Localization of parathyroid enlargement: experience with technetium-99m methoxyisobutylisonitrile and thallium-201 scintigraphy,ultrasonography and computed tomography

Technetium-99m methoxyisobutylisonitrile (MIBI), like thallium-201, has recently been introduced as a myocardial perfusion agent and is now also showing very promising results in parathyroid scintigrapy. The results of ²⁰¹Tl/^99mTc-pertechnetate and ^99mTc-MIBI/^99mTc-pertechnetate subtraction scintigraphy, ultrasonography and computed tomography are presented in a series of 43 patients operated on for hyperparathyroidism. All four imaging modalities were confirmed to be reliable, scintigraphy being the most accurate. Sensitivities ranged from 81% to 95%, that of ^99mTc-MIBI being the highest. Moreover this tracer, which has more favourable physical and also biochemical properties, yielded images of superior quality. This allowed localization of the lesion by visual inspection only in as many as 86% of the patients with positive ^99mTc-MIBI/^99mTc-pertechnetate subtraction scintigraphy. We believe that the higher sensitivity, superior image quality and lower cost of ^99mTc-MIBI imaging will make ^99mTc-MIBI the new radiopharmaceutical of choice for parathyroid scintigraphy (when one takes into account the stability of labelling with large activities it is possible to perform three or four cardiac studies together with one parathyroid scintigraphic examination using one lyophililzed vial).     

A comparison of scintigraphy, thermography, ultrasound and phlebography in grading of clinical varicocele

Varicocele, a varicosity of the pampiniform plexus, usually on the left side, is a common urologic problem. It may be associated with symptoms of local discomfort or abnormal spermatogenesis. Internal spermatic vein phlebography is the "gold standard" investigative technique, but it is invasive. Noninvasive studies include: labeled blood-pool scintigraphy, thermography and ultrasound. Two hundred sixty-three patients were investigated with various combinations of these modalities. The degree of abnormality for each modality was graded semiquantitatively and the results compared. In addition, the results of semen analysis were correlated to imaging results. Ninety-six patients were investigated with all four tests (scintigraphy, thermography, ultrasound and phlebography). The correlation of positive phlebography to positive scintigraphy was 98%, to thermography 100% and to ultrasound 98%. The concordance (grade for grade) was 71% for scintigraphy, 68% for thermography and 62% for ultrasound. There was no obvious correlation between abnormalities of semen analysis and grading of varicocele. We conclude that the diagnostic accuracy and grading of severity by noninvasive techniques (including scintigraphy) compare very favorably with that of phlebography. Moreover, scintigraphy allows the noninvasive evaluation of reflux through the internal spermatic vein, which may be useful in planning therapy.     

Artifacts, anatomical and physiological variants, and unrelated diseases that might cause false-positive whole-body 131-I scans in patients with thyroid cancer

The whole body 131-I scan remains an important component in the postoperative treatment of patients with well-differentiated thyroid cancer. Because normal thyroid tissue remnants and residual or metastatic foci of well-differentiated thyroid cancer have the unique ability to concentrate, organify, and store 131-I, the whole body scan provides a depiction of those tissues that can be ablated with therapeutic doses of 131-I. Over time, it has become obvious that the whole body scan may also reveal foci of 131-i uptake owing to a wide variety of other causes. We provide a detailed pathophysiological classification of the artifacts, anatomic and physiological variants, and nonthyroidal diseases that may give rise to false-positive whole body scans in postoperative patients with thyroid cancer. These include ectopic foci of normal thyroid tissue; nonthyroidal physiological sites (eg, choroid plexus, salivary glands, gastric mucosa, urinary tract); contamination by physiological sections; ectopic gastric mucosa; other gastrointestinal abnormalities; urinary tract abnormalities; mammary abnormalities; serous cavities and cysts; inflammation and infection; nonthyroidal neoplasms; and currently unexplained causes. This article also provides a detailed review of the widely scattered English language literature in which these phenomena were originally described.     

Antigranulocyte monoclonal antibody immunoscintigraphy in inflammatory bowel disease in children and young adolescents

Aim: Diagnostic delay for inflammatory bowel disease (IBD) is frequent, especially in paediatric patients. Scintigraphy with labelled leucocytes has been proposed as a very sensitive diagnostic tool for detecting bowel inflammation. The aim of this study was to evaluate the sensitivity and specificity of immunoscintigraphy in the diagnosis and follow-up of children with IBD and to compare this technique with other diagnostic techniques.

Methods: Sixty-six children with histologically confirmed IBD were enrolled in the study. Twenty-one children in whom IBD was suspected but subsequently not confirmed were used as controls. A total of 138 immunoscintigraphies were performed using 99m Technetium-labelled monoclonal anti-granulocyte antibodies. Immunoscintigraphy was also compared with other diagnostic techniques.

Results: Overall sensitivity of monoclonal antibody immunoscintigraphy (MoAb-IS) in patients with clinically active disease was 94% for Crohn's disease (CD) and 85% for ulcerative Ultrasonography, endoscopy and radiology were carried out at the same time in 29 patients with CD and in 6 patients with UC: sensitivity of IS was 90% compared with 76% of colonoscopy, 75% for enemas, and 55% for sonography. IS was negative (specificity) in 24% of patients with CD and in 67% of patients with UC during remission, and in 64% of controls with other causes of intestinal inflammation. Diagnostic delay was significantly shorter when compared with a historical cohort of patients.

Conclusion: Immunoscintigraphy is a highly sensitive detector of intestinal inflammation in young patients with IBD and can be useful for reducing diagnostic delay. However, its specificity is low and all positive cases must be confirmed histologically. colitis (UC).     

Adrenal cortical adenoma causing Cushing's syndrome: correct localization by functional scintigraphy despite nonlocalizing morphological imaging studies

A 60-year-old woman with Cushing's syndrome in whom high-dose dexamethasone failed to suppress glucocorticoids was studied by ultrasound and CT. Neither of these morphological studies was interpreted as revealing any adrenal abnormality. Functional imaging with NP-59 (131-I-beta-iodomethylnorcholesterol) revealed unequivocal, intense, unilateral uptake in the left adrenal gland and subsequent surgery removed a 2.5 cm adrenocortical adenoma from this site. Following surgery the patient was temporarily adrenocortically insufficient but later returned to normal. It is unusual for adrenocortical adenomas causing Cushing's syndrome not to be correctly located by CT. NP-59 scintigraphy in addition to being highly accurate in the location of adrenocortical adenomas also has the advantage of correctly depicting bilateral cortical nodular hyperplasia in which CT will frequently reveal only the largest nodule, which may be incorrectly designated a unilateral adenoma. Furthermore, scintigraphy provides evidence of suppression of the contralateral, normal adrenal cortical tissue in Cushing's syndrome caused by an adrenal adenoma and predicts the vulnerability of such patients to postoperative adrenocortical insufficiency.     

Radioembolisation in patients with hepatocellular carcinoma that have previously received liver-directed therapies

Purpose

Radioembolisation is part of the multimodal treatment of hepatocellular carcinoma (HCC) at specialist liver centres. This study analysed the impact of prior treatment on tolerability and survival following radioembolisation.

Methods

This was a retrospective analysis of 325 consecutive patients with a confirmed diagnosis of HCC, who received radioembolisation with yttrium-90 resin microspheres at eight European centres between September 2003 and December 2009. The decision to treat was based on the clinical judgement of multidisciplinary teams. Patients were followed from the date of radioembolisation to last contact or death and the nature and severity of all adverse events (AEs) recorded from medical records.

Results

Most radioembolisation candidates were Child-Pugh class A (82.5%) with multinodular HCC (75.9%) invading both lobes (53.1%); 56.3% were advanced stage. Radioembolisation was used first-line in 57.5% of patients and second-line in 34.2%. Common prior procedures were transarterial (chemo)embolisation therapies (27.1%), surgical resection/transplantation (17.2%) and ablation (8.6%). There was no difference in AE incidence and severity between prior treatment subgroups. Median (95% confidence interval [CI]) survival following radioembolisation was similar between procedure-naive and prior treatment groups for Barcelona Clinic Liver Cancer (BCLC) stage A: 22.1 months (15.1–45.9) versus 30.9 months (19.6–46.8); p?= 0.243); stage B: 18.4 months (11.2–19.4) versus 22.8 months (10.9–34.2); p?= 0.815; and stage C: 8.8 months (7.1–10.8) versus 10.8 months (7.7–12.6); p?= 0.976.

Conclusions

Radioembolisation is a valuable treatment option for patients who relapse following surgical, ablative or vascular procedures and remain suitable candidates for this treatment.

     

Parathyroid scintigraphy.

Parathyroid scintigraphy, first proposed in the seventies, has developed an irreplaceable role in the preoperative location of enlarged parathyroid tissues. The contribution of Ferlin, who in the early eighties proposed the use of the potassium analogue 201Thallium and subtraction scintigraphy to obviate thyroid tissue interference was especially important. At the present time, this imaging modality, is widely accepted for the preoperative localization of parathyroid adenomas owing to its high accuracy and reproducibility. Various modified acquisition and processing protocols have been reported and 201Thallium still continues to be used, but other radiopharmaceuticals, such as 99mTc-methoxyisobutyl isonitrile (99mTc-MIBI) and 99mTc-tetrofosmin are now often preferred, especially because of the more favourable physical properties of the Technetium labelling. In some cases, thyroid subtraction scintigraphy can be replaced by dual phase 99mTc-methoxyisobutyl isonitrile acquisition. There is also an increasing interest in SPECT studies, which have the potential to more accurately locate the sites of adenomas and allow for detection of smaller lesions, which further increases total sensitivity and accuracy of the technique.     

Sequential salivary scintigraphy in Sj?gren's syndrome: proposal for a new method of evaluation

Thirty-seven non-elderly primary Sj?gren's syndrome (I SS) patients, and 27 controls complaining of xerostomia and/or recurrent or persistent swelling of at least one parotid or submandibular gland due to other selected disorders, were studied. A new scintigraphic score (scsc) is proposed for a standardised semiquantitative evaluation of salivary involvement by qualitative sequential salivary scintigraphy (SSS), and is compared with two other well-known methods generally used for this purpose. The scsc proved to be much more suitable for such an evaluation: the other criteria did not allow us either to classify or to score a great number of cases. Furthermore, the scsc allowed us to obtain better SSS sensitivity (89.2%) and specificity (96.3%) values for I.SS (33 of the 37 I SS patients and 26 of the 27 controls were correctly classified by discriminant analysis, for scsc values greater than 8). This was made possible by the different "weights" which we assigned to the various glandular and oral parameters in the scsc determination.