Asia Oceania Journal of Nuclear Medicine & Biology
Year:2017 | Volume:5 | Issue:1|Papers Count:11

AOJNMB has a very successful year in 2016 and is indexed in PubMed Central from the first issue. Now AOJNMB could easily be searched in NLM database and full text of articles could freely be downloaded in HTLM or PDF format from PubMed Central. I am deeply grateful to many scientists and physicians who contributed to this success either by publishing their excellent works in AOJNMB or providing critical scientific review of the submitted manuscripts, introduction of the AOJNMB in their countries and sending me their suggestions and comments for improvement of the journal. My special thanks go to our Japanese colleagues who submitted the highest number of manuscripts to AOJNMB in the last few years...

Objective(s): It is difficult to investigate the whole-body distribution of an orally administered drug by means of positron emission tomography (PET), owing to the short physical half-life of radionuclides, especially when 11C-labeled compounds are tested. Therefore, we aimed to examine the whole-body distribution of donepezil (DNP) as an acetyl cholinesterase inhibitor by means of 11C-DNP PET imaging, combined with the oral administration of pharmacological doses of DNP.Methods: We studied 14 healthy volunteers, divided into group A (n=4) and group B (n=10). At first, we studied four females (mean age: 57.3±4.5 y), three of whom underwent 11C-DNP PET scan at 2.5 h after the oral administration of 1 mg and 30 mg of DNP, respectively, while one patient was scanned following the oral administration of 30 mg of DNP (group A). Then, we studied five females and five males (48.3±6.1 y), who underwent 11C-DNP PET scan, without the oral administration of DNP (group B). Plasma DNP concentration upon scanning was measured by tandem mass spectrometry. Arterialized venous blood samples were collected periodically to measure plasma radioactivity and metabolites. In group A, 11C-DNP PET scan of the brain and whole body continued for 60 and 20 min, respectively. Subjects in group B underwent sequential whole-body scan for 60 min. The regional uptake of 11C-DNP was analyzed by measuring the standard uptake value (SUV) through setting regions of interest on major organs with reference CT.Results: In group A, plasma DNP concentration was significantly correlated with the orally administered dose of DNP. The mean plasma concentration was 2.00 nM (n=3) after 1 mg oral administration and 0.06 nM (n=4) after 30 mg oral administration. No significant difference in plasma radioactivity or fraction of metabolites was found between groups A and B. High 11C-DNP accumulation was found in the liver, stomach, pancreas, brain, salivary glands, bone marrow, and myocardium in groups A and B, in this order. No significant difference in SUV value was found among 11C-DNP PET studies after the oral administration of 1 mg of DNP, 30 mg of DNP, or no DNP.Conclusion: The present study demonstrated that the whole-body distribution of DNP after the oral administration of pharmacological doses could be evaluated by 11C-DNP PET studies, combined with the oral administration of DNP.

Objective(s): The study objective was to assess the diagnostic performance of positron emission tomography (PET) for gliomas using the novel tracer 18F-fluciclovine (anti- [18F] FACBC) and to evaluate the safety of this tracer in patients with clinically suspected gliomas.Methods: Anti- [18F] FACBC was administered to 40 patients with clinically suspected high- or low-grade gliomas, followed by PET imaging. T1-weighted, contrast-enhanced T1-weighted, and fluid-attenuated inversion recovery (or T2-weighted) magnetic resonance imaging (MRI) scans were obtained to plan for the tissue collection. Tissues were collected from either "areas visualized using anti- [18F] FACBC PET imaging but not using contrast-enhanced T1-weighted imaging" or "areas visualized using both anti- [18F] FACBC-PET imaging and contrast-enhanced T1-weighted imaging" and were histopathologically examined to assess the diagnostic accuracy of anti- [18F] FACBC-PET for gliomas.Results: The positive predictive value of anti- [18F] FACBC-PET imaging for glioma in areas visualized using anti- [18F] FACBC-PET imaging, but not visualized using contrast-enhanced T1- weighted images, was 100.0% (26/26), and the value in areas visualized using both contrast-enhanced T1-weighted imaging and anti- [18F] FACBC-PET imaging was 87.5% (7/8). Twelve adverse events occurred in 7 (17.5%) of the 40 patients who received anti- [18F] FACBC. Five events in five patients were considered to be adverse drug reactions; however, none of the events were serious, and all except one resolved spontaneously without treatment.Conclusion: This Phase IIb trial showed that anti- [18F] FACBC-PET imaging was effective for the detection of gliomas in areas not visualized using contrast-enhanced T1-weighted MRI and the tracer was well tolerated.

Objective(s): This study aimed to evaluate the role of pretreatment SUVmax and volumetric FDG positron emission tomography (PET) parameters in the differentiation between benign and malignant mediastinal tumors. In addition, we investigated whether pretreatment SUVmax and volumetric FDG-PET parameters could distinguish thymomas from thymic carcinomas, and low-risk from high-risk thymomas.Methods: This study was conducted on 52 patients with mediastinal tumors undergoing FDG-PET/CT. Histological examination indicated that 29 mediastinal tumors were benign, and 23 cases were malignant. To obtain quantitative PET/CT parameters, we determined the maximum standardized uptake value (SUVmax), volumetric parameters, metabolic tumor volume (MTV), and total lesion glycolysis (TLG) for primary tumors using SUVmax cut-off value of 2.5. SUVmax, MTV and TLG of benign and malignant tumors were compared using the Mann-Whitney U test. Moreover, receiver-operating curve (ROC) analysis was applied to identify the cut-off values of SUVmax, MTV and TLG for the accurate differentiation of benign and malignant tumors. SUVmax, MTV and TLG were compared between thymomas and thymic carcinomas, as well as low-risk and high-risk thymomas.Results: Mean SUVmax, MTV and TLG of malignant mediastinal tumors were significantly higher compared to benign tumors (P<0.001). Sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of SUVmax were 78.2%, 86.2%, 82.6%, 81.8%, and 83.3%, respectively. These values were estimated at 82.6%, 96.6%, 90.4%, 95%, and 87.5% for MTV and TLG, respectively. Additionally, optimal cut-off values for the differentiation of benign and malignant mediastinal tumors were determined at 4.2 and 22.3 mL and 79.7 g for SUVmax, MTV and TLG, respectively. Mean SUVmax, MTV and TLG of thymic carcinomas were significantly higher compared to thymomas (P<0.01), while no significant differences were observed in the mean quantitative parameters between low-risk and high-risk thymomas.Conclusion: Although SUVmax, MTV and TLG could not distinguish between low-risk and high-risk thymomas, these parameters might be able to differentiate benign tumors from malignant mediastinal tumors noninvasively. These parameters could be used to distinguish between thymomas and thymic carcinomas as well. Therefore, FDG-PET/CT parameters seem to be accurate indices for the detection of malignant mediastinal tumors.

Objective(s): In positron emission tomography (PET) studies, thoracic movement under free-breathing conditions is a cause of image degradation. Respiratory gating (RG) is commonly used to solve this problem. Two different methods, i.e., phase-gating (PG) and amplitude-gating (AG) PET, are available for respiratory gating. It is important to know the strengths and weaknesses of both methods when selecting an RG method for a given patient. We conducted this study to clarify whether AG or PG is preferable for measuring fluorodeoxyglucose (FDG) accumulation in lung adenocarcinoma and to investigate patient conditions which are most suitable for AG and PG methods.Methods: A total of 31 patients (11 males, 20 females; average age: 11.6±70.1 yrs) with 44 lung lesions, diagnosed as lung adenocarcinoma between April 2012 and March 2013, were investigated. Whole-body FDG-PET/CT scan was performed with both PG and AG methods in all patients. The maximum standardized uptake value (SUVmax) of PG, AG, and the control data of these two methods were measured, and the increase ratio (IR), calculated as IR (%)= (Post – Pre) /Pre×100, was calculated. The diameter and position of lung lesions were also analyzed. We defined an ‘effective lesion’ of PG (or AG) as a lesion which showed a higher IR compared to AG (or PG).8 (25.8%) Results: The average SUVmax and average IR were 7.94±8.99 and 25.6±21.4% in PG and 6.70±7.60 and 14.4±4.0% in AG, respectively. Although there was no significant difference between the average SUVmax of PG and AG (P=0.09), the average IR of PG was significantly higher than that of AG (P<0.01). The number of PG- and AG-effective lesions was 32 (72.7%) and 12 (28.3%), respectively. There was no significant difference in the average diameter or position of the lesions between the PG- and AG-effective lesions. There were 23 (74.2%) PG-effective and 8 (25.8%) AG-effective patients. No significant difference was observed in sex or age between PG- and AG-effective patients.Conclusion: The PG method was more effective for measuring FDG accumulation of lung lesions under free-breathing conditions in comparison with the AG method.

Objective(s): Iodine-123 metaiodobenzylguanidine (123I-MIBG) myocardial scintigraphy has been used to evaluate cardiac sympathetic denervation in Lewy body disease (LBD), including Parkinson’s disease (PD) and dementia with Lewy bodies (DLB). The heart-to-mediastinum ratio (H/M) in PD and DLB is significantly lower than that in Parkinson’s plus syndromes and Alzheimer’s disease. Although this ratio is useful for distinguishing LBD from non-LBD, it fluctuates depending on the system performance of the gamma cameras. Therefore, a new, simple quantification method using 123I-MIBG uptake analysis is required for clinical study. The purpose of this study was to develop a new uptake index with a simple protocol to determine 123I-MIBG uptake on planar images.Methods: The 123I-MIBG input function was obtained from the input counts of the pulmonary artery (PA), which were assessed by analyzing the PA time-activity curves. The heart region of interest used for determining the H/M was used for calculating the uptake index, which was obtained by dividing the heart count by the input count.Results: Forty-eight patients underwent 123I-MIBG chest angiography and planar imaging, after clinical feature assessment and tracer injection. The H/M and 123I-MIBG uptake index were calculated and correlated with clinical features. Values for LBD were significantly lower than those for non-LBD in all analyses (P<0.001). The overlapping ranges between non-LBD and LBD were 2.15 to 2.49 in the H/M method, and 1.04 to 1.22% in the uptake index method. The diagnostic accuracy of the uptake index (area under the curve (AUC), 0.98; sensitivity, 96%; specificity, 91%; positive predictive value (PPV), 90%; negative predictive value (NPV), 93%; and accuracy, 92%) was approximately equal to that of the H/M (AUC, 0.95; sensitivity, 93%; specificity, 91%; PPV, 90%; NPV, 93%; and accuracy, 92%) for discriminating patients with LBD and non-LBD.Conclusion: A simple uptake index method was developed using 123I-MIBG planar imaging and the input counts determined by analyzing chest radioisotope angiography images of the PA. The diagnostic accuracy of the uptake index was approximately equal to that of the H/M for discriminating patients with LBD and non-LBD.

Objective(s): In this study, we aimed to evaluate the efficacy of thyroid volume measurement using 99mTc pertechnetate single-photon emission computed tomography (SPECT) images, acquired by the standardized uptake value (SUV) -shape scheme designed by our expert team.Methods: A total of 18 consecutive patients with Graves’ disease (GD) were subjected to both ultrasonographic and 99mTc pertechnetate SPECT examinations of thyroid within a five-day interval. The volume of thyroid lobes and isthmus was measured by ultrasonography (US) according to the ellipsoid volume equation. The total thyroid volume, determined as the sum of the volume of both lobes and isthmus, was recorded as TV-US (i.e., thyroid volume measured by US) and set as the reference. The thyroid volume was defined according to our SUV-shape scheme and was recorded as TV-SS (i.e., thyroid volume determined by the SUV-shape scheme). The data were analyzed using the Bland-Altman plot, linear regression analysis, Spearman’s rank correlation, and paired t-test, if necessary.Results: The values of TV-SS (40.2±29.4 mL) and TV-US (43.0±34.7 mL) were not significantly different (t=0.813; P=0.43). The linear regression equation of the two values was determined as TV-US=1.072×TV-SS − 0.29 (r=0.906; P<0.01).Conclusion: The new scheme, i.e., SUV-shape scheme, exhibited potential for the measurement of thyroid volume in patients with GD.

Objective(s): BONENAVI, a computer-aided diagnostic system, is used in bone scintigraphy. This system provides the artificial neural network (ANN) and bone scan index (BSI) values. ANN is associated with the possibility of bone metastasis, while BSI is related to the amount of bone metastasis. The degree of uptake on bone scintigraphy can be affected by the type of bone metastasis. Therefore, the ANN value provided by BONENAVI may be influenced by the characteristics of bone metastasis. In this study, we aimed to assess the relationship between ANN value and characteristics of bone metastasis.Methods: We analyzed 50 patients (36 males, 14 females; age range: 42–87 yrs, median age: 72.5 yrs) with prostate, breast, or lung cancer who had undergone bone scintigraphy and were diagnosed with bone metastasis (32 cases of prostate cancer, nine cases of breast cancer, and nine cases of lung cancer). Those who had received systematic therapy over the past years were excluded. Bone metastases were diagnosed clinically, and the type of bone metastasis (osteoblastic, mildly osteoblastic, osteolytic, and mixed components) was decided visually by the agreement of two radiologists. We compared the ANN values (case-based and lesion-based) among the three primary cancers and four types of bone metastasis.Results: There was no significant difference in case-based ANN values among prostate, breast, and lung cancers. However, the lesion-based ANN values were the highest in cases with prostate cancer and the lowest in cases of lung cancer (median values: prostate cancer, 0.980; breast cancer, 0.909; and lung cancer, 0.864). Mildly osteoblastic lesions showed significantly lower ANN values than the other three types of bone metastasis (median values: osteoblastic, 0.939; mildly osteoblastic, 0.788; mixed type, 0.991; and osteolytic, 0.969). The possibility of a lesion-based ANN value below 0.5 was 10.9% for bone metastasis in prostate cancer, 12.9% for breast cancer, and 37.2% for lung cancer. The corresponding possibility were 14.7% for osteoblastic metastases, 23.9% for mildly osteoblastic metastases, 7.14% for mixed-type metastases, and 16.0% for osteolytic metastases.Conclusion: The lesion-based ANN values calculated by BONENAVI can be influenced by the type of primary cancer and bone metastasis.

Objective(s): To review the findings of the patients with Sjogren’s syndrome (SS) having technetium-99m-pertechnetate (99mTc-pertechnetate) and gallium-67 citrate (Ga-67) salivary gland scintigraphy in the past eight years.Methods: The patients with SS, who were referred to our department for salivary gland scintigraphy during January 2008-December 2015 were studied using both 99mTc-pertechnetate and Ga-67 citrate scintigraphy.Results: Eighteen patients were included in the study, 17 of whom had positive findings on 99mTc-pertechnetate salivary gland scintigraphy. One patient had negative parotid glands findings on 99mTc-pertechnetate, but positive findings in Ga-67 study. Four patients had asymmetric involvement of the parotid glands, and one patient had asymmetric involvement of the submandibular glands in 99mTc-pertechnetate salivary gland scintigraphy. On the other hand, one patient had only submandibular gland involvement in the 99mTc-pertechnetate scan. Nine patients (9/18) had positive parotid gland findings on Ga-67 study. The involvements of the parotid glands were all symmetrical, except for one patient. No abnormal gallium uptake in the submandibular glands in our patients was noted.Conclusion: 99mTc-pertechnetate salivary gland scintigraphy is sufficient for the assessment in the majority of patients with SS. Ga-67 scintigraphy may be a useful supplementary test, especially if the result of 99mTc-pertechnetate scintigraphy is not conclusive.

A 65 year old male with metastatic colorectal cancer (mCRC) in the liver was referred for selective internal radionuclide therapy (SIRT) following a history of extensive systemic chemotherapy.90Y PET imaging was performed immediately after treatment and used to confirm lesion targeting and measure individual lesion absorbed doses. Lesion dosimetry was highly predictive of eventual response in the follow-up FDG PET performed 8 weeks after therapy. The derived radiation dose map was used to plan a second SIRT procedure aiming to protect healthy liver by keeping absorbed dose below the critical dose threshold, whilst targeting the remaining lesions that had received sub-critical dosing. Again, 90Y PET was performed immediately post-treatment and used to derive absorbed dose measures to both lesions and healthy parenchyma. Additional follow-up FDG PET imaging again confirmed the role of the 90Y PET dose map as an early predictor of response, and a tool for safe repeat treatment planning.

Pleural epithelioid hemangioendothelioma (EHE) is a rare malignancy of vascular-endothelial origin with non-specific symptoms and an unpredictable outcome. Diagnosis of this condition by imaging modalities is challenging, and no standard therapeutic approaches have been established in this regard. In this paper, we described the case of a patient with a low-grade fever, coughing and chest pain who underwent 18F-FDG PET/CT after a positive thorax CT showing multiple bilateral calcified pulmonary nodules and extensive right-sided pleural effusion. Moreover, PET/CT revealed increased tracer uptake on the nodular pleural thickening and one nodule in the upper lobe of the right lung. A diagnostic thoracentesis was performed to obtain the pleural fluid. However, cytology was not diagnostic, and the subsequent thoracotomy with pleural fluid drainage and pleural biopsy was positive for pleural EHE. The study showed also an abundant non-FDG-avid pleural effusion in the collapsed right lung. Despite chest tube insertion and partial drainage of the volume, patient’s condition deteriorated, and patient passed away six months after the PET scan.