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Background/objectives: Primary and metastatic pancreatic neuroendocrine tumours (PNET) can be treated with combination of surgery, locoregional and systemic therapy. Survival benefits from individual treatments have been well reported, however, the combined outcome from multimodal treatments are not well described in the literature. We report outcomes in a cohort of PNET patients treated with proactive, multimodality therapy., Methods: 106 patients were identified from a single tertiary referral centre prospective database. Outcomes of treatment were studied, with the primary end point being death from any cause., Results: Median follow-up was 71 months and overall 5-year survival of 62%. In patients with stage I-III disease (51 patients) estimated 5-year survival was 90%. Median survival in patients with stage IV disease was 51 months with an estimated 5-year survival of 40% in this group. A total of 80 patients (75%) had surgery of which 16% suffered complications requiring intervention. There was no perioperative mortality., Conclusions: This study demonstrates that proactive multimodal treatment is safe and may confer a survival benefit to patients in this cohort compared to historical data., (Copyright © 2017 IAP and EPC. Published by Elsevier B.V. All rights reserved.)

Primary and secondary liver malignancies are common and associated with a poor prognosis. Surgical resection is the treatment of choice; however, many patients have unresectable disease. In these cases, several liver directed therapies are available, including selective internal radiation therapy (SIRT). SIRT is a multidisciplinary treatment involving nuclear medicine, interventional radiology and oncology. High doses of localised internal radiation are selectively delivered to liver tumour tissues, with relative sparing of adjacent normal liver parenchyma. Side effects are minimal and radiation protection measures following treatment are straightforward. In patients who have progressed following chemotherapy, clinical trials demonstrate prolonged liver progression-free survival. SIRT is offered at 10 centres in England via the NHS England Commissioning through Evaluation programme and is approved by the National Institute for Health and Care Excellence for certain liver malignancies. SIRT holds unique promise for personalised treatment of liver tumours., (© Royal College of Physicians 2017. All rights reserved.)

Background: The purpose of the present study was to determine whether intrahepatic injection of (131)I-lipiodol (Lipiodol) is effective against recurrence of surgically resected hepatocellular carcinoma (HCC)., Methods: From June 2001 through March 2007, this nationwide multi-center prospective randomized controlled trial enrolled 103 patients 4-6 weeks after curative resection of HCC with complete recovery (52: Lipiodol, 51: Control). Follow-up was every 3 months for 1 year, then every 6 months. Primary and secondary endpoints were recurrence-free survival (RFS) and overall survival (OS), respectively, both of which were evaluated by the Kaplan-Meier technique and summarized by the hazard ratio (HR). The design was based on information obtained from a similar trial that had been conducted in Hong Kong., Results: The Lipiodol group showed a small, and nonsignificant, improvement over control in RFS (HR = 0.75; 95 % confidence interval [95 % CI] 0.46-1.23; p = 0.25) and OS (HR = 0.88; 95 % CI 0.51-1.51; p = 0.64). Only two serious adverse events were reported, both with hypothyroidism caused by (131)I-lipiodol and hepatic artery dissection during angiography., Conclusions: The randomized trial provides insufficient evidence to recommend the routine use of (131)I-lipiodol in these patients.

Introduction: Radioiodine (I-131) is a useful therapeutic modality of hyperthyroidism when medical therapy fails. Traditionally, the nuclear physicians undertake the prescription of I-131 therapy. However, endocrinologists are increasingly being recognized for their competence in prescribing individualized doses of I-131 for the treatment of various thyroid disorders., Methods: In this pilot prospective study, we collaborated with our nuclear medicine colleagues to determine the outcomes of 80 patients with hyperthyroidism who underwent I-131 ablation as prescribed by the endocrinologist. Doses administered were based primarily on thyroid volume with adjustments contingent on adverse factors, and fixed assumptions on target absorbed dose (R) and uptake (U) were used. Seventy-three had Graves' disease (GD) and seven had toxic nodular goitre (TNG) or toxic adenomas (AFTN). Therapeutic success was defined as achievement of hypothyroidism or euthyroidism., Results: 95.9 percent (70 of 73) of GD patients and 85.7 percent (6 of 7) of those with TNG/AFTN achieved successful outcomes after a single dose of endocrinologist-directed I-131 therapy. More than 50 percent of patients became hypothyroid by three months and about two-thirds became hypothyroid by six months post I-131 therapy., Conclusion: Our results indicate that the success rate of endocrinologist-directed I-131 therapy exceeds 95 percent with a single dose and compares favourably with nuclear physician-directed therapy outcomes., (Copyright J. A. Barth Verlag in Georg Thieme Verlag KG Stuttgart . New York.)

In our previous publication, we proposed to increase the injection activity for overweight patients. We have now implemented this for our patients, i.e. increasing the activity for patients above 99 kg. In the present study, we audited whether this increased activity for overweight patients improved the myocardial counts effectively and also whether it improved the image quality for these patients. 125 consecutive normal myocardial perfusion studies were included into the study. The total left ventricular myocardial count was calculated, as was the total left ventricular myocardial volume using the Cedar Sinai QPS program. The myocardial count per millilitre of the myocardium (c ml(-1)) was correlated with patient weight using regression analysis. There was no significant difference (p = 0.120) among the mean myocardial counts for patients over 99 kg (n = 40, 1548 c ml(-1)) compared with patients in the 70-79 kg range (n = 26, 1746 c ml(-1)). This indicates that the previously proposed algorithm for adjusting injection activity maintains the count density in the myocardium and should be used for all patients over 99 kg. There was, however, a significant steady decrease with increased weight in the myocardial counts for patients under 100 kg (p<0.001), a range in which injection activity was not adjusted for weight. To correct for this, we now propose that the injection activity should be adjusted for all patients over 80 kg, using the previously proposed algorithm.

Purpose: Intra-arterial injections (IAI) of 131I-lipiodol is effective in treating hepatocellular carcinoma patients, but is expensive and requires a 7-day hospitalization in a radioprotection room. 188Re is inexpensive, requires no patient isolation, and can be used with lipiodol., Methods and Materials: This International Atomic Energy Agency-sponsored phase II trial aimed to assess the safety and the efficacy of a radioconjugate 188Re + lipiodol (188Re-Lip) in a large cohort of hepatocellular carcinoma patients from developing countries. A scout dose is used to determine the maximal tolerated dose (lungs <12 Gy, normal liver <30 Gy, bone marrow <1.5 Gy) and then the delivery of the calculated activity. Efficacy was assessed using response evaluation criteria in solid tumor (RECIST) and alpha-feto-protein (alpha FP) levels and severe adverse events were graded using the Common Toxicity Criteria of the National Cancer Institute scale v2.0., Results: The trial included 185 patients from eight countries. The procedure was feasible in all participating centers. One treatment was given to 134 patients; 42, 8, and 1 received two, three, and four injections, respectively. The injected activity during the first treatment was 100 mCi. Tolerance was excellent. We observed three complete responses and 19 partial responses (22% of evaluable patients, 95% confidence interval 16-35%); 1- and 2-year survivals were 46% and 23%. Some factors affected survival: country of origin, existence of a cirrhosis, Cancer of the Liver Italian Program score, tumor dose, absence of progression, and posttreatment decrease in alpha FP level., Conclusions: IAI of 188Re-Lip in developing countries is feasible, safe, cost-effective, and deserves a phase III trial.

Carcinoma of the thyroid arising in an autonomously functioning or "hot" nodule is uncommon. The majority of thyroid carcinomas present as a "cold" nodule on radionuclide scintigraphy. We report a poorly-differentiated thyroid carcinoma developing in a long-standing "hot" nodule in a 51-year-old Chinese woman. Fluorine-18-fluorodeoxyglucose positron emission tomography (FDG PET) showed focal FDG uptake in the thyroid nodule, as well as in the cervical and pulmonary hilar lymph nodes. This case illustrates that the incidence of thyroid carcinoma in a "hot" nodule is not negligible. The role of FDG PET in the differentiation of benign from malignant thyroid nodules is still unclear. In contrast, FDG PET has been shown to have a role in the follow-up of thyroid cancer patients after thyroidectomy and subsequent radioactive iodine-131 (I-131) ablation. It may be useful in the identification and localisation of recurrent cancer foci in patients with elevated thyroglobulin levels but a negative I-131 whole body scan.

Introduction: This study aims to examine the usefulness of fluorine-18-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in thyroid carcinoma patients with elevated serum thyroglobulin (Tg) but negative iodine-131 (I-131) whole body scans., Methods: 17 patients with differentiated thyroid carcinoma who underwent FDG PET/CT scans were reviewed retrospectively over a period of one year from July 2003 to June 2004. All these patients had completion thyroidectomy and subsequently presented with elevated serum Tg but negative post-therapy I-131 whole body scans. Nine of these patients underwent FDG PET/CT in a hypothyroid state, while the remainder underwent FDG PET/CT while on thyroxine replacement., Results: 15 out of 17 PET/CT scans revealed lesions consistent with metastases, giving a sensitivity of 88.2 percent. Four of these patients were amendable to surgical treatment. Two scans were negative., Conclusion: FDG PET/CT is a sensitive diagnostic tool to detect radioiodine-negative recurrences/metastases in patients with thyroid carcinoma. Our preliminary results are comparable with published results based on PET.

Iodine-131 whole-body scintigraphy has been used extensively to detect thyroid remnants as well as metastatic disease in thyroid carcinoma postthyroidectomy. Over the years, numerous causes of false-positive scans have been reported. The authors report a novel case of a false-positive result resulting from a subdural hematoma mimicking a skull or cerebral metastasis.

Radionuclide synovectomy has been identified as the procedure of choice in treating chronic haemophilic synovitis among Caucasian populations. Its effectiveness among East Asians has not been studied. A retrospective study was carried out on 12 Asian haemophiliacs who underwent 12 radionuclide synovectomies. The average follow-up was 30.7 months (range 6-55) for primary procedures. 32P chromic phosphate and 188Re-tin colloid were injected into target joints according to protocol. There was a significant 80% decrease in the median frequency of haemarthrosis from 1.4 per month (range 0.2-7.0) to 0.25 per month (range 0.0-1.8) (P<0.05). Half of the patients had excellent results by 1 year of synovectomy. The median factor usage for target joint haemarthrosis postsynovectomy was 792 units per month (range 0-3209) reduced significantly from a presynovectomy level of 1452 units per month (range 306-7125) (P<0.05). Patients also reported a reduction in joint pain scores, and an improvement in joint mobility and quality of life. The majority of patients were satisfied with the overall outcome of radionuclide synovectomy. Radionuclide synovectomy appears to be effective in reducing the incidence of target joint haemarthrosis and quantity of factor usage for such bleeds among Asians with haemophilic synovitis.

Introduction: Nasopharyngeal carcinoma (NPC) is mainly treated by radiation therapy. A common complication of radiotherapy is xerostomia. Direct measurements of the amount of saliva produced using suction cups and volumetric assessments are cumbersome and time-consuming. Sequential radionuclide sialography is a reproducible and convenient method of measuring salivary function., Materials and Methods: Patients with newly diagnosed NPC underwent a pilot study using technetium-99m pertechnetate sequential radionuclide sialography to assess their salivary function before and at 3 months post radiation therapy. From the sialography, time activity curves were obtained for analysis of salivary function. The shape of the time activity curve with citric acid stimulation was classified into 4 types according to the degree of radiation-induced dysfunction., Results: All 14 patients had worse (P < 0.005) time activity curves for both parotids and submandibular glands after radiation therapy. All patients with abnormal curves before radiation therapy presented type IV (non-functioning) curve after radiation therapy. A ratio of pre- and post-stimulation counts allowed for quantification of the degree of stimulatory response. We found a significant decrease in Rc before and after radiation therapy for all salivary glands (P < 0.001). The salivary gland to background ratio, which is a reflection of the degree of salivary gland functional uptake, also had a significant reduction after radiation., Conclusion: It is feasible to use technetium-99m pertechnetate in the measurement of salivary gland function in nasopharyngeal cancer patients treated with radiation therapy.

Introduction: Hepatocellular carcinoma (HCC) is a common malignancy worldwide. Surgical resection is generally accepted as the first choice treatment of HCC. Many non-surgical techniques have been developed and used for the treatment of inoperable HCC, with limited efficacy. This paper studies the role of radionuclide therapy in the treatment of inoperable HCC and in an adjuvant setting following curative resection of HCC., Materials and Methods: Relevant articles published between 1980 and 2002 were reviewed. Articles were identified through a Medline search using the key words hepatocellular carcinoma, iodine-131 (I-131), lipiodol, yttrium-90 (Y-90), rhenium-188 (Re-188), monoclonal antibodies and anti-ferritin., Results: The objective response rate of patients with HCC treated with intra-arterial I-131 lipiodol was 40% to 70% and the median survival was between 6 and 9 months. The efficacy of I-131 lipiodol was similar to transarterial chemo-embolisation, but appears to be better tolerated by patients. A median survival of 9.4 months to 54 weeks was achieved using intra-arterial Y-90 microspheres for the treatment of HCC. Tumours in 4 patients became resectable after treatment. Re-188 lipiodol is a relatively new radiopharmaceutical used for the treatment of HCC. The results of a pilot study have shown Re-188 lipiodol to be a safe and cost-effective radiopharmaceutical for the treatment of HCC via the intra-arterial route. Its efficacy should be subjected to further evaluation. The use of radio-labelled monoclonal antibodies, such as anticarcinoembryonic antigen and antiferritin, for the treatment of HCC has yielded encouraging results but these forms of treatment are largely experimental and limited to a few centres. Intra-arterial treatment using I-131 lipiodol in an adjuvant setting for patients following curative resection of HCC has resulted in improved disease-free and overall survival. The 3-year survival for the treatment and control groups were 86.4% and 46.3%, respectively., Conclusion: Radionuclide therapy presents another interesting option for the treatment of HCC amidst the wide array of non-surgical modalities available.

Aims: The diagnosis of deep seated bacterial infections, such as intra-abdominal abscesses, endocarditis, and osteomyelitis, can be difficult and delayed, thereby compromising effective treatment. This study assessed the efficacy of a new radioimaging agent, Tc-99m ciprofloxacin (Infecton), in accurately detecting sites of bacterial infection., Methods: Eight hundred and seventy nine patients with suspected bacterial infection underwent Infecton imaging and microbiological evaluation. The sensitivity and specificity of Infecton in detecting sites of bacterial infection were determined with respect to Centres of Disease Control, World Health Organisation, and Dukes's criteria., Results: Five hundred and seventy four positive and 295 negative images were produced. These included 528 true positives, 46 false positives, 205 true negatives and 90 false negatives, giving an overall sensitivity of 85.4% and a specificity of 81.7% for detecting infective foci. Sensitivity was higher (87.6%) in microbiologically confirmed infections., Conclusions: Infecton is a sensitive technique, which aids in the earlier detection and treatment of a wide variety of deep seated bacterial infections. The ability to localise infective foci accurately is also important for surgical intervention, such as drainage of abscesses. In addition, serial imaging with Infecton might be useful in monitoring clinical response and optimising the duration of antimicrobial treatment.

Introduction: In a minority of the cases, resection of hepatocellular carcinoma (HCC) is potentially curative but local recurrence is common. Adjuvant intra-arterial radio-conjugate therapy could potentially reduce the rate of local recurrence and increase disease-free and overall survival. However, in the majority of cases, treatment of HCC is largely palliative. A wide range of palliative treatment options are available and these include external radiation, hepatic intra-arterial chemo-embolisation, systemic chemotherapy and percutaneous ethanol injection. The long-term survival rate is poor. Hepatic intra-arterial radio-conjugate therapy provides a new and promising means of palliation., Materials and Methods: We share our initial experience in the treatment of patients with HCC. A total of 32 patients were recruited between October 1999 and June 2001. Group 1 comprised 15 patients who had potentially curative resection of HCC who were treated with Iodine-131 (I131) lipiodol as a form of adjuvant therapy. Group 2 comprised 17 patients with unresectable HCC, 12 of whom were treated with Yttrium-90 (Y90) microspheres and 5 with Rhenium-188 (Re188) lipiodol. The radio-conjugates were administered via the intra-arterial route., Results: Thirteen of the 15 patients in group 1 who were treated with I131 lipiodol following curative resection of HCC were free of disease, 1 patient died and 1 patient who developed recurrence was retreated with Re188 lipiodol and was subsequently free of disease. The 6-month disease-free survival rate was 100% and the 12-month disease-free and overall survival rates were 72% and 85%, respectively. Of the 12 patients in group 2 who were treated with Y90 microspheres for unresectable HCC, 6 had stable disease, 2 showed tumour regression and 4 died. The 6-month and 12-month survival rates were 75% and 66%, respectively. Of the 5 patients in group 2 who were treated with Re188 lipiodol for unresectable HCC, 4 had stable disease and 1 had regression of the right lobe tumour but progression of the left lobe tumour., Conclusion: Our results in the adjuvant treatment of patients with I131 lipiodol following curative resection of early HCC and in the palliative treatment of unresectable HCC using Y90 microspheres and Re188 lipiodol are preliminary and not fully conclusive. These preliminary results have to be confirmed in larger groups of patients and by prospective, randomised, controlled trials. This study highlights the preliminary experience in radionuclide therapy of HCC using hepatic intra-arterial radio-conjugates in a local context.

Introduction: Medullary thyroid carcinoma (MTC) is a rare thyroid malignancy but accounts for a significant mortality. We present 2 cases of MTC and review the literature regarding its management and genetic screening., Clinical Picture: Patient 1 presented after a routine health screening and subsequently was found to have a germline mutation for MEN 2A. Patient 2 presented with sweating irritability and a thyroid mass which illustrates the progressive relentless nature of the disease and highlights current imaging practice., Treatment: Both patients underwent extensive surgery and received postoperatively ablative dose of radioactive iodine. Patient 2 also had a large dose I-131 MIBG therapy and further surgery., Outcome: In Patient 1, postoperative calcitonins remained elevated indicating residual disease. Patient 2 underwent further radioguided surgery; however, his postoperative calcitonins remained elevated., Conclusion: MTC can be relentless. Routine genetic screening of all patients with MTC, Tc-99m pentavalent (V) DMSA imaging, near total thyroidectomy with routine central neck dissections and removal of all lymph nodes in the central neck compartment should be performed.

Objective: In the light of a reported 30-40% prevalence of pulmonary embolism (PE) in intermediate probability lung scans (IPLS) based on results of the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED) study, we examined the frequency of documented PE in 82 patients with IPLS, the management strategy employed in these patients with regards to additional imaging (e.g. further evaluation with venous sonography or spiral computed tomographic angiography (CTA)), anticoagulation therapy, and subsequent follow-up outcomes., Method: Retrospective review of the medical records of 82 patients with intermediate probability ventilation-perfusion (V/Q) lung scans from January 1998 to July 1999., Results: 14.1% of V/Q scans were reported as having an intermediate probability of PE. 72% of IPLS were subject to further evaluation with venous Doppler ultrasound and/or CTA, and 39% of these patients had evidence of thrombo-embolic disease. All patients with imaging evidence of thromboembolic disease were started on anticoagulation therapy. In addition, 19 patients were treated based on clinical judgement. Amongst the 35 patients who were not treated, 17 (49%) were based on clinical findings without further imaging. There was no mortality on follow-up of 28 cases of untreated IPLS., Conclusion: The majority of IPLS will have further imaging, out of which over one-third will have thrombo-embolic disease. Approximately half of IPLS cases will receive anticoagulation therapy. No mortality or PE was found on follow-up of patients who were not treated.

Introduction: The aim of this study was to investigate the potential of using 188Re Lipiodol for selective internal radiation therapy of inoperable hepatocellular carcinoma (HCC)., Clinical Picture: A 33-year-old female with poorly-differentiated multicentric HCC, elevated alpha-fetoprotein (AFP) and increased serum alkaline phosphatase., Treatment: Over a 2-month interval, the patient was treated twice with 4GBq of 188Re-TDD-Lipiodol., Outcomes: There was good localisation of 188Re Lipiodol in the tumours, but also in thyroid (first treatment) and gastrointestinal tract (both treatments). So far (5 months post-treatment), the patient remains well with stable disease., Conclusions: 188Re Lipiodol can be an effective radiopharmaceutical for the treatment of HCC; however, more work must be done to minimise the uptake in bowel.

Introduction: The aim of this study was to evaluate the usefulness of technetium-99m (Tc-99m) ciprofloxacin in imaging inflammation/infection. The ciprofloxacin for labelling, as a kit, was obtained from St Bartholomew's Hospital in London., Materials and Methods: Patients were injected intravenously with Tc-99m ciprofloxacin and imaging was done at 10 minutes, 4 hours and 24 hours if necessary. Tomographic images (SPECT) were obtained in a few patients. Ninety-six patients were studied using Tc-99m ciprofloxacin. Forty-eight patients had bone scans and 22 had Tc-99m IgG scans. Eight patients were imaged using Tc-99m HMPAO labelled white blood cell, and bacteriological culture results were available in 24 patients. Organisms cultured included Acinetobacter baumanii, Streptococcus, Staphylococcus aureus, Pseudomonas, Klebsiella, Blastococidia, Methicillin-resistant S. aureus, Salmonella and Candida., Results: Findings were evaluated against microbiology, alternative imaging modalities and clinical outcome. There were 47 true positives, 33 true negatives, 5 false positives and 11 false negatives, giving a sensitivity of 81% and specificity of 87%. The positive and negative predictive values were 90% and 75%, respectively. There were no side effects and the scan was particularly useful in the evaluation of painful joint prosthesis to exclude infection. Repeat studies on 8 patients given antibiotics over a long period were very useful in deciding on termination of the antibiotic treatment.

Unlabelled: 99mTc-sestamibi whole-body scanning has been used in the postoperative assessment of differentiated thyroid carcinoma together with 131I whole-body scanning and serum thyroglobulin (Tg) estimation. This study compared 99mTc-sestamibi whole-body scanning with 131I whole-body scanning in the context of initial serum Tg levels of patients after total or near-total thyroidectomy who were taken off thyroxine suppression therapy and who had no 131I ablation before surgery., Methods: A prospective study of 360 patients was undertaken. 99mTc-sestamibi whole-body scintigraphy was performed at least 5 wk after thyroidectomy and was followed by 131I whole-body scanning. The patients had no thyroxine suppression for 5 wk, and Tg was measured thereafter. Radiologic studies (chest radiography, CT, MRI, sonography, and bone scanning) and histopathologic examinations were performed to clarify the presence of metastases with positive uptake on either 99mTc-sestamibi scans or 131I whole-body scans. Positive scans were defined as those with the presence of thyroid remnants, lymph node disease, or metastases., Results: Two hundred fifty-nine (71.9%) of the 360 patients had initial serum Tg levels < 30 ng/mL (group 1), whereas 101 (28.1%) had initial serum Tg levels > or = 30 ng/mL (group 2). Of the 259 group 1 patients, 82 had positive 99mTc-sestamibi scans and 113 had positive 131I scans; 71.7% of patients with positive 1311 scans also had positive 99mTc-sestamibi scans, and 98.8% of patients with positive 99mTc-sestamibi scans also had positive 131I scans. Of the 101 group 2 patients, 81 had positive 99mTc-sestamibi scans and 97 had positive 131I scans; 83.5% of patients with positive 131I scans also had positive 99mTc-sestamibi scans, and all patients with positive 99mTc-sestamibi scans also had positive 131I scans. Of those with initial serum Tg levels > or = 30 ng/mL (group 2), 27.2% had thyroid remnants and 68.8% had lymph node disease or metastases. 131I scanning detects more thyroid remnants and lung metastases than does 99mTc-sestamibi scanning., Conclusion: Our findings suggest that, compared with 131I scanning, 99mTc-sestamibi scanning is less sensitive in detecting thyroid remnants and lung metastases but appears to be more useful in the detection of lymph node disease before initial 131I treatment.

Introduction: Reperfusion therapy with either thrombolysis or angioplasty has been shown to be beneficial in acute myocardial infarction. Tc-99m sestamibi is a myocardial tracer that can be used to assess myocardial salvage because of its property of very limited redistribution., Materials and Methods: To assess the feasibility of this technique locally, Tc-99m sestamibi was injected before and after reperfusion therapy with angioplasty (n = 11) or streptokinase (n = 18) in 29 patients with acute myocardial infarction (anterior = 25, inferior = 4). Single-photon emission computed tomography (SPECT) was performed within 4 hours of reperfusion and repeated 5 to 7 days later., Results: Initial perfusion defect size ranged from 6% to 78% (mean 36.3 +/- 18.7%), and final defect size from 0% to 50% of the left ventricle (mean 23.7 +/- 14.8%, P < 0.001). Patients with proximal left anterior descending artery (LAD) lesions had larger defects compared to those with mid LAD lesions (mean defect size 52% for pLAD versus 28% for mLAD, P < 0.013). However, there were wide variations in initial defect size (myocardium at risk) for a given infarct-related artery location. The mean decrease in defect size was 12% in the 28 patients with patent arteries compared to only 2% in the patient with an occluded artery (47% to 45%). There was no significant difference in amount of salvage between patients who had thrombolysis (mean 13%, P = 0.0003) and patients who had percutaneous transluminal coronary angioplasty (PTCA) (mean 12%, P = 0.005)., Conclusions: Assessment of myocardial salvage is feasible using Tc-99m sestamibi SPECT imaging. It allows for quantitation of myocardium at risk and the amount of myocardial salvage, which is not possible by angiography alone.

The speed of sound (SOS) and the broadband ultrasound attenuation (BUA), as determined by quantitative ultrasound at the calcaneum, were correlated with the bone mineral density (BMD) measurements using dual-energy X-ray absorptiometry at the femoral neck and the lumbar spine in 110 females. There were moderate correlations of 0.629, 0.623 and 0.594 between the BMD at the anterior-posterior lumbar spine, lateral lumbar spine and femoral neck with the SOS at the calcaneum (all P < 0.001). The corresponding correlations with BUA were 0.646, 0.643 and 0.628 respectively (all P < 0.001). This suggests that quantitative ultrasound may be reasonably accurate and useful for the assessment of osteoporosis.

Radioiodine (I-131) is one of the accepted forms of treatment for thyrotoxicosis. The major drawback of this treatment is the definite incidence of hypothyroidism, which is either early or late, and is cumulative. We set out to analyse the local incidence of this outcome. Patients with hyperthyroidism, treated with radioiodine from 1984 to end of 1989, and still on follow-up with the Department of Nuclear Medicine, Singapore General Hospital were analysed for the incidence of hypothyroidism. Three hundred and eighty-two patients were analysed (305 females, 77 males). Their ages ranged from 14 to 85 years (mean 48.2, SD 11.1 years). The doses of radioiodine ranged from 4 to 18 mCi (mean 7.6 mCi, SD 1.8 mCi). Two hundred and sixty-two patients who received I-131 only required a single dose, while 87 needed one repeated dose of I-131, and 33 needed more than 2 doses. Of the 382 patients, 271(70.9%) became clinically hypothyroid, 6 (1.6%) were subclinically hypothyroid, 100 (26.7%) were euthyroid and 3 (0.8%) remained hyperthyroid. One hundred and eighty-one patients (47.4%) were clinically hypothyroid at the end of 1 year, and an average rise of 4.8% per year was observed from the second to the fifth year. From the sixth year onwards, the average incidence of hypothyroidism was 1% per year. I-131 is indeed an effective means of controlling thyrotoxicosis (99.2% were no longer hyperthyroid). The main problem with this treatment is hypothyroidism, and this is easily managed with L-thyroxine.

Radionuclide imaging using the 99mTc sestamibi either singly or as a subtraction technique with pertechnetate is a recent and reliable method in localising parathyroid adenomas prior to surgery. This is of use in pre-operative planning, as well as in failed first neck exploration. Four local patients with primary hyperparathyroidism whose parathyroid adenomas were localised by this scintigraphy are presented. The value and limitations of this imaging modality are discussed.

Oral thyrotrophin-releasing hormone (TRH) and lithium were given to patients on follow-up for well-differentiated thyroid carcinoma to see their effect on serum thyrotrophin level (TSH) and radioiodine (I-131) uptake (RAIU). The study was randomised and doubled-blinded and consisted of a total of 19 patients in 3 groups. Group 1 received placebo and TRH, group 2 received lithium and placebo, and group 3 received lithium and TRH. Serum TSH and RAIU at 24 hours were measured before, and after treatment, with TRH, lithium, and/or placebo. In group 1, mean (+/-SEM) TSH increased from 48.9 (+/-15.2) mU/l to 148.2 (+/-48.0) mU/l (p < 0.05); in group 2, the change of 24.9 (+/- 15.9) mU/l to 31.7 (+/-14.1) mU/l in TSH was not statistically significant; and in group 3, TSH increased from 108.1 (+/-13.8) mU/l to 187.0 (+/-39.1) mU/l (p < 0.05). However, despite the significant change in TSH, there was no significant increase in I-131 uptake in any group: 7.70% to 10.43%, 7.15% to 7.43% and 2.49% to 2.61%, in groups 1, 2 and 3 respectively (p > 0.05). We conclude that while oral TRH will increase endogenous serum TSH significantly, there is no significant increase in I-131 uptake. Lithium was not an useful adjunct in increasing serum TSH or I-131 uptake in these patients.

Patients with TSH of decreased bioactivity have had previous surgery or no known cause (idiopathic). We describe eight patients with nasopharyngeal carcinoma treated with irradiation alone more than 5 yr ago. All had hypothalamic hypothyroidism with low FT4 and normal TSH. Iv TRH gave an exaggerated TSH response, with 60 min greater than 20 min values, without any FT4 or TT3 response at 24 h to the hypersecreted TSH. Radioiodine uptake in 2 patients before and after 3 days of bovine TSH increased from 13 to 31%, and 11 to 28%, respectively. Oral TRH given for 20 days to 5 patients showed a distinctive pattern in serum TSH, FT4 and TT3. Serum TSH rose markedly in the initial few days, dropped to moderate levels for a few days and finally dropped further towards normal values. In contrast, the FT4 and TT3 remained unchanged at hypothyroid levels in the first few days, despite the very elevated TSH; but increased to euthyroid levels and remained higher even while the serum TSH declined further. Direct measurement of TSH bioactivity in FRTL-5 cells in 3 patients showed low values of bioactivity to immunoactivity ratios: 0.4, < 0.2, and 0.35 (NR 0.6-2.1) which increased in 2 patients to 0.9 and 0.8 after 20 days TRH. Serum free alpha-subunit levels were low and unchanged (0.3 to 1.1 micrograms/L) with prolonged TRH. These observations suggest that cranial irradiation may cause hypothalamic hypothyroidism with TSH with decreased bioactivity, and that prolonged TRH administration may restore normal bioactivity.

It has long been recognised that significant bone tracer localisation in the myocardium is a good indicator for amyloid involvement of the heart in the clinical context of systemic amyloidosis. In this case report, although myocardial tissue diagnosis of amyloidosis was not made, the massive myocardial uptake of bone tracer strongly suggested the presence of amyloid infiltration in the heart, and this finding eventually led to the histological diagnosis of familial amyloid polyneuropathy by skin and sural nerve biopsy. Interesting findings were noted in the single photon emission computerised tomography (SPECT) studies of the myocardium with Technetium-99m diphosphono-propanedicarboxylic acid bone agent and Technetium-99m sestamibi myocardial perfusion agent. Such findings suggest that there is a lack of correlation between the intensity of myocardial uptake of bone tracer and viability of the myocardium, and that amyloid will not deposit in infarcted myocardial tissue.

99Tcm-sestamibi (99Tcm-MIBI) is used for myocardial perfusion imaging but has also been reported to localize in tumours. The usual thyroid scanning radionuclide is 99Tcm-pertechnetate. Altogether, 161 patients with clinically solitary thyroid nodules had both 99Tcm-MIBI and 99Tcm-pertechnetate thyroid scans, with the nodules being reported as cold, warm or hot. Fine-needle aspiration cytology (FNAC) and surgery were performed in those patients who consented to these procedures. Of 131 patients who had FNAC, only 58 proceeded to surgery. In the surgically treated group, 14 of 58 (24%) were confirmed to have thyroid cancer, whereas 44 of 58 (76%) had benign lesions. The 14 cancerous nodules were cold on the 99Tcm-pertechnetate scan, whereas with 99Tcm-MIBI 11 were warm and 3 were either cold or hot nodules. Of the 44 benign lesions, 18 were cold, 9 were warm and 17 were hot nodules. In those 131 patients who had FNAC, the cytology was reported as benign in 120 of the nodules and malignant in 11. The three false-negative cytologies were reported as follicular adenomas. The benign lesions noted on FNAC and surgery were thyroiditis, adenomas and haemorrhagic or colloid cysts. The results from the 58 surgically treated patients suggest that the warm nodules would need surgery, whereas the cold and hot nodules are unlikely to be malignant. The overall sensitivity of the 99Tcm-MIBI scan was 79% and the specificity 80%, with the warm nodule on 99Tcm-MIBI scan having a positive predictive value of 55% and a negative predictive value of 92%.

While continuous ambulatory peritoneal dialysis (CAPD) offers several advantages over haemodialysis in patients with end-stage renal disease, several complications have been recognised. The intraperitoneal instillation of dialysate increases intra-abdominal pressure and consequently predisposes to leaks and herniations through defects in the abdominal wall. This can lead to disruption of CAPD therapy. Peritoneal scintigraphy with Tc99m colloid has been used to identify such leaks of dialysate. This report analyses the clinical role of peritoneal scintigraphy in patients on the CAPD programme in the Singapore General Hospital. The results of 25 scans performed over a two-and-a-half year period were correlated with clinical and surgical findings. The clinical presentations of suspected dialysate leakage were varied, but can be broadly classified into three subsets for this analysis: (A) swellings confined to the inguinal and genital region, (B) peri-catheter, umbilical and incisional swellings, and (C) diffuse pattern of swellings in the abdominal wall, pelvic and genital region. In group A, the scan proved to be clearly helpful, correctly identifying 10/10 inguinal hernias, all of which resolved after herniorrhaphy. In group B, the scan correctly identified 7/9 leaks and hernias in the ventral abdominal wall. There was one false negative scan in a patient with a peri-catheter leak, and an equivocal result in another with fluid leakage in the lower anterior abdominal wall. In group C, which presented the greatest difficulty in clinical diagnosis, 2/3 cases were correctly diagnosed by scintigraphy. An equivocal result was seen in a patient who had had multiple operations for recurrent incisional hernias.(ABSTRACT TRUNCATED AT 250 WORDS)

An ideal diagnostic imaging method in cancer management should be one which surveys the entire body for occult or small tumour foci in a single procedure. Imaging with radiolabelled antibodies appears to have such potential if the limiting factors which we have encountered in the last 40 years can be completely eliminated. These factors include antibody-dependent factors, radionuclide-dependent factors, host-dependent factors and imaging modality-dependent factors. Advances in immunology and bio-genetic engineering have enabled production of various antibody fragments and genetically engineered antibody molecules (i.e. chimeric/humanized antibodies and the single-chain antigen binding protein), giving a promise of overcoming the problem of cross-reactivity and host immuno-response. The rapid development in radiopharmacy and labelling chemistry has led to the establishment of various pre-targetted methods which are aimed to improve the tumour to non-tumour ratio. The recent success of producing Tc99m labelled monoclonal antibodies preparation in a kit form has certainly encouraged its clinical applications and made antibody imaging a less tedious task. The progression in computer technology has made "image fusion" possible and hence improve the accuracy of anatomical localization of tumour foci in antibody imaging. It would appear possible to overcome most, if not all, of the limiting factors mentioned above in the near future. The prospect of radiolabelled antibodies in tumour imaging is promising and the dream of a "magic bullet" will soon be fulfilled.

Technetium-99m sestamibi (MIBI) is a routinely used myocardial perfusion imaging agent. We have studied groups of patients with differentiated thyroid carcinoma, in order to evaluate the usefulness of this agent in localising regional neck and nodal disease and metastases. There are three groups of patients. Group 1 consisted of patients with known nodal disease or metastases (22 patients) and with raised serum thyroglobulin levels (Tg). Group 2 comprised patients with normal I-131 scans and normal Tg levels (nine patients). Non-thyroid malignancies (six patients) comprised an additional group 3. In group 1, the MIBI scan showed 47 sites of metastases, while the I-131 scan revealed 49 sites. The MIBI scan was positive in two patients where the I-131 scan was negative, while in two other patients, the MIBI study was negative whereas the I-131 scan was positive. In group 2, 6/9 patients had no disease, 2/9 had thyroid remnants, and 1/9 had a fresh primary lung tumour, unrelated to the earlier thyroid cancer. All of them had normal MIBI scans. In group 3, two patients with lung cancer and two with breast cancer and metastases had normal MIBI scans. A further two patients with nasopharyngeal cancer (NPC) had mildly increased MIBI localisation in neck nodes and bone metastases. In summary, Tc-99m sestamibi appears to be as good as I-131 in search for thyroid carcinoma metastatic spread, especially nodal disease and this tracer does not localise well in the primary or metastases of other cancers.(ABSTRACT TRUNCATED AT 250 WORDS)