These findings support the hypothesis of MDMA-induced protracted alterations of the serotonergic system and indicate that the reduced availability of serotonin transporter, as measured by PET, might be reversible. Women appear to be more susceptible than men to MDMA-induced alterations of the serotonergic system.

Life-threatening cardiac toxicity is rare after BMT, occurring in less than 2% of all patients. Although the occurrence of cardiac toxicity is correlated with a reduction of EF before BMT, life-threatening cardiac toxicity cannot be predicted in individual patients.

Resectional surgery offers a curative intent and a survival benefit for patients with hilar cholangiocarcinoma, but is associated with high morbidity. Since morphological imaging cannot solve differential diagnosis preoperatively, in order to exclude patients inappropriate to this aggressive surgery, we evaluated the impact of functional imaging using fluorodeoxyglucose positron emission tomography (FDG PET) in the detection of cholangiocarcinoma and its usefulness in the differentiation from benign Klatskin tumour-mimicking lesions. Fifteen consecutive patients aged 47-78 years underwent standardized whole-body FDG PET with attenuation correction before potentially curative surgery using a conventional full-ring PET scanner with an axial field-of-view of 16.2 cm. FDG PET was evaluated visually and semiquantitatively using tumour-to-background ratios (T/B) ratios. All lesions were evaluated histopathologically. FDG PET presumed to be indicative for carcinoma was positive in 12 of 15 patients, true positive in 10 (T/B ratio, 3.2+/-1.9) and false positive in two of them (T/B ratios, 2.1 and 2.8) with Klatskin tumour-mimicking lesions. While all true positive PET results were seen in the tubular type of cholangiocarcinoma with a high amount of tumour cells and only low production of mucus, a false negative FDG PET in three patients was observed in mucinous adenocarcinoma. Additionally, FDG PET detected locoregional lymph nodes in two patients and distant metastases in a further three patients. Due to false positive results FDG PET does not allow the differentiation of benign from malignant lesions, and FDG PET should be avoided in patients with mucinous cholangiocarcinoma. However, FDG PET may have significant influence on the treatment strategy in as much as 20% of the patients, since it may detect distant metastases.

ObjectiveTo assess the utility of 2-[18 F] fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) to detect recurrent disease in the follow-up of patients with well-differentiated thyroid cancer (WDTC) who have negative diagnostic 131 I scans and abnormal thyroglobulin levels. Summary Background DataIn general, patients with WDTC have an excellent long-term prognosis when appropriate surgical treatment and follow-up are carried out. After total thyroid ablation, whole-body 131 I scintigraphy and measurement of serum thyroglobulin are useful diagnostic tools to detect persistent or recurrent malignancy. In case of tumor dedifferentiation, decreased or lost iodine-accumulating ability may lead to false-negative 131 I scanning results. The diagnostic and therapeutic delay is responsible for a poor prognosis in this subgroup of patients. Efforts have been made in the search for suitable imaging modalities capable of early detection of recurrent thyroid carcinoma. MethodsThe authors prospectively analyzed 24 patients with WDTC, negative results of whole-body 131 I scintigraphy, and elevated serum thyroglobulin concentrations. Attenuation-corrected whole-body FDG-PET scans from the neck to the upper legs were performed. In addition, all patients underwent cervical ultrasonography. The results of the imaging studies were compared with histopathologic findings. If no resection of the suspicious lesion was carried out, computed tomography data were used as control criteria. ResultsOverall, FDG-PET disclosed 38 hot spots. The sensitivity of the method was 94.6%, but the specificity was lower (25.0%). The diagnostic accuracy was 87.8%. There were three false-positive results in two patients with benign cervical lymph nodes. In one patient with regional lymph node metastases in the neck, two false-negative results were obtained. Ultrasound classified both findings as malignant, however. Because of unexpected findings, FDG-PET suggested potential modification of the surgical management in nine patients. Distant metastases could be disclosed using FDG-PET in only three patients. ConclusionsFDG-PET is a useful diagnostic tool in the follow-up of thyroidectomized patients with WDTC, negative 131 I scanning results, and abnormal serum thyroglobulin concentrations. The method detects metastatic disease in 94.6% of cases. PET results changed surgical tactics in a significant number of patients. Accurate staging of locoregional cancer recurrence in the neck may be consummately obtained by concomitant analysis of PET and ultrasound results.

The popular recreational drug, 'ecstasy', mainly contains 3,4-methylenedioxymethamphetamine (MDMA) as the psychotropic agent. MDMA is suspected of causing neurotoxic lesions to the serotonergic system as demonstrated by animal studies, examinations of human cerebrospinal fluid, and the first positron emission tomography (PET) studies using the serotonin transporter ligand [11C]-McN5652. Damage of serotonergic afferents might mediate long-lasting alterations of cerebral glucose metabolism as a secondary effect. To study a relationship between ecstasy use and long-lasting alterations, PET using 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) was performed in 93 ecstasy users and 27 subjects without any known history of illicit-drug abuse. As an index of glucose metabolism, mean normalized FDG uptake was determined in both groups using a computerized brain atlas, and was compared for a selected number of brain regions. FDG uptake was normalized in each individual by dividing local FDG uptake by the maximum FDG uptake in the individual's brain. Within the group of ecstasy users we examined the relationship between FDG uptake and cumulative ecstasy dose, time since last ecstasy ingestion at the time of PET scanning, and age at first ecstasy use, respectively. Normalized FDG uptake was reduced within the striatum and amygdala of ecstasy users when compared to controls. No statistically significant correlation of the FDG uptake and the cumulative dose of ecstasy was detected. A positive correlation was found in the cingulate between FDG uptake and the time since last ecstasy ingestion. As compared to the control group, normalized FDG uptake in the cingulate was reduced in ecstasy users who took ecstasy during the last 6 months, while it was elevated in former ecstasy users who did not consume ecstasy for more than 1 year. FDG uptake was significantly more affected in ecstasy users who started to consume ecstasy before the age of 18 years. In conclusion, ecstasy abuse causes long-lasting effects on glucose metabolism in the human brain. These effects are more severe in the case of very early abuse. However, several questions still remain to be answered, i.e. the correlation of the neuronal alterations and the history of ecstasy use (cumulative dose, and time since the last dose) and its reversibility.