A. J.W. Hilson

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.

Epirubicin-lipiodol chemotherapy versus 131iodine-lipiodol radiotherapy in the treatment of unresectable hepatocellular carcinoma

Background. Arterially administered iodized oil (Lipiodol) is selectively retained by hepatocellular carcinomas (HCCs), and has been used as a vehicle for delivery of therapeutic agents to these tumors. This study compared the efficacy of Lipiodol‐targeted epirubicin chemotherapy with Lipiodol‐131I radiotherapy.

SNM Practice Guideline for Lung Scintigraphy 4.0

The Society of Nuclear Medicine (SNM) is an international scientific and professional organization founded in 1954 to promote the science, technology, and practical application of nuclear medicine. Its 16,000 members are physicians, technologists, and scientists specializing in the research and practice of nuclear medicine. In addition to publishing journals, newsletters, and books, the SNM also sponsors international meetings and workshops designed to increase the competencies of nuclear medicine practitioners and to promote new advances in the science of nuclear medicine. The SNM will periodically define new practice guidelines for nuclear medicine practice to help advance the science of nuclear medicine and to improve the quality of service to patients throughout the United States. Existing practice guidelines will be reviewed for revision or renewal, as appropriate, on their fifth anniversary or sooner, if indicated. Each practice guideline, representing a policy statement by the SNM, has undergone a thorough consensus process in which it has been subjected to extensive review, requiring the approval of the Committee on Guidelines and SNM Board of Directors. The SNM recognizes that the safe and effective use of diagnostic nuclear medicine imaging requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guideline by those entities not providing these services is not authorized. These guidelines are an educational tool designed to assist practitioners in providing appropriate care for patients. They are not inflexible rules or requirements of practice and are not intended, nor should they be used, to establish a legal standard of care. For these reasons and those set forth below, the SNM cautions against the use of these guidelines in litigation in which the clinical decisions of a practitioner are called into question. The ultimate judgment regarding the propriety of any specific procedure or course of action must be made by the physician or medical physicist in light of all the circumstances presented. Thus, there is no implication that an approach differing from the guidelines, standing alone, was below the standard of care. To the contrary, a conscientious practitioner may responsibly adopt a course of action different from that set forth in the guidelines when, in the reasonable judgment of the practitioner, such course of action is indicated by the condition of the patient, limitations of available resources, or advances in knowledge or technology subsequent to publication of the guidelines. The practice of medicine involves not only the science, but also the art, of dealing with the prevention, diagnosis, alleviation, and treatment of disease. The variety and complexity of human conditions make it impossible to always reach the most appropriate diagnosis or to predict with certainty a particular response to treatment. Therefore, it should be recognized that adherence to these guidelines will not ensure an accurate diagnosis or a successful outcome. All that should be expected is that the practitioner will follow a reasonable course of action based on current knowledge, available resources, and the needs of the patient to deliver effective and safe medical care. The sole purpose of these guidelines is to assist practitioners in achieving this objective.

Fluoro-deoxyglucose positron emission tomography imaging for the detection of occult disease in multiple myeloma

Summary. Positron emission tomography with 2‐deoxy‐2‐[18]fluoro‐d‐glucose (FDG‐PET) imaging has been extensively used to detect occult metastatic malignant lesions in patients with carcinoma. We describe its use in three patients with multiple myeloma, each representing a particular clinical situation in which this imaging modality offered advantages over plain radiography, computerized tomography or magnetic resonance imaging. FDG‐PET provides a whole body image showing sites of occult disease. This is of particular value in patients with non‐secretory myeloma, solitary plasmacytoma or for those that relapse with focal disease following autologous or allogeneic stem cell transplantation.

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 patients 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.

SNM practice guideline for hepatobiliary scintigraphy 4.0.

VOICE Credit: This activity has been approved for 1.0 VOICE (Category A) credit. For CE credit, participants can access this activity on page 15A or on the SNM Web site (http://www.snm.org/ce_online) through December 31, 2012. You must answer 80% of the questions correctly to receive 1.0 CEH (Continuing Education Hour) credit.

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 (McNemars 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.

Can scintimammography with 99mTc-MIBI identify multifocal and multicentric primary breast cancer?

Scintimammography with 99mTc-MIBI has been shown to be an effective adjunct to imaging of the breast with mammography. Uptake of 99mTc-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 99mTc-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.

Inter-observer agreement in the reporting of 99Tcm-DMSA renal studies

SummaryThe early identification of renal cortical scarring secondary to urinary reflux and/or renal infection is important in the management of patients with recurrent disease. Scintigraphic imaging of the renal cortex using 99Tcm-dimercaptosuccinic acid (DMSA) is often considered the standard method for the diagnosis of renal scars in both adults and children. Consistent reporting of 99Tcm-DMSA is nevertheless essential in ensuring that the clinician can act on the data reported. In this study, seven experienced observers were asked to report, independently, 99Tcm-DMSA data sets from 32 patients. The observers were asked to note the presence of a space occupying lesion or of a renal cortical scar(s) and to conclude if the kidney was normal or abnormal. There was marked variation in the number of renal cortical scars reported, the total number of scars seen and whether or not the kidney was normal or abnormal. After peer review of all data, consensus and referenced criteria were arrived at for a reanalysis of data. All scans were reread by the observers. There was some improvement in the concordant reporting of kidneys with renal scars (51 vs 61%) and whether or not the kidney was normal or abnormal (53 vs 63%). However, this was not statistically significant (at a level of P < 0.05). This study demonstrated significant inter-observer variation regarding the reporting of 99Tcm-DMSA studies. A consensus with agreed guidelines for data interpretation did not significantly affect this apparent lack of consistency of reporting.

Prediction of clinical outcome in treated neuroendocrine tumours of carcinoid type using functional volumes on 111In-pentetreotide SPECT imaging.

The quantification of the tumour volume is essential for the assessment of therapy-induced changes. Traditional methods of assessing the response of neuroendocrine tumours using radiological methods yield poor results, particularly within the liver. The aim of this study was to establish whether it would be possible to identify a method using functional volumes to predict the response of tumours to various therapies. Twenty-two patients with neuroendocrine tumours of carcinoid type in the liver were treated with chemotherapy, chemo-embolization or 90Y-radiolabelled somatostatin analogues. All patients underwent 111In-pentetreotide single-photon emission computed tomography (SPECT) and computed tomography (CT) scan pre- and post-treatment. The tumour functional volume, a measure of metabolically active tumour tissue, was calculated from the SPECT images using a 10-point display; regions of interest were drawn around 50% of the maximum tumour activity, slice by slice, and then multiplied by the slice thickness (9.3 mm). Any difference in functional volume was compared with the CT response, using the Response Evaluation Criteria in Solid Tumours (RECIST), and clinical outcome. At 6 months after treatment, 14 patients showed a good clinical response, as measured by a reduction in pain, flushing or abdominal symptoms; the functional volume of the tumours in these patients decreased by a mean of 25% (range, 1–52%). Of the eight patients who showed no symptomatic relief, or in whom symptoms worsened, the functional volume increased by a mean of 74%. Using a change in functional volume of more than 25% as significant, SPECT predicted 13 of the 22 (59%) clinical outcomes correctly; if a 10% change was used, 18 of the 22 (81.1%) clinical outcomes were correctly predicted. However, CT, using RECIST, only predicted eight of the 22 (36%) clinical outcomes correctly. The assessment of the total functional volume by SPECT quantification is more useful than CT in monitoring tumour response after treatment, and the changes in functional volumes after therapy correlate well with the clinical response.