Iranian Journal of Nuclear Medicine
Volume:23 Issue: 1, Winter-Spring 2015

High-dose radioactive iodine therapy in differentiated thyroid cancer (DTC) may adversely affect the salivary gland function. This study is aimed to evaluate the effect of radioactive iodine (RAI) with dose of 100 mCi in DTC patients compared to lower doses of less than 30 mCi in hyperthyroid cases. Fifty four patients (13 men and 41 women) age: 42.3±14.3 (21-71) years were enrolled in the study. Twenty seven hyperthyroid cases received less than 30 mCi of I-131 for the treatment, and 27 DTC patients were treated with 100 mCi of I-131. All patients underwent Tc-99m pertechnetate scintigraphy before and three months after radioiodine therapy. Salivary gland excretion fractions (EF) were compared between groups. A decrease of more than 5% in EF was considered significant. The total frequency of salivary dysfunction was 41.7%. In patients received a dosage of 100 mCi of I-131, this frequency was 49.1%, while with less than 30 mCi, it was 34.3% (p<0.01). The right parotid gland was affected more than the left following 100 mCi treatment. Risk ratio of salivary gland involvement in high-dose versus low-dose group was significant (risk ratio=1.04-1.98, CI (95%); p=0.019). However, there was no significant difference in symptom presentation, i.e. xerostomia between two groups. RAI therapy may cause salivary gland dysfunction and this effect is more frequent in DTC patients with higher dose of 100 mCi compared to hyperthyroid cases with lower doses of less than 30 mCi.

In the current study, we compared h5-index provided by Google Scholar (GS), impact factor (IF) provided by web of sciences (WOS), and SCImago journal rank indicator (SJR) provided by SCOPUS for quality assessment of nuclear medicine journals. 2013 h5-index, 2012 IF, and 2011 SJR of nuclear medicine journals were extracted from their publishers namely GS, WOS, and SCOPUS. Rank of each journal according to each index was provided. Spearman correlation was used for evaluation of the correlation between metrics. Overall 22 journals were identified. Spearman correlation coefficients between h5-index and other journal metrics were 0.907 for 2012 IF, 0.979 for 2011 JCR, and 0.978 for 2011 SCOPUS h-index (all p-values<0.00001). Wilcoxon signed ranks test showed no statistically meaningful difference between rankings according to h5-index and other journal metrics (p values of 0.589, 0.565, and 0.542 for 2012 IF, 2011 SJR, and 2011 SCOPUS h-index respectively). The new GS journal metrics are reliable tools for quality assessment of the nuclear medicine journals. In our opinion, h5-index, IF, and SJR should be used in a combination as their combination would give a more holistic view of journal quality. Development of new journal metrics in addition to SJR and IF by GS should be welcomed by the scientific community.

99mTc-TRODAT-1 is a promising new radiopharmaceutical with the potential for routine use as the radiopharmaceutical for dopamine transporters scintigraphy as far as its image quality and daily availability are concerned. Here we describe the development of a freeze-dried kit formulation based on the tricine exchange labeling approach for the preparation of this radiopharmaceutical in a clinical setting. A freeze-dried formulation contained of TRODAT-1, tricine, SnCl2 and manitol was prepared. Labeling was performed by addition of 1480 MBq 99mTc sodium pertechnetate in a total volume of 2 mL and incubation for 15 min in a boiling water bath. Radiochemical analysis involved ITLC and HPLC methods. The stability of radioconjugate was checked in the presence of human serum at 37 °C up to 24 h. 99mTc-TRODAT-1 was prepared with a radiochemical purity of >95% and a high stability up to 24 h of the final preparation, and retained biological activity. The developed kit formulation forms the basis for further clinical evaluation of this promising new radiopharmaceutical.

Differentiated thyroid cancer (DTC) is the most common endocrine malignancy. This malignancy generally has an excellent prognosis with more than 90% long term survival. Consequently, life quality improvement is the first priority especially in the young DTC survivors. In classic management of a new DTC patient, each therapeutic modality can significantly induce morbidities. In the current study, we investigated the main complaints in DTC patients during the follow up. Clinical symptoms of 300 randomly selected DTC patients were collected during their follow up visiting sessions. Related symptoms were any clinical complaint directly due to DTC or its management. The correlation between the most common complaint and age, gender, TNM staging, RAI therapy, external beam radiotherapy and neck surgery was assessed. Three hundred randomly selected DTC patients (66 male and 234 female) were included. The mean duration of follow up was 5.18±3.48. External radiotherapy of the neck, frequency of radioiodine therapy and repetitive neck operations were associated with more clinical symptoms during long term follow up. The most frequent DTC related complaint was neck discomfort which was reported in 40% of patients. The main background source of patients'' complaints was hypothyroidism followed by subclinical hyperthyroidism (p<0.01). The most common reasons of long term morbidity in DTC patients were related to hypothyroid or subclinical hyperthyroidism. Neck discomfort was the most frequent single complaint with more frequency in patients with repetitive neck operation. The current study could be the first step to discover the unfavorable clinical symptoms of DTC patients.

Asymptomatic diabetic patients are at increased risk of cardiovascular complications. Myocardial perfusion scan may be effective in risk evaluation in this population. 106 asymptomatic diabetic patients (age: min: 37, max: 82, mean: 57.73±8.88), including 56 females (52.8%) and 50 males (47.2%) were enrolled in the study. Myocardial perfusion scintigraphy was performed by Gated Single Photon Emission Computed Tomography (Gated-SPECT) method. Perfusion and function status was evaluated by qualitative and semi-quantitative parameters. By visual analysis totally 40 out of 106 patients (37.7%) showed abnormal scan. From which, 26(24.5%) showed involvement in one, 13(12.3%) in two, and 1(0.9%) in all three vessel territories. By semi-quantitative method, from 103 patients, 28 (27.2%) were abnormal and 75 (72.8%) were normal. From all the asymptomatic diabetic patients, 11 patients (10.4%) had dilated left ventricles. Transient Ischemic Dilation (TID) was noted in 10 patients (9.4%), and Transient Right ventricle visualization in 7 patients (6.6%). Heart failure (EF<45%) was observed in 14% of asymptomatic diabetic patients. From underlying factors, long duration of diabetes disease correlated to abnormal myocardial perfusion imaging (MPI) findings (Odds Ratio: 2.77; CI: 1.07-7.12). Severe coronary artery disease leading to the pattern of severe ischemia or infarction in MPI, was significantly higher in men than women (P=0.05). Also smoking correlated with higher involvement of LAD coronary artery (P=0.011) and as compared with RCA territory (P=0.079). In asymptomatic diabetic patients myocardial perfusion scintigraphy can be used in early diagnosis of coronary artery disease (CAD) and can be suggested as screening study in these patients.

In continuation of recent development of possible C-X-C chemokine receptor type 4 (CXCR4) imaging agents, we report the development of a possible CXCR4 targeted therapy agent. [153Sm]labeled 1,1′-[1,4-phenylenebis(methylene)] bis-1,4,8,11-tetraazacyclo -tetradecane ([153Sm]-AMD3100) was prepared using [153Sm]SmCl3 and AMD-3100 for 24h at 50°C in acetate buffer.Stability tests, partition coefficient determination, toxicity tests and biodistribution studies of the complex in wild-type rats were determined. The radiolabeled complex was prepared in high radiochemical purity (>95%; RTLC and >99% HPLC) and specific activity of 278 GBq/mmol and demonstrated significant stability up to 48h at 37 °C (in presence of human serum). Partition coefficient determination was calculated Log P= -1.09.Hepatotoxicity experiments demonstrated no distinguishable effect on hepatic enzymes in 10 days post injection.Initial complex biodistribution data showed significant liver and kidney accumulation in wild-type rats. Since lung and spleen are considered as CXCR4 rich organs, the best lung/blood and spleen/blood ratios were achieved 12 and 7 at 24 h post injection. Further investigations are needed especially on therapeutic properties of this agent.

Bone metastases are the most common cause of cancer-related pain in various primary malignant tumors, most often, breast and prostate. 188Re-hydroxyethylidene diphosphonate (188Re-HEDP) is a new and less expensive bone seeking radiopharmaceutical with favorable physical characteristics of the radionuclide such as short half life of 16.9h, maximal β energy of 2.1 MeV with a 15% γ-component of 155 keV and easily available from an in-house 188W/188Re generator. The aim of this study is to evaluate the therapeutic efficacy and safety profile of bone palliative therapy following administration of 188Re-HEDP. Twenty patients with painful metastatic bone lesions secondary to breast, prostate, multiple myeloma, ampulla of vater and lung cancers received 1 mCi/kg of 188Re-HEDP. Four hours after treatment, post-therapy scintigraphy was performed. All patients were interviewed using a standard set of questions (visual analogue scale: VAS) concerning their pain relief before, and after therapy at weekly intervals for the first month and every 2 weeks for the following 4 months. The general condition of the patients was also evaluated by Karnofsky-index and ECOG (Eastern Cooperative Oncology Group) performance status. Hematologic profiles were recorded before treatment and every two weeks up to 8 weeks after treatment. Overall pain relief was found in 68.8% of patients. Decreased from 8.37±2.12 to 5.68±2.98 at VAS was observed 4 weeks after treatment. The osteoblastic lesions (breast and prostate) showed rather similar response to the treatment. Mean platelet counts decreased in 6th week and returned to baseline level in 8th week. One patient showed grade III leukopenia without any serious complication. 188Re-HEDP is an effective radiopharmaceutical for metastatic bone pain palliation therapy. Side effects include mild and transient thrombocytopenia and leucopenia and no life threatening side effect is observed.

Different software tools for quantification of myocardial perfusion SPECT (MPS) studies are routinely used. Several perfusion parameters can be computed automatically. Interpretation of the MPS should start with visual inspection of the rotating planar images, visual analysis of reconstructed SPECT slices and then quantitative analysis to confirm the visual impression. Quantification should be used routinely as complementary to visual analysis. Advantages of quantification are: greater confidence in interpretation, better reproducibility, diagnostic accuracy and measuring the degree of abnormality even subtle changes for serial comparisons. In this review, we look at the common features of such quantitative tools: 17-segment scoring system, polar maps including: raw, severity and extent polar maps, lung-to-heart ratio, transient ischemic dilation ratio, total perfusion deficit and spherecity index.

Necrotizing fasciitis is a part of a spectrum of necrotizing soft tissue infections that usually follow a surgical intervention or a chronic / acute medical illness. Diagnosis is often based on symptoms which classically start within hours after an injury. There are no reports on the use of PET/CT in this condition. Sparing reports of its association in patients with malignancy (Ca of colon and rectum) are available. Here we present a young lady in remission from acute myeloid leukemia (AML) with sudden onset right knee pain and fever after a trivial foot injury. Clinically an osteomyelitis or acute septic arthritis was suspected, although the location is not appropriate for osteomyelitis. 99mTc-MDP bone scan was performed followed by 18F-FDG PET. 18F-FDG PET scan was incremental in diagnosing subcutaneous infection around right knee even before appearance of an ulcer or skin erosion. Tissue culture confirmed necrotizing fasciitis. This is the first case report highlighting necrotizing fasciitis in a patient with AML.

Multifocal avascular osteonecrosis is an uncommon entity having a predominant association with steroids and less commonly with alcohol abuse. In literature only few cases of alcohol induced multifocal avascular osteonecrosis involving both hips and shoulder are reported. To the best of our understanding this is the first case report or contribution from nuclear medicine court and it would help the nuclear physicians to mull about this entity in alcoholics presented with assumed “polyarthritis”.