Combined visual and quantitative assessment of somatostatin receptor scintigraphy for staging and restaging of neuroendocrine tumors.

PURPOSE: Somatostatin receptor scintigraphy (SRS) using 111In-DTPA-DPhe1-octreotide (pentetreotide) has become an integral part of neuroendocrine neoplasm management. The lack of precise quantification is a disadvantage of SRS. This study aimed to adapt the standardized uptake value (SUV) to SRS, establish the SUV range for physiological uptake in the liver, kidney, and spleen, and elucidate the utility of combined visual and quantitative SRS assessment for staging and restaging of neuroendocrine tumors (NETs). MATERIALS AND METHODS: This study included 21 patients with NETs who underwent 111In-pentetreotide SRS. The SUV of physiological and pathological uptake was calculated using bone single-photon emission computed tomography (SPECT) quantitative analysis software (GI-BONE). For visual analysis, the primary and metastatic lesions were scored visually on planar and SPECT images using a five-point scale. We assessed the relationships between the SUVs of the liver, kidney, and spleen in the dual phase, and among quantitative indices, visual score, and pathological lesions classification. RESULTS: Sixty-three NEN lesions were evaluated. The mean ± standard deviation maximum SUVs (SUVmax) were liver: 4 h, 2.6 ± 1.0; 24 h, 2.2 ± 1.0; kidney: 4 h, 8.9 ± 1.8; 24 h, 7.0 ± 2.0; and spleen; 4 h, 11.3 ± 4.5; 24 h, 11.5 ± 7.6. Higher SUVmax was significantly associated with higher visual scores on dual-phase SPECT (4 h, p < 0.001; 24 h, p < 0.001) (4 h: scores 3 and 4, p < 0.05; scores 3 and 5: p < 0.01; scores 4 and 5: p < 0.01; 24 h: scores 3 and 4, p = 0.0748; scores 3 and 5: p < 0.01; scores 4 and 5: p < 0.01). CONCLUSION: We adapted the SUV to SRS and established the range of SUV for physiological uptake in the liver, kidney, and spleen. Combined visual and quantitative assessment is useful for imaging individual lesions in greater detail, and may serve as a new tumor marker of SRS for staging and restaging of NETs.

Nuclear medicine practice in Japan: a report of the ninth nationwide survey in 2022.

Subcommittee on Survey of Nuclear Medicine Practice in Japan has performed a nationwide survey of nuclear medicine practice every 5 years since 1982 to survey contemporary nuclear medicine practice and its changes over the years. The subcommittee sent questionnaires, including the number and category of examinations as well as the kind of the radiopharmaceuticals during the 30 days of June 2022 to all nuclear medicine institutes in Japan. The total numbers of them for the year 2022 were estimated depends on the 1-month data. A total of 1095 institutes responded to the survey, including 364 positron emission tomography (PET) centers. The recovery rate was 90.6%. The number of gamma cameras installed was 1299 in total, with 2.5% decrease in 5 years. Dual-head cameras and hybrid SPECT/CT scanners accounted for 83.8% and 35.5%, respectively. The number of single-photon tracer studies in 2022 was 1.11 million which means increase in 2.7% in 5 years. Bone scintigraphy was a leading examination (31.0%), followed by myocardial scintigraphy (27.1%) and cerebral perfusion study (23.8%) in order. The percentage of SPECT studies showed an increase from 63.5% in previous survey to 66.8% in this survey. PET centers have also increased from 389 to 412, as compared with the previous one. One hundred and twenty-two PET centers have installed one or two in-house cyclotrons. Increasing trends of the PET studies were observed from 1992 to 2017, the trend changed and PET studies showed 1.5% decrease in 5 years. 18F-FDG accounted for 98.6% (610,497 examinations). PET examinations using 11C-methionine, 13N-NH3 and 11C-PIB have decreased, with 1624, 2146 and 525 examinations, respectively in 2022. The total number of nuclear medicine examination was eventually increased by 1.0%. Therapies for pheochromocytoma or paraganglioma (PPGL) with 131I-MIBG and for neuroendocrine tumor with 177Lu-DOTA-TATE were newly started, however, a total number of targeted radionuclide therapy was decreased by 17.7% because 131I-radioiodine and 223Ra targeted therapies were decreased and supply of some radioisotopes was discontinued. 131I-radioiodine targeted therapy showed a decrease in 5 years (- 15.9%), including 4099 patients for thyroid cancer. The number of out-patient thyroid bed ablation therapy with 1110 MBq of 131I was also decreased to 1015 per year. The number of admission rooms specialized for radionuclide targeted therapy increased from 157 to 160. The number of 223Ra targeted therapies for castration-resistant metastatic prostate cancer (mCRPC) was 1041 patients. This survey was performed during COVID-19 pandemic, however, total number of nuclear medicine examinations was almost same as previous survey (+ 1.0%). Radionuclide therapies with 131I-MIBG and 177Lu-DOTA-TATE were newly started, and new radionuclide therapy will be available in future, therefore, the development of radionuclide therapy will be continued. We are convinced that this survey report is useful in understanding the current status of the nuclear medicine practice in Japan, and in devising the new strategy to strengthen a role of nuclear medicine.

Technologies, Physician's Caring Competency, and Patient Centered Care:A Systematic Review.

This study aimed to conduct a systematic review to clarify patient understanding, understanding of caring concepts, understanding of technology, competency to express compassion, appropriate involvement in caring, and ethical and moral attitudes and responses toward patients. This systematic review was conducted through an electronic search across PubMed, Google Scholar, MEDLINE, and Science Direct. Authors independently appraised the methodological quality of the studies using the Mixed Method Appraisal Tool. A narrative synthesis approach was used to present these findings. Nine studies met the inclusion criteria and quality appraisal guidelines. Through thematic analysis, four major themes were identified:Technology and caring competency, Technology and patient-centered care, Empathetic skills, and Caring competency. This review has shown that patients choose physicians considering their emotions and communicate well with them, empowering them to take responsibility of their own or their loved ones' healthcare. In the age of technological advancement and availability of vast sources of information, it is expected of physicians to adapt to these character priorities while maintaining their sense of humanness, not only focusing on healing modalities, but also to guide, educate, and appropriately empower their patients toward achieving their healthcare goals. J. Med. Invest. 70 : 307-316, August, 2023.

Early Prediction of Radiotherapeutic Efficacy in a Mouse Model of Non-Small Cell Lung Carcinoma Using 18F-FLT and 18F-FDG PET/CT.

This study investigated the usefulness of [18F]-3'-deoxy-3'-fluorothymidine (18F-FLT) and [18F]-fluoro-2-deoxy-D-glucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) imaging for predicting the therapeutic efficacy of non-small cell lung cancer (NSCLC) irradiation at an early stage after radiation treatment. Mice were xenografted with the human lung adenocarcinoma line A549 or large cell lung cancer line FT821. Tumour uptake of 18F-FLT and 18F-FDG was imaged using PET/CT before and 1 week after irradiation. In A549 tumours, 18F-FLT uptake was significantly decreased, and 18F-FDG uptake was unchanged post-irradiation compared with pre-irradiation. In FT821 tumours, uptake of both 18F-FLT and 18F-FDG uptake was substantially decreased post-irradiation compared with pre-irradiation. In both xenografts, tumour volumes in the irradiated groups were significantly decreased compared with those in the control group. 18F-FLT is expected to contribute to individual NSCLC therapy because it accurately evaluates the decrease in tumour activity that cannot be captured by 18F-FDG. 18F-FDG may be useful for evaluating surviving cells without being affected by the inflammatory reaction at an extremely early stage, approximately 1 week after irradiation. Combined use of 18F-FLT and 18F-FDG PET/CT imaging may increase the accurate prediction of radiotherapy efficacy, which may lead to improved patient outcomes and minimally invasive personalised therapy. J. Med. Invest. 70 : 361-368, August, 2023.

Noise Reduction Using Singular Value Decomposition with Jensen-Shannon Divergence for Coronary Computed Tomography Angiography.

Coronary computed tomography angiography (CCTA) is widely used due to its improvements in computed tomography (CT) diagnostic performance. Unlike other CT examinations, CCTA requires shorter rotation times of the X-ray tube, improving the temporal resolution and facilitating the imaging of the beating heart in a stationary state. However, reconstructed CT images, including those of the coronary arteries, contain insufficient X-ray photons and considerable noise. In this study, we introduce an image-processing technique for noise reduction using singular value decomposition (SVD) for CCTA images. The threshold of SVD was determined on the basis of minimization of Jensen-Shannon (JS) divergence. Experiments were performed with various numerical phantoms and varying levels of noise to reduce noise in clinical CCTA images using the determined threshold value. The numerical phantoms produced 10% higher-quality images than the conventional noise reduction method when compared on a quantitative SSIM basis. The threshold value determined by minimizing the JS-divergence was found to be useful for efficient noise reduction in actual clinical images, depending on the level of noise.

Axillary Lymph Node Uptake on 18F-FDG PET/CT after COVID-19 Vaccination: A Direct Comparison Study with Influenza Vaccination.

Objectives: To compare vaccinated-side axillary lymph node uptake on 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) after coronavirus disease-2019 (COVID-19) and influenza vaccination. Methods: We retrospectively analyzed 177 patients who underwent 18F-FDG PET/CT after COVID-19 or influenza vaccination. We compared the uptake of the vaccinated-side axillary lymph nodes of 109 COVID-19 vaccinated patients with those of a lot of influenza-vaccinated patients. We also compared the uptake between 66 patients who received the first COVID-19 vaccination with 43 who received the second COVID-19 vaccination. Results: 18F-FDG-avid axillary lymph nodes on the vaccinated side were significantly more frequently observed in the COVID-19 group (45%) than in the influenza group (19%) (p<0.001). When the interval between vaccination to PET/CT was within 7 days, there was no significant difference in the frequency of 18F-FDG-avid vaccinated-side axillary lymph nodes between the groups (COVID-19 group: 41% vs. influenza group: 45%, p=0.724). When the interval was over 7 days, 18F-FDG-avid lymph nodes were much more frequent in the COVID-19 group (47%) than in the influenza group (7%) (p<0.001). Comparing the first and second COVID-19 groups, 18F-FDG-avid lymph nodes were more frequent in the second vaccination group than in the first vaccination group, but the difference was not significant. Conclusion: 18F-FDG-avid vaccinated-side axillary lymph nodes were more frequently observed in the COVID-19 group than in the influenza group. In the case of the COVID-19 vaccine, a delay of 18F-FDG PET/CT examination is recommended by a longer interval from vaccination than in the influenza vaccine.

11C-Methionine PET/CT and 18F-FDG PET/CT in the Evaluation of Adult Alveolar Rhabdomyosarcoma.

A 70-year-old man with a tumor in the nasal and paranasal space, was pathologically diagnosed with an alveolar rhabdomyosarcoma, with right cervical lymph node metastasis. Magnetic resonance imaging revealed a primary tumor in the nasal and paranasal sinuses, with associated intracranial infiltration. 11C-methionine positron emission tomography/computed tomography (PET/CT) revealed increased uptake in the primary tumor and right cervical lymph node metastasis. 18F-fluorodeoxyglucose PET/CT also revealed increased uptake in the primary tumor and right cervical lymph node. However, the physiological brain uptake overlapped with the primary tumor uptake. Our case suggests the usefulness of 11C-methionine PET/CT for accurately assessing the extent of alveolar rhabdomyosarcoma, especially in cases with intracranial infiltration or those approximating the brain.

New quantitative indices of cardiac amyloidosis with 99mTc-pyrophosphate scintigraphy.

PURPOSE: Amyloid light chain (AL) and transthyretin (ATTR) are the major subtypes of cardiac amyloidosis (CA). 99mTc-pyrophosphate (PYP) scintigraphy is used to differentiate ATTR from other CA subtypes. We adapted the standardized uptake value (SUV) for 99mTc-PYP and proposed two quantitative indices, amyloid deposition volume (AmyDV) and total amyloid uptake (TAU). This study aimed to evaluate the utility of these quantitative indices in differentiating ATTR from non-ATTRs. MATERIALS AND METHODS: Before the SUV measurement, the Becquerel calibration factor (BCF) of 99mTc was obtained by a phantom experiment. Thirty-two patients who had undergone hybrid SPECT/CT imaging 3 h after injection of 99mTc-PYP (370 MBq) were studied. CT attenuation correction for image reconstruction was applied in all. We calculated SUV, AmyDV, and TAU using a quantitative analysis software program for bone SPECT (GI-BONE) and analyzed AmyDV using two methods: threshold method (set 40%); and constant value method (average SUVmax of ribs). We assessed the diagnostic ability of heart-to-contralateral lung (H/CL) ratio, SUV, AmyDV, and TAU to differentiate ATTR from non-ATTR using receiver operating characteristic (ROC) analysis. RESULTS: Statistically significant differences in all quantitative indices were observed between ATTR and non-ATTR. The area under the curve of each quantitative index for discriminating between ATTR and non-ATTR were as follows: H/CL, 0.997; SUVmax, 0.953; SUVmean (M1), 0.964; SUVmean (M2), 0.969; AmyDV (M1), 0.875; AmyDV (M2), 0.974; and TAU, 0.974. The AmyDV (M2) had higher diagnostic ability than AmyDV (M1). Thus, TAU was calculated as AmyDV (M2) × SUVmean (M2). In the ROC curve, SUV, AmyDV, and TAU had almost the same diagnostic ability as H/CL in distinguishing ATTR from non-ATTRs. CONCLUSIONS: We propose two novel 3D-based quantitative parameters (AmyDV and TAU) that have almost equal ability to discriminate ATTR from non-ATTR.

18F-FDG PET/CT Showing Rare Mediastinal Growing Teratoma Syndrome Following Chemotherapy.

Growing teratoma syndrome (GTS) is a condition in which poorly differentiated cells in a mixed-germ cell tumor (GCT) regress after chemotherapy, and the number of well-differentiated components increases. A 60-year-old man had an 8.0 cm mediastinal tumor with strong 18F-fluorodeoxyglucose (FDG) uptake [maximum standardized uptake value (SUVmax): 9.2], which was diagnosed as a GCT. After chemotherapy, serum alpha fetoprotein, beta-human chorionic gonadotropin, and tumor 18F-FDG uptake decreased (SUVmax: 3.9), but the tumor volume increased. The tumor was completely resected, and pathology confirmed the diagnosis of GTS. 18F-FDG positron emission tomography after chemotherapy reflects the proliferation of highly differentiated tumor components with poor 18F-FDG uptake.

Multicystic Biliary Hamartoma With Xanthogranulomatous Inflammation on 18F-FDG PET/CT.

ABSTRACT: A 70-year-old man with a liver tumor was pathologically diagnosed with multicystic biliary hamartoma with xanthogranulomatous inflammation. Plain CT revealed an inhomogeneous low-density liver tumor, measuring 43 × 35 mm. Dynamic contrast-enhanced CT revealed a cyst, measuring approximately 15 mm, with a ring-shaped enhancement, within the tumor. There was delayed enhancement on the outer portion of the tumor. Mild peripheral bile duct dilation was also observed. 18F-FDG PET/CT showed focal high uptake with an SUVmax of 5.2 near the cyst. The findings of this case mimicked that of intrahepatic cholangiocellular carcinoma.

Increased physiological [18F]FDG uptake in the liver and blood pool among patients with impaired renal function.

BACKGROUND: In the daily clinical course, the liver uptake may seem to be increased in patients with renal failure. The purpose of this study was to investigate whether or not the FDG uptake of the liver, and the FDG uptake of blood pool which is generally used as a reference site as well as liver, is increased in patients with renal failure. MATERIAL AND METHODS: We retrospectively analyzed 233 patients who underwent FDG positron emission tomography/computed tomography (PET/CT). Renal failure is defined as an estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m2. We compared the FDG uptake in the liver and mediastinal blood pool of 67 patients with impaired renal function to that in 166 patients with a normal renal function (eGFR ≥ 60 mL/min/1.73 m2). Correlations between the liver or mediastinal blood pool FDG uptake and the eGFR were also analyzed by Spearman's correlation test. RESULTS: Maximum and mean standardized uptake values (SUVmax and SUVmean, respectively) of the liver and the SUVmean of the mediastinal blood pool were 3.48 ± 0.57, 2.56 ± 0.37, and 1.90 ± 0.28 in the impaired renal function group, respectively, and 3.13 ± 0.45, 2.29 ± 0.33, and 1.66 ± 0.23, in the normal group, respectively. The SUVmax and SUVmean of the liver and SUVmean of the mediastinal blood pool in the impaired renal function group were significantly higher than those in the normal group (p < 0.001, < 0.001, and < 0.001, respectively). The SUVmax and SUVmean of the liver and SUVmean of the mediastinal blood pool of patients showed a significant negative correlation with the eGFR (Spearman's p = -0.25, -0.30, and -0.40, respectively, each p < 0.001). CONCLUSIONS: FDG uptake in both the liver and mediastinal blood pool was higher in patients with impaired renal function.

Increased 18F-FDG Uptake in the Axillary Lymph Nodes of the Vaccinated Side Associated with COVID-19 Vaccination.

A 50-year-old female patient underwent (18fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) following modified radical mastectomy for cancer of the left breast. Ten days before the PET/CT, the coronavirus disease-2019 (COVID-19) vaccine was injected intramuscularly into the right deltoid muscle. Increased (18F-FDG uptake of maximum standardized uptake value (11.0) was observed in the lymph nodes of the right axilla, which had not been observed in the previous PET/CT. The size of the oval-shaped lymph nodes was up to approximately 11×9 mm; however, it was larger than that observed on the previous PET/CT. We contemplate that the increased (18F-FDG uptake was a reactive change in the lymph nodes associated with the COVID-19 vaccine.

Effect of different examination conditions on image quality and quantitative value of amyloid positron emission tomography using 18F-flutemetamol.

OBJECTIVE: The recommended start time for 18F-flutemetamol amyloid positron emission tomography (PET) examination is 60-120 min after 18F-flutemetamol injection, while an acquisition time of 10-30 min is generally recommended. We aimed to elucidate the effects of different examination conditions on image quality, diagnostic ability, and quantitative value of amyloid PET using 18F-flutemetamol. METHODS: We acquired data on a Discovery PET/computed tomography 710 scanner using Hoffman brain and pillar phantoms with 20 MBq of 18F for 30 min. The images were reconstructed into 10-, 20-, and 30-min periods. The ordered subset-expectation maximization algorithm was used for image reconstruction, which uses a 2- or 4-mm Gaussian filter and a combination of iteration and subset numbers. The percentage contrast and coefficient of variation (CV; as the image noise) were used as physical evaluation indices for reconstructed images, and images with superior contrast and low image noise were selected for clinical evaluation. The imaging data of 15 symptomatic patients (n = 7 and n = 8 for positive and negative diagnoses of Alzheimer's disease, respectively) were reconstructed under the phantom study conditions. Radiographers visually evaluated and ranked the clinical images based on the overall contrast and image noise, and nuclear medicine specialists diagnosed Alzheimer's disease. We compared the standardized uptake value ratio (SUVR) obtained with different acquisition conditions. RESULTS: The basic study using the phantom revealed high convergence of contrast and image noise in five patterns of acquisition time and filter strengths. Regarding visual evaluation, the use of a 2-mm Gaussian filter caused difficulties in diagnosis because the brain parenchymal accumulation was mottled with high image noise. Differences in image quality and diagnostic ability due to different examination times were not significant. Differences in the SUVR were not significant in patients with a negative Alzheimer's disease diagnosis; in patients with a positive diagnosis, the SUVR showed significant fluctuation depending on the acquisition conditions. CONCLUSION: The differences in image quality and diagnostic performance due to the differences in 10-min acquisition time were not significant; however, of note, SUVR showed significant fluctuation depending on the acquisition conditions in patients diagnosed with Alzheimer's disease.

A reduced physiological 18F-fluorodeoxyglucose uptake in the brain and liver caused by malignant lymphoma being deprived of the tracer.

Purpose : To investigate whether or not the physiological brain and liver FDG uptake are decreased in patients with highly accelerated glycolysis lesions. Methods : We retrospectively analyzed 51 patients with malignant lymphoma. We compared the FDG uptake in the brain and liver of the patients with that in a control group. In 24 patients with a complete response (CR) or partial response (PR) to treatment, we compared the brain and liver uptake before and after treatment. Results : The maximum standardized uptake value (SUVmax) and total glycolytic volume (TGV) of the brain as well as the SUVmax and mean standardized uptake value (SUVmean) of the liver in malignant lymphoma patients were 13.1 ±â€…2.3, 7386.3 ±â€…1918.4, 3.2 ±â€…0.5, and 2.3 ±â€…0.4, respectively ; in the control group, these values were 14.9 ±â€…2.4, 8566.2 ±â€…1659.5, 3.4 ±â€…0.4, and 2.5 ±â€…0.3, respectively. The SUVmax and TGV of the brain and the SUVmean of the liver in malignant lymphoma patients were significantly lower than the control group. The SUVmax and TGV of the brain after treatment were significantly higher than before treatment. Both the SUVmax and SUVmean of liver after treatment were higher than before treatment, but not significant. Conclusion : A decreased physiological brain and liver FDG uptake is caused by highly accelerated lesion glycolysis. J. Med. Invest. 68 : 181-185, February, 2021.

Clinical application of dynamic 18F-fluorodeoxyglucose positron-emission tomography / computed tomography in the differential diagnoses of musculoskeletal lesions.

We aimed to assess the differential diagnostic efficacy of dynamic F-18 fluorodeoxyglucose (FDG) positron emission tomography / computed tomography (PET / CT) and to evaluate the appropriate scan timings for diagnosis of musculoskeletal lesions (MSLs). Dynamic scans (5-15 [phase 1], 15-25 [phase 2], and 25-35 [phase 3] min after F-18 FDG injection) and dual-time-point scans (1 and 2 h after injection) were acquired for 23 MSLs [4 benign MSLs (BMSLs). 10 primary malignant musculoskeletal tumors (PMMSTs), and 9 metastatic musculoskeletal tumors (MMSTs)]. We compared the maximum standardized uptake values (SUVmax) and corresponding retention indices for dynamic (RI-SUVdyn) and dual-time-point (RI-SUVdual) scans and evaluated diagnostic efficacy using receiver operating characteristic (ROC) curve analyses. The SUVmax gradually decreased or was almost identical with minimal fluctuation in 3 BMSLs and 1 PMMST. SUVmax increased over time after phase 2 in 18 malignant MSLs (MMSLs). There were significant differences in SUVmax (for all time phases) and RI-SUV dual between BMSLs and MMSLs and between PMMSTs and MMSTs. In the ROC analyses, the areas under the curve for SUV in phases 2 and 3 were highest for differentiating BMSLs from MMSLs and PMMSTs from MMSTs, respectively. Dynamic F-18 FDG PET / CT is valuable for diagnosis of musculoskeletal lesions. J. Med. Invest. 68 : 96-104, February, 2021.

A new quantitative index in the diagnosis of Parkinson syndrome by dopamine transporter single-photon emission computed tomography.

OBJECTIVE: Dopamine transporter single-photon emission computed tomography (DAT SPECT) has been widely used to diagnose Parkinson syndrome. Using the standardized uptake value (SUV) of DAT SPECT, we propose "functional dopamine transporter volume (f-DTV)" as a new quantitative index to evaluate the three-dimensional volume of functional dopamine transporters and assess its diagnostic ability in differentiating dopaminergic neurodegenerative diseases (dNDD) from non-dNDD. METHODS: Seventy-nine patients were enrolled (42 dNDD, 37 non-dNDD; 38 men; age 24-88 years). We analyzed seven quantitative indices. The specific binding ratio (SBR) was calculated using a program specialized for DAT SPECT (SBR_Bolt). The SUVmax, SUVpeak, and SUVmean were calculated using a quantification program for bone SPECT. SBR_SUV was calculated by dividing striatal SUVmean by the average of background SUVmean. The cutoff value of the active dopamine transporter level was examined using three methods (threshold of 40% of SUVmax, SUV 2, and SUV 3) to calculate the active dopamine transporter volume (ADV). The f-DTV was calculated by multiplying ADV and SUVmean. We assessed the correlations between SBR_Bolt and SBR_SUV, and compared the mean value of each index between the dNDD and non-dNDD groups. The abilities of SBR_Bolt, SBR_SUV, SUVmax, SUVpeak, SUVmean, ADV, and f-DTV in differentiating dNDD from non-dNDD were determined by the area under the receiver operating curve (AUC) generated by the receiver operating characteristics analysis. RESULTS: The SBR_Bolt and SBR_SUV highly correlated with each other (r = 0.71). The cutoff value of the active dopamine transporter level was determined as SUV 3. All seven quantitative indices showed lower values in the dNDD group than in the non-dNDD group, and the difference between the two groups was statistically significant (p < 0.05). Sensitivity, specificity, and AUC of f-DTV were slightly lower than those of SBR_Bolt (71%, 79%, and 0.81, respectively, for f-DTV, and 81%, 84%, 0.88, respectively, for SBR_Bolt). The difference in AUC between f-DTV and SBR_Bolt was not statistically significant. CONCLUSIONS: This study demonstrates the utility of f-DTV as a novel quantitative index for evaluating the three-dimensional volume of functional dopamine transporters, and that f-DTV has almost the same diagnostic ability to differentiate dNDD from non-dNDD using DAT SPECT.

The Utility of a Combination of 99mTc-MIBI Washout Imaging and Cardiac Magnetic Resonance Imaging in the Evaluation of Cardiomyopathy.

Background: In cardiomyopathy, 99mTc-MIBI washout can reflect mitochondrial dysfunction and late gadolinium enhancement (LGE) on cardiac magnetic imaging (MRI) is associated with tissue fibrosis. We sought to determine the relationship between 99mTc-MIBI uptake, 99mTc-MIBI washout, and LGE on MRI in patients with cardiomyopathy. Methods: Twenty-one patients underwent rest myocardial perfusion scintigraphy at 45 minutes (early) and 4 hours (delayed) after intravenous 99mTc-MIBI administration and cardiac MRI. We assessed myocardial perfusion, 99mTc-MIBI washout, and LGE. We divided the left ventricle (LV) wall into 16 segments using a polar map. Then, we classified each segment into 5 groups according to 99mTc-MIBI uptake in early-rest images and washout. Additionally, we created a contingency table based on LGE presence/absence in the groups. Results: We evaluated 336 segments in 21 patients. 99mTc-MIBI uptake was decreased in 168 segments in the early-rest 99mTc-MIBI images. 99mTc-MIBI washout was observed in 108 segments with either normal perfusion or reduced perfusion in the early-rest 99mTc-MIBI images. LGE was positive in 104 segments. A contingency table analysis with Fisher's exact test showed that LGE was observed significantly more frequently in the segments with decreased 99mTc-MIBI uptake (p<0.001). In segments without a decreased 99mTc-MIBI uptake, there was a significant correlation between increased 99mTc-MIBI washout and the presence of LGE (p=0.033). Conclusions: In cardiomyopathy, the mitochondrial dysfunction in the early stage is shown as 99mTc-MIBI washout, and fibrotic changes in the myocardium in advanced stages are shown as LGE on cardiac MRI. The severity of myocardial damage and the clinical stage of cardiomyopathy can be evaluated using multimodal imaging.

Diagnosis of recurrence and follow-up using FDG-PET/CT for postoperative non-small-cell lung cancer patients.

BACKGROUND: There is currently no consensus regarding the best program for postoperative follow-up and surveillance after a curative resection for non-small-cell lung cancer (NSCLC) patients. We examined the diagnostic capability of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for detecting recurrence in postoperative NSCLC patients, and we evaluated the results of postoperative surveillance using FDG-PET/CT in asymptomatic patients. PATIENTS AND METHODS: Between 2005 and 2013, 496 FDG-PET/CT examinations were performed to detect recurrences for 187 NSCLC patients who had undergone potentially curative operations at our institution. Follow-up FDG-PET/CT was performed ≥ 1 × /year in principle in 172 asymptomatic patients without clinical or radiological evidence of recurrence, and the results were retrospectively reviewed. RESULTS: FDG-PET/CT correctly diagnosed recurrence in 46 of 47 (97.9%) patients and 68 of 69 (98.6%) recurrent sites. The following were obtained: 97.9% sensitivity, 97.1% specificity, 92.0% positive predictive value, 99.3% negative predictive value, and 97.3% accuracy. In six patients, other diseases were detected and treated appropriately. In asymptomatic patients, the detection rate of recurrence in the stage III group was significantly higher than the detection rates in the stage I and II groups, and FDG-PET/CT performed ≤ 3 years post-resection detected significantly more FDG-positive lesions compared to that performed after 4 years. CONCLUSION: FDG-PET/CT is very useful for detecting recurrence in NSCLC patients after a potentially curative operation. It might be sufficient to perform follow-up FDG-PET/CT until 3 years post-resection for advanced-stage patients. Further randomized clinical trials are needed to determine whether the early detection of recurrences leads to better prognoses.

Semiquantitative assessment of fluorodeoxyglucose uptake in primary tumours on dynamic PET/computed tomography for lymph node metastasis evaluation in patients with lung cancer: a prospective study.

OBJECTIVE: To semiquantitatively estimate fluorine-18-fluorodeoxyglucose (FDG) uptake in primary lung cancer cells using dynamic and dual-time-point (DTP) PET/computed tomography (PET/CT) to obtain a diagnostic index for lymph node metastasis. METHODS: Forty-five patients with lung cancer underwent dynamic and DTP PET/CT examinations. All primary lesions and lymph node metastases were evaluated pathologically. At each time phase, we assessed the maximum standardised uptake value (SUVmax), metabolic tumour volume (MTV) and total lesion glycolysis (TLG) of the primary tumours. We investigated the relationship between semiquantitative index and the presence of lymph node metastasis for each case and for all cases satisfying indications for segmentectomy. In cases with lymph node metastasis, we assessed the SUVmax of pathologically proven metastatic lymph nodes and nonmetastatic lymph nodes in each dynamic phase for evaluating temporal change. RESULTS: Among 45 patients, 15 had 17 lymph node metastasis. SUVmax, MTV and TLG of primary tumours at each time phase were significantly associated with lymph node metastasis (P < 0.05). In receiver operating characteristic analysis, dynamic second and third phases showed high diagnostic ability for lymph node metastasis. The temporal change in SUVmax in the dynamic phase between primary tumours and metastatic lymph nodes were significantly different (P = 0.065). The temporal change in SUVmax was significantly lower in nonmetastatic lymph nodes than in primary tumours and metastatic lymph nodes (P < 0.0001). CONCLUSIONS: Semiquantitative assessment of FDG uptake in dynamic second and third phases and the assessment of temporal changes in SUVmax on dynamic PET/CT scans were important predictors in diagnosing lymph node metastasis.

Preliminary clinical assessment of dynamic carbon-11 methionine positron-emission tomography/computed tomography for the diagnosis of the pathologies in patients with musculoskeletal lesions: a prospective study.

BACKGROUND: This study prospectively assessed the diagnostic capacity of dynamic carbon-11 methionine (C-11 MET) positron-emission tomography (PET)/computed tomography for the diagnosis of pathologies in patients with primary unknown musculoskeletal lesions (MSLs). In total, 13 patients with MSLs underwent dynamic scans (5-10 [phase 1], 10-15 [phase 2], 15-20 [phase 3], 20-25 [phase 4], 25-30 [phase 5], and 30-35 [phase 6] min post-injection of C-11 MET). We statistically compared the maximum standardised uptake values (SUVmax) and corresponding retention index for dynamic scans (RI-SUV) for five benign MSLs (BMSLs), five primary malignant musculoskeletal tumours (PMMSTs), four metastatic musculoskeletal tumours (MMSTs), and three malignant lymphoma (ML) cases and explored their diagnostic capacities using receiver operating characteristic (ROC) curve analyses. RESULTS: SUVmax gradually decreased or remained similar with minimal fluctuations in all BMSL cases and four of five PMMST cases. In contrast, SUVmax increased over time in one case of PMMST and in all cases of MMST and ML. Significant differences were observed in SUVmax for all time phases and RI-SUV between BMSLs and MMSLs, in SUVmax for all time phases between PMMSTs and BMSLs, in SUVmax for all time phases and RI-SUV between non-PMMST-malignant tumours and BMSL, and in RI-SUV between non-PMMST-malignant tumours and PMMST. In ROC analyses, the areas under the curve yielded the highest values at 1.00 for differentiating most intergroup comparisons. CONCLUSIONS: Dynamic C-11 MET PET scans have the potential to be good predictors of discriminating MSLs in patients with primary unknown MSLs in clinical practice.