Proactive multi-modality treatment of Pancreatic Neuroendocrine Tumours (PNETs): Potential survival benefits.

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.

Adjuvant hepatic intra-arterial iodine-131-lipiodol following curative resection of hepatocellular carcinoma: a prospective randomized trial.

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.

Initial experience in use of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography in thyroid carcinoma patients with elevated serum thyroglobulin but negative iodine-131 whole body scans.

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.

Detection of thyroid malignancy in a hot nodule by fluorine-18-fluorodeoxyglucose positron emission tomography.

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.

99mTc-sestamibi and 131I whole-body scintigraphy and initial serum thyroglobulin in the management of differentiated thyroid carcinoma.

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.

Imaging bacterial infection with (99m)Tc-ciprofloxacin (Infecton).

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.

Evaluation of thyroid nodules for malignancy using 99Tcm-sestamibi.

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%.

99Tcm-(tin) colloid scans in the evaluation of renal transplant rejection.

Technetium-99m-(tin) colloid uptake in renal transplants was quantified to evaluate rejection. A dynamic acquisition following i.v. injection of 110 MBq of this radiopharmaceutical enabled quantification of 15 to 20 min transplant uptake (PU), in terms of percentage of an injected dose after allowing for attenuation in the patient. An uptake ratio (UR) i.e. the ratio of 15 to 20 min uptake over the 0 to 5 min uptake was also derived. Normal values were obtained in 20 stable functioning transplants (normal PU less than or equal to 1%, normal UR less than or equal to 0.7). In 66 patients, PU and UR were compared with clinical, biochemical, histological and radiological, evidence of rejection. A sensitivity of 70% and specificity of 85% was obtained for this 99Tcm-(tin) colloid study in the diagnosis of renal transplant rejection.

99Tcm-polyclonal IgG and 99Tcm nanocolloid scans in orthopaedics: a comparison with conventional bone scan.

The bone scan is sensitive in detection of active bone/joint lesions. A normal bone scan virtually excludes the presence of an inflammatory process with high precision, but the poor specificity of bone scans is well known. In recent years, various new agents including 99Tcm-hexamethylpropylene amine oxime (HMPAO)-labelled white blood cells, nanocolloid, polyclonal IgG, anti-granulocyte antibody, 111In-labelled IgG, leucocytes, chemotactic peptides etc. have been widely evaluated in inflammatory imaging, especially in the orthopaedic context. This study was undertaken to compare the usefulness of 99Tcm-nanocolloid and 99Tcm-polyclonal IgG in the detection of focal bone/joint inflammation. Twenty-seven patients with a common presentation of bone/joint pain resulting from various pathologies were included in the study. A total of 47 lesions were imaged. The overall sensitivity and specificity of both nanocolloid scan and IgG scan were identical with 95% sensitivity and 100% specificity, in detecting inflammatory foci. However, specificity dropped to 18% with nanocolloid scans and 16% with IgG scans when an attempt was made to distinguish noninfective from infective inflammatory processes; thus neither type of scan permits differentiation between septic and nonseptic inflammatory processes with sufficient accuracy. As both nanocolloid and IgG scans are equally sensitive and specific in detecting inflammation, the choice of type of scan will depend on cost, imaging time and availability of the radiopharmaceutical.

A non-invasive isotope dilution technique for quantifying hepatic blood flow using radiolabelled red blood cells.

Clinically significant changes in hepatic haemodynamics accompany the development of portal hypertension, hepatocellular carcinoma, liver metastases and liver cirrhoses, and after major liver resection. Hepatic blood flow parameters, such as hepatic arterial flow (HAF), hepatic portal flow (HPF), total hepatic blood flow (THBF) and hepatic perfusion index (HPI), are useful adjuncts to the diagnosis of liver pathology, the evaluation of disease progress and prognostication. Here, we describe a non-invasive method that combines the measurement of these parameters in a single study in real time. Red blood cells from eight pigs were labelled with 99Tc(m) using an in-vitro method and re-injected into the pigs. Data acquisition over the heart, lungs, liver and kidneys was started immediately and a blood sample was obtained 15 min post-injection. Hepatic arterial flow was determined from the ratio of the maximum gradients between the integrated time-activity curve of the left ventricle and the first-pass time-activity curve of the liver before the peak of the kidneys time-activity curve. The hepatic perfusion index was determined by comparing the slope of the liver time-activity curve before and after the kidney peak. Hepatic portal flow was determined from the hepatic arterial flow and the hepatic perfusion index, and total hepatic blood flow was determined as the sum of arterial and portal flow. The results were compared against those obtained from a clearance method using 99Tc(m)-DISIDA. The average hepatic perfusion index was 0.38, and the average hepatic arterial flow and hepatic portal flow were 168.3 +/- 52.9 and 274.6 +/- 60.1 ml x min(-1) respectively. The average total hepatic blood flow was 442.8 +/- 53.5 ml x min(-1), while the total hepatic flow determined by 99Tc(m)-DISIDA clearance was 419.7 +/- 62.6 ml x min(-1). No significant difference in total hepatic blood flow was found between the two methods. The results of this study show that it is possible to obtain all hepatic haemodynamics data in a single study using a non-invasive method.

Clinical studies of alveolar-capillary permeability using technetium-99m DTPA aerosol.

Soluble radioaerosols such as technetium-99m diethylene triamine pentacetate (DTPA) permit simple quantitative studies of alveolar-capillary permeability to be performed, since the submicronic aerosols are deposited mainly at the lung periphery and are cleared across the alveolar-capillary membrane. Regional alterations in permeability can also be noted using this radionuclide technique. We have measured the pulmonary epithelial permeability in normal subjects and the alteration in smokers, in glue-sniffers, in patients with inhalation burns, in chronic obstructive pulmonary disease (COPD) and in patients with lung metastases from thyroid cancer treated with radioiodine 131I. In the normal volunteers, the time taken for 50% of inhaled 99mTcDTPA to be cleared form the lungs (T1/2) was 66 minutes +/- 1sd of 12 mins. The smokers had a mean T1/2 of 20 mins +/- 1sd 4 min. In the hard-core glue-sniffing group, the majority were smokers who had stopped smoking and glue-sniffing for periods varying from 1 day to 42 days, and it was possible to note the changes in clearance times against period of abstinence. In the patients with inhalations burns, there was change in lung clearance arising from pulmonary epithelial damage; these patients showed increased rate of clearance (short T1/2) with mean T1/2 of 36 min +/- 1sd of 11 mins, while the retention images revealed regional lung damage in moderately severe inhalation burns. Twenty-four patients with COPD had inhalation scans done with Tc-99m tin colloid radioaerosol, and these images were compared with the perfusion lung scans done with 99mTc macroaggregated albumin (MAA); in general the perfusion images matched the defects noted in the inhalation scans. The 99mTc DTPA clearance rate in these patients was normal i.e. T 1/2 = 78 +/- 14 mins. In the thyroid cancer patients with lung metastases, who had high doses of radioiodine treatment, the T 1/2 values were normal or prolonged slightly, mean T1/2 = 76 min +/- 23.

Effect of lithium and oral thyrotrophin-releasing hormone (TRH) on serum thyrotrophin (TSH) and radioiodine uptake in patients with well differentiated thyroid carcinoma.

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.

Radionuclide imaging in primary hyperparathyroidism using 99mTc sestamibi--four case reports.

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.

Intermediate probability lung scans (IPLS): retrospective review of 82 cases.

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.

Radioiodine (I-131) uptakes and hormonal (T4) levels in hyperthyroid patients receiving radioiodine therapy while on anti-thyroid drugs and relation to incidence of hypothyroidism at one year.

Radioactive iodine (I-131) uptakes (RAIU) and serum T4 levels were observed in 72 patients referred for radioiodine therapy. Of 65 patients whose results could be evaluated 47 had these tests while on carbiomazole (CMZ). 17 of these 47 patients had repeat tests a week later and the differences were not significant. In the remaining 18 patients of the 65, the tests were performed after stopping the CMZ for 1-5 days and again at 8-12 days. The differences in the results were again not significant. The incidence of hypothyroidism at 1 year was noted in the group receiving radioiodine therapy while on CMZ as compared to those stopping the CMZ for 1-12 days. The difference was again not significant, though the number of these patients becoming hypothyroid was small. Serum T4 levels were measured in 21 patients, two weeks after treatment with radioiodine and there was no real difference from the baseline T4 levels.

Radionuclide studies in surgical oncology.

Over the last forty years radionuclides have come to play a useful role in diagnosis and treatment of tumours. Radionuclide scintigraphy provides information on morphology and function of tumours; functional studies have become more relevant with advances in instrumentation such as digitised gamma-cameras, single-photon emission tomography (SPECT), position-emission tomography (PET), and with advances in radiopharmaceuticals. A significant contribution in recent years has been the use of radiolabelled antibodies in immunoscintigraphy and immunotherapy; an increasing role is envisaged also for the use of tests for tumour markers in vitro.

Prospects for tumour imaging with radiolabelled antibodies.

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.

Radionuclide lung scanning in the management of respiratory burns.

Soluble radioaerosols such as technetium-99m diethylene triamine pentacetate (DTPA) permit simple quantitative studies of alveolar-capillary permeability to be performed, since the submicronic aerosols are deposited mainly at the lung periphery and are cleared across the alveolar-capillary membrane. Regional alterations in permeability can also be noted using this radionuclide technique. We have measured the alteration in pulmonary epithelial permeability in normal subjects and in patients with inhalation burns using a computer-linked gamma-camera. In the normal volunteers, the time taken for 50% of inhaled Tc-99m DTPA to be cleared from the lungs (T1/2) was 66 minutes +/- 1sd of 12 minutes. In the 42 patients with inhalation burns, besides the T1/2, retention images of uncleared Tc-99m DTPA in the lungs were obtained to note regional differences, if any, in lung clearance arising from pulmonary epithelial damage; these patients showed increased rate of clearance (short T1/2) with mean T1/2 of 36 minutes +/- 1sd of 11 minutes, while the retention images revealed regional lung damage in moderately severe inhalation burns. In 18 patients with abnormal T1/2, 16 (89%) had abnormal bronchoscopy findings. Fifteen patients also had lung perfusion scans with Tc-99m MAA (macroaggregated albumin). The regional defects in perfusion when present were generally matched with the defects seen on ventilation scans. The Tc-99m DTPA lung clearance measurement and imaging has clinical usefulness in suspected inhalation burns.

Tissue polypeptide antigen (TPA) and beta 2-microglobulin (beta 2-MG) as tumour markers in nasopharyngeal cancer.

The levels of tissue polypeptide antigen (TPA) and beta 2 microglobulin (beta 2-MG) were measured in the serum of 38 patients with nasopharyngeal carcinoma (NPC). Using sera from 35 normal volunteers and blood donors, a normal range for these two tumour markers was established. The normal range for TPA was 40-148 IU/L (mean = 93), while that for beta 2-microglobulin was 0.9-2.0 mg/L (mean = 1.3). In the patients with NPC but without known metastases the range was 63-178 IU/L for TPA (mean = 111) and for beta 2-MG, the range was 1.0-3.1 mg/L (mean = 1.7). For those NPC patients with metastases to bone or liver, the mean TPA was 464 IU/L and the mean beta 2-MG was 4.3 mg/L. It appears that TPA and beta 2-MG are useful markers for the monitoring of NPC patients for metastatic disease, particularly TPA.

Case report of a parathyroid adenoma demonstrated by dual tracer (T1-201 and Tc-99m) subtraction scan.

It is generally agreed that the Technetium-Thallium Subtraction Scan is a reliable method for locating abnormal parathyroid glands in patients with clinical and biochemical evidence of parathyroid hyperactivity. This report illustrates the value of scintigraphy in diagnosis and in the subsequent surgical management of a patient with primary hyperparathyroidism.