The development status of PET radiotracers for evaluating neuroinflammation.

Neuroinflammation is associated with the pathophysiologies of neurodegenerative and psychiatric disorders. Evaluating neuroinflammation using positron emission tomography (PET) plays an important role in the early diagnosis and determination of proper treatment of brain diseases. To quantify neuroinflammatory responses in vivo, many PET tracers have been developed using translocator proteins, imidazole-2 binding site, cyclooxygenase, monoamine oxidase-B, adenosine, cannabinoid, purinergic P2X7, and CSF-1 receptors as biomarkers. In this review, we introduce the latest developments in PET tracers that can image neuroinflammation, focusing on clinical trials, and further consider their current implications.

Assessing the applicability of PMOD residence times model for PET image-based radiation dosimetry.

The effective dose represents the overall internal radiation exposure to the whole body when exposed to radiation sources. This study aims to compare conventional and software-aided methods to derive the effective dose. In the present study, 8F-T807 and 18F-Mefway, specific radiotracers for the paired helical tau and serotonin 1A receptor, were administered to healthy subjects (n = 6, each radiotracer), following which whole-body positron emission tomography (PET) images were obtained for 2 h. Subsequently, time-activity curves for major organs were obtained, and the residence times were calculated using the "conventional" and "Residence Times model" tools in PMOD software. The residence times from each method was input into OLINDA/EXM software, and the effective dose was estimated. The differences in the average residence times of the brain, heart, lung, and liver were 18.4, 20.8, 10.4, and 13.3% for 18F-T807, and 17.5, 16.4, 18.1, and 17.5% for 18F-Mefway, respectively. For the mean effective dose, the error rates between the methods were 3.8 and 1.9% for 18F-T807 and 18F-Mefway, respectively. The organs that showed the greatest difference in the absorbed dose were the urinary bladder for 18F-T807 (40.4%) and the liver for 18F-Mefway (14.1%). This method of obtaining the residence time using PMOD can be easily used to derive the effective dose, and is applicable in evaluating the safety of radiotracers for clinical trials.

Prediction of Microsatellite Instability in Colorectal Cancer Using a Machine Learning Model Based on PET/CT Radiomics.

PURPOSE: We investigated the feasibility of preoperative 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) radiomics with machine learning to predict microsatellite instability (MSI) status in colorectal cancer (CRC) patients. MATERIALS AND METHODS: Altogether, 233 patients with CRC who underwent preoperative FDG PET/CT were enrolled and divided into training (n=139) and test (n=94) sets. A PET-based radiomics signature (rad_score) was established to predict the MSI status in patients with CRC. The predictive ability of the rad_score was evaluated using the area under the receiver operating characteristic curve (AUROC) in the test set. A logistic regression model was used to determine whether the rad_score was an independent predictor of MSI status in CRC. The predictive performance of rad_score was compared with conventional PET parameters. RESULTS: The incidence of MSI-high was 15 (10.8%) and 10 (10.6%) in the training and test sets, respectively. The rad_score was constructed based on the two radiomic features and showed similar AUROC values for predicting MSI status in the training and test sets (0.815 and 0.867, respectively; p=0.490). Logistic regression analysis revealed that the rad_score was an independent predictor of MSI status in the training set. The rad_score performed better than metabolic tumor volume when assessed using the AUROC (0.867 vs. 0.794, p=0.015). CONCLUSION: Our predictive model incorporating PET radiomic features successfully identified the MSI status of CRC, and it also showed better performance than the conventional PET image parameters.

Role of Enlarged Perivascular Space in the Temporal Lobe in Cerebral Amyloidosis.

OBJECTIVE: Although growing evidence suggests that perivascular space (PVS) serves as a clearance route for amyloid and tau, the association between enlarged PVS (EPVS) and Alzheimer disease is highly inconsistent across studies. As the conventional visual rating systems for EPVS were insufficient to predict amyloid/tau/neurodegeneration (A/T/N) status, we developed a new rating scale for EPVS located in the temporal lobe (T-EPVS). METHODS: EPVS located in the basal ganglia (BG-EPVS), centrum semiovale (CS-EPVS), and T-EPVS was visually rated in 272 individuals (healthy controls, n = 96; mild cognitive impairment, n = 106; dementia, n = 70) who underwent structural magnetic resonance imaging (MRI) and dual positron emission tomography scans (18 F-flortaucipir and 18 F-florbetaben). T-EPVS and BG-EPVS were defined as high degree when the counts in any hemisphere were >10, and the CS-EPVS cutoff was >20. Logistic regression models were constructed to investigate whether the regional EPVS burden was predictive of A/T/N status. The derived models were externally validated in a temporal validation cohort (n = 195) that underwent MRI studies using a different scanner. RESULTS: Compared with those with low-degree T-EPVS (23/136, 16.9%), individuals with high-degree T-EPVS/CS-EPVS but low-degree BG-EPVS were more likely to exhibit amyloid positivity (46/56, 82.1%). High-degree T-EPVS burden (odds ratio [OR] = 7.251, 95% confidence interval [CI] = 3.296-15.952) and low-degree BG-EPVS (OR = 0.241, 95% CI = 0.109-0.530) were predictive of amyloid positivity. Although high-degree T-EPVS was associated with tau positivity, the association was no longer significant after adjusting for amyloid and neurodegeneration status. INTERPRETATION: Investigating the burden and topographic distribution of EPVS including T-EPVS may be useful for predicting amyloid status, indicating that impaired perivascular drainage may contribute to cerebral amyloidosis. ANN NEUROL 2023;93:965-978.

18F-FDG uptake of visceral adipose tissue on preoperative PET/CT as a predictive marker for breast cancer recurrence.

Glucose utilization by visceral adipose tissue (VAT) reflects inflammatory activity, which also promotes tumor growth and carcinogenesis. The effect of metabolically active VAT on survival outcomes in breast cancer is unknown. We investigated survival outcomes in patients with breast cancer based on the standardized uptake value (SUV) of VAT (SUVmean-VAT) using 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). A total of 148 patients with breast cancer were divided into high- and low groups according to their SUVmean-VAT and SUVmax-tumor. Clinical characteristics and survival outcomes were compared between the groups. High SUVmean-VAT was associated with poor recurrence-free survival (RFS; hazard ratio [HR], 2.754; 95% confidence interval [CI], 1.090-6.958, p = 0.032) and distant metastasis-free survival (DMFS; HR, 3.500; 95% CI, 1.224-10.01, p = 0.019). Multivariate analysis showed that high SUVmean-VAT was a significant factor for poor RFS and poor DMFS (p = 0.023 and 0.039, respectively). High SUVmax-tumor was significantly associated with short RFS (p = 0.0388). Tumors with a high SUV tended to have a short DMFS, although the difference was not significant (p = 0.0718). Our findings showed that upregulated glucose metabolism in the VAT measured using 18F-FDG PET/CT may be a prognostic biomarker for adverse outcomes in breast cancer.

Different prognostic impact of glucose uptake in visceral adipose tissue according to sex in patients with colorectal cancer.

The purpose of this study was to investigate whether sex differences in visceral fat volume and glucose uptake measured by positron emission tomography/computed tomography (PET/CT) in abdominal visceral fat can stratify overall survival (OS) in patients with colorectal cancer (CRC). We retrospectively enrolled 293 patients diagnosed with CRC who underwent PET/CT before surgical resection. Fluorodeoxyglucose uptake of visceral adipose tissue (VAT-SUV) and subcutaneous adiposity tissue (SAT-SUV) were measured using PET/CT. The relative VAT (rVAT) was defined as the visceral fat volume normalized to the total volume of fat (VAT plus SAT). We defined sex-specific cutoff values for VAT-SUV, SAT-SUV, and rVAT. Univariate and multivariate analyses using Cox proportional hazard regression analysis were performed to identify the independent prognostic factors. The study population comprised 181 men and 112 women. The rVAT (0.40 vs. 0.29, p < 0.001) and VAT-SUV (0.55 vs. 0.48, p = 0.007) were significantly greater in men than in women. High rVAT (than low rVAT) and high VAT-SUV (than low VAT-SUV) showed a worse prognosis in male and female patients, respectively. Multivariate analysis indicated that the combination of rVAT and VAT-SUV was an independent prognostic factor for predicting OS in both male and female patients. The combination of rVAT and VAT-SUV could differentiate the patients with the best survival outcome from the other three individual groups in female patients, but not in males. Glucose uptake and relative volume of visceral fat may provide a new risk stratification for patients with CRC, especially female patients.

Prognostic Role of Pre-Treatment [18F]FDG PET/CT in Patients with Anaplastic Thyroid Cancer.

Anaplastic thyroid carcinoma (ATC) is a rare but highly lethal disease. Therefore, its diagnosis at an early stage and a rapid and accurate establishment of a proper treatment strategy is warranted. Tumor glycolysis assessed by 18fluorodeoxyglucose ([18F]FDG) positron emission tomography (PET)/computed tomography (CT) is predictive of many cancers despite its limited proven applicability to ATC. We investigated the prognostic capability of [18F]FDG PET/CT in patients with ATC. Forty patients with ATC were subjected to [18F]FDG PET/CT for pre-treatment evaluation. The tumor size and stage, overall survival (OS), and PET parameters, including the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were analyzed. The 1-year OS rate was 17.5% with a mean life expectancy of 7.1 months. Distant metastasis was detected solely using PET/CT in 37.5% of cases. High SUVmax, MTV, and TLG were significantly associated with poor prognosis (p < 0.001, p = 0.002, and p < 0.001, respectively). A significant difference (p < 0.001) was observed in OS between patients with a high and low tumor SUVmax. Glucose metabolism assessed by [18F]FDG PET/CT was significantly associated with the OS of patients with ATC. PET-derived parameters such as SUVmax, MTV, and TLG are useful prognostic biomarkers for ATC.

Prognostic significance of bone marrow and spleen 18F-FDG uptake in patients with colorectal cancer.

Serum inflammatory markers are used in the prognostication of colorectal cancer (CRC); however, the corresponding role of positron emission tomography (PET)-derived inflammatory markers remains unclear. This study aimed to investigate the prognostic value of 18F-fluorodeoxyglucose (FDG) uptake in the bone marrow and spleen of patients with CRC and evaluate the relationship between FDG uptake estimates in these organs and serum inflammatory markers. In total, 411 patients who underwent preoperative FDG PET/computed tomography (CT) within 1 month of surgery were enrolled. The mean standardized uptake values of the bone marrow and spleen were normalized to the value of the liver, thereby generating bone marrow-to-liver uptake ratio (BLR) and spleen-to-liver uptake ratio (SLR) estimates. The value of BLR and SLR in predicting overall survival (OS) was assessed using the Cox proportional hazards model. The correlation between BLR or SLR and neutrophil-to-lymphocyte ratio (NLR) was evaluated. The predictive accuracy of BLR alone and in combination with SLR was compared using the integrated area under the receiver operating characteristic curves (iAUC). In the univariate analysis, BLR (> 1.06) and SLR (> 0.93) were significant predictors of OS. In the multivariate analysis, BLR was an independent predictor of OS (hazard ratio = 5.279; p < 0.001). Both BLR and SLR were correlated with NLR (p < 0.001). A combination of BLR and SLR was better than BLR alone at CRC prognostication (iAUC, 0.561 vs. 0.542). FDG uptake estimates in the bone marrow and spleen may be useful imaging-derived biomarkers of systemic inflammation, supporting CRC prognostication.

Effect of APOE ε4 genotype on amyloid-ß and tau accumulation in Alzheimer's disease.

BACKGROUND: To assess the effects of apolipoprotein E (ApoE) ε4 genotype on amyloid-ß (Aß) and tau burden and their longitudinal changes in Alzheimer's disease (AD) spectrum. METHODS: Among 272 individuals who underwent PET scans (18F-florbetaben for Aß and 18F-flortaucipir for tau) and ApoE genotyping, 187 individuals completed 2-year follow-up PET scans. After correcting for the partial volume effect, we compared the standardized uptake value ratio (SUVR) for Aß and tau burden between the ε4+ and ε4- groups. By using a linear mixed-effect model, we measured changes in SUVR in the ApoE ε4+ and ε4- groups. RESULTS: The ε4+ group showed greater baseline Aß burden in the diffuse cortical regions and greater tau burden in the lateral, and medial temporal, cingulate, and insula cortices. Tau accumulation rate was higher in the parietal, occipital, lateral, and medial temporal cortices in the ε4+ group. In Aß+ individuals, baseline tau burden was greater in the medial temporal cortex, while Aß burden was conversely greater in the ε4- group. Tau accumulation rate was higher in the ε4+ group in a small region in the lateral temporal cortex. The effect of ApoE ε4 on enhanced tau accumulation persisted even after adjusting for the global cortical Aß burden. CONCLUSIONS: Progressive tau accumulation may be more prominent in ε4 carriers, particularly in the medial and lateral temporal cortices. ApoE ε4 allele has differential effects on the Aß burden depending on the existing amyloidosis and may enhance vulnerability to progressive tau accumulation in the AD spectrum independent of Aß.

Clinicopathologic risk factors of radioactive iodine therapy based on response assessment in patients with differentiated thyroid cancer: a multicenter retrospective cohort study.

PURPOSE: We investigated whether predictive clinicopathologic factors can be affected by different response criteria and how the clinical usefulness of radioactive iodine (RAI) therapy should be evaluated considering variable factors in patients with differentiated thyroid carcinoma (DTC). METHODS: A total of 1563 patients with DTC who underwent first RAI therapy after total or near total thyroidectomy were retrospectively enrolled from 25 hospitals. Response to therapy was evaluated with two different protocols based on combination of biochemical and imaging studies: (1) serum thyroglobulin (Tg) and neck ultrasonography (US) and (2) serum Tg, neck US, and radioiodine scan. The responses to therapy were classified into excellent and non-excellent or acceptable and non-acceptable to minimize the effect of non-specific imaging findings. We investigated which factors were associated with response to therapy depending on the follow-up protocols as well as response classifications. Multivariate logistic regression analysis was performed to identify factors significantly predicting response to therapy. RESULTS: The proportion of patients in the excellent response group significantly decreased from 76.5 to 59.6% when radioiodine scan was added to the follow-up protocol (P < 0.001). Preparation method (recombinant human TSH vs. thyroid hormone withdrawal) was a significant factor for excellent response prediction evaluated with radioiodine scan (OR 2.129; 95% CI 1.687-2.685; P < 0.001) but was not for other types of response classifications. Administered RAI activity, which was classified as low (1.11 GBq) or high (3.7 GBq or higher), significantly predicted both excellent and acceptable responses regardless of the follow-up protocol. CONCLUSIONS: The clinical impact of factors related to response prediction differed depending on the follow-up protocol or classification of response criteria. A high administered activity of RAI was a significant factor predicting a favorable response to therapy regardless of the follow-up protocol or classification of response criteria.

Off-Target 18F-AV-1451 Binding in the Basal Ganglia Correlates with Age-Related Iron Accumulation.

Off-target binding in the basal ganglia is commonly observed in the 18F-AV-1451 PET studies of the elderly. We sought to investigate the relationship between this phenomenon in the basal ganglia and iron accumulation using iron-sensitive R2* MRI. Methods: Fifty-nine healthy controls and 61 patients with Alzheimer disease and mild cognitive impairment underwent 18F-AV-1451 PET and R2* MRI studies. A correlation analysis was performed for age, 18F-AV-1451 binding, and R2* values. Results: There was an age-related increase in both 18F-AV-1451 binding in the basal ganglia and R2* values in the putamen in both the controls and the Alzheimer disease/mild cognitive impairment patients. 18F-AV-1451 binding in the basal ganglia increased with R2* values. Conclusion: Off-target 18F-AV-1451 binding in the basal ganglia is associated with the age-related increases in iron accumulation. Postmortem studies are required to further investigate the nature of this association.

Comparison of standardized uptake value of 18F-FDG-PET-CT with 21-gene recurrence score in estrogen receptor-positive, HER2-negative breast cancer.

BACKGROUND: We investigated the relationship between 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG-PET-CT) standardized uptake value (SUV) and 21-gene recurrence score (RS) in estrogen receptor (ER)-positive/HER2-negative breast cancer. MATERIALS AND METHODS: One hundred sixty-seven patients were identified among those who underwent preoperative 18F-FDG-PET-CT and had RS. Maximum SUV was obtained from 18F-FDG-PET-CT; the cut-off point was 4. RESULTS: The continuous RS and SUV correlated positively (Pearson's R = 0.555; P < 0.001). An inverse correlation was found between progesterone receptor (PR) expression by reverse transcriptase-polymerase chain reaction, and SUV (Pearson's R = -0.408; P < 0.001). Good agreement between dichotomized RS (<26 vs. ≥26) and SUV (<4 vs. ≥4) was observed in 137 of 167 patients (82.0%; 95% confidence interval [CI], 76.2-87.9). Among patients with low SUV, 114 of 115 (99.1% [95% CI, 97.4-100.0]) had tumors with lower RS (<26). Although 23 of 52 women (44.2% [95% CI, 30.7-57.7]) with high SUV had higher RS (≥26), all 13 women with high RS (≥31) had high-SUV tumors. Most cases with disagreements between SUV and RS (n = 30) were classified as high SUV/lower RS (n = 29). The discordant group had higher grade or elevated Ki67 expression (≥20%) compared with the low SUV/lower RS group (n = 109), but higher PR expression compared with the high SUV/higher RS group (n = 23). Multiple logistic regression analysis showed that high SUV were associated with higher RS (≥26). CONCLUSIONS: SUV, as a biologic parameter represented using a continuous variable, was found to associate with RS in ER-positive, HER2-negative breast cancer. Further studies may reveal the biology underlying the discordance between the markers.

Shear-Wave Elastography for the Differential Diagnosis of Breast Papillary Lesions.

OBJECTIVE: To evaluate the diagnostic performance of shear-wave elastography (SWE) for the differential diagnosis of breast papillary lesions. METHODS: This study was an institutional review board-approved retrospective study, with a waiver of informed consent. A total of 79 breast papillary lesions in 71 consecutive women underwent ultrasound and SWE prior to biopsy. Ultrasound features and quantitative SWE parameters were recorded for each lesion. All lesions were surgically excised or excised using an ultrasound-guided vacuum-assisted method. The diagnostic performances of the quantitative SWE parameters were compared using the area under the receiver operating characteristic curve (AUC). RESULTS: Of the 79 lesions, six (7.6%) were malignant and 12 (15.2%) were atypical. Orientation, margin, and the final BI-RADS ultrasound assessments were significantly different for the papillary lesions (p < 0.05). All qualitative SWE parameters were significantly different (p < 0.05). The AUC values for SWE parameters of benign and atypical or malignant papillary lesions ranged from 0.707 to 0.757 (sensitivity, 44.4-94.4%; specificity, 42.6-88.5%). The maximum elasticity and the mean elasticity showed the highest AUC (0.757) to differentiate papillary lesions. CONCLUSION: SWE provides additional information for the differential diagnosis of breast papillary lesions. Quantitative SWE features were helpful to differentiate breast papillary lesions.

Biodistribution and Radiation Dosimetry of [18F]Mefway in Humans.

PURPOSE: [18F]Mefway is a positron emission tomography (PET) radioligand for quantification of the brain serotonin 1A (5-HT1A) receptor density. The purpose of this study was to evaluate the radiation safety of [18F]Mefway in humans. PROCEDURES: Six healthy volunteers (three males and three females) were whole-body PET scanned for 114 min after injection of [18F]Mefway (226 ± 35 MBq). Estimated radiation doses were determined by the OLINDA/EXM software. RESULTS: [18F]Mefway was safe and well tolerated by all subjects. Residence time ranges from 0 (gallbladder) to 0.822 h (urinary bladder wall). While the estimated radiation doses in the reproductive and blood-forming organs were below 13.35-22.87 µSv/MBq, radiation dose in the urinary bladder wall was 471 µSv/MBq. The mean effective dose was 40.23 ± 6.63 µSv/MBq. CONCLUSION: For a typical single injection of 185 MBq (5 mCi), the dose will result in 87.1 mSv for the urinary bladder wall. To reduce radiation burden, the bladder voiding can be used before [18F]Mefway PET scan.

Human Radiation Dosimetry of [(18)F]AV-1451(T807) to Detect Tau Pathology.

PURPOSE: [(18)F]AV-1451 is a positron emission tomography (PET) radioligand for detecting paired helical filament tau. Our aim was to estimate the radiation dose of [(18)F]AV-1451 in humans. PROCEDURES: Whole-body PET scans were acquired for six healthy volunteers (three male, three female) for 128 min after injection of [(18)F]AV-1451 (268 ± 31 MBq). Radiation doses were estimated using the OLINDA/EXM software. RESULTS: The estimated organ doses ranged from 7.81 to 81.2 µSv/MBq. The critical organ for radiation burden was the liver. Radiation doses to the reproductive and blood-forming organs were 14.15, 8.43, and 18.35 µSv/MBq for the ovaries, testes, and red marrow, respectively. The mean effective dose was 22.47 ± 3.59 µSv/MBq. CONCLUSIONS: A standard single injection of 185 MBq (5 mCi) results in an effective dose of 4.7 mSv in a healthy subject. Therefore, [(18)F]AV-1451 could be used in multiple PET scans of the same subject per year.

Relationship Between 18F-Fluorodeoxyglucose Uptake and V-Ki-Ras2 Kirsten Rat Sarcoma Viral Oncogene Homolog Mutation in Colorectal Cancer Patients: Variability Depending on C-Reactive Protein Level.

To evaluate clinical values of clinicopathologic and 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT)-related parameters for prediction of v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutation in colorectal cancer (CRC) and to investigate their variability depending on C-reactive protein (CRP) levels. In total, 179 CRC patients who underwent PET/CT scans before curative resection and KRAS mutation evaluation following surgery were enrolled. Maximum standardized uptake value (SUV max), peak standardized uptake value (SUV peak), metabolic tumor volume, and total lesion glycolysis were determined semiquantitatively. Associations between clinicopathologic and PET/CT-related parameters and KRAS expression were analyzed. Elevated CRP (> 6.0 mg/L; n = 47) was associated with higher primary tumor size, higher SUV max, SUV peak, metabolic tumor volume, and total lesion glycolysis, compared with those for the group with a CRP lower than that the cutoff value (< 6.0 mg/L; n = 132). Interestingly, the CRC patients (having CRP < 6.0 mg/L) with KRAS mutations had significantly higher (P < 0.05) SUV max and SUV peak values than the patients expressing wild-type KRAS mutations. Multivariate analysis revealed SUV max and SUV peak to be significantly associated with KRAS mutations (odds ratio = 3.3, P = 0.005, and odds ratio = 3.9, P = 0.004), together with histologic grade and lymph node metastasis. 18F-FDG uptake was significantly higher in CRC patients with KRAS mutations and with normal CRP levels. A severe local inflammation with raised CRP levels, however, might affect accurate 18F-FDG quantification in CRC tumors. Positron emission tomography/computed tomography-related parameters could supplement genomic analysis to determine KRAS expression in CRC; however, care should be exercised to guarantee proper patient selection.

P-Glycoprotein, not BCRP, Limits the Brain Uptake of [(18)F]Mefway in Rodent Brain.

PURPOSE: The aim of this study was to determine whether the brain uptake of [(18)F]Mefway is influenced by the action of P-glycoprotein (P-gp) and breast cancer resistance protein (Bcrp) in rodents. PROCEDURES: [(18)F]Mefway was applied to rats pharmacologically inhibited with tariquidar (TQD) and to genetically disrupted mice. RESULTS: Pretreatment of TQD results in 160% higher hippocampal uptake compared with control rats. In genetically disrupted mice, a maximal brain uptake value of 3.2 SUV in the triple knockout mice (tKO, Mdr1a/b((-/-))Bcrp1((-/-))) was comparable to that of the double knockout mice (dKO, Mdr1a/b((-/-))) and 2-fold those of the wild-type and Bcrp1((-/-)) knockout mice. The differences of binding values were statistically insignificant between control and experimental groups. The brain-to-plasma ratios for tKO mice were also two to five times higher than those for other groups. CONCLUSIONS: [(18)F]Mefway is modulated by P-gp, and not by Bcrp in rodents.

Usefulness of (131)I-SPECT/CT and (18)F-FDG PET/CT in Evaluating Successful (131)I and Retinoic Acid Combined Therapy in a Patient with Metastatic Struma Ovarii.

Metastatic struma ovarii is an extremely rare disease, and the treatment of choice has not been established. Here, we introduce the case of a 36-year-old female pregnant patient with metastatic struma ovarii. Initial treatment was an exploratory laparotomy to remove multiple peritoneal masses. After delivery, a total thyroidectomy was done for the further (131)I-therapy. (131)I-SPECT/CT and (18) F-FDG PET/CT showed multiple hepatic metastases and extensive peritoneal seeding nodules. Multiple (131)I and retinoic acid combination therapies were performed, resulting in marked improvement. (131)I-SPECT/CT and (18) F-FDG PET/CT were quite useful for evaluating the biologic characteristics of the metastases.

Usefulness of 18F-fluorodeoxyglucose Positron Emission Tomography-Computed Tomography in Monitoring Adhesive Capsulitis After Breast Cancer Treatment.

OBJECTIVES: We aimed to assess the usefulness of F-fluorodeoxyglucose (F-FDG) positron emission tomography-computed tomography (PET/CT) in the monitoring of adhesive capsulitis (AC), a joint problem commonly observed in the upper arm after breast cancer treatment. METHODS: This retrospective study included 230 patients who underwent F-FDG PET/CT before and after modified radical mastectomy of whom 22 patients were identified as having AC and categorized into 2 groups: with severely and mildly limited range of motion in the shoulder joint. The F-FDG uptake patterns and mean and maximum standardized uptake values (SUVs) were analyzed. RESULTS: The overall incidence of AC after MRM was 9.57%. The SUVs were significantly higher in patients with severely limited range of motion compared with the other group. There was no association between the SUV and radiotherapy. The F-FDG uptake pattern differed between the groups. CONCLUSIONS: F-fluorodeoxyglucose PET/CT is useful in evaluating AC after breast cancer treatment.

Prognostic significance of standardized uptake value on preoperative ¹8F-FDG PET/CT in patients with ampullary adenocarcinoma.

PURPOSE: The purpose of this study was to investigate the prognostic value of (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in patients with ampullary adenocarcinoma (AAC) after curative surgical resection. METHODS: Fifty-two patients with AAC who had undergone (18)F-FDG PET/CT and subsequent curative resections were retrospectively enrolled. The maximum standardized uptake value (SUVmax) and tumor to background ratio (TBR) were measured on (18)F-FDG PET/CT in all patients. The prognostic significances of PET/CT parameters and clinicopathologic factors for recurrence-free survival (RFS) and overall survival (OS) were evaluated by univariate and multivariate analyses. RESULTS: Of the 52 patients, 19 (36.5%) experienced tumor recurrence during the follow-up period and 18 (35.8%) died. The 3-year RFS and OS were 62.3 and 61.5%, respectively. Preoperative CA19-9 level, tumor differentiation, presence of lymph node metastasis, SUVmax, and TBR were significant prognostic factors for both RFS and OS (p < 0.05) on univariate analyses, and patient age showed significance only for predicting RFS (p < 0.05). On multivariate analyses, SUVmax and TBR were independent prognostic factors for RFS, and tumor differentiation, SUVmax, and TBR were independent prognostic factors for OS. CONCLUSION: SUVmax and TBR on preoperative (18)F-FDG PET/CT are independent prognostic factors for predicting RFS and OS in patients with AAC; patients with high SUVmax (>4.80) or TBR (>1.75) had poor survival outcomes. The role of and indications for adjuvant therapy after curative resection of AAC are still unclear. (18)F-FDG uptake in the primary tumor could provide additive prognostic information for the decision-making process regarding adjuvant therapy.