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Nuclear Medicine Communications - Current Issue

Nuclear Medicine Communications - Current Issue
  1. Interim 18F-FDG PET/CT and BCL2 for predicting the prognosis of patients with diffuse large B-cell lymphoma in the rituximab era
    imageObjective In this study, we investigated the prognostic role of interim fluorine-18-fluorodeoxyglucose PET/computed tomography (I-PET/CT) and BCL2 in diffuse large B-cell lymphoma (DLBCL) patients treated with rituximab-containing chemotherapy. Materials and methods A total of 106 patients with newly diagnosed DLBCL underwent PET/CT scans at baseline and a subsequent I-PET/CT after the fourth cycle of chemotherapy. I-PET/CT was analyzed using the Deauville five-point score. The prognostic significance of I-PET/CT and BCL2 was evaluated by predicting progression-free survival (PFS) and overall survival (OS). Results With a median follow-up of 25 months, the 2-year PFS and OS were 78 and 95% in the I-PET/CT-negative group and 33 and 57% in the I-PET/CT-positive group (P<0.001). Patients with BCL2 positivity showed a shorter PFS than the BCL2-negative patients (P=0.002), but not in OS (P=0.068). In multivariate analysis, I-PET/CT and BCL2 were independent variables in assessing the outcome of PFS. I-PET/CT was also an independent factor for OS. Irrespective of the results of BCL2, patients with I-PET/CT positivity had a significant inferior outcome than the I-PET/CT-negative patients. In the I-PET/CT-negative group, patients with BCL2 positivity had a significantly shorter PFS than the BCL2-negative patients (P=0.005). Conclusion I-PET/CT and BCL2 were two significant independent indicators of outcome for patients with DLBCL in the rituximab era. I-PET/CT was much better than BCL2 for patient stratification. BCL2 showed its supplementary role for further patient stratification when I-PET/CT was negative.



  2. Which is the optimal threshold for defining functional lung in single-photon emission computed tomography lung perfusion imaging of lung cancer patients?
    imagePurpose The aim of this study was to investigate the optimal threshold for the functional lung (FL) definition of single-photon emission computed tomography (SPECT) lung perfusion imaging. Patients and methods Forty consecutive stage III non-small-cell lung cancer patients underwent SPECT lung perfusion scans and PET/CT scans for treatment planning, and the images were coregistered. Total lung and perfusion lung volumes corresponding to 10, 20, …, 60% of the maximum SPECT count were segmented automatically. The SPECT-weighted mean lung dose (SWMDx%) and the percentage of FL volume receiving more than 20 Gy (Fx%V20) of different thresholds were investigated using SPECT-weighted dose–volume histograms. Receiver–operator characteristic curves were used to identify SWMD and FV20 of different thresholds in predicting the incidence of radiation pneumonitis (RP). Results Eleven (27.5%) patients developed RP (grades 1, 2, 3, and 4 were 10.0, 7.5, 7.5, and 2.5%, respectively) after treatment. The largest area under the receiver–operator characteristic curve was 0.881 for the ability of SWMD to predict RP with 20% as the threshold and 0.928 for the ability of FV20 with 20% as the threshold. Conclusion The SWMD20% and FV20 of FL using 20% of the maximum SPECT count as the threshold may be better predictors for the risk of RP.



  3. 68Ga-PSMA-HBED-CC PET/CT imaging in Black versus White South African patients with prostate carcinoma presenting with a low volume, androgen-dependent biochemical recurrence: a prospective study
    imageObjective To compare the diagnostic accuracy of 68Ga-prostate-specific membrane antigen (PSMA)-HBED-CC PET/computed tomography (CT) imaging for the detection of androgen-dependent recurrent prostate carcinoma (ADPC) in Black South Africans (BSAs) versus White South Africans (WSAs) with increasing serum prostate-specific antigen (PSA) values below or equal to 10 ng/ml. Patients and methods A total of 61 patients with ADPC were prospectively included in the study (mean age: 66.7 years): 38 WSAs and 23 BSAs. 68Ga-PSMA-HBED-CC PET/CT imaging results obtained were related to serum PSA levels and to ethnicity. Results A total of 41 (67%) patients had a positive 68Ga-PSMA-HBED-CC scan result. 68Ga-PSMA-HBED-CC PET/CT positivity was significantly higher in patients with PSA values more than 2 ng/ml [32/38 (84%) patients] when compared with patients with PSA values less than 0.5 ng/ml [6/11 (55%) patients] or PSA values of 0.5–2 ng/ml [3/12 (25%) patients] (P=0.0001). Mean PSA values proved not significantly different in patients presenting with extrapelvic involvement when compared with those with intrapelvic involvement or between patients who presented with bone involvement versus those who did not on 68Ga-PSMA-HBED-CC PET/CT) (P≥0.147). Age, Gleason-scores, median PSA values, the frequency of a positive scan result, the frequency of bone involvement, and extrapelvic involvement proved similar in WSAs and BSAs (P≥0.417). Conclusion 68Ga-PSMA-HBED-CC PET/CT imaging identified a recurrence in 67% of the patients under study. Higher PSA levels were associated with 68Ga-PSMA-HBED-CC PET/CT positivity and the detection rate. Imaging results obtained proved similar in BSAs and WSAs, suggesting that the tumor burden and growth rate of ADPC are similar in both races.



  4. Expression of ADAMTS2 and ADAMTS5 in the salivary gland of rats after radioiodine therapy
    imageObjective The aim of this study was to investigate the presence of ADAMTS2 and ADAMTS5 in the salivary gland (SG) of rats after high-dose radioiodine therapy. Methods A total of 36 male Wistar albino rats were used for this study. Thirty-six male rats were divided randomly into six groups: control and five radioactive iodine (RAI) treatment groups of six rats each. All animals were killed. The evaluation of biodistribution and histopathological studies were carried out on the SGs removed. Real-time PCR and immunohistochemical analysis were carried out to determine mRNA and protein expression levels of ADAMTS genes. Differences between the groups were evaluated statistically. Results In RAI-treated groups, ADAMTS2 and ADAMTS5 gene expression was observed to increase, whereas there was no mRNA or protein expression in the control group. There were statistically significant increases in the mRNA expression of ADAMTS2 (all RAI-administered groups in parathyroid gland and at 4, 24, and 48 h in submandibular gland) and ADAMTS5 (all RAI-administered groups, except on the 30th day in the parathyroid gland and all RAI groups in submandibular gland). Through immunohistochemical analysis, the staining pattern in the extracellular source was also observed in the overexpressed ADAMTS2 and ADAMTS5 groups. Nuclear coarsening and partial focal subnuclei vacuolization were determined in all RAI-administered groups with histopathological examinations. Conclusion An increase in the mRNA expression levels of ADAMTS2 and ADAMTS5 genes was detected in the RAI-administered groups. These results suggested that ADAMTS2 and ADAMTS5 genes might play a role in radiation exposure and radioiodine-induced SG changes.



  5. 18F-Fluorodeoxyglucose PET/CT and dynamic contrast-enhanced MRI as imaging biomarkers in malignant pleural mesothelioma
    imagePurpose The purpose of this study was to compare the use of fluorine-18-fluorodeoxyglucose (18F-FDG) PET with computed tomography (CT) and dynamic contrast-enhanced (DCE) MRI to predict prognosis and monitor treatment in malignant pleural mesothelioma. Patients and methods 18F-FDG PET/CT and DCE-MRI studies carried out as part of the South West Area Mesothelioma Pemetrexed trial were used. 18F-FDG PET/CT and DCE-MRI studies were carried out before treatment, and after two cycles of chemotherapy, on patients treated with pemetrexed and cisplatin. A total of 73 patients were recruited, of whom 65 had PET/CT and DCE-MRI scans. Baseline measurements from 18F-FDG PET/CT (maximum standardized uptake value, metabolic tumour volume and total lesion glycolysis) and DCE-MRI (integrated area under the first 90s of the curve and washout slope) were compared with overall survival (OS) using Kaplan–Meier and Cox regression analyses, and changes in imaging measurements were compared with disease progression. Results PET/CT and DCE-MRI measurements were not correlated with each other. Maximum standardized uptake value, metabolic tumour volume and total lesion glycolysis were significantly related to OS with Cox regression analysis and Kaplan–Meir analysis, and DCE-MRI washout curve shape was significantly related to OS. DCE-MRI curve shape can be combined with 18F-FDG PET/CT to give additional prognostic information. Changes in measurements were not related to progression-free survival. Conclusions 18F-FDG PET/CT and DCE-MRI give prognostic information in malignant pleural mesothelioma. Neither PET/CT nor DCE-MRI is useful for monitoring disease progression.


  6. Area at risk can be assessed by iodine-123-meta-iodobenzylguanidine single-photon emission computed tomography after myocardial infarction: a prospective study
    imageBackground Myocardial salvage is an important surrogate endpoint to estimate the impact of treatments in patients with ST-segment elevation myocardial infarction (STEMI). Aim The aim of this study was to evaluate the correlation between cardiac sympathetic denervation area assessed by single-photon emission computed tomography (SPECT) using iodine-123-meta-iodobenzylguanidine (123I-MIBG) and myocardial area at risk (AAR) assessed by cardiac magnetic resonance (CMR) (gold standard). Patients and methods A total of 35 postprimary reperfusion STEMI patients were enrolled prospectively to undergo SPECT using 123I-MIBG (evaluates cardiac sympathetic denervation) and thallium-201 (evaluates myocardial necrosis), and to undergo CMR imaging using T2-weighted spin-echo turbo inversion recovery for AAR and postgadolinium T1-weighted phase sensitive inversion recovery for scar assessment. Results 123I-MIBG imaging showed a wider denervated area (51.1±16.0% of left ventricular area) in comparison with the necrosis area on thallium-201 imaging (16.1±14.4% of left ventricular area, P<0.0001). CMR and SPECT provided similar evaluation of the transmural necrosis (P=0.10) with a good correlation (R=0.86, P<0.0001). AAR on CMR was not different compared with the denervated area (P=0.23) and was adequately correlated (R=0.56, P=0.0002). Myocardial salvage evaluated by SPECT imaging (mismatch denervated but viable myocardium) was significantly higher than by CMR (P=0.02). Conclusion In patients with STEMI, 123I-MIBG SPECT, assessing cardiac sympathetic denervation may precisely evaluate the AAR, providing an alternative to CMR for AAR assessment.



  7. The clinical value of PET and PET/CT in the diagnosis and management of suspected cervical cancer recurrence
    imageThe aim of this study was to evaluate the clinical value of PET and PET/CT in suspected recurrent cervical cancer. The recurrence of cervical cancer has a poor prognosis. Earlier intervention would lead to a better prognosis. PET and PET/CT were promising in early diagnosis of recurrence because they could detect the biological and molecular changes before the anatomical size changes occurred. However, few data concerning the clinical effect of PET and PET/CT were available. The database for PET (or positron emission tomography or FDG or fluorodeoxyglucose) AND cervical cancer (or cervical tumor or cervical neoplasm or cervical carcinoma) AND recurrence or relapse was searched. The diagnostic value of PET or PET/CT was evaluated in both person-based and region-based analyses. Seventeen studies with 707 cases were included in the meta-analysis. For patients who were suspected of cervical cancer recurrence, the pooled sensitivity of PET and PET/CT was 0.97 (0.95–0.99). For patients who were suspected of relapse owing to elevated squamous cell carcinoma antigen, the pooled sensitivity was 0.99 (0.93–1.00). Moreover, the region-based diagnostic value in lung, mediastinum, liver/spleen, inguinal lymph node, supraclavicular lymph node, and para-aortic lymph node was high, from which we can see that PET and PET/CT had a favorable diagnostic value on distant metastasis. In addition, 57% of the therapeutic plans were modified owing to PET and PET/CT. PET and PET/CT are valuable tools in suspected recurrence of cervical cancer and provide valuable information for treatment decisions.



  8. Excretion and whole-body retention of radium-223 dichloride administered for the treatment of bone metastases from castration resistant prostate cancer
    imageObjective The aim of the study was to determine the fraction of administered activity that was excreted and retained by a small cohort of patients who each received treatment with radium-223 dichloride (223Ra). 223Ra is an α-emitting radionuclide that has been approved for use in the treatment of bone metastases that are secondary to castration resistant prostate cancer. Patients and methods Six patients received two weight-based administrations of 223Ra 6 weeks apart. Activity excreted in the urine and faeces during the first 48 h following each treatment was assessed by direct counting of the excreta. During the same period the whole-body retention of 223Ra was also determined using a single probe counting system. The results of the excreta counting and the whole-body counting were compared to determine whether whole-body counting was a suitable surrogate for assessing excretion. Further whole-body retention counts were made at around 3, 4, 7 and 42 days following treatment. Results Patterns of excretion and retention of 223Ra varied significantly between patients, but were similar for each patient’s pair of treatments. The cumulative maximum activity excreted in the initial 8-h period following the 223Ra administration was 2.6% that increased to 39% at 48 h. The median excreted activity at ~1 and 6 weeks after treatment was 70 and 86%, respectively. Skeletal retention of 223Ra at 6 weeks ranged from 11 to 60% of the administered activity.



  9. Quantitative PET/CT in clinical practice: assessing the agreement of PET tumor indices using different clinical reading platforms
    imageObjective The aim of this study was to determine whether various fluorine-18-fluorodeoxyglucose PET/CT-derived parameters used in oncology vary significantly depending on the interpretation software systems used in clinical practice for multiple human solid tumors. Patients and methods A total of 120 fluorine-18-fluorodeoxyglucose PET/CT studies carried out in patients with pancreatic, lung, colorectal, and head and neck cancers were evaluated retrospectively on two different vendor software platforms including Mirada and MIMVista. Regions of interest were placed on the liver to determine the liver mean standardized uptake value at lean body mass (SUL) and on each tumor to determine the SULmax, SULpeak. Total lesion glycolysis (TLG) and metabolic tumor volume (MTV) were determined using fixed thresholds of 50% of SULmax and SULpeak. Inter-reader, intersystem intraclass correlations, systematic bias, and variability reflected by the 95% limits of agreement, and precision were determined. Results There was excellent inter-reader reliability between the readers and the two software systems, with intraclass correlations more than 0.9 for all PET metrics, with P values less than 0.0001. The bias and SD on Bland–Altman analysis between the two software platforms for tumor SULmax, SULpeak, Max50MTV, and Peak50MTV, respectively, for Reader 1 were −1.52±2.24, 0.80±3.67, −0.80±13.01, and −4.49±20.6. For Reader 2, the biases were −1.62±1.95, 0.18±3.60, −0.27±4.64, and −3.13±8.30. The precision between the two systems was better for SULmax and SULpeak, with less variance observed, than for volume-based metrics such as Max50MTV and Peak50MTV or TLG. Conclusion Excellent correlation has been found between two tested software reading platforms for all PET-derived metrics in a dual-reader analysis. Overall, the SULmax and SULpeak values had less bias and better precision compared with the MTV and TLG.



  10. Apoptosis and cell proliferation in short-term and long-term effects of radioiodine-131-induced kidney damage: an experimental and immunohistochemical study
    imageObjective Radioiodine-131 is a radionuclide that is used for therapeutic purposes in hyperthyroidism and thyroid cancer. The aim of this study was to evaluate apoptotosis and proliferative changes in radioiodine-related kidney damage. Materials and methods Three groups (n=10/group) of rats were used as follows: the rats were in group 1 untreated, and the rats in groups 2 and 3 were treated once with oral radioiodine (111 MBq). The animals in group 2 were killed at the end of the seventh day and the rats in group 3 were killed at the end of the 10th week. The kidneys were removed and evaluated immunohistochemically. The presence of radioiodine in the kidneys was shown by the Na+/I−symporter antibody and proliferating cell nuclear antigen, Ki-67, caspase-3, caspase-8, caspase-9, and terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labeling assay were used to detect cell proliferation and apoptosis. Results Na+/I−symporter protein accumulation in the kidneys was observed to be significantly greater in group 2 than in group 3 (P<0.05). All the immunohistochemical analyses showed that cell proliferation and apoptosis began on the seventh day and peaked in the 10th week. The proliferating cell nuclear antigen, Ki-67, and caspase expressions and terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate nick end labeling values were all found to be statistically significantly increased in group 3 compared with the other groups (P<0.05). Conclusion Radioiodine caused cell proliferation and apoptosis as shown by immunohistochemistry.


  11. Physiologic uptake of 18F-FDG in transposed ovaries may mimic metastasis on 18F-FDG PET/CT imaging
    imageBackground Ovarian transposition is aimed at preserving ovarian function before irradiation in pelvic malignancies. The extrapelvic location of the ovaries and their physiologic fluorine-18-fluorodeoxyglucose (18F-FDG)-uptake is a potential source of misdiagnosis as metastasis on 18F-FDG PET/CT. We describe the 18F-FDG PET/CT characteristics of transposed ovaries and their changes over time. Patients and methods We reviewed 18F-FDG PET/CT studies of all consecutive women with pelvic malignancies who underwent ovarian transposition between 2007 and 2013. Studies were grouped according to the time period over which they were carried out. Findings were categorized by location, size, appearance (solid/mixed/cystic), presence of surgical clips, ovarian 18F-FDG uptake (maximum standardized uptake value), and attenuation values on CT (Hounsfield units). Group time-period differences were assessed. Results Seventy-nine 18F-FDG PET/CT studies were reviewed, 30 before and 49 after transposition. Time-period groups after transposition were up to 4 months (18 studies), 4.1–12 months (n=14), and more than 12 months (n=17). After transposition, ovaries were located mainly in the paracolic gutter (n=32) and subhepatic regions (n=18). Surgical clips were present in 67%. Both ovaries appeared more solid 1 year after surgery than preoperatively (13.7% before vs. 61.3% after surgery; P<0.001). Transient 18F-FDG-avidity was observed in 11 ovaries. Hounsfield unit values were higher within 4 months after surgery than preoperatively, reverting thereafter to preoperative values. Conclusion After ovarian transposition, nonanatomic location, loss of cysts formation in favor of solid appearance over time, and intermittent 18F-FDG uptake of functioning transposed ovaries might mimic metastatic lesions. Careful interpretation of 18F-FDG PET/CT findings is mandatory in women with pelvic malignancies who have undergone ovarian transposition.



  12. [DTPA-(PABn)-Leu5]-des-acyl ghrelin(1–5) as a new carrier of radionuclides and potential precursor of radiopharmaceuticals
    imageBackground Ghrelin is a peptide consisting of 28 aminoacids and an octadecyl side chain (acyl group) binding to the growth hormone secretagogue receptor type 1a (GHS-R1a). Its des-acylated form, des-acyl ghrelin (DAG) binds to the corticotropin releasing factor receptor type 2a (CRF2a) located on endocrine cancer cells such as the prostate carcinoma cell line DU 145. Aim The aim of this study is to develop a new DAG-based carrier of radionuclides with potential application in therapy. Materials and methods Trunctated C-terminal five aminoacids chain of the DAG peptide (H2N-Gly-Ser-Ser-Phe-Leu-COOH) was linked to DTPA to obtain [DTPA-(PABn)-Leu5]-DAG(1–5). For therapeutic application the lutetium-177 (177Lu) radionuclide was coordinated to the peptide. To determine biological and chemical properties of newly synthesized radiopharmaceutical, two iodine-131 (131I)-labelled compounds were used: [131I]-Tyr4-DAG(1–5) and full length [131I]-DAG(1–28) together with their nonradioactive forms: DAG(1–28) and DAG(1–5). Results Identical HPLC elution profiles of [177Lu-DTPA-(PABn)-Leu5]-DAG(1–5) before and after incubation with human serum proved its stability. The lipophilicity profile of [177Lu-DTPA-(PABn)-Leu5]-DAG(1–5) was log DO/W=-2.68±0.05, pH 7.4. Receptor affinity of the nonradioactive conjugate [Lu-DTPA-(PABn)-Leu5]-DAG(1–5) was IC50 (21.06 nmol/l), as shown against the [131I]-DAG(1–28) used as a competitor. The 3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyltetrazolium bromide assay indicated the significant cytotoxicity of the newly synthesized compounds, similar to that of [131I]-Tyr4-DAG(1–5). Conclusion The results obtained suggest the potency of the [DTPA-(PABn)-Leu5]-DAG(1–5) as a new carrier of radionuclides in radiopharmacy.



  13. Implementation of [18F]-labeled amyloid brain PET imaging biomarker in the diagnosis of Alzheimer’s disease: first-hand experience in Thailand
    imageNo abstract available



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