No abstract

After (near) total thyroidectomy and successful (131)I ablation, RFS does not differ between patients classified as high-risk and those classified as low-risk based on TNM stage at diagnosis. Consequently, the follow-up protocol should be determined on the basis of the result of initial treatment rather than on the initial tumour classification.

Individualised dosage models are frequently applied for radioiodine therapy in patients with Graves' hyperthyroidism, especially in Europe. In these dosage schemes the thyroid volume is an important parameter. Thyroid volume determinations are usually made with ultrasonography or with thyroid scintigraphy, although the accuracy of planar scintigraphy for this purpose is not well established. The aim of this study was to compare the accuracy of three modalities for the determination of the thyroid volume in patients with Graves' disease: planar scintigraphy (PS), single-photon emission tomography (SPET) and ultrasonography (US). These three modalities were compared with magnetic resonance imaging (MRI) as the gold standard. Thyroid volume estimations were performed in 25 patients with Graves' disease. The PS images were subjected to filtering and thresholding, and a standard surface formula was used to calculate the thyroid volume. With SPET the iteratively reconstructed thyroid images were filtered, and after applying a threshold method an automatic segmentation algorithm was used for the volume determinations. Thyroid volumes were estimated from the US images using the ellipsoid volume model for multiple two-dimensional measurements. For MRI, thyroid segmentation was performed manually in gadolinium-enhanced T1-weighted images and a summation-of-areas technique was used for the volume measurements. The thyroid volumes calculated with MRI were 25.0+/-13.8 ml (mean+/-SD, range 7.0-56.3 ml). PS correlated poorly with MRI ( R(2)=0.61) and suffered from a considerable bias (-4.0+/-17.6 ml). The differences between PS and MRI volume estimations had a very large spread (33+/-58%). For SPET both the correlation with MRI ( R(2)=0.84) and the bias (1.8+/-11.9 ml) were better than for PS. US had by far the best correlation with MRI ( R(2)=0.97) and the best precision, but the bias (6.8+/-7.5 ml) was not negligible. In conclusion, SPET is preferred over PS for accurate measurements of thyroid volume. US is the most accurate of the three modalities, if a correction is made for bias.

Objective-To determine the contribution of 58FDG PET, "IC-flumazenil PET, and 123I-iomazenil SPECT to the presurgical evaluation of patients with medically intractable complex partial seizures. Methods-Presurgical evaluation was performed in 23 patients, who were considered candidates for temporal lobe resective surgery (14 females and nine males with a median age of 34 (range 13 to 50) years).The presurgical diagnosis was based on seizure semiology as demonstrated with ictal video recording, ictal and interictal scalp EEG recordings, and MRI. Results-Eighteen patients had convergent findings in clinical semiology, interictal and ictal EEG with scalp and sphenoidal electrodes, and MRI that warranted surgery without depth EEG (DEEG). In five patients with insufficient precision of localisation, DEEG with intracerebral and subdural electrodes was performed. MRI showed abnormalities in 22 out of 23 patients. Of these 22, 18 had mesial temporal sclerosis. This was limited to the mesial temporal lobe in four and more widespread in the temporal lobe in 14 patients. In one patient only enlargement of the temporal horn was found and in three others only white matter lesions were detected. 18FDG PET showed a large area of glucose hypometabolism in the epileptogenic temporal lobe, with an extension outside the temporal lobe in 10 of 23 patients. Only in one of these patients DEEG showed extratemporal abnormalities that were concordant with a significant extratemporal extension of hypometabolism in 18FDG PET. 55FDGPET was compared with the results of scalp EEG: in none of the patients was an anterior temporal ictal onset in scalp EEG related to a maximum hypometabolism in the mesial temporal area. By contrast, the region of abnormality indicated by 55C-flumazenil PET was much more restricted, also when compared with DEEG findings. Extension of abnormality outside the lobe of surgery was seen in only two patients with "IC-flumazenil and was less pronounced compared with the intratemporal abnormality. Both 18FDGPET and "IC-flumazenil PET reliably indicated the epileptogenic temporal lobe.

No uniform treatment results expressed per thyroid weight category were obtained, in spite of standardizing the treatment Na131I dose (3.7 MBq per g thyroid). Graves' patients with a thyroid smaller than 20 g and those with less than 60% 24-h radioiodine uptake have a 50-90% chance of hypothyroidism at the 12-month follow-up.

From a Dutch questionnaire, it was apparent that nearly all institutions used percentage of radioiodine uptake for calculation of the radioiodine dose in Graves' disease. Although there is a general belief that fluctuations in radioiodine uptake may occur, with few exceptions relatively long intervals were accepted between the uptake measurement and the actual therapy dose. With the aim of optimizing the pretherapeutic work-up, we evaluated the stability of iodine uptake over time in patients with Graves' disease who were referred for 131I therapy. 131I uptake was measured in 300 consecutive patients for the calculation of the required 131I therapy dose; data were complete for 291 patients (97%). After discontinuing thyroid medication for 3 days, standardized thyroid probe measurements were performed 5 and 24 h after ingestion of a capsule containing 0.37 MBq 131I-NaI. Measurements were performed at the time of scintigraphic diagnosis (test 1), as well as immediately before 131I therapy (test 2). The time interval between test 1 and test 2 ranged from 2 to 421 (median 40) days. A relative increase or decrease greater than 10% between tests 1 and 2 occurred in 180 of 291 cases (62%) at 5 h and in 158 of 291 patients (54%) at 24 h. These changes were not related to the interval between the tests or to initial uptake values, thyroid mass, gender or age. Rapid turnover of radioiodine (5 h/24 h uptake ratio > 1) was noted in 17% of the patients during test 1 and in 15% during test 2. Rapid turnover was persistent (present in both tests 1 and 2) in only 9%. We conclude that patients with Graves' disease show considerable changes in 131I uptake over relatively short periods of time, and the turnover rate of 131I in this condition is not constant.

Objectives: To assess the impact of the intra-articular distribution of 90 yttrium-citrate ( 90 Y) on the clinical effect of radiosynoviorthesis (RSO) of the knee and on 90 Y leakage from this joint. Methods: Patients with arthritis of the knee received 185 MBq 90 Y combined with a glucocorticoid, followed by clinical bed rest. Intra-articular 90 Y distribution, measured with a dual-head gamma camera immediately or after 24 hours, was scored as mainly diffuse or mainly focal. Leakage to regional lymph nodes, the liver and spleen was assessed with a dual-head gamma camera after 24 hours. Clinical effect was scored after 6 months by a composite change index (CCI), range 0-12; responders were defined as having a CCI >6. Results: Seventy-eight knees of 69 patients, mostly suffering from undifferentiated arthritis (42%) or RA (28%), were treated. 90 Y distribution was mainly diffuse in 54% and mainly focal in 46% with clinical response rates of 40% versus 56%, respectively, p = 0.3. CCI was not correlated with distribution. 90 Y leakage was found only to the liver and the spleen (mean leakage 0.4% and 1.1%, respectively). Leakage was significantly less in case of diffuse intra-articular 90 Y distribution, whereas leakage to the liver was correlated with distribution (r = 0.68, p,0.001). 90 The mechanism of action is local radiation inducing necrosis of the synovial membrane, followed by fibrosis and sclerosis. After injection of 90 Y, the needle is flushed with glucocorticoids (GC) to prevent a chemically induced flare-up of arthritis and reflux of 90 Y, and to help to bridge the lag phase before the effect of RSO, which is assumed to last 3-6 months.1 3 GC could also reduce leakage of 90 Y into the blood by reducing within several hours synovitis and associated hypervascularity. It would seem plausible that a diffuse 90 Y distribution would predict a better outcome of RSO than focal distribution, 4 because of less surface contact between 90 Y and the inflamed synovial tissue in the latter situation. However, whether the distribution of 90 Y in the joint cavity after the injection is of importance for the clinical effect of RSO, has sparsely been investigated.The aim of this study was to investigate the impact of the intra-articular 90 Y distribution on the clinical outcome of RSO and on its leakage from the joint. PATIENTS AND METHODS PatientsIn a Dutch randomised clinical trial (RCT) the clinical effect of intra-articular 90 Y and GC versus that of GC was compared. 5Detailed data on the RCT have been described elsewhere. 5 Main outcome measure was a composite change index (CCI) (range 0-12), assessed 6 months after therapy being the lag phase of 90 Y. 6 The CCI included a functional disability score, Visual Analogue Scale of pain, joint tenderness, swelling and effusion of the knee, and patient's and physician's global assessment of the effect of therapy. Successful therapy was defined as CCI >6.Crossover therapy was applied afterwards if there was treatment failure. The subgroups of RSO patients in whom distribu...

The objectives were to investigate the efficacy and safety of yttrium-90 colloid (Y-90) synovectomy in joints with persistent synovitis and to examine the effect of a second synovectomy using a double dose after an initial inadequate response. Of the 45 patients at the University Hospital Utrecht who underwent Y-90 synovectomy between July 1987 and October 1995, the effectiveness and side-effects of all yttrium procedures (n = 83) were assessed retrospectively. Glucocorticoids were administered together with the yttrium, except in 1987. Radiation synovectomy had an overall success rate of 75% (complete or almost complete remission of synovitis) initially, i.e. within 1 month of the procedure, partly due to co-administration of glucocorticoids. However, in October 1995, only 17 joints (22%) were still in remission with a mean (S.D.) duration of remission of 20.8 months (22.0), range 1-95 months (median 16 months). In 60 joints (78%), synovitis was present at that time because of an unsatisfactory initial response to the Y-90 injection (19 joints) or recurrent synovitis during follow-up (41 joints); the mean (S.D.) duration of remission of these 60 joints was 3.3 months (5.9), range 0-22 months. A second injection of a double dose of Y-90 after an initial inadequate response (n = 8) did not contribute significantly to a better result. Short-term side-effects occurred in two cases after two Y-90 injections (2%) without glucocorticoid co-administration: a post-injection flare-up of synovitis and a local skin burn lesion. Persistent synovitis can be treated by Y-90 synovectomy with an overall success rate of 75% within 1 month. However, prolonged remission of synovitis is only achieved in 29% of joints with a good initial response. It does not appear worthwhile to perform a second synovectomy with a double dose if the initial response was inadequate. Y-90 synovectomy leads to only minor short-term side-effects (2%).