Parkinson disease (PD), progressive supranuclear palsy (PSP), and multiple-system atrophy (MSA) are known to affect dopaminergic neurons of the brain stem and striatum with different preferential involvement. Here we investigated differences in striatal subregional dopamine transporter loss in PD, PSP, and MSA and assessed the diagnostic value of ¹⁸F-fluorinated-N-3-fluoropropyl-2-β-carboxymethoxy-3-β-(4-iodophenyl)nortropane (¹⁸F-FP-CIT) PET in differentiating PSP and MSA from PD. Methods: Forty-nine patients with PD, 19 patients with PSP, 24 patients with MSA, and 21 healthy people (healthy controls) were examined with ¹⁸F-FP-CIT PET. The PET images were spatially normalized and analyzed with 12 striatal subregional volume-of-interest (VOI) templates (bilateral ventral striatum [VS], anterior caudate [AC], posterior caudate, anterior putamen, posterior putamen [PP], and ventral putamen [VP]) and 1 occipital VOI template. The nondisplaceable binding potential (BP_ND) and intersubregional ratio (ISR; defined as the ratio of the BP_ND of one striatal subregion to that of another striatal subregion) of subregional VOIs were calculated. Results: The BP_ND of all VOIs in the PD, MSA, and PSP groups were significantly lower than those in the healthy controls (P < 0.05). The BP_ND of AC and the AC/VS ISR in the PSP group were significantly lower than those in the PD group. The BP_ND of VP was significantly lower, but the PP/VP ISR was significantly higher in the MSA group than in the PD group. At the cutoff value for the AC/VS ISR (0.65), the sensitivity and specificity for differentiating MSA from PD were 90% and 45%, respectively. The diagnostic accuracy of visual analysis was similar to that of quantitative analysis for differentiating PSP from PD but was significantly higher for differentiating MSA from PD. Conclusion: Compared with PD, PSP and MSA showed more prominent and earlier dopamine transporter loss in the AC and VP, respectively. These findings could be useful for suggesting PSP or MSA in parkinsonian cases without characteristic atypical features.

To evaluate the usefulness of F-18 fluoro-fluorodeoxygulose positron emission tomography computed tomography (F-18 FDG PET-CT) in detecting clinically defined active disease in patients with Takayasu arteritis. F-18 FDG PET-CT was performed in 32 patients with Takayasu arteritis. Disease activity was assessed clinically by the National Institutes of Health (NIH) criteria. In 10 of the 32 patients, F-18 FDG PET-CT was performed while the patients were taking immunosuppressive drugs. Two nuclear physicians visually assessed the degree of F-18 FDG uptake in the walls of the aorta, its major branches and the pulmonary artery using a 4-point scale from grade 0 to III. F-18 FDG uptake greater than grade I in the thoracic aorta or greater than grade 0 in other areas were interpreted as active vasculitic lesions. Ten patients had active lesions on F-18 FDG PET-CT. According to the NIH criteria, 9 patients had active disease and 23 had inactive disease. Compared with disease activity assessed by the NIH criteria, F-18 FDG PET-CT had a sensitivity of 78% and a specificity of 87%. The erythrocyte sedimentation rate and CRP levels were significantly higher in F-18 FDG PET-CT-positive than in F-18 FDG PET-CT-negative patients. There was no significant difference in the proportion of positive PET scans according to the use of glucocorticoids. The sensitivity of F-18 FDG PET-CT for detecting active disease was higher in patients with higher erythrocyte sedimentation rate values. Although the specificity of F-18 FDG PET-CT was high, owing to the low sensitivity of the NIH criteria in detecting active disease, further studies are needed.

The aim of this study was to explore the ability of ¹⁸F-fluoroestradiol (¹⁸F-FES) PET/CT imaging to predict pathologic response to neoadjuvant therapy in postmenopausal women with estrogen receptor (ER)–rich breast cancer. Methods: This was a prospective, single-center study conducted as a substudy of the neoadjuvant study of chemotherapy versus endocrine therapy in postmenopausal patients with primary breast cancer (NEOCENT) trial. Patients with ER-rich breast cancer were randomized to neoadjuvant chemotherapy (NC) or neoadjuvant endocrine therapy (NET). The baseline SUV_max of ¹⁸F-FES PET/CT was measured. The pathologic response was assessed by the Miller–Payne system as nonresponse (grades 1 and 2) and response (grades 3–5). Results: Twenty-six patients were enrolled, with pathologic response achieved in 25 (NC, 12; NET, 13). Two patients achieved pathologic complete response after NC, but the remaining 23 patients had residual disease after NC or NET. Eight of 12 patients responded to NC, and 4 of 13 to NET; the difference was marginally significant (P = 0.07). In the NC group, the 2 patients with ¹⁸F-FES–negative tumors and none of the 10 patients with ¹⁸F-FES–avid tumors achieved pathologic complete response (P = 0.02). No difference in the SUV_max between responders and nonresponders was observed in either group. However, 5 of 7 NC patients with a baseline SUV_max of less than 7.3 achieved pathologic response, whereas none of the 5 NET patients with an SUV_max of less than 7.3 were responders (P = 0.03). The SUV_max values of the NC group were negatively correlated with percentage reduction of tumor cellularity (r = −0.63, P = 0.03), whereas those of the NET group showed positive correlation (r = 0.62, P = 0.02). During the median follow-up of 74 mo (range, 44–85 mo), recurrence occurred in only 4 NET patients. In patients with an SUV_max of less than 7.3, recurrence occurred in none of the 8 NC patients and 2 of the 5 NET patients (P = 0.13). Conclusion: Postmenopausal women who are ER-positive, but ¹⁸F-FES–negative, may benefit from NC rather than NET. ¹⁸F-FES PET/CT has the potential to predict response to neoadjuvant therapy in postmenopausal women with ER-rich breast cancer.

Objective This study evaluated the usefulness of adding single-photon emission computed tomography (SPECT)/computed tomography (CT) (SPECT/CT) to technetium Tc 99m (^99mTc) hexamethylpropylene amine oxime (HMPAO)-labeled leukocyte imaging for diagnosing infections in hip or knee joint prostheses. Methods The ^99mTc-HMPAO-labeled leukocyte scans of 164 patients (71 with hip prostheses and 93 with knee prostheses) with clinically suspected prosthetic infections were reviewed retrospectively. Planar images were taken 4 to 6 and 21 to 26 hours after injecting the labeled leukocytes and SPECT/CT images were obtained 4 to 6 hours after the injection. The final diagnosis of infection was based on pathologic findings (n = 70), bacteriological data (n = 61), or clinical follow-up (n = 33). Results Of the 164 patients, 89 patients had a diagnosis of prosthetic joint infections. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy of the planar images alone were 82.0%, 88.0%, 89.0%, 80.5%, and 84.8%, respectively. When the planar images were combined with SPECT, the sensitivity, specificity, PPV, NPV, and diagnostic accuracy were 91.0%, 88.0%, 90.0%, 89.2%, and 89.6%, respectively. When the planar images were combined with SPECT/CT, these values increased further to 93.3%, 93.3%, 94.3%, 92.1%, and 93.3%, respectively. Adding CT to SPECT resulted in a greater increase in sensitivity and specificity for hip prosthesis infections than for knee prosthesis infections. SPECT/CT mainly contributed by precisely localizing the anatomical site of the active inflammatory lesion and by delineating the extent of the lesion after diagnosis with SPECT. Conclusions Single-photon emission computed tomography/CT combined with ^99mTc-HMPAO-labeled leukocyte imaging was useful for diagnosing prosthesis infections, particularly in hip prosthesis infections, as it improved diagnostic accuracy and provided anatomical localization data.

The purpose of this study was to determine the 18F-FDG avidity of MALT lymphoma and the additional utility of 18F-FDG PET/CT in MALT lymphoma staging. Pretreatment 18F-FDG PET/CT scans of 222 patients with 227 MALT lymphoma lesions were retrospectively analyzed. 18F-FDG avidity of lesions was noted in 28%. The proportion was lower for gastric MALT lymphomas than for non-gastric lesions (9% vs. 60%, p<0.0001) and higher for mass-forming lesions than for superficial lesions (82% vs. 2%, p<0.0001). 18F-FDG PET/CT showed the presence of additional lesions in 23 patients: four of six true-positive lesions had 18F-FDG avid primary lesions, and 15 of 17 false-positive lesions had 18F-FDG-non avid lesions. 18F-FDG avidity differed according to the location and gross morphologic characteristics of the MALT lymphoma. Most gastric MALT lymphomas were superficial and had low 18F-FDG avidity. For staging, 18F-FDG PET/CT can be helpful mainly for 18F-FDG avid primary MALT lymphomas.

Sarcopenia- or cachexia-related muscle atrophy is due to imbalanced energy metabolism and oxidative stress-induced muscle dysfunction. Monoterpenes play biological and pharmacological reactive oxygen species (ROS) scavenging roles. Hence, we explored the effects of camphene, a bicyclic monoterpene, on skeletal muscle atrophy in vitro and in vivo. We treated L6 myoblast cells with camphene and then examined the ROS-related oxidative stress using Mito Tracker^TM Red FM and anti-8-oxoguanine antibody staining. To investigate lipid metabolism, we performed real-time polymerase chain reactions, holotomographic microscopy, and respiratory gas analysis. Rat muscle atrophy in in vivo models was observed using ¹⁸F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography and immunocytochemistry. Camphene reversed the aberrant cell size and muscle morphology of L6 myoblasts under starvation and in in vivo models. Camphene also attenuated E3 ubiquitin ligase muscle RING-finger protein-1, mitochondrial fission, and 8-oxoguanine nuclear expression in starved myotubes and hydrogen peroxide (H₂O₂)-treated cells. Moreover, camphene significantly regulated lipid metabolism in H₂O₂-treated cells and in vivo models. These findings suggest that camphene may potentially affect skeletal muscle atrophy by regulating oxidative stress and lipid metabolism.