Success rate of thyroid remnant ablation for differentiated thyroid cancer based on 5550 MBq post-therapy scan.

BACKGROUND: Success rate of thyroid remnant ablation in patients with low-risk differentiated thyroid cancer (DTC) is commonly based on measurement of serum thyroglobulin levels and 185 MBq (5 mCi) diagnostic 131I scanning or neck ultrasound, performed 6-9 months after ablation. In the present study, we report the rates of successful 131I ablation based on a 5550 MBq (150 mCi) post-therapy scan performed 6-9 months after ablation. METHODS: Retrospective cohort study of 77 adult patients with DTC, stage T1-T3, N0 or N1, M0, demonstrating thyroid remnant uptake one week after a 2775 MBq (75 mCi) ablation dose. Six to nine months later, all patients received a 5550 MBq dose of 131I, followed by a post- therapy scan after one week. Complete thyroid ablation was defined as no thyroid remnant uptake and a thyroglobulin level < 0.2 µg/l after thyroid hormone withdrawal. RESULTS: Thyroid ablation was complete in 20 patients (26%). Forty-eight patients (62%) demonstrated persistent remnant uptake. This was associated with thyroglobulin levels > 0.2 µg/l in 24/48, and positive thyroglobulin antibodies in 4/48 patients. CONCLUSION: Thyroid remnant ablation success assessed by 5550 MBq post-therapy scanning was much lower than reported in studies evaluating ablation success based on 185 MBq diagnostic 131I scanning or neck ultrasound. The latter techniques may be too inaccurate to detect thyroid remnants and thus may not be sufficiently reliable to predict long-term disease outcome.

[18 FDG PET imaging of the brain in the analysis of a dementia syndrome]. / De rol van de 18-fDG PET-scan bij de diagnose dementie.

According to current dementia guidelines from 2005 (CBO) functional brain imaging by PET-scan of the brain has no place in the analysis of a dementia syndrome. Differential diagnosis between Alzheimer disease and other causes of dementia remains important because there are differences in natural course and treatment. Here we present three patients aged 62, 71 and 68 years with dementia syndrome who were assessed at an outpatient memory clinic. After geriatric assessment and subsequent brain MRI the etiology of the dementia remained unclear. In all three patients the etiology became clear after using a 18 FDG PET-scan of the brain. We conclude that 18 FDG PET imaging of the brain has added value in the analysis of dementia syndrome with an unclear etiology after initial analysis.

[Results from a general training hospital for the implementation of a diagnostic workup for pulmonary embolism according to the Dutch Institute for Health Care Improvement]. / Resultaten van het invoeren van diagnostiek naar longembolie volgens de CBO-richtlijn in een algemeen opleidingsziekenhuis.

OBJECTIVE: To evaluate the active implementation of the Dutch Institute for Healthcare Improvement's guideline for the diagnostic work-up for pulmonary embolism in a general training hospital, and to analyse reasons for not following the guideline strategy. DESIGN: Partly retrospective and partly prospective. METHOD: The diagnostic strategy was analysed for all consecutive patients with clinically suspected pulmonary embolism who underwent a perfusion lung scintigraphy. The extent to which the guideline was followed was investigated in the year before (July 1999-June 2000; n = 384) and the year after (July 2000-June 2001; n = 380) its active implementation. The possible reasons for not completing the strategy in the prospective cohort of the study were also analysed. RESULTS: Following a non-high-probability perfusion-ventilation scan, the guideline was completed in 23/117 (20%) patients prior to the implementation and in 50/109 (46%) patients after the implementation of the guideline. In 27% and 60%, respectively, an additional duplex ultrasound of the legs was made to check for deep vein thrombosis, and in 65% and 70% respectively, pulmonary angiography was performed after a normal ultrasound result. The main reasons for not following the diagnostic work-up included low clinical probability (41%, without a proper alternative diagnosis), an alternative diagnosis (36%; pneumonia, heart failure, malignancy) and a reluctance to perform angiography. The mean age of the patients for whom the guideline was completed was lower (51 years) compared to patients for whom the guideline was not followed (65 years; p < 0.001). The risk of not completing the diagnostic workup in accordance with the guideline was six-fold higher for patients > or = 80 years compared with patients < 40 years of age, whereas an alternative diagnosis was not more prevalent in patients > or = 65 years. CONCLUSION: Although active implementation of the guideline-based diagnostic work-up for pulmonary embolism increased the number of adequate diagnoses, the diagnostic work-up was not completed in half of the patients with inconclusive lung scans. The main reasons for this were the advanced age of the patient, alternative diagnoses, and a reluctance to perform pulmonary angiography.