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Biomedical subjects

J R Buscombe

Publications and source records attributed to J R Buscombe.

At least 37 records · Page 2Linked to original sources
PubMed2001

Comparison of functional imaging and standard CT in evaluation of disease extent in patients with tumours showing neuroendocrine features.

BACKGROUND: The diagnostic approach that should be used in disseminated neuroendocrine tumours (NET) remains a significant clinical problem. A novel approach has been the use of 111In Octreotide as functional imaging to find NETs. Therefore, the aim of this retrospective study is to report our comparison with direct CT as standard anatomical imaging. MATERIAL AND METHODS: A total of 48 patients (aged 16-79 years; mean age 55, SD 14 years) were imaged using both techniques with final histological confirmation of NET. Histology was as follows: 26 carcinoids; 2 pheochromocytomas; 4 gastrinomas, 1 islet tumour; 2 paragangliomas, 1 modullary carcinoma of the thyroid, 8 undetermined NET and 4 other tumours with signs of neuro-ectodermal cancers (2 hepatocellular carcinomas (HCC), fibrolamellar HCC and fibrous tumour). All patients had (111)In Octreotide and 30 had (123)I mIBG scans followed by spiral CT with contrast enhancement. 26 patients had single functional scans and 22 had multiple, up to 6 scans. Extent of disease as number of lesions was compared between CT and octreotide. RESULTS: CT was the best modality in 11 patients, in 6 it was as good as (111)In Octreotide. mIBG was the best in 6 patients; in 3 patients mIBG was as good as octreotide study. In 22 patients (111)In Octreotide was the most effective modality. In one patient there was no advantage with any of the tests. Comparison of the number of organs involved indicated that an octreotide study was much more effective than CT scanning (Wilcoxon matched pairs test, p < 0.001) and also the overall number of lesions detected using (111)In Octreotide was greater than with CT (Wilcoxon Matched Pairs test p < 0.01). CONCLUSION: Our results confirm the recommendation of the European NET group that functional imaging should be performed in patients with suspected NET.

Journal Article↗
PubMed2000

Preoperative diagnosis of ovarian carcinoma with a novel monoclonal antibody.

OBJECTIVE: This study was undertaken to determine whether preoperative radioimmunoscintigraphy of complex ovarian masses with technetium Tc 99m MAb-170 (Tru-Scint AD; Biomira Inc, Edmonton, Alberta, Canada), a murine whole immunoglobulin G monoclonal antibody that has been found to have panadenocarcinoma affinity, would predict surgical findings. STUDY DESIGN: The age range of studied patients was 42 to 83 years (mean, 60.3 years). Planar computed tomographic imaging and single-photon emission computed tomographic imaging were performed at 15 minutes, 6 to 8 hours, and 18 to 24 hours after injection of 1000 MBq technetium Tc 99m MAb-170. Laparotomy was performed within 10 days. RESULTS: Eighteen patients had borderline or invasive ovarian cancers verified by histologic examination. All primary malignancies or deposits (including intrahepatic deposits) yielded positive results on radioimmunoscintigraphic imaging. Radioimmunoscintigraphy was able to identify serosal deposits not seen on computed tomographic or ultrasonographic scans. False-positive localization of the antibody was noted in 6 of the 9 patients with benign pathologic processes. CONCLUSION: It is possible to detect with technetium Tc 99m MAb-170 all patients who have cancer (including sites not seen on computed tomographic or ultrasonographic scan); however, the low specificity (33%) means that patients still require surgical verification of disease.

Adenocarcinoma↗
PubMed2000

Tc-99m MIBI in suspected recurrent breast cancer.

A prospective trial was performed to assess the accuracy of Tc-99m MIBI scintimammography in 63 women (mean age 65, range 33-85 years) with suspected recurrent breast cancer in the breast and/or loco-regional tissues. All patients had been diagnosed with breast cancer 1-23 years before the scintimammography. A total of 27 breasts had been removed by mastectomy so scintimammography was compared with mammography in the remaining 99 breasts. Pathological follow-up of patients confirmed 33 sites of recurrent disease within the breast, 26 (78%) were identified by scintimammography and 14 (42%) by mammography; 30 (90%) were positive on one test or the other. In addition Tc-99m MIBI scintimammography identified 10/16 (63%) of axillary lymph nodes with recurrent tumour and 4/6 sites of recurrent tumour present elsewhere. Tc-99m MIBI scintimammography is more accurate in identifying recurrent disease in the breast than mammography and can identify loco-regional recurrence outside of the breast.

Adult↗
PubMed2000

Toxicity of high-activity 111In-Octreotide therapy in patients with disseminated neuroendocrine tumours.

Disseminated neuroendocrine tumours are difficult to treat and are generally not responsive to radiotherapy or chemotherapy. Nuclear medicine techniques using a radiolabelled somatostatin analogue, 111In-Octreotide, have been used for the diagnosis of neuroendocrine tumours. It has been suggested that high activities of such an agent may have a therapeutic effect. The aims of this study were to assess toxicity and to determine if there had been evidence of efficacy. Eight patients with known disseminated neuroendocrine tumours were enrolled in the study; six had carcinoid tumours, one had a medullary cell carcinoma of the thyroid and one patient had a malignant gastrinoma. Between 1.3 and 4.6 GBq of 111In-Octreotide were administered to each patient for up to five administrations over 12 months. A total of 23 administrations were given. Tests of vital signs, renal, liver and endocrine function as well as haematological markers were taken before and after treatment. The treatment was well tolerated with only one patient suffering from a sensation of flushing during the infusion but no changes in vital sings. There was a transient (up to 48 h) drop in circulating lymphocytes in four patients and platelets in two patients; no supportive therapy was needed. One patient with severe renal impairment had a slight reduction in glomerular filtration rate. We conclude that high-activity 111In-Octreotide is well tolerated with low toxicity and can be considered for use in patients with disseminated neuroendocrine tumours. Further work is now being performed to assess efficacy.

Adult↗
PubMed2000

Diagnostic accuracy of mammography and scintimammography in detection of primary breast cancer related size of the tumour.

BACKGROUND: The detection of breast cancer relies on physical examination and mammography (XMM). The sensitivity of conventional imaging is lesions-size dependent. However, mammography has good sensitivity in small tumours when microcalcification is present, but the sensitivity is relatively low in other small tumours. The use of scintimammography with Tc-99m sestaMIBI (SMM) may be helpful in this situation. The aim of this study is to compare the diagnostic accuracy of mammography and scintimammography across all groups with different sizes of lesions. METHODS: Data for 273 patients aged 26 to 84 years (mean 52; SD 12) with 298 lesions were analysed. All lesions were removed and final histology and pathological size of the tumours were retrospectively reviewed (mean size 2.9 cm, SD 2.4 cm). All patients had XMM and SMM. Each imaging study was graded using five grades of certainty. SMM images were reviewed by an independent specialist blinded to clinical presentation and XMM results. The diagnostic accuracy of each test, overall and by each lesions size subgroup, was compared using receiver operating characteristic curve (ROC) analysis. RESULTS: The sensitivity of scintimammography was consistently high across all size groups; overall 89% (82?100%) compared with 68% (51?88%) for mammography. In those tumours below 2 cm, the area under the ROC was significantly larger with SMM than XMM (p < 0.05), with 80% certainty indicative of greater diagnostic accuracy. Also in all patients the area under the ROC was significantly larger with SMM than XMM (p < 0.05), with 90% certainty indicative of greater diagnostic accuracy. In other groups of lesions size the area under ROC for SMM was larger in lesions size between 2 and 4 cm and slightly smaller in lesions over 4 cm, but it was not significant. CONCLUSION: Scintimammography using Tc-99m sestaMIBI seems to be a sensitive and consistently reliable diagnostic test for breast cancer independent of the size of the tumour.

Journal Article↗
PubMed2000

Detection of DCIS using 99mTc-MIBI scintimammography in patients with suspected primary breast cancer, comparison with conventional mammography.

BACKGROUND: Scintimammography using Tc-99m MIBI (SMM) is often used clinically as a second line diagnostic test for the detection of breast cancer in cases where there is concern about the results of x-ray mammography (XMM) and ultrasound. Both of these methods, but particularly XMM, may miss a significant proportion of ductal carcinoma in situ (DCIS). MATERIAL AND METHODS: This study was performed to determine the possible accuracy of SMM in finding DCIS and comparing this with the accuracy of XMM in the same patient. Over a 3 year period 353 patients with no previous history of breast cancer were imaged with both XMM and SMM. The histology of any suspect area was verified by pathological examination of biopsy material. There were 203 malignant breast tumours. RESULTS: In those 203 cancers there were 15 pure DCIS cancers. SMM correctly diagnosed 12 of these (sensitivity was 80%). XMM diagnosed correctly 8 DCIS (sensitivity 53%) and was equivocal in 2. Combining of both SMM and XMM provided the best result with all but one DCIS identified (sensitivity 93%). CONCLUSIONS: This study shows that the SMM is helpful in detecting DCIS in those cases where XMM failed to detect DCIS or was equivocal. The combination of the two techniques produces a higher sensitivity result than either modality alone.

Journal Article↗
PubMed2000

Use of lung and brain perfusion imaging in the HELLP syndrome.

Patients with multi-organ disorders may present with a plethora of confusing symptoms and signs. Often early diagnosis of significant disease is essential and can be difficult with standard radiological techniques. This case report presents the use of two radioisotopic techniques to assess brain and lung perfusion in a patient with such an acute-multi-organ disorder-the HELLP syndrome.

Journal Article↗
PubMed1999

Cognitive impairment in patients with renal failure is associated with multiple-infarct dementia.

PURPOSE: Patients undergoing long-term renal replacement therapy (such as dialysis) have an increased risk for significant cognitive impairment, which may result in memory problems and subsequently missed attendance at dialysis. The aim of this study was to try to identify any abnormalities of cerebral perfusion that could explain a patient's cognitive impairment and to determine if the pattern of these abnormalities would suggest a cause. MATERIALS AND METHODS: 17 patients (13 men; mean age, 60 years; age range, 29-74 years) in end-stage renal failure or on dialysis had SPECT imaging 10 minutes after injection of 550 MBq (15 mCi) Tc-99m HMPAO. Two of the patients had a history of previous stroke. Other risk factors for stroke were noted in most of the patients (hypertension in 10 patients, smoking or former smoking in 10 patients, and cardiac atherosclerosis in 7 patients). In all patients, attenuation correction was applied and the images were reconstructed into three sets of orthogonal slices. Activity in the frontal and temporal lobes was compared by quantification against the ipsilateral and contralateral cerebellum. RESULTS: Discrete cortical defects consistent with infarcts were seen in 14 patients. The mean right and left frontal-to-cerebellar ratio was 0.837 (SD, 0.09) and 0.837 (SD, 0.08), respectively. This was not significantly different from the right and left temporal-to-cerebellar ratios of 0.843 (SD, 0.07) and 0.848 (SD, 0.07), respectively. Both were within normally accepted ranges. CONCLUSIONS: Patients in end-stage renal failure who also had cognitive impairment appear to have a high number of cortical defects consistent with infarcts (suggesting a multiple-infarct type of dementia). There was no evidence of Alzheimer-type dementia.

Adult↗
PubMed1999

Prone SPET scintimammography.

Prone single photon emission tomography (SPET) was performed in 24 patients with suspected primary or recurrent breast cancer to determine if this technique offers more accurate imaging than that obtained from planar scintimammography. All patients were imaged on a specially designed couch with two cushion inserts. The first insert was lined with lead and was used to perform prone lateral planar scintimammography 5 min after the injection of 740 MBq 99Tcm-MIBI. The second insert did not contain lead and was used to perform a prone SPET acquisition for 30 min immediately after planar imaging. The results of both studies were read independently and there was agreement between the two techniques in 23 cases (96%). All cases of cancer proven on histology were found on planar imaging, but a 4-mm ductal cancer was missed on prone SPET. This was thought to be due to activity from this medial cancer being obscured by the star artefact produced by back-projection reconstruction from activity in the heart. There were two false-positive studies with both techniques. However, prone SPET enabled better localization and characterization of breast cancers than planar imaging. Prone SPET imaging of the breast produces results similar to prone lateral imaging and may be used instead of planar imaging if a reduced total acquisition time is desirable. Care must be taken when reading scans in the presence of small tumours near the heart when back-projection reconstruction techniques are used.

Adult↗
PubMed1999

Scintimammography: a review.

Scintimammography with 99mTc-MIBI is a new technique which has expanded the use of nuclear medicine to a new group of patients in whom scintigraphy was not been widely used. When performed correctly, and in those patients, such as the young, where x-ray mammography is often non-diagnostic, the sensitivity of scintimammography can exceed that of x-ray mammography with a similar specificity. A combination of the two techniques in this patient group can provide sensitivities greater than 98%. The mechanism of uptake of 99mTc-MIBI in breast tissue is better understood as is the efflux of the pharmaceutical from the tumour cell. The relationship between the efflux rate of 99mTc-MIBI and the expression of the multi-drug resistance gene may help in determining important aspects of tumour function, such as the response to cytotoxic chemotherapy. More recently the role of scintimammography has been found in those patients with suspected breast cancer recurrence where methods depending on the anatomical structure of the breast, such as mammography and MRI, are of less use. Scintimammography, when correctly performed and correctly applied, is able to deliver unique information which is of use to the patient with suspected primary or recurrent breast cancer.

Journal Article↗
PubMed1998

Carcinoid tumour.

Carcinoid tumours are often indolent asymptomatic tumours. However, a small but significant proportion are malignant and difficult to manage. Multiple endocrine neoplasia type 1 (MEN-1) may be associated with carcinoid tumours and should therefore be considered in the investigation of these patients. This review puts into context the use of newer imaging modalities, including octreotide scintigraphy. The therapeutic treatment options are discussed, including the use of octreotide, the role of receptor-targeted therapy, hepatic-artery embolisation, and the arguments against chemotherapy. We review the need for careful patient selection when considering curative and palliative surgery, including liver transplantation. We conclude that there are now better diagnostic tools and therapeutic options available for those patients with malignant carcinoid tumours, and that these patients are best managed by a multidisciplinary approach. Earlier detection and treatment of these tumours should lead to improved quality of life and survival, which, ideally, should be assessed in formal trials.

Carcinoid Tumor↗
PubMed1998

Comparison of accuracy of scintimammography and X-ray mammography in the diagnosis of primary breast cancer in patients selected for surgical biopsy.

Mammography, whilst remaining the first line imaging investigation of suspected primary breast cancer, can be difficult to interpret in patients with fibrous or dense breasts. Radionuclide imaging of the breast (scintimammography) has been suggested as an additional test. The aim of this study was to perform prospectively a comparison of the two techniques in a population with suspected breast cancer. Seventy such patients, mean age 54 years (range 57 years, 28-85) with 74 suspicious breast lesions were studied. They were imaged 5-10 min after intravenous injection of 740 MBq of Tc-99m sestamibi. Prone lateral and anterior supine views with and without markers were performed. All patients had histological confirmation of the nature of the breast lesions by limited incisional biopsy or definitive wide local excision, or cytological confirmation on fine needle aspiration. All patients had X-ray mammography. There were 53 malignant breast tumours and 21 benign lesions. Scintimammography correctly diagnosed 47 breast cancers, and yielded true-negative results in 12 benign breast lesions. There were six cases of false-negative results and nine false-positive results. Four scans were reported as equivocal. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were 89%, 52%, 84% and 67%, respectively. X-ray mammography diagnosed correctly 37 malignant tumours, and in 12 benign lesions the results were true negatives. Ten studies were reported as equivocal. The sensitivity, specificity, PPV and NPV were 70%, 57%, 80% and 43%, respectively. The accuracy of Tc-99m sestamibi scintimammography was better than X-ray mammography though this was not significant (McNemar's test). Fewer equivocal results were obtained with scintimammography. Scintimammography may therefore have a role in the diagnosis of primary breast cancer when X-ray mammography is equivocal or unhelpful.

Adult↗
PubMed1998

Use of 99Tcm-MIBI in the assessment of patients with suspected recurrent breast cancer.

A prospective trial was performed to assess the accuracy of 99Tcm-methoxyisobutyl isonitrile (99Tcm-MIBI) scintimammography and X-ray mammography in 18 patients (mean age 58 years, range 46-79 years) with suspected recurrent breast cancer in the breast and/or loco-regional tissues. All patients had been diagnosed to have breast cancer 1-23 years before scintimammography. Two patients had undergone mastectomy, so that a total of 34 breasts were studied with X-ray mammography and with prone-lateral and anterior scintimammography. Any abnormalities on X-ray mammograms and scintimammograms were noted, as was any additional local or nodal uptake of 99Tcm-MIBI. The nature of any lesion seen with either modality, or in which there was a clinical suspicion of recurrence, was confirmed by cytological or histological examination of tissue samples. There were nine breasts with recurrent cancer in eight patients. X-ray mammography identified six of these cancers. 99Tcm-MIBI scintimammography identified eight of nine recurrent breast cancers (the one cancer not seen was positive on X-ray mammography). In the 26 breasts without cancer, two were reported as having changes consistent with cancer and one was reported equivocal. There were three false-positive and one equivocal scintimammograms. The accuracy of 99Tcm-MIBI scintimammography within the breast (85%) was similar to X-ray mammography (82%). Axillary lymph node recurrence occurred in five patients, four of whom were positive with 99Tcm-MIBI. An additional patient had focal uptake of 99Tcm-MIBI at the site of recurrent cancer on the anterior chest wall. In conclusion, 99Tcm-MIBI scintimammography may provide useful complementary information in patients with suspected recurrence of cancer in the breast or loco-regional tissues.

Aged↗