Evaluation of renal function following treatment with 5-aminosalicylic acid derivatives in patients with ulcerative colitis.

BACKGROUND: A number of cases of nephrotoxicity have been reported in patients with inflammatory bowel disease taking oral 5-aminosalicylic acid (5-ASA). AIM: To evaluate the effects of 9 months of therapy with mesalazine or olsalazine on renal function in patients with ulcerative colitis in remission. METHODS: Forty patients with ulcerative colitis in complete remission for 6 months were randomized to either olsalazine (n=20) or mesalazine (n=20 for nine months). Thirty-six of the 40 patients were on prior salicylate therapy. Disease activity was the measure ofclinical efficacy and was assessed by the Harvey-Bradshaw Index (HBI). Laboratory efficacy measurements included glomerular filtration rate (GFR), microalbuminuria, urinary gluthathione S-transferase (GST) and serum C-reactive protein (CRP). Safety analysis consisted of documentation of adverse events and laboratory values. RESULTS: There was no significant reduction in the GFR overall on therapy. The levels of GFR adjusted for baseline were similar in the two treatment groups after 3, 6 and 9 months. A significantly higher percentage of mesalazine-treated patients experienced drug related adverse events, all of a minor nature. The incidence of adverse events causing early withdrawal was similar in the two treatment groups. CONCLUSION: Treatment with mesalazine or olsalazine for 9 months had no significant impact on GFR.

Dose reduction in double contrast barium enema by use of low fluoroscopic current.

Under standard conditions double contrast barium enema (DCBE) was carried out on a selected patient cohort using either standard (1.5 mA) or low (0.5 mA) fluoroscopic current. A statistically significant (p < or = 0.01) reduction in total dose was achieved by use of low screening current. This reduction was of the order of 40%. Fluoroscopic image quality was analysed both objectively and subjectively, and was found not to be significantly degraded when the lower current was used. On blinded evaluation all examinations were found to be of diagnostic quality. The use of low fluoroscopic current results in a reduction in patient dose, without compromising fluoroscopic image quality or diagnostic standard of the examination. Low fluoroscopic current technique has been adopted as the standard in our department.

Imaging of medullary carcinoma of the thyroid using 111In-labelled anti-CEA monoclonal antibody fragments.

The distribution of 111In-labelled anti-carcinoembryonic antigen (CEA) monoclonal antibody fragments [F(Ab')2] was studied in five patients either with known inoperable medullary carcinoma of the thyroid (MCT) or evidence of recurrence/metastases based on elevated calcitonin (hCT) levels. All five cases had elevated serum CEA levels and positive immunohistochemical stains for both hCT and CEA prior to scintigraphy. In two patients with identified inoperable disease both planar and SPECT scans were positive. In the remaining three patients, where the recurrence/metastatic sites were unknown, SPECT images were positive in two. Of these, only one had positive planar images. These results indicate that 111In-labelled anti-CEA F(ab')2 scintigraphy, especially in conjunction with SPECT, is useful for the diagnostic evaluation of patients with MCT. The limiting factor of this technique is the high level of non-specific uptake, particularly in the liver, but improvements in the specificity of newer anti-CEA antibodies and the ability to label these with 99Tcm is addressing this problem.

Somatostatin and somatostatin analogues in medullary thyroid carcinoma.

Medullary thyroid carcinoma (MTC) is a neuroendocrine tumour characterized by the production and secretion of calcitonin. MTC tumours may express functional somatostatin receptors (hSSTR). A significant proportion of hSSTR receptor-positive MTC tumours, including metastatic disease, may be visualized in vivo through 111In-pentetreotide scintigraphy. Four patients with recurrent/metastatic disease, who had previously been assessed with 111In-anti-CEA monoclonal antibody fragment [F(ab')2] imaging, were evaluated. 111In-pentetreotide scintigraphy localized all known disease sites. Furthermore, mediastinal disease was detected in one patient with negative conventional, and 111In-anti-CEA F(ab')2 imaging studies. The detection of somatostatin within the tumour (2 patients), or negative octreotide challenges (2 patients), did not affect the outcome of 111In-pentetreotide scintigraphy. In conclusion, 111In-pentetreotide scintigraphy appears at least as effective as 111In-anti-CEA F(ab')2 imaging and should be considered in the diagnostic evaluation of MTC, particularly in the setting of recurrent/metastatic disease not detected by conventional means.

Low-dose radioisotope scanning and quantitative analysis in the diagnosis of congenital hypothyroidism.

Quantitative thyroid scanning using low doses of 99mTc sodium pertechnetate (1.85-3.7 MBq) was performed in 38 cases of congenital hypothyroidism. Of these 38 cases, 29 were scanned at 14 +/- 6 days old, and 9 at 1 year old. The scans show the full range of gland anatomy from athyreotic to normal. All morphologically normal scans had grossly increased uptakes of 99mTc. The incidence of the various thyroid anatomies was different in each age group. The average radiation dose to the thyroid was 2.29 mGy, with at least 70% of patients receiving a dose of 3.0 mGy or less. Such low doses of 99mTc should allow further scanning in later life. Neonatal thyroid scanning reveals the aetiology of congenital hypothyroidism and enables the clinician to assess the short- and long-term needs of the child.

Image processing of videofluoroscopy of patients with velopharyngeal insufficiency and hypernasal speech.

Eleven patients with hypernasal speech and velopharyngeal insufficiency (VPI), together with five normals, were evaluated by videofluoroscopy to assess velopharyngeal movement, velar lift and lateral pharyngeal wall movement. Computer processing of the images obtained was used to compensate for initial poor quality images by contrast and edge enhancement techniques and to provide objective measurement of the movements involved. It was demonstrated that objective computer aided analysis of videofluoroscopic images is feasible and may provide additional subtle diagnostic information when nasendoscopy is unavailable. In addition, results obtained showed an increased degree of velar lift and lateral pharyngeal wall movement for the more severely affected patients. These suggest a compensatory mechanism in operation for the more severe cases of VPI.

An assessment of dynamic gastric scanning with 99Tcm-pertechnetate.

Following intravenous injection, technetium-99m (99Tcm) is selectively taken up by the stomach, and this uptake, which is stimulated by pentagastrin, may be quantified using a gamma camera. Using this property of 99Tcm as a means of assessing gastric function, we found that the mean rate of 99Tcm uptake was significantly greater in 24 duodenal ulcer patients than in 10 healthy controls (P less than 0.01). Scanning values did not correlate with BAO of MAO which were measured on a separate day. Both vagotomy (n = 10) and cimetidine infusion (n = 5) significantly reduced the rate of uptake of 99Tcm (P less than 0.01). Thus, although 99Tcm reflects a function of the stomach which is similar to acid secretion, scanning did not give a good estimate of acid secretion in this group of subjects.

Imaging of bronchial carcinoid tumours with indium-111 pentetreotide.

Neuroendocrine tumours are characterised by the expression of high affinity binding sites for somatostatin. The detection of bronchial carcinoid tumours through scintigraphic imaging is described in two patients using the novel radiolabelled somatostatin analogue indium-111 pentetreotide.

Scintigraphic imaging of small-cell lung cancer with [111In]pentetreotide, a radiolabelled somatostatin analogue.

Recent work suggests that between 50 and 75% of small-cell lung cancer (SCLC) tumours have specific high-affinity binding sites for somatostatin. This study evaluated the potential role of the radiolabelled somatostatin analogue, [111In]pentetreotide, in the detection and staging of SCLC in patients prior to and after chemotherapy using scintigraphic imaging techniques. Thirteen patients were studied prior to chemotherapy. Following standard staging six patients had limited stage disease and seven extensive disease. [111In]pentetreotide imaging led to the detection of all primary sites of disease, including a primary site of disease not detectable with chest radiograph or computerised tomography (CT) of the thorax. Five of ten metastatic sites detected by standard staging were also imaged. Furthermore, a cerebellar metastasis was detected in a patient thought to have disease confined to the right hemithorax. This was subsequently confirmed with a CT brain scan. Following chemotherapy [111In]pentetreotide imaging detected residual intrathoracic disease in two of three patients with complete remissions by standard staging and in two patients who had had a partial response to chemotherapy. These results suggest that [111In]pentetreotide imaging may have a role to play in the clinical evaluation of patients with SCLC. Specifically, this technique may be of particular value in detecting residual intrathoracic disease in patients thought to be in complete remission by conventional staging methods.