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Biomedical subjects

J Bomanji

Publications and source records attributed to J Bomanji.

At least 37 records · Page 2Linked to original sources
PubMed1993

Radioimmunoscintigraphy with technetium-99m-labelled monoclonal antibody, SM3, in gynaecological cancer.

Radioimmunoscintigraphy (RIS) with technetium-99m labelled SM3, a monoclonal antibody reacting with a polymorphic epithelial mucin glycoprotein core antigen, is evaluated. No adverse effects or thyroid uptake were observed. Studies in 45 patients (one twice) had a sensitivity for gynaecological malignancy of 100% (35/35) and a specificity of 73% (8/11), giving an overall accuracy of 93% (43/46). These results have led to the routine adoption of 99mTc RIS in the management of patients suspected of or having primary or recurrent gynaecological cancer.

Adult↗
PubMed1993

Imaging neuroendocrine tumours with radiolabelled somatostatin analogues and X-ray computed tomography: a comparative study.

Various endocrine neoplasms, including a number of carcinoid and pancreatic islet cell tumours, express somatostatin receptors. These tumours may be difficult to localize using conventional techniques. Radiolabelled somatostatin analogues 123I-Tyr-3-octreotide and 111In-pentatreotide have been used for imaging these tumours. In a retrospective study of 24 patients, the sensitivities of somatostatin receptor scintigraphy and X-ray computed tomography (CT) were compared. Ten patients were scanned using 123I-Tyr-3-octreotide and 14 with 111In-pentatreotide. All patients had CT scans. Twenty patients had neuroendocrine tumours with a total of 45 lesions in the anatomical areas included on both scans. CT detected 42 while somatostatin receptor scanning detected 31 of these lesions. Three lesions were missed by CT which were detected by scintigraphy, and there were six CT false positive lesions. In a further four patients investigated for suspected neuroendocrine tumours, no lesion was shown using either modality and subsequent investigations and clinical follow-up have shown no evidence of a tumour. We conclude that while CT is more sensitive than somatostatin receptor scintigraphy, the techniques are complementary, especially in patients with disseminated pathology, equivocal lesions on CT, or a negative CT and strong clinical or biochemical evidence of a neuroendocrine tumour.

Adolescent↗
PubMed1993

Treatment of malignant phaeochromocytoma, paraganglioma and carcinoid tumours with 131I-metaiodobenzylguanidine.

131I-metaiodobenzylguanidine (MIBG) has been used for the therapy of neural crest tumours. We report our experience with this agent in nine patients (malignant phaeochromocytoma 2; malignant paragangliomas 3; malignant carcinoid tumours 4). Six patients had soft tissue metastases alone while three had both soft tissue and bone metastases. The follow-up period ranged from 8 to 110 months, the number of doses ranged from one to seven with 3.1 to 11.1 GBq per administration and a cumulative activity from 4.8 to 40.1 GBq, while the tumour response was assessed according to World Health Organization (WHO) criteria. None of the patients showed complete tumour regression. Five patients showed complete symptomatic and three showed complete hormonal responses. Three patients with carcinoid tumours died. 131I-MIBG is thus a useful therapeutic modality which provides temporary palliation of these difficult tumours, but is rarely curative.

3-Iodobenzylguanidine↗
PubMed1993

A pilot study of flaccid penile blood flow patterns in normal subjects and patients with erectile dysfunction.

Dynamic penile scintigraphy was performed using 99Tcm-labelled autologous erythrocytes in five normally potent volunteers and 22 patients with erectile dysfunction including 11 patients with psychogenic and 11 patients with vasculogenic impotence (four arteriogenic, three venogenic, three arteriogenic and venogenic, one arteriogenic and neurogenic). Penile radioactivity changes in the flaccid state were monitored by a gamma camera for 60 min after injection of the radionuclide. The penile time-activity curves of the normal controls characteristically showed secondary pulses of increased activity of variable amplitude, duration and frequency, consistent with phasic increase in penile blood pool. This normal rhythmic pattern was impaired in patients with penile arterial insufficiency whereas a blunted pattern was seen in most patients with functional impotence as well as in patients with nonarteriogenic organic impotence with a psychological overlay. This study provides new insights into the flaccid penile circulatory physiology, which may contribute to our understanding of the pathophysiology of erectile dysfunction. In arteriogenic subjects, the impaired response may be attributable to an inadequacy of penile arterial inflow as well as secondarily due to the resultant sinusoidal dysfunction subsequent to penile ultrastructural damage due to an altered nutritive environment. Increased adrenergic activity in patients with psychogenic impotence may be responsible for the observed deviation from the normal pattern.

Adolescent↗
PubMed1993

Localization of neuroendocrine tumours and insulinomas using radiolabelled somatostatin analogues, 123I-Tyr3-octreotide and 111In-pentatreotide.

OBJECTIVE: A number of neoplasms are known to express somatostatin receptors; the use of somatostatin receptor imaging in their localization has recently been described, but the resolution and discrimination of the isotopes used remains sub-optimal. We have looked at the use of a new 111In-labelled analogue of somatostatin, pentatreotide, in the visualization and functional characterization of a number of neoplastic conditions. PATIENTS: Thirteen patients with proven neoplasms were scanned using this agent. Planar and single-photon-emission computerized tomographic (SPECT) images of the relevant part of the body were obtained using a gamma-camera at 10 minutes and 4 and 21 hours after injection of the radiopharmaceutical. In six patients (three carcinoid, three insulinomas) scanning was also performed using 123I-Tyr-3-octreotide. RESULTS: Primary tumours or metastases were visualized in six of the seven patients with neuroendocrine tumours, and three of six patients with insulinoma. One patient with an insulinoma who had a positive scan showed absent uptake when rescanned after tumour removal. A rise in blood glucose (more than twice basal) in response to octreotide was seen only in those insulinoma patients with positive scans. In cases where both 111In-pentratreotide and 123I-Tyr-3-octreotide scans were performed, both radiopharmaceuticals identified the same 4/6 tumours; however, tumour definition (reflecting high tumour to background ratio) was better with pentatreotide on the 21-hour images with minimum biliary and gut activity, allowing better resolution of the tumour image. CONCLUSION: It appears that 111In-pentatreotide scintigraphy is a rapid and safe procedure for the visualization of neuroendocrine tumours possessing somatostatin binding sites. A positive scan may be predictive of neuroendocrine responsiveness to octreotide therapy. In addition, it also appears that 111In-pentatreotide has superior kinetics compared to 123I-Tyr-3-octreotide, typically achieving more satisfactory tumour to background ratios, and may thus be more useful in the localization of endocrine tumours.

Adult↗
PubMed1993

Clinical evaluation of 99mTc diaminocyclohexane, a renal tubular agent with cationic transport: results in healthy human volunteers.

As alternatives to anionically transported hippuran, structure distribution experiments on a series of 99mTc-labelled primary substituted ethylene diamine compounds led to selection of 99mTc diaminocyclohexane (DACH) for clinical evaluation, 99mTc DACH, a cation with the structure trans-[O2(DACH)2 99mTc]+ is prepared by mixing 50 mumol DACH, 1 mumol stannous tartrate and 500 MBq of 99mTc. Seven normal volunteers underwent renal imaging and clearance studies using 150 MBq of 99mTc DACH and 1 MBq of 125I hippuran simultaneously. The images with 99mTc DACH revealed good uptake and excretion. The mean +/- 2 SD values of parenchymal and whole-kidney transit time indices and mean parenchymal transit time were 46 +/- 33, 75 +/- 64 and 141 +/- 51 s, respectively, similar to mercaptoacetyl triglycine. The mean clearance of 99mTc DACH was found to be 163 ml/min (SD = 32). Following cationic blockade with 900 mg oral thiamine, significant reduction (p < 0.001) in DACH clearance was noted, but hippuran clearance remained unaltered. The results support the hypothesis that 99mTc DACH is transported cationically.

Adult↗
PubMed1992

Volume-dependent intracavernous hemodilution during pharmacologically induced penile erections.

The change in the cavernous hematocrit following induction of pharmacological erection by an intracavernous injection of papaverine hydrochloride was documented in normal controls and patients with impotence. Blood samples taken from the penile cavernosa showed a significantly lower hematocrit compared to the systemic venous blood in all normal subjects. The decrease in the cavernous hematocrit was attributable to dilution of the cavernous blood pool by the injected volume of the drug, since this was not observed in erections produced by visual sexual stimulation. It appears that a restriction of the cavernous venous outflow in response to papaverine injection causes sequestration of the diluted blood in the cavernous compartment. The degree of cavernous hemodilution was found to aid in the differential diagnosis and was especially valuable in differentiating patients with arteriogenic impotence from those with venous leakage.

Adult↗
PubMed1992

Clinical outcomes of patients with suspected pulmonary embolism using 99Tcm-Technegas as a ventilatory agent for lung scanning.

Clinical outcome analysis was carried out in 175 of 206 consecutive patients referred for a lung scan with clinical suspicion of pulmonary embolism (PE). The follow-up time period ranged from 4 to 18 months. High-quality ventilation images corresponding to the six standard perfusion images were obtained using Technegas as a ventilatory agent. Lung scan reports showed that 22% of the patients had a high, 14% indeterminate, 18% low and 9% very low probability for PE and 37% were normal lung scans. These reports usually supported the referring clinicians' provisional diagnosis and were confirmed by the clinical outcome analysis of these patients giving an apparent sensitivity for the lung scan of 96% and specificity 93%. A strategy for lung scanning in PE is proposed.

Adolescent↗
PubMed1992

A pharmacological guide to medicines which interfere with the biodistribution of radiolabelled meta-iodobenzylguanidine (MIBG).

Radiolabelled meta-iodobenzylguanidine (MIBG) is widely used in the diagnosis, follow-up and treatment of patients with tumours of neural crest origin. Some commonly prescribed and readily available over-the-counter medicines interfere with the uptake and biodistribution of this radiopharmaceutical. This may lead to poor concentration of radiolabelled MIBG within the target organs and tissues. The clinical implications are a potentially inaccurate assessment of tumour burden during diagnostic studies and a suboptimal radiation dose when MIBG is employed for targetted radiotherapy. In order to avoid false negative results a comprehensive list of prescribed and over-the-counter medicines that have the potential to inhibit uptake of MIBG has been compiled. It is hoped that this will help nuclear medicine physicians to avoid this pitfall.

3-Iodobenzylguanidine↗
PubMed1992

The effect of intracavernosal haemodilution on the radionuclide quantification of penile vascular changes during pharmacologically induced penile erections.

Radionuclide phallography was performed using 99Tcm-labelled red blood cells in conjunction with pharmacologically induced penile erections. The radioactivity content of aliquots of systemic venous blood taken from the antecubital vein was compared with aliquots of blood withdrawn from the penile cavernosa 20 min after an intracavernosal injection of 10 micrograms prostaglandin E1. The cavernosal samples showed significantly lower counts per unit of blood compared to the systemic venous blood indicating a comparatively lower concentration of tagged red blood cells. On haematological analysis, a significant difference in the haematocrit of the two samples was also established. The fall in the cavernosal haematocrit was found to result from dilution of the cavernosal blood pool by the injected volume of the drug since larger volumes of injection produced a greater fall in the haematocrit. Restriction of the cavernosal venous outflow in response to the injection of the vasoactive drug causes sequestration of the diluted blood in the cavernosal compartment. This factor might affect the quantification of penile blood volume using radiotracer methods.

Adult↗
PubMed1992

Pituitary imaging using a labelled somatostatin analogue in acromegaly.

OBJECTIVE: A number of neoplasms are known to express somatostatin receptors, and the use of somatostatin receptor imaging in their localization has recently been described. We have looked at the use of an 123I-labelled Tyr3-octreotide analogue of somatostatin in the visualization and functional characterization of growth hormone-secreting pituitary adenomas. PATIENTS: Fifteen patients with biochemically-proven acromegaly were scanned using this agent. In eight of these we also assessed acute GH responses to octreotide in order to correlate these responses with tumour uptake characteristics. MEASURES: Planar and single-photon-emission computerized tomographic (SPECT) images of the head were obtained using a gamma-camera at 10 minutes, and 4 and 24 hours, after injection of the radiopharmaceutical. Blood for serum GH was sampled for 12 hours after administration of a single dose of 100 micrograms octreotide. RESULTS: Twelve of the acromegalic subjects showed significant uptake of the radiopharmaceutical in the pituitary fossa. Of the eight patients in whom we assessed acute GH responses, five demonstrated a significant fall in GH in response to octreotide. These subjects also showed positive uptake in the pituitary on scanning. The three patients who had no fall in GH had no uptake on scanning. CONCLUSIONS: Uptake of 123I-labelled Tyr3-octreotide in the pituitary fossa appears to correlate closely with the presence of a therapeutic response to octreotide.

Acromegaly↗
PubMed1992

A scintigraphic comparison of iodine-123-metaiodobenzylguanidine and an iodine-labeled somatostatin analog (Tyr-3-octreotide) in metastatic carcinoid tumors.

A number of neoplasms are known to express somatostatin receptors, and the use of somatostatin receptor imaging in their localization has recently been described. We compared an 123I-labeled somatostatin analog Tyr-3-octreotide (TOCT) and 123I-labeled metaiodobenzylguanidine (MIBG) scintigraphy in seven patients with histologically proven metastatic carcinoid tumors. The optimum time for identifying tumor uptake on scanning after [123I]MIBG was 24-48 hr, and after 123I-TOCT 10-30 min postinjection. Both radiopharmaceuticals showed a varying spectrum of tracer uptake ([123I]MIBG showed no uptake in one patient; minimal in two; moderate in two; and intense in two; 123I-TOCT showed no uptake in two patients; minimal uptake in one; moderate uptake in two; and intense uptake in two). In two patients, 123I-TOCT identified metastatic lesions not seen by [123I]MIBG scintigraphy. These preliminary results suggest that [123I]MIBG and 123I-TOCT are useful and complementary imaging techniques for detecting metastatic carcinoid tumors.

3-Iodobenzylguanidine↗
PubMed1991

Pulmonary embolism, pulmonary hypertension, and choriocarcinoma.

A rare cause of pulmonary embolism and pulmonary artery hypertension in young women is choriocarcinoma growing in the pulmonary artery. This growth is reversible, and the disorder can be cured. We describe three patients with this feature who have been treated with appropriate high-risk chemotherapy and who are now in remission. Contrast-enhanced computed tomography can be used to identify major emboli, and progress of the disease can be monitored by serial ventilation/perfusion scans and measurement of serum human chorionic gonadotropin. Recognition of this rare syndrome is important because of the generally excellent outlook with appropriate treatment.

Adult↗
PubMed1991

Cerebral uptake of MIBG: adrenoceptors visualized?

Radiolabelled metaiodobenzylguanidine (MIBG) localizes in adrenergic neurons. A study was carried out to evaluate the uptake of this radiopharmaceutical in cerebral tissues. Twenty-three patients with neural crest tumours, who had no evidence of central nervous system disease, were evaluated. Each patient underwent a diagnostic MIBG study, followed by a therapy dose with 131I-MIBG and subsequent scintigraphy. Focal uptake was seen in the cerebellum (CB), basal nuclei and thalamic region (BNTr), 24 and 48 h postinjection on the diagnostic images. The BNTr to cerebral cortex ratio ranged from 1.05 to 1.79. Uptake was also seen on the days 2, 3, 4 and 6 post-therapy images. Single photon emission computed tomography (SPECT) clearly outlined the uptake in the CB and BNTr. The BNTr to cerebral cortex ratio ranged from 1.10 to 1.85 and CB to cerebral cortex ratio from 1.18 to 2.01. It is hypothesized that the focal uptake observed in the CB and BNTr is due to adrenergic receptor binding. It is felt that SPECT with radiolabelled MIBG may prove to be a useful tracer for mapping the adrenergic receptors in the human brain.

3-Iodobenzylguanidine↗
PubMed1991

Metastatic melanoma of the orbit. A case report.

We report a metastatic cutaneous melanoma of the medial rectus muscle of the right orbit which presented with diplopia, exophthalmos and retrobulbar pain. Radioimmunoscintigraphy using melanoma-specific monoclonal antibody was used to confirm the diagnosis and to show the presence of disseminated disease in other areas. Effective palliation was achieved with external beam irradiation.

Antibodies, Monoclonal↗
PubMed1990

Radioimmunoscintigraphy of orbital metastases from ovarian carcinoma.

Radioimmunoscintigraphy with I-123 labeled monoclonal antibody HMFG1 has been used for imaging primary and metastatic ovarian neoplasms. Uptake of I-123 labeled HMFG1 is reported in a patient with an orbital metastasis from a primary ovarian adenocarcinoma. Radioimmunoscintigraphy may have a role to play in imaging metastatic orbital neoplasms.

Adenocarcinoma↗
PubMed1990

Quantitation of pharmacologically-induced penile erections: the value of radionuclide phallography in the objective evaluation of erectile haemodynamics.

This study combines the pharmacologically-induced penile erection (PIPE) technique with radionuclide phallography (RNP) for the non-invasive study of penile haemodynamic changes during erection. Penile erections produced by the intracavernosal injections of two different vasoactive drugs, prostaglandin E1 (PGE1) and papaverine HCl (PPV) were assessed by quantitation of the dynamic RNP and parameters of erection were defined and compared. PGE1 intracavernosal injections were seen to elicit a better erectile response than PPV. Dynamic radionuclide phallography was performed using 99Tcm-labelled autologous RBCs in five normally potent volunteers, sixteen patients with psychogenic impotence, seven patients with vasculogenic impotence (three arteriogenic, four venous leakage) and one patient with neurogenic impotence. Physical parameters of erection including the penile length and circumference changes during erection and the erectile angle were compared with the indices of penile blood flow and volume derived through quantitation of the RNP. There was a close correlation between the penogram index (an index of penile blood volume) and penile circumference increase during erection (r = 0.77, p less than 10(-6). The erectile angle, a measure of penile rigidity, correlated strongly (r = 0.82, p less than 10(-6) with the flow index, a measure of penile blood volume. Patterns specific to various categories of impotence were observed and these aided in the diagnosis, especially in equivocal cases with a suboptimal clinical response to the intracavernosal injection. Quantitative RNP offers a non-invasive method which allows direct objective assessment of the erectile response providing several quantitative parameters for analysis.

Adult↗