[Indium-111-DTPA-phenyl-pentetreotide somatostatin receptors' scintigraphy in the evaluation of patients with suspected gastro-entero-pancreatic tumors. Comparison with computerized tomography].

Gastro-entero-pancreatic tumors (GEP) contain, in their majority, somatostatin receptors. In-111-DTPA-phenyl-pentetreotide has been proved to have high affinity for somatostatin receptors subtypes 2, 3 and 5. The aim of the present study was to evaluate the utility of (111)In-DTPA-O somatostatin receptors' scintigraphy (SRS) in the diagnosis of suspected GEP. Thirty-five consecutive patients (17 males and 18 females-mean age 57.9+/-7.6) with GEP as a possible diagnosis were enrolled in the study. The primary diagnosis was diarrheic syndrome susceptive of intestinal carcinoid tumor (24 patients), carcinoid of the rectum (2 patients), adenocarcinoma of the pancreas (2 patients), insulinoma (2 patients), gastrinoma (3 patients) and hepatocellular carcinoma (2 patients). All patients were submitted to computerized tomography (CT) of the thorax and the abdomen and pentetreotide SRS was performed 4 h (total body and SPET acquisition) and 24 h (planar views), post iv injection of 185 MBq of the radiolabeled compound. Results showed: Four of the patients were false positive diagnosed as having inflammatory intestinal disease and gallbladder dilatation. At the time of the evaluation, 14 of the remaining patients were free of disease, concerning secondary involvement. In these cases, CT and SRS studies matched each other, with no pathological lesions and no abnormal accumulation of the radiopharmaceutical respectively. Concerning pathological cases, only one SRS study in a patient with rectum carcinoid was normal, with liver lesions in the CT study. These lesions were considered as subtypes 2, 3 and 5 somatostatin receptors negative. SRS revealed three lesions more than CT. According to these results, sensitivity of SRS study was 93.8% and specificity 86.9%. The authors believe that molecular imaging of somatostatin receptors, is a sensitive method for the evaluation of patients with GEP tumors. However, in cases of intestinal disease, we should be aware of false positive results due to inflammatory processes and the presence of lymphocyte infiltration.

[The clinical and laboratory findings in Graves' multinodular type disease].

Graves' disease (GD) is an autoimmune thyroid disease characterized among other findings by diffuse goiter. It is possible in GD to find a multinodular goiter (mGD). Are they two different diseases that coexist, or do we have a multinodular type of GD. Questions arise as for the time that this mGD appears in the process of GD and also, as for the clinical and laboratory characteristics of mGD. To answer these questions, we have studied retrospectively and randomly from the archives of the Department of Nuclear Medicine of AHEPA University Hospital, from 2000-2004, 20 female patients with multinodular type of GD (Group A) as first diagnosed by us and 50 female patients with diffuse type of GD (Group B) of about the same age. Patients with mGD had been examined before by us and their GD was documented. No other cause for exophthalmus except GD was found. Patients with any other additional disease were excluded from the study. All patients had 7-10 signs of hyperthyroidism (thyroid index). Many of the patients, after the present study, were given (131)I therapeutically. These groups were divided in subgroups of pre- and menopausal women (A1, B1 and A2, B2 respectively). The mean age of our patients in Groups A and B were 46 and 50 years with a range of 25-65 and 38-69 years respectively. Serum free triodothyronine (FT3), free thyroxine (FT4), thyroid stimulating hormone (TSH), thyroid peroxidase antibodies (AbTPO), antithyroglobulin antibodies (AbTG) and anti receptors of thyroid stimulating hormone antibodies (AbTSHR) were tested in all subjects studied by radioimmunoassays (RIA) or radioimmunometric assays (IRMA). All patients were under antithyroid treatment interrupted for about 10 days before the thyroid scan. Thyroid scintiscan was performed 24 h after oral intake of 1.8 MBq of (131)I. Clinical findings were evaluated by a clinical index of hyperthyroidism as modified by us. The time that the mGD appeared since the beginning of GD and the time the GD started were also studied. Our findings were as follows: A mean time of 10.35+/-6.7 years had elapsed from the start of GD till mGD was first diagnosed by us. A mean time of 3.1+/-1.6 years had elapsed after the start of the GD till patients of Group B were examined in this study. No difference in the values of FT3, FT4 and TSH between the two Groups or the Subgroups was found as expected because the clinical status of the patients varied. AbTG, AbTPO and AbTSHR were found in a much higher incidence and in higher values in Group A versus Group B (P=0.007 and 0.001 respectively) and in Subgroups A1, A2 versus B1 and B2 respectively. This increase was significant for AbTG and AbTPO in A2 versus B2 Subgroups and for AbTPO in A1 versus B1 Subgroups (P=0.007, 0.001 and 0.014 respectively). We were unable to find a similar work in the literature. In conclusion, we suggest that mGD as compared to GD: a)develops late in GD and thus patients had more relapses, b) has a higher incidence of abnormal values of AbTPO, AbTG and AbTSHR, c) has significantly higher values of AbTPO and less of AbTG than GD and d) thyroid hormones, clinical index of hyperthyroidism and the incidence of exophthalmos do not differ. Based on the above, we suggest that mGD is a late evolutionary type of GD. The study of patients of both sexes having GD of the same duration as mGD, the study of iodine metabolism and of thyroid gland pathology in these patients, is needed.

[Findings from molecular imaging with SPET camera and 123I-ioflupane in the differential diagnosis of Parkinsonism and essential tremor].

The aim of the present study was to evaluate the use of the radiopharmaceutical 123I-ioflupane in the diagnosis and differential diagnosis of Parkinsonism (P) and essential tremor (ET). Forty-three consecutive patients, aged 35-72 years, presenting symptoms and signs compatible with P, plus 11 normal volunteers, aged 40-60 years, were enrolled for the study. The radiopharmaceutical was injected iv in a dose of 185 MBq and tomographic acquisition in a single-headed Pegasys gamma-camera (ADAC, USA), 3-4 hours post injection was performed in order to evaluate the activity of the presynaptic nigro-striatal dopaminergic transporter. After reconstruction and reorientation, semiquantitative analysis was performed evaluating counts/pixel: a) in the striatum and its parts (caudate nucleus and putamen) of both hemispheres and b) in the visual cortex representing non specific binding. According to our results, all 21 individuals with ET were correctly evaluated with this method, whilst 21/22 patients were diagnosed as having P. No statistical difference concerning the binding of the radioligand to the striatum and its parts was found between normal volunteers and patients with ET. Based on the present results in 21 of our patients, the diagnosis and treatment procedure were changed, while in the remaining 22 patients diagnosis and treatment were confirmed. According to our data, as well as to the data from others, molecular imaging (SPET) with 123I-ioflupane can properly differentiate individuals with ET from those having P, in order to avoid an unnecessary use of drugs that may even cause side effects. All our patients were re-examined after eight months. At that time the above results and the treatment that was given to them meanwhile, were positively evaluated.

Oprimizing the protocol for the calculation of the doses of (131)I administered for the treatment of benign thyroid disease.

The administration of (131)I for the treatment of benign thyroid disease is widely used in clinical practice. The appropriate dose of (131)I, so as the gland could receive the specified absorbed dose, is determined by various methods. The mostly used is the one based on the 24 h uptake. In the present study we examined the time to measure (131)I uptake which better represents the total accumulated activity in the thyroid gland and consequently is more reliable for dose calculation. Fourteen patients, who were referred to the Nuclear Medicine Department of AHEPA University Hospital, were included in the study. 1.85 MBq of (131)I were administered and the uptake at 24, 48, 72 and 192 h was measured. From the curve of the activity vs time we calculated the area under it, which represents the total accumulated thyroid activity. We compared the uptakes of every individual with the total area and we found that the 192 h uptake was best correlated with it (r=0.996). The absorbed dose to the thyroid was calculated in the following ways: a) was based on the 24 h uptake and b) was based on the total accumulated activity on the 192 h uptake. We found differences from -19.9% to +33.7%. In conclusion, the 192 h uptake consists the most representative and reliable parameter for the estimated activity of (131)I given to the thyroid for the treatment of hyperthyroidism.