Overlying urostomy bag simulating urinary leak in a postrenal transplant MAG3 study.
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Biomedical subjects
Publications and source records attributed to J R Buscombe.
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Over the past 10 years, there has been an unprecedented explosion in new agents suggested for imaging infection. These agents have been based on our understanding of the processes involved in invasive infection of the body by microorganisms and the body's response to them. Work with antibodies has traditionally yielded the most likely candidates, 3 of which have entered clinical use in Europe and the USA. However, the expense and limitations of producing antibodies have resulted in investigations into the use of cytokine and anti-microbial radiolabelled peptides. This work is very promising in that these types of tracers may be more specific for infection than labelled leukocytes. There remains a big question mark, however, as to whether or not these will progress from phase I/II trials to phase III trials and, ultimately, to clinical use. Finally, the investigation of radiolabelled anti-microbials continues and may prove to be most useful with anti-fungals especially in the immuno-suppressed host. We live in exciting times in the evolution of infection imaging; time and commercial constraints will determine which, if any of these tracers make it to the market and will they do so before PET rules all nuclear medicine?
BACKGROUND: The aim of the study was to determine the value of radioisotope bone scans in the preoperative staging of patients with hepatopancreatobiliary (HPB) cancer. METHODS: Bone scanning was performed as part of a routine staging protocol in 402 consecutive patients with HPB cancer over a period of 5 years. Patients with positive bone scans underwent coned radiography, computed tomography with review on bone windows, or a bone biopsy. Bone scans were reviewed along with staging investigations, surgical and histological findings. Patients were followed for a minimum of 6 months. RESULTS: There were 171 patients with colorectal liver metastases, 106 with suspected pancreatic cancer, 47 with hepatocellular cancer, 52 with gallbladder cancer or cholangiocarcinoma, and 26 with other types of HPB cancer. Bone scans were negative in 377 patients (93.8 per cent) and positive in 25 patients (6.2 per cent). Of the 25 positive scans, 16 were falsely positive as a result of degenerative bone disease. Of nine patients with a true-positive bone scan, four had locally irresectable disease and four distant metastases. In only one patient did the bone scan result alone influence the decision to resect the HPB cancer. Overall sensitivity was 100 per cent, specificity 95.9 per cent, positive predictive value 36.0 per cent and negative predictive value 100 per cent. CONCLUSION: Bone scanning should not be included in the routine staging protocol for HPB cancer.
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Though positron emission tomography (PET) has attained a rightful place in the vanguard of nuclear oncology imaging there is still much that can be done using single photon tracers. Whether or not it is the use of general agents such as (201)Tl or receptor targeting using somatostatin analogues many cancers and the processes involved with them are still best seen with g-emitting radionuclides and gamma cameras. This article reviews the scope of using these tracers in oncology and emphasises that in nuclear oncology we are as much concerned with the questions as what the cancer is doing and how can be exploit differences between the cancer and normal tissue to aid diagnosis. The advent of new radionuclide therapy techniques will mean that preassessment with diagnostic agents will increase the need to have high quality single photon imaging. New receptor systems such as those using gastrin and bombesin are being developed. We can also use (99m)Tc based agents to identify hypoxia in cancer, angiogenesis and apoptosis. For those who are interested in the biology of cancer and interested in exploiting this for treatment will find that there is still much that can be done without a PET scanner and normally at a lower cost. About this issue, it is important to consider the recent development of dual-modality integrated imaging systems (SPET/CT) that allows to co-register the acquired images by means of the hardware in the same session. These new devices have a particular added value in tumour imaging since they provide the exact localisation of lesions and exclude some non correct interpretations of the physiologic uptakes for SPET findings. In addition there are many evidences that the fused images can give additional information in the diagnostic work up of patients by improving the accuracy of single photon scintigraphy. These new technologies lead to a continuous optimisation in the quality of imaging and contribute more and more to integrate the nuclear medicine modalities in the clinical management of cancer diseases.
Breast tumors can be imaged by different modalities: mammography is the most widely used technique because of its diagnostic value, patient compliance and low costs. Some techniques such as ultrasound (US) are often indicated, while others, such as digital mammography and magnetic resonance imaging (MRI) are still under evaluation and seem to be very promising. Among the nuclear medicine techniques breast scintigraphy with (99m)Tc-labelled lipophilic cations (SestaMIBI or tetrofosmin), positron emission tomography (PET) with 18F-2-deoxy-2-fluoro-D-glucose (FDG) have been evaluated in many clinical trials. At present breast scintigraphy has limited applications due to its poor spatial resolution, which has a minimum of 8 mm. It is questionable whether single photon emission tomography (SPECT) can offer any substantially better information on the breast; however, SPECT is more accurate in detecting axillary lymph nodes. Recent approaches using breast dedicated collimators and cameras have greatly improved the SPECT resolution and sensitivity. The most interesting technique offered by nuclear medicine today are PET and lymphoscintigraphy with the intraoperative detection of handled gamma probe. The sentinel node detection has achieved a large consensus of reliability and at present it has an important place in the clinical management. In the same time many authors have acknowledged the value of PET in the differential diagnosis of breast lesions and in locoregional staging, since breast cancer is strongly avid for glucose. PET demonstrated also its efficacy in detecting axillary lymph node metastases. Even in some clinical trials its accuracy proved nearly comparable to that of lymphoscintigraphy with sentinel node biopsy, other studies showed that PET scanning does not currently have adequate spatial resolution to detect both micro- and small macrometastatic disease in axillary lymph nodes. The added value of PET in breast cancer staging is that with a single examination PET allows the characterisation of breast lesions, in addition to complete viewing of the entire body. Whole-body PET may substitute other diagnostic assessments by examining the various regions of potential tumour spread. The current diagnostic work-up for pre- and postoperative staging includes various examinations: chest X-rays, US of the abdomen, mammography of the contralateral breast. Bone scintigraphy with (99m)Tc-diphosphonates and laboratory tests can also be considered in women with large tumors or in symptomatic patients. Computed tomography (CT) and MRI may be used in order to resolve particular diagnostic problems. The current application of some of these modalities depends on the risk of the single patient of developing metastatic spread, which is revealed by a number of prognostic parameters of tumor aggressiveness and of course, clinical stage. Bone scintigraphy and PET may be useful in monitoring therapy response and in detecting tumour relapses during follow-up. In particular PET guided by tumor markers measurements shows to detect more lesions than other non nuclear medicine modalities.
BACKGROUND: Somatostatin analogues are the best therapy for controlling the symptoms of malignant carcinoid syndrome. Octreotide acetate given as subcutaneous injection up to three times daily, intramuscular Lanreotide injection given once per 1-2 weeks and monthly intramuscular Sandostatin LAR have demonstrated similar efficacy in short-term studies. AIM: To assess the long-term effect of Sandostatin LAR on the management of patients with malignant carcinoid syndrome. METHODS: This was a 3-year retrospective study. Twenty-seven patients were assessed with a median follow-up of 23 months. Thirteen patients were switched from subcutaneous octreotide and 14 patients were octreotide naive. All patients showed avid uptake on indium-111 octreotide imaging. RESULTS: Ten of the 13 patients previously on subcutaneous octreotide and 13 of the 14 patients who were octreotide naive had good symptom control on Sandostatin LAR. Over the period of follow-up, many patients showed progression of their tumour and required additional therapies. Patients expressed a preference for monthly intramuscular Sandostatin LAR as opposed to daily subcutaneous injections of octreotide. Although Sandostatin LAR was difficult to administer in certain instances, overall it was well tolerated. CONCLUSIONS: Sandostatin LAR provides good long-term symptomatic control in patients with malignant carcinoid syndrome; it is well tolerated and patients expressed improved satisfaction in their management.
Chronic enteroviral meningoencephalitis (CEMA) is a rare complication of immunodeficient individuals and may present as insidious intellectual deterioration. Diagnosis requires isolation or PCR identification of enterovirus from the CSF. Pleconaril, a novel anti-picornaviral compound is available on a compassionate release basis to treat patients with potentially life threatening enteroviral infection. Non-invasive neuroimaging is an important new technique for both the diagnosis of encephalitis and as an objective assessment of response to treatment. We report two immunodeficient patients, one with common variable immunodeficiency and one with HIV, with an insidious presentation of CEMA. In both patients, perfusion single photon emission tomography scans were effective in monitoring treatment, correlating with clinical and virological response to pleconaril.
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Breast cancer remains one of the most common cancers in the developed world. New treatments are proving effective against both limited disease and metastases. Nuclear medicine is in a unique position as it is one of the only methods used to image the breast which is linked to cell cycle changes, the receptors on the cell surface and the cells' response to chemotherapy. Nuclear medicine is unaffected by the anatomical changes seen post-chemotherapy and radiotherapy and is uniquely placed to become a major methodology in the continued assessment of the breast cancer patient. However, before this can happen the utility of nuclear medicine techniques must be proved in multi-centre trials.
The range of cancers which can be successfully treated by radioisotopes can be expanded by the use of combined pharmacological and physical targeting of the relevant radioisotope. This has been used extensively in the management of hepatocellular cancer (HCC) which has been treated with (131)I iodized poppy seed oil (Lipiodol) or (90)Y labelled glass microspheres infused into the liver under radiological control via a catheter placed into the right or left hepatic artery. In the treatment of extensive disease survival may not be changed but there is an improved quality of life after treatment. If given in the adjuvant setting, improved survival has been noted. These techniques have now been applied to other tracers for example in the use of (131)I-mIBG in treatment of rare tumours where concise localization and destruction of tumours in vital structures needs to occur without the risk of damage to surrounding tissues.
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Scintimammography with (99m)Tc-MIBI has been shown to be an effective adjunct to imaging of the breast with mammography. Uptake of (99m)Tc-MIBI is particularly high in sites of non-calcified cancer and ductal carcinoma in situ (DCIS), and as a consequence it may be possible to use this method of imaging in identifying multifocal or multicentric disease. The aim of this study was to evaluate the efficacy of preoperative scintimammography in the detection of multifocal and multicentric breast cancer and compare these results with mammography. A retrospective review was performed of 353 women imaged with (99m)Tc-MIBI as part of the clinical assessment of their suspected primary breast cancer. The results of the scintimammography and mammography were then compared with the final pathological diagnosis obtained after mastectomy in all patients. Histopathological assessments of breast tissue from mastectomy confirmed 40 women (12%) had multifocal (34) or multicentric (six) breast cancer. Scintimammography correctly identified 39 of these cancers and the multifocal or multicentric character of the cancer was identified in 22 (52%) of these patients. Anatomical imaging performed in all 40 patients including 25 with mammography alone, mammography and ultrasound in 11 cases and ultrasound alone in four patients. Anatomical imaging identified cancer to be present in 28 patients (70%) and the combination of mammography and ultrasound identified correctly that the cancer was multifocal or multicentric in eight patients (22%). In this study scintimammography was able to identify more cases of multifocal and multicentric cancer than mammography and/or ultrasound. In patients where pre-operative identification of multicentric or multifocal disease can alter treatment scintimammography may be a useful investigative tool.
OBJECTIVE: To assess the effectiveness of a dual head coincidence gamma camera in identifying ovarian cancer as a less expensive alternative to the traditional 2-[18F] fluoro-2-deoxy-D-glucose (18FDG) system using positron emission tomography. DESIGN: Prospective study. POPULATION: Twenty consecutive women suspected of having ovarian carcinoma. Inclusion was based on abnormal serum CA125 (reference range is 0-35 units/L), ultrasound, computerised tomography or clinical findings. METHODS: Women underwent assessment before staging laparotomy. Two nuclear medicine physicians, who were blinded to the pre-operative assessment, reported on 18FDG- dual head coincidence gamma camera imaging. MAIN OUTCOME MEASURES: The histology and operative staging were compared with the 18FDG- dual head coincidence gamma camera findings. RESULTS: Twelve women had pelvic malignancies (nine primary and three recurrences), seven women had benign pathology and one patient had a borderline malignancy. We were able to image accurately all malignant pelvic masses with dual head coincidence gamma camera, as well as accurately demonstrate disease spread. Two of the benign pelvic masses localised 18FDG. The positive predictive value for detecting malignancy was 86%. CONCLUSIONS: Dual head coincidence gamma camera offers accurate and affordable imaging in suspected ovarian masses, with improved specificity over CA125, ultrasound and computerised tomography. These results are similar to those obtained on more expensive dedicated PET systems. We report on a series of patients believed to have primary or recurrent carcinoma and recognise the need to include patients more likely to have benign lesions to assess false positive results. However, we believe that dual head coincidence gamma camera is useful in the pre-operative assessment of women with suspected ovarian cancer.
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UNLABELLED: The aim of this study was to compare the accuracy of 99mTc-methoxyisobutylisonitrile scintimammography (SMM) and conventional mammography in patients presenting with suspected primary breast cancer. Receiver-operating-characteristic (ROC) curve analysis was applied to determine if a combination of x-ray mammography (XMM) and SMM was more accurate than a single test alone. METHODS: The results of SMM, XMM, and a combination of both studies performed over a 3-y period on 374 suspicious lesions in 353 patients with no previous history of breast cancer were reviewed. Each scan report was reviewed and graded as follows: grade 1, definitely normal or benign; grade 2, probably normal or benign; grade 3, equivocal; grade 4, probably cancer; and grade 5, definitely cancer. The results were verified by pathologic examination of biopsy material obtained from each suspicious mass. ROC curves were generated from these results. RESULTS: There were 204 malignant breast tumors and 170 nonmalignant breast lesions. SMM diagnosed correctly 181 breast cancers and was true-negative in 122 benign breast lesions: sensitivity, 89%; specificity, 71%; positive predictive value (PPV), 79%; and negative predictive value (NPV), 84%. XMM diagnosed correctly 143 malignant tumors and was true-negative in 117 nonmalignant lesions. The sensitivity, specificity, PPV, and NPV for XMM were 70%, 69%, 73%, and 66%, respectively. Using a combination of the two tests, the combined sensitivity was 93%, specificity was 72%, PPV was 80%, and NPV was 90%. Using the index of the area under the ROC curve obtained by the rating method showed that the combination of XMM and SMM was significantly more accurate than either of the individual tests if performed alone (P < 0.05). CONCLUSION: This study shows that the combination of XMM and SMM produces more accurate results than either modality alone. Therefore, if there is doubt about the accuracy of XMM, SMM should be used as the second-line test in breast imaging.
BACKGROUND: With the increasing demand for breast conservation surgery, the probability of recurrent tumour within the breast increases. Traditionally x-ray mammography (XMM) was used to assess the post-surgical breast, but post-surgery and radiotherapy changes have reduced the accuracy of this method. Scintimammography (SMM) has also been proposed and appears to be more accurate than XMM. MATERIAL AND METHODS: A total of 101 women received (Tc99m) MIBI SMM and 88 had a subsequent XMM. There were 142 sites suspected of loco-regional recurrence breast cancer. During the study the patients did not receive any treatment other then hormonotherapy. SMM was performed by the standard Diggles-Khalkhali method and XMM was performed using standard 2 views. Analysis was performed and the results of each type of imaging compared with histology. In the ROC curve analysis 5 points of certainty were used: from 1 being definitely normal to 5 being definitely cancer; grades 4 and 5 were counted as positive. RESULTS: The overall sensitivity value of SMM was 84% and specificity was 85%, compared with a sensitivity of 52% for XMM and a specificity of 84%. Analysis of areas under ROC curves provides statistically significant difference between SMM and XMM (p < 0.05). Combining the two tests did not significantly improve the diagnostic accuracy of sequence imaging over SMM. CONCLUSION: ROC curve analysis demonstrates that scintimammography should be the primary investigation in suspected local recurrence following breast conservation surgery.