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H Y Oei

Publications and source records attributed to H Y Oei.

At least 19 recordsLinked to original sources
PubMed2001

Somatostatin receptor scintigraphy useful in stage I-II Hodgkin's disease: more extended disease identified.

Somatostatin receptor (SS-R) scintigraphy successfully shows primary cancers and metastases in patients with a variety of SS-R-positive tumours. In vitro studies have shown that SS-Rs are present in lymph nodes from patients with Hodgkin's disease (HD). We performed a prospective study in 126 newly diagnosed patients with HD and compared the results of SS-R scintigraphy with conventional staging procedures, i.e. physical examination, computerized tomography (CT) scanning and other imaging techniques. We report positive scintigraphy in all patients. The lesion-related sensitivity was 94% and varied from 98% for supradiaphragmatic lesions to 67% for infradiaphragmatic lesions. In comparison with CT scanning and ultrasonography, SS-R scintigraphy provided superior results for the detection of Hodgkin's localizations above the diaphragm. In the intra-abdominal region, the CT scan was more sensitive than the SS-R scan. A false-positive scan was rarely seen. In stages I and II supradiaphragmatic HD patients, SS-R scintigraphy detected more advanced disease in 18% (15 out of 83) of patients, resulting in an upstaging to stage III or IV, thus directly influencing patient management. Our data would support the validity of SS-R scanning as a powerful imaging technique for the staging of patients with HD.

Adolescent↗
PubMed2001

Somatostatin receptor scintigraphy in the initial staging of low-grade non-Hodgkin's lymphomas.

UNLABELLED: In this prospective study, somatostatin receptor (SS-R) scintigraphy was compared with conventional staging procedures for the initial staging of patients with low-grade non-Hodgkin's lymphoma (NHL). METHODS: Fifty consecutive untreated patients with low-grade NHL underwent SS-R scintigraphy as part of their initial staging. Planar images were obtained 24 and 48 h after intravenous injection of 220 MBq (111)In-pentetreotide. SPECT images of the upper abdomen were obtained from all patients. SS-R scans were evaluated blindly without knowledge of the results of the conventional staging methods. SS-R scintigraphy findings were compared with the results of physical and radiologic examinations. RESULTS: SS-R scintigraphy findings were positive in 42 of 50 patients (84%). In 10 patients (20%), the SS-R scan revealed new lesions that had not been revealed by conventional staging procedures. These 10 patients were all upgraded to a higher stage. Consequently, the treatment plan would have been altered in 5 patients (10%). However, in 19 patients (38%), lesions apparent after conventional staging methods were missed by SS-R scintigraphy. The sensitivity of SS-R scintigraphy varied from 62% for supradiaphragmatic lesions to 44% for infradiaphragmatic lesions. The specificity of SS-R scintigraphy was high (98%-100%). In comparison with CT scanning and sonography, SS-R scintigraphy is inferior for the visualization of NHL lesions in the thorax and abdomen. CONCLUSION: Although SS-R scintigraphy findings are positive in a large proportion of patients with low-grade NHL, in most patients only part of the lesions can be visualized. Because of the limited sensitivity, we recommend SS-R scintigraphy for initial staging of patients with low-grade NHL only in selected conditions and not for the general work-up.

Female↗
PubMed1999

Report of the Radionuclides in Nephrourology Committee for evaluation of transplanted kidney (review of techniques).

Comprehensive evaluation of renal transplants has been important in differential diagnosis of medical and surgical complications in the early post-transplantation period and in the long-term follow-up. If performed well, it yields excellent functional and good anatomic information about the graft that can be effectively used in the patient. That includes selection of patients for biopsy and for various drug regimens. This is true especially in patients with anuric acute tubular necrosis (ATN) and in patients with developing chronic rejection. Improving indices of renal function (effective renal plasma flow, uptake of tubular tracers) can indicate resolution of tubular injury (ATN) while there is still no improvement in plasma creatinine. In patients with chronic rejection, plasma creatinine increases only after approximately 30% of renal function is lost due to graft fibrosis. Early recognition of this condition could permit treatment and delay of retransplantation. The protocol recommended at the Copenhagen meeting includes a flow study, scintigram of the kidneys, prevoid and postvoid bladder image, injection site image (quality control), time/activity curves of the graft and bladder, and quantitative data of perfusion, function, and tracer transit. The flow study obtained during the initial transit of the bolus through the graft could be performed either with 99mTc mercaptoacetyltriglycine, or 99mTc diethylenetriaminepentaacetate (DTPA). Quantitative analysis of perfusion facilitates interpretation of the study during the early post-transplantation period. ATN, common in cadaver transplants, typically shows adequate perfusion. The function phase should include images and time/activity curves. Images alone are insufficient. Quantitative data such as clearance or other indices of function and indices of tracer transit are essential for correct interpretation of the results. Normal images and normal graft function reliably exclude clinically important complications. A single scintigram demonstrating prolonged tracer transit with decreased function cannot separate acute rejection and ATN. On serial studies, decline in function and poor perfusion are indicative of acute rejection. A normally appearing scintigram without cortical retention, but with low function, is consistent with chronic rejection. Pharmacological intervention to exclude obstruction (diuretic renogram) or hemodynamically significant renal artery stenosis (angiotensin converting enzyme challenge) should be used whenever indicated.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1999

Randomized comparison of prevertebral and retrosternal gastric tube reconstruction after resection of oesophageal carcinoma.

BACKGROUND: After potentially curative resection of oesophageal cancer and prevertebral gastric tube reconstruction, approximately one-quarter of patients develop secondary dysphagia due to locoregional recurrence. In half of them dysphagia can be prevented by using an extra-anatomical reconstruction route. The present randomized study was conducted to compare the technical and functional results after prevertebral and retrosternal gastric tube reconstruction. METHODS: Sixty patients underwent resection of a carcinoma of the oesophagus or gastro-oesophageal junction with curative intent. Subsequently, these patients were randomly allocated to either prevertebral (n = 30) or retrosternal (n = 30) gastric tube reconstruction. Early and late complications and functional results were carefully monitored. RESULTS: Creation of the retrosternal tunnel was not accompanied by any perioperative complications. Postoperative recovery, anastomotic leakage and benign stricture formation were not significantly different between the two groups. Functional results, as measured by scintigraphic gastric emptying, quantitative and qualitative oral food intake, and changes in body-weight were similar in the two groups. CONCLUSION: After subtotal oesophagectomy retrosternal gastric tube reconstruction can be performed easily and safely, and gives functional results similar to those obtained with prevertebral reconstruction. In patients at high risk for developing secondary malignant dysphagia the extra-anatomical route is the reconstruction of first choice.

Adult↗
PubMed1997

The place of renal scintigraphy in the diagnosis of renal artery stenosis. Fifteen years of clinical experience.

BACKGROUND: Renal scintigraphy with radiolabeled pentetic acid (diethylenetriamine pentaacetic acid [DTPA]) or, more recently, mertiatide (mercaptoacetyltriglycine [MAG3]), with or without captopril challenge, is widely recommended as a diagnostic test for renal artery stenosis. OBJECTIVES: To address (1) whether the diagnostic accuracy has been improved by the use of captopril and the introduction of mertiatide and (2) whether a renal scan that shows abnormalities is a useful criterion to select patients for renal arteriography. PATIENTS AND METHODS: A standard diagnostic protocol, using both scintigraphy and arteriography, was followed in 505 consecutive high-risk hypertensive patients who were evaluated for renovascular hypertension at the University Hospital Dijkzigt, Rotterdam, the Netherlands, from 1978 to 1992. RESULTS: Renal artery stenosis (> or = 50%) was present in 263 patients. When the single-kidney fractional uptake was used as a diagnostic criterion, a specificity of 0.90 was obtained at a cutoff value of 35% for the worst kidney in scintigraphy using pentetic acid without captopril challenge (n = 225) and at a cutoff value of 37% after captopril challenge (n = 280). This was associated with sensitivity levels of 0.65 and 0.68, respectively. The difference between the uptake of pentetic acid with and without captopril challenge in the 85 patients who were studied under both circumstances was no more accurate as a predictor of renal artery stenosis. In the 93 patients who were studied with mertiatide as well as with pentetic acid, both after captopril challenge, the diagnostic accuracy was no better with mertiatide than with pentetic acid; mertiatide failed to offer any advantage not only when the single-kidney fractional uptake was used as a criterion, but also with the use of other scintigraphic parameters (eg, time to peak, time to pyelum, overall shape of renographic curve, and kidney size). CONCLUSIONS: The diagnostic accuracy of renal scintigraphy has not been improved by the introduction of mertiatide or by the use of captopril. The usefulness of scintigraphy as a diagnostic test for the presence of renal artery stenosis remains questionable. The physician will always confront either a substantial number of arteriograms that do not show abnormalities when renal scintigraphy is omitted as a screening step or a substantial number of missed diagnoses when a renal scan that shows abnormalities is used as a prerequisite for arteriography.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1996

Echocardiographic and radionuclide pulmonary blood flow patterns after transcatheter closure of patent ductus arteriosus.

BACKGROUND: Transcatheter occlusion of patent ductus arteriosus (PDA) has been associated with protrusion of the occluder device into the left pulmonary artery (LPA). This study was conducted to evaluate the significance of occluder protrusion and its implications for potential obstruction of the LPA and associated decrease of left lung perfusion. METHODS AND RESULTS: Fifty-two patients underwent successful transcatheter PDA occlusion over a period of 5 years. In this study, 49 were reexamined between March and June 1995. In addition to clinical and echocardiographic examination, lung scintigraphy was performed. Protrusion into the LPA was present in 5 of 49 patients (10%). In these patients, maximal flow velocity in the LPA was significantly (P < .01) increased. Decreased left lung perfusion, defined as < 40% of total pulmonary blood flow, was found in 7 of 49 patients (14%). Although mean left pulmonary perfusion was significantly (P = .02) decreased in patients with protrusion, there was considerable overlap with patients without protrusion, and only a weak correlation was found (r = -.35, P = .01) between flow-velocity and left lung perfusion. CONCLUSIONS: Our results demonstrate that protrusion of the device in the LPA is an infrequent finding. If present, it is associated with increased maximal flow velocity in the LPA and diminished left lung perfusion. However, echocardiography and lung scintigraphy are weakly correlated: Increased maximal blood flow velocities in the proximal LPA proved to be a poor indicator or impaired left lung perfusion. Also, decreased perfusion occurs in the absence of echocardiographic evidence of device protrusion.

Blood Flow Velocity↗
PubMed1996

Digital subtraction arthrography in preoperative evaluation of painful total hip arthroplasty.

OBJECTIVE: The objective of this clinical study was to define the diagnostic value of plain radiography, digital subtraction arthrography and two-phase bone scintigraphy in patients with clinically loose or infected hip prostheses. DESIGN: Digital subtraction arthrograms, scintigrams and plain radiographs of 70 consecutive patients who underwent revision hip arthroplasty were scored individually and in masked fashion for the presence or absence of features indicating loosening of femoral and/or acetabular components. The operative findings acted as the gold standard. RESULTS: Digital subtraction arthrography was best (P < 0.001) for predicting a loose acetabular component, while no significant additional predictive value was found for plain radiographs (P = 0.24) and scintigraphy (P = 0.27). Digital subtraction arthrography was also the most important modality for predicting a loose femoral component (P = 0.001), while the plain radiograph was of significant (P = 0.04) additional value and scintigraphy was of no additional value (P = 0.13) on multivariate analysis. CONCLUSION: Digital subtraction arthrography gives the best results in the prediction of loosening of acetabular and femoral components. Plain radiographs give additional information on loosening of the femoral component, but scintigraphy offers no additional advantage.

Adult↗
PubMed1996

Somatostatin receptor scintigraphy in cutaneous malignant lymphomas.

BACKGROUND: Lymphoid cells may express somatostatin receptors (SS-Rs) on their cell surface. Therefore radiolabeled somatostatin analogues may be used to visualize SS-R-positive lymphoid neoplasms in vivo. Exact staging is the basis for treatment decisions in cutaneous malignant lymphoma. We considered the possibility that SS-R scintigraphy might offer a clinically useful method of diagnostic imaging in patients with cutaneous malignant lymphoma. OBJECTIVE: We evaluated SS-R scintigraphy in comparison with conventional staging methods in the staging of cutaneous malignant lymphoma. METHODS: We conducted a prospective study in 14 consecutive patients with histologically proven cutaneous malignant lymphoma. SS-R scintigraphy was compared with physical, radiologic, and bone marrow examinations. Lymph node excisions were performed in patients with palpable lymph nodes. RESULTS: SS-R scintigraphy was positive in the lymph nodes in all four patients with malignant lymph node infiltration and negative in the three patients with dermatopathic lymphadenopathy. In two patients, previously unsuspected lymphoma localizations were visualized by SS-R scintigraphy. In only three patients all skin lesions were visualized by SS-R scintigraphy; these three patients had not been treated with topical corticosteroids. SS-R scintigraphy failed to detect an adrenal mass in one patient and bone marrow infiltration in two patients. CONCLUSION: SS-R scintigraphy may help distinguish dermatopathic lymphadenopathy from malignant lymph node infiltration in patients with cutaneous malignant lymphoma.

Administration, Topical↗
PubMed1996

Somatostatin receptor scintigraphy in the initial staging of Hodgkin's disease.

Somatostatin receptor (SS-R) scintigraphy has been successfully used in the visualization of a variety of neuroendocrine tumours. In vitro studies have shown that SS-Rs are present in human malignant lymphomas. We conducted a prospective study in 56 consecutive untreated patients with histologically proven Hodgkin's disease (HD) and compared the results of SS-R scintigraphy with physical and radiological examinations as initial evaluation. SS-R scintigraphy was positive in 55/56 (98%) patients at sites of documented disease. In 20 patients SS-R scintigraphy disclosed lymphoma localizations not revealed following procedures of conventional staging. As a result in 12 patients (21%) SS-R scintigraphy produced a change of stage and in seven patients (13%) the additional information obtained from SS-R scintigraphy led to a change of treatment. SS-R scintigraphy failed to visualize sites of HD in four patients, mainly in the abdominal area. In three patients a false-positive result was obtained. These data show that SS-R scintigraphy provides an imaging technique that appears to visualize tumours in most patients with HD and may be clinically useful in the management of these patients.

Adolescent↗
PubMed1996

In vivo imaging of pituitary tumours using a radiolabelled dopamine D2 receptor radioligand.

OBJECTIVE: Knowledge of the dopamine D2 receptor status of pituitary tumours may play a predictive role in differential diagnosis and therapeutic decisions. This study was performed to evaluate the value of pituitary dopamine D2 receptor scintigraphy with (S)-2-hydroxy-3-123I-iodo-6-methoxy-N-[(1-ethyl-2-pyrrolidinyl) methyl]benzamide (123I-IBZM) in the diagnostic evaluation of patients with pituitary tumours. DESIGN AND PATIENTS: Scintigraphy using 123I-IBZM was performed in 5 patients with PRL-secreting macroadenomas, 2 patients with PRL-secreting microadenomas, 17 patients with clinically non-functioning pituitary adenomas (NFPAs), 12 patients with GH-secreting adenomas and 1 patient with a TSH-secreting macroadenoma. RESULTS: Single-photon emission tomography (SPECT) showed significant uptake of 123I-IBZM in the pituitary region in 3/5 macroprolactinoma patients. These results closely correlated with the response of plasma PRL levels to the dopamine D2 receptor agonist quinagolide. In two scan-positive prolactinoma patients, repeated SPECTs during therapy with quinagolide showed a reduction in the pituitary uptake of 123I-IBZM. Pituitary SPECT was negative in the 2 microprolactinoma patients, who responded to quinagolide administration. In 4/17 patients with NFPA, significant uptake of the radioligand in the pituitary region was observed. In 2/3 scan-positive NFPA patients, who were treated with quinagolide, shrinkage of the pituitary tumours was observed. Treatment with quinagolide resulted in stabilization of tumour growth in the other scan-positive patients. Four out of 17 patients with NFPA and a negative SPECT were treated with quinagolide. Tumour growth was observed in 1 patient, and tumour size did not change in the other 3 patients. The pituitary region of none of the 12 acromegaly patients showed significant uptake of 123I-IBZM. Sensitivity of the GH-secreting adenomas to quinagolide was demonstrated in 8/12 patients in vivo by an acute test, and in 6/9 of the tumours in vitro. Pituitary SPECT was negative in the patient with the TSH-secreting macroadenoma and this tumour also showed no sensitivity to quinagolide in vivo or in vitro. CONCLUSIONS: We conclude that 123I-IBZM is a ligand for in vivo imaging of dopamine agonist- sensitive macroprolactinomas, but not for microprolactinomas or GH-secreting adenomas. The technique potentially provides a means of predicting the dopamine agonist-responses of non-functioning pituitary adenomas in vivo.

Adenoma↗
PubMed1996

Somatostatin receptor scintigraphy in non-medullary thyroid cancer.

8 patients with papillary cancer (4 with metastases, 4 in remission), 7 follicular cancer patients (6 with metastases), 2 patients with anaplastic thyroid cancer and 4 other non-medullary thyroid cancer patients all received an intravenous bolus injection of 220 MBq [111In-DTPA-D-Phe1]octreotide. Planar anterior and posterior gamma camera images of head-neck, chest and abdomen were obtained 24 and 48 h after injection. All primary cancers showed [111In-DTPA-D-Phe1] octreotide uptake; none occurred in patients in remission. The results were compared with conventional radio-iodine scintigraphy in patients with metastasised, differentiated thyroid cancer.

Carcinoma, Papillary↗
PubMed1995

Dopamine-producing paraganglioma not visualized by iodine-123-MIBG scintigraphy.

A patient with an aorticopulmonary paraganglioma was found to have normal plasma norepinephrine and epinephrine levels and elevated dopamine levels. Iodine-123-MIBG scintigraphy did not visualize this tumor. The same finding on a negative MIBG scan in two patients with exclusively dopamine-secreting chemodectomas has been previously reported. In our patient, [111In-DTPA-D-Phe1]-octreotide scintigraphy proved to be an effective imaging technique.

3-Iodobenzylguanidine↗
PubMed1994

[Preoperative noninvasive tests for localization of enlarged parathyroid glands in 115 patients with hyperparathyroidism].

OBJECTIVE: To evaluate results of preoperative localisation techniques in patients operated for hyperparathyroidism (HPT). SETTING: Rotterdam University Hospital. DESIGN: Retrospective study. METHOD: Results of 4 non-invasive preoperative localisation techniques in 115 patients with HPT were compared with operative findings of 116 explorations. Sensitivity and specificity were calculated for single versus multiple gland disease, primary exploration versus re-explorations and anatomical versus ectopic localisation. RESULTS: Sensitivity of preoperative ultrasound, thallium-technetium subtraction scintigraphy, computed tomography and 99mTc-sestamibi (MIBI) scanning in patients with single gland disease was 56%, 65%, 67% and 83% respectively. In multiple gland disease preoperative localisation techniques were much less successful. For MIBI scintiscanning this question remains unanswered. Specificity of all techniques was high. Success rates of preoperative localisation studies for primary operations and re-explorations were similar. Mean weight of parathyroid tumours that were missed preoperatively was lower than of successfully localised tumours. Only computed tomography and thallium-technetium scintigraphy were able to localise retrosternal parathyroid tumours. CONCLUSION: Review of the literature reveals that there is additional benefit of the preoperative localisation studies in re-exploration for HPT, in contrast to primary exploration. By combining localisation techniques more tumours are visualised. Preliminary results of MIBI scanning are favourable.

Adult↗
PubMed1994

Somatostatin-receptor scintigraphy in primary breast cancer.

Somatostatin-receptor (SS-R) scintigraphy successfully shows primary cancers and distant metastases in most patients with carcinoids, islet cells tumours, and paragangliomas. Previous in-vitro studies indicated that somatostatin receptors are present in human breast cancers. We report positive scintigraphy with [111In-DTPA-D-Phe1]-octreotide in 39 of 52 primary breast cancers (75%). Parallel in-vitro autoradiography with [125I-Tyr3]-octreotide of 30 of these showed a corresponding somatostatin-receptor status in 28. Significantly more invasive ductal cancers could be shown than invasive lobular carcinomas (85% vs 56%; p < 0.05). Also the number of T2 cancers which were shown was higher than T1 (86% vs 61%; p < 0.05). Imaging of the axillae showed non-palpable cancer-containing lymph nodes in 4 of 13 patients with subsequently histologically-proven metastases. In the follow-up after a mean of 2.5 yr, SS-R scintigraphy in 28 of the 37 patients with an originally SS-R-positive cancer, was positive in the 2 patients with clinically-recognised metastases, as well as in 6 of the remaining 26 patients who were symptom-free. Raised carcinoembryonic antigen (CEA) and CA 15-3 values were observed in only 2 and 1, respectively, of these patients. Most primary breast cancers can be shown by SS-R scintigraphy, especially invasive ductal cancers. This technique may be of value in selecting patients for clinical trials with somatostatin analogues or other medical treatments. Furthermore, SS-R scintigraphy is more sensitive than measurements of the usual serum cancer markers for detecting recurrences of SS-R-positive breast cancer.

Adult↗