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F M van der Zant

Publications and source records attributed to F M van der Zant.

6 recordsLinked to original sources
PubMed2003

Effect of increased (99m)Tc/(99)Tc ratios on count rates in sentinel node procedures: a randomised study.

The aim of this study was to evaluate the count rates of sentinel lymph nodes (SLNs) in patients with breast cancer in the operating theatre, using (99m)Tc-Nanocoll with different ratios of technetium-99m to technetium-99. After written informed consent had been obtained, we tested different ratios of (99m)Tc/(99)Tc-Nanocoll in a double-blinded randomised study performed in 161 patients. Twenty-five MBq/ microg (99m)Tc-colloid albumin was prepared in vacuum. In 87 patients (group A) a 2-h elution was used and in 74 patients (group B) a 24-h elution was used. Patients were subcategorised into subgroups 1 and 3, in which an SLN procedure for breast carcinoma was performed simultaneously with lumpectomy, and subgroups 2 and 4, in which an SLN procedure was performed 2-3 weeks after prior excision biopsy. All patients were injected along the lateral border of the areola (two injections: 50 MBq/0.3 ml intradermally and 50 MBq/2 ml intraparenchymally). Ex vivo measurement of count rates was performed with a gamma probe. Comparing groups A and B in respect of registered counts per second (cps) of excised SLNs, a significant difference was found ( P<0.004). When comparisons were made between subgroups 1 and 2 (2-h elution) and between subgroups 3 and 4 (24-h elution) in respect of registered cps of excised SLNs, no significant difference was found (subgroup 1 vs 2, P=0.825; subgroup 3 vs 4, P=0.915). Use of a 2-h elution in vacuum yielded a significantly higher count rate of maximum specific activity of (99m)Tc-colloid albumin in SLNs than was achieved using a 24-h elution in vacuum. SLN procedures performed 2-3 weeks after prior excision biopsy proved reliable as compared to SLN procedures performed simultaneously with lumpectomy.

Adult↗
PubMed1999

Octreotide-scintigraphy is a disease-activity parameter in Graves' ophthalmopathy.

OBJECTIVE: It is thought that immunosuppressive treatment of Graves' ophthalmopathy should be restricted to patients with active eye disease, but assessing disease activity is difficult. Octreotide scintigraphy has been claimed to differentiate active from inactive disease. Here we study the intraobserver variability and diagnostic accuracy of the quantitative measurement of orbital octreotide uptake. PATIENTS AND DESIGN: Twenty-two consecutive patients with moderately severe ophthalmopathy were treated with retrobulbar radiotherapy. Pretreatment octreotide scintigraphic data were related to the response at six months after radiotherapy, using Receiving-Operator-Characteristic curves. MEASUREMENTS: Octreotide uptake was measured at 4 and 24 h after i.v. injection of approximately 3 mCi (= 111 MBq; range 75-150 MBq) 111Indium-DTPA-Octreotide with a neuro-SPECT camera. Counts were measured in fixed regions-of-interest in 4 transversal slices of the orbit, the temporal and the occipital area. Measurements were done twice and intraobserver variability was analysed by coefficients of variations (CV). Uptake is expressed as orbital/background ratio. The nature of the temporal uptake was studied by matching an octreoscan with a technetium scan and MRI. RESULTS: Intra-observer variability of measuring octreotide uptake was acceptable, and the coefficient of variation slightly better using the orbital/occipital ratio (11%), than the orbital/temporal ratio (16%). From matching studies it appears that the temporal uptake takes place, in part, in the parotid gland. The orbital/occipital ratio was used to predict the outcome of radiotherapy. Mean (+/- SD) uptake on the 4 h scan was higher in responders (2.2 +/- 0.66) than in nonresponders (1.7 +/- 0.39; P = 0.04). From the Receiving-Operator-Characteristic curve we determined a cut-off value of 1.85, which yielded a positive predictive value of 92% and a negative predictive value of 70%. The 24 h scan could not predict a response. CONCLUSION: Quantitative measurement of orbital octreotide uptake is possible. Using the orbital/occipital ratio on the 4 h scan, the octreoscan seems useful in predicting response to subsequent radiotherapy. The 24 h scan seems not to be useful in predicting therapeutic outcome.

Adult↗
PubMed1997

Pulmonary embolism in deep venous thrombosis of the upper extremity: more often in catheter-related thrombosis.

BACKGROUND: Pulmonary embolism (PE) is a major complication of deep venous thrombosis (DVT) of the lower extremities. The incidence is approximately 50%. The incidence of DVT of the upper extremity (DVTUE) is increasing mainly due to the increasing use of central venous catheters. The percentage of PE secondary to DVTUE is still being investigated. METHODS: The occurrence of PE in DVTUE was retrospectively analyzed in 78 patients with proven DVTUE. Furthermore, the literature was reviewed. RESULTS: Of the identified patients with DVTUE 16 showed a primary DVTUE and 62 a secondary DVTUE. Secondary DVTUE was catheter-related in 41 (60%), which is 53% of all DVTUE. In this study the percentage of PE as a complication of DVTUE was 6 (95% CI: 0.2-30) in primary DVTUE, 13 (95% CI: 6-24) in secondary DVTUE and 17 (95% CI: 7-32) in catheter-related DVTUE. The relative risk for PE of catheter-related DVTUE versus other causes was 3.4 (95% CI: 0.4-53.5). The overall percentage was 12 (95% CI: 5-21). The literature review showed a percentage of 7 (95% CI: 4-9) in the retrospective studies and 17 (95% CI: 12-23) in the prospective studies. CONCLUSIONS: Indwelling catheters are the most common cause of DVTUE. PE is not an uncommon complication of DVTUE, and is more common in catheter-related DVTUE. The difference between the incidence of PE in DVTUE and DVT of the lower extremity may be explained by a number of factors, such as differences in fibrinolytic activity, mechanical forces and venous flow patterns.

Adult↗
PubMed1995

[Compliance with consensus 'Diagnosis pulmonary embolism' in clinical practice].

OBJECTIVE: Evaluation of clinical management in patients suspected of pulmonary embolism as compared with the Dutch consensus for diagnosing pulmonary embolism. DESIGN: Retrospective. SETTING: Medical Centre Alkmaar. METHOD: Retrospective analysis of clinical management in patients subjected to ventilation-perfusion scintigraphy on suspicion of pulmonary embolism. RESULTS: In 55 (24%) of the 225 patients included a high-probability scan was found, in 68 (30%) a non-high-probability scan and in 102 (45%) a normal scan. The clinical management in all patients with a normal or high-probability scan was according to the consensus. In the 68 patients with a non-high-probability scan the consensus was completely followed in 16%, partially in 18% and not at all in 66%. CONCLUSION: Clinical management of patients with a non-high-probability scan in the vast majority of cases was not according to the consensus. The consensus was followed in all patients with a normal or high-probability scan.

Anticoagulants↗