[en] Thyrotropin, free triodothyronine and thyroxine represent the standard serological parameters for the diagnostic work-up of the thyroid but only a minority of thyroid nodules present with subclinical or overt thyroid disorders. Besides a review of the regulation and principle of function of thyroid hormones as well as the effects of subclinical or overt hyperthyroidism, the significant role of these parameters beyond the assessment of hyperthyroidism in thyroid nodules is discussed. There is evidence that the level of thyrotropin within the normal range is predictive for the relevance of autonomous functioning nodules and the risk of malignancy of non-functioning thyroid nodules. Furthermore, the ratio of triodothyronine and thyroxine indicates the etiology of hyperthyroidism. Thyrotropin represents the main parameter to determine the adequate dose of thyroid hormone therapy of thyroid nodules. (orig.)

[en] Positron emission tomography with ¹⁸F-fluoro-deoxyglucose (FDG PET) is a promising imaging tool for detecting and staging of primary or recurrent head and neck cancer. The aim of this study was to evaluate a dual-head gamma camera modified for coincidence detection (KGK-PET) in comparison to computed tomography (CT) and dedicated PET (dPET). 50 patients with known or suspected primary or recurrent head and neck cancer were enrolled. 32 patients underwent KGK-PET and dPET using a one-day protocol. The sensitivity for the detection of primary/ recurrent head and neck cancer for KGK-PET and CT was 80% and 54%, respectively, specificity was 73% and 82%, respectively. The sensitivity and specificity for the detection of lymph node metastases based on neck sides with KGK-PET was 71% (CT: 65%) and 88% (CT: 89%) respectively. In comparison to dPET, KGK-PET revealed concordant results in 32/32 patients with respect to primary tumor/recurrent disease and in 55/60 evaluated neck sides. All involved neck sides that were missed by KGK-PET were also negative with dPET. These results indicate that in patients with head and neck cancer KGK-PET reveals information, that are similar to dPET and complementary to CT. (orig.)

[en] CERN employs a large number of Programmable Logic Controllers (PLCs) to implement industrial processes. These PLCs provide critical functions and must be placed under permanent monitoring. However, owing to their proprietary architecture, it is difficult to both monitor the status of these automates using vendor-provided software packages and integrate the resulting data with the CERN accelerator infrastructure, which itself relies on CERN-specific protocols and configuration facilities. This paper exposes the architecture of a stand-alone ^PLC diagnostics monitoring Linux daemon, which provides live diagnostics information through standard means and protocols, namely file logging, CERN protocols, and Java Management Extensions. Such information is currently consumed by the EN-ICE MOON supervision software used by the EN-ICE Standby Service to monitor the status of critical industrial applications used in the LHC and the CERN DIAMoN monitoring console used by the LHC operators. Both applications are used daily to monitor and diagnose critical PLC hardware running all over CERN. (author)

[en] Early diagnosis and accurate staging of gynecological tumors based on noninvasive imaging remains a challenge. US, CT and MRI lack sensitivity and specificity for diagnosis and staging of primary disease, residual mass and recurrent disease. FDG-PET may add some important diagnostic information, but currently available results from initial studies indicate that it will not replace other staging tools for specific questions to be answered during work-up. (orig.)

[en] Aim of this study is the validation of a simple method for evaluating the depth of the target volume within the radioiodine test by analyzing the emitted iodine-131 energy spectrum. Patients, methods: In a total of 250 patients (102 with a solitary autonomous nodule, 66 with multifocal autonomy, 29 with disseminated autonomy, 46 with Graves' disease, 6 for reducing goiter volume and 1 with only partly resectable papillary tyhroid carcinoma), simultaneous uptake measurements in the Compton scatter (210±110 keV) and photopeak (364-45/+55 keV) windows were performed over one minute 24 hours after application of the 3 MBq test dose, with subsequent calculation of the respective count ratios. Measurements with a water-filled plastic neck phantom were carried out to perceive the relationship between these quotients and the average source depth and to get a calibration curve for calculating the depth of the target volume in the 250 patients for comparison with the sonographic reference data. Another calibration curve was obtained by evaluating the results of 125 randomly selected patient measurements to calculate the source depth in the other half of the group. Results: The phantom measurements revealed a highly significant correlation (r=0,99) between the count ratios and the source depth. Using these calibration data, a good relationship (r=0,81, average deviation 6 mm corresponding to 22%) between the spectrometric and the sonographic depths was obtained. When using the calibration curve resulting from the 125 patient measurements, the average deviation in the other half of the group was only 3 mm (12%). There was no difference between the disease groups. Conclusion: The described method allows an easy to use depth correction of the uptake measurements providing good results. (orig.)

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[en] At CERN there are currently 200 ventilation air handling units in production, used in many different applications, including building ventilation, pressurization of safe rooms, smoke extraction, pulsion/extraction of experimental areas (tunnel, cavern, etc.), and the ventilation of the computing centre. The PLC applications which operate these installations are currently being revamped to a new framework (UNICOS CPC). This work began 3 years ago, and we are now in a position to standardize the development of these HVAC applications, in order to reduce the cost of initial development (including specification and coding), testing, and long-term maintenance of the code. In this paper we will discuss the various improvements to the process, and show examples, which can thus help the community develop HVAC applications. Improvements include templates for the ^Functional Analysis specification document, standardized HVAC devices and templates for the PLC control logic, and automatically generated test documentation, to help during the Factory Acceptance Test (FAT) and Site Acceptance Test (SAT) processes. (author)

[en] With regard to the treatment of differentiated non-medullary thyroid carcinoma, there is controversy over whether radiation from a diagnostic radioiodine (¹³¹I) application really does have a suppressive effect on the uptake of subsequent therapeutic ¹³¹I (so-called thyroid stunning). However, inherent difficulties in exact remnant/metastatic tissue volumetry make it difficult to quantify how much diagnostic ¹³¹I is actually absorbed (absorbed energy dose) and hence to decide whether a threshold absorbed dose exists beyond which such stunning would occur. Since in benign thyroid disease the target volume can be readily quantified by ultrasonography, we sought to determine definitely whether stunning of thyroid cells occurs upon a second application of radioiodine 4 days following the first one. We therefore studied 171 consecutive patients with benign thyroid disease (diffuse goitre, Graves' disease, toxic nodular goitre) who received two-step ¹³¹I therapy during a single in-patient stay. For application of both calculated ¹³¹I activities we performed kinetic dosimetry of ¹³¹I uptake, effective half-life and absorbed dose. At the second application, patients showed significant stunning (a 31.7% decrease in ¹³¹I uptake, from 34.7%±15.4% at first application to 23.7%±12.3% at second application, P<0.0005) without a significant difference in effective half-life (4.9±1.3 vs 5.0±1.7 days, P>0.2). ANOVA showed that the extent of stunning was influenced significantly only by the absorbed energy dose at first application (F=13.5, P<0.0005), while first-application ¹³¹I activity, target volume, gender and thyroid function had no influence (all F≤0.71, all P>0.4). There was no significant correlation between extent of thyroid stunning and first-application ¹³¹I activity (r=0.07, P>0.3), whereas there was a highly significant correlation between thyroid stunning and first absorbed energy dose (r=0.64, P<0.00005), the latter correlation fitting a logarithmic model best. Multivariate factor analysis also revealed first absorbed energy dose to be the only decisive stunning factor. In conclusion, our study confirms that stunning exists in benign thyroid conditions and that it is a purely radiobiological inhibitory phenomenon related to absorbed dose. (orig.)

[en] Aim of the present study was to investigate the feasibility of 2-[fluorine-18]-fluoro-2-deoxy-D-glucose (FDG) imaging in oncological patients with a dual head gamma camera modified for coincidence detection (MCD). Methods: Phantom studies were done to determine lesion detection at various lesion-to-background ratios, system sensitivity and spatial resolution. Thirty-two patients with suspected or known malignant disease were first studied with a dedicated full-ring PET system (DPET) applying measured attenuation correction and subsequently with an MCD system without attenuation correction. MCD images were first interpreted without knowledge of the DPET findings. In a second reading, MCD and DPET were evaluated simultaneously. Results: The phantom studies revealed a comparable spatial resolution for DPET and MCD (5.9 x 6.3 x 4.2 mm vs. 5.9 x 6.5 x 6.0 mm). System sensitivity of MCD was less compared to DPET (91 cps/Bq/ml/cm_FOV vs. 231 cps/Bq/ml/cm_FOV). At a lesion-to-background ratio of 4:1, DPET depicted a minimal phantom lesion of 1.0 cm in diameter, MCD a minimal lesion of 1.6 cm. With DPET, a total of 91 lesions in 27 patients were classified as malignant. MCD without knowledge of DPET results revealed increased FDG uptake in all patients with positive DPET findings. MCD detected 72 out of 91 DPET lesions (79.1%). With knowledge of the DPET findings, 11 additional lesions were detected (+12%). MCD missed lesions in six patients with relevance for staging in two patients. All lesions with a diameter above 18 mm were detected. Conclusion: MCD FDG imaging yielded results comparable to dedicated PET in most patients. However, a considerable number of small lesions clearly detectable with DPET were not detected by MCD alone. Therefore, MCD cannot yet replace dedicated PET in all oncological FDG studies. Further technical refinement of this new method is needed to improve imaging quality (e.g. attenuation correction). (orig.)