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A J Hilson

Publications and source records attributed to A J Hilson.

At least 19 recordsLinked to original sources
PubMed2006

Training of staff for the delivery of PET/CT services in the UK.

Evidence for the cost effectiveness of PET/CT imaging is now driving the widespread introduction of PET/CT services throughout the UK. The provision of PET/CT facilities will require a workforce of medical, scientific, technical and engineering staff who are adequately trained and fit for purpose. Suitably trained staff in this speciality are scarce. The development and accreditation of training courses and other educational resources for training programmes in all disciplines will therefore be required at a national and regional level. The implementation of PET/CT training can be achieved more cost-effectively by developing multi-professional learning resources whenever possible. It is intended that the recommendations would be implemented by close co-operation of both public and private healthcare providers together with educational establishments.

Curriculum↗
PubMed2002

A phase I trial of antibody directed enzyme prodrug therapy (ADEPT) in patients with advanced colorectal carcinoma or other CEA producing tumours.

Antibody-directed enzyme prodrug therapy is a targeted therapy in which a prodrug is activated selectively at the tumour site by an enzyme, which has been targeted to the tumour by an antibody (antibody-enzyme conjugate). Previous clinical trials have shown evidence of tumour response, however, the activated drug had a long half-life, which resulted in dose-limiting myelosuppression. Also, the targeting system, although giving high tumour to blood ratios of antibody-enzyme conjugate (10 000 : 1) required administration of a clearing antibody in addition to the antibody-enzyme conjugate. The purpose of this current study therefore was to attempt tumour targeting of the antibody-enzyme conjugate without the clearing antibody, and to investigate a new prodrug (bis-iodo phenol mustard, ZD2767P) whose activated form is highly potent and has a short half-life. Twenty-seven patients were treated with antibody-directed enzyme prodrug therapy using A5CP antibody-enzyme conjugate and ZD2767P prodrug, in a dose-escalating phase I trial. The maximum tolerated dose of ZD2767P was reached at 15.5 mg m(-2)x three administrations with a serum carboxypeptidase G2 level of 0.05 U ml(-1). Myelosuppression limited dose escalation. Other toxicities were mild. Patients' quality of life was not adversely affected during the trial as assessed by the measures used. There were no clinical or radiological responses seen in the study, but three patients had stable disease at day 56. Human anti-mouse antibody and human anti-carboxypeptidase G2 antibody were produced in response to the antibody enzyme conjugate (A5CP). The antibody-enzyme conjugate localisation data (carboxypeptidase G2 enzyme levels by HPLC on tumour and normal tissue samples, and gamma camera analysis of I-131 radiolabelled conjugate) are consistent with inadequate tumour localisation (median tumour: normal tissue ratios of antibody-enzyme conjugate of less than 1). A clearance system is therefore desirable with this antibody-enzyme conjugate or a more efficient targeting system is required. ZD2767P was shown to clear rapidly from the circulation and activated drug was not measurable in the blood. ZD2767P has potential for use in future antibody-directed enzyme prodrug therapy systems.

Adult↗
PubMed2001

Can scintimammography with (99m)Tc-MIBI identify multifocal and multicentric primary breast cancer?

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.

Adult↗
PubMed2001

The clinical application of a dual head gamma camera with coincidence detection in 20 women with suspected ovarian cancer.

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.

Adult↗
PubMed2001

Prediction of the usefulness of combined mammography and scintimammography in suspected primary breast cancer using ROC curves.

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.

Adult↗
PubMed2001

The role of scintimammography and mammography in recurrent breast cancer. Evaluation of their accuracy using ROC curves.

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.

Journal Article↗
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

Radioimmunoguided surgery in colorectal cancer using a genetically engineered anti-CEA single-chain Fv antibody.

In radioimmunoguided surgery (RIGS), a radiolabeled antibody is given i.v. before surgery and a hand-held gamma-detecting probe is used to locate tumor in the operative field. The rapid blood clearance and good tumor penetration of single-chain Fv antibodies (scFv) offer potential advantages over larger antibody molecules used previously for RIGS. A Phase I clinical trial is reported on RIGS with scFv (MFE-23-his) to carcinoembryonic antigen (CEA). Thirty-four patients undergoing surgery for colorectal carcinoma (17 primary tumors, 16 liver metastases, and 1 anastomotic recurrence) and 1 patient with liver metastases of pancreatic carcinoma received 125I-labeled MFE-23-his scFv (125I-MFE-23-his) 24, 48, 72, or 96 h before operation. 125I-MFE-23-his showed biexponential blood clearance with alpha and beta half-lives of 0.32 and 10.95 h, respectively. The abdomen was scanned during surgery with a hand-held gamma detecting probe (Neoprobe Corp.). 125I-MFE-23-his showed good tumor localization; comparison with histology showed overall accuracy of 84%. Highest median ratios for tumor:normal tissue and tumor:blood were recorded 72 or 96 h after scFv injection for patients undergoing resection of liver metastases. High levels of radioactivity were found in the kidneys. Five patients had grade 1 fever, and three had a grade 1 rise in blood pressure according to the Common Toxicity Criteria. There was a significant correlation between these ratios and those measured in excised tissues using a laboratory gamma counter (P < 0.001). MFE-23-his scFv antibody localizes in CEA-producing carcinomas. The short interval between injection and operation, the lack of significant toxicity, and the relatively simple production in bacteria make MFE-23-his scFv suitable for RIGS.

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

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

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↗