analyzed the causes of error. Ten disseminated localizations were identified. Possible developments in terms of therapeutic strategy are discussed. The agreement between our findings and data reported in the literature prompted us to develop a study protocol using 18-fluorodeoxyglucose PET in patients with bronchogenic cancer.