Value SUVmax Research Articles

FAPI PET/CT provides higher uptake and better target to back ground in recurrent and metastatic tumors of patients with Iodine refractory papillary thyroid cancer compared with FDG PET CT.

The role of fibroblast activation protein inhibitor (FAPI) PET CT scan is not well documented in papillary thyroid cancer (PTC) patients. Patients with radioiodine refractory PTC and high thyroglobulin levels need PET/CT scan which is generally done by 18F FDG. In the current study, the diagnostic performance of 68Ga FAPI and FDG PET/CT scans were compared head to head in patients with radioiodine refractory PTC. Fourteen patients with negative whole body Iodine scans and high thyroglobulin levels underwent whole body PET scans with, respectively, 120-310 and 145-370 MBq 68Ga FAPI-46 and 18F FDG. SUVmax of the back ground in the blood pool and liver and the hottest, largest and average neck, mediastinum, lung and bone lesions were calculated and compared. Ten patients had at least one active (SUVmax>blood pool) lesion similarly in two scans. The liver and blood pool SUVmax values were 1.25(0.2) and 1.7(0.2) in FAPI and 2.65(0.2) and 2.0(0.2) in FDG PET images, respectively. The difference was significant (p=0.001). Standard SUV of the hottest lesion to liver was above 3 in all FAPI scans but in half of FDG scans. Target lesion number and intensity were similar between two PET studies but in a patient out of 5 pulmonary metastatic patients, pulmonary nodules were negative (SUVmax=0.9) in FDG while positive (SUVmax= 3.8) in FAPI images (i.e. 20% patient upstaged). FAPI accumulates in the recurrent and metastatic lesions of patients with Iodine refractory PTC at least as well as FDG with particular privileges as lower injected activity and lower back ground.

18F-Sodium fluoride PET-CT visualizes disease activity in chronic nonbacterial osteitis in adults.

Chronic nonbacterial osteitis (CNO) is a rare disease spectrum, which lacks biomarkers for disease activity. Sodium fluoride-18 positron emission tomography/computed tomography ([18F]NaF-PET/CT) is a sensitive imaging tool for bone diseases and yields quantitative data on bone turnover. We evaluated the capacities of [18F]NaF-PET/CT to provide structural and functional assessment in adult CNO. A coss-sectional study was performed including 43 adult patients with CNO and 16 controls (patients referred for suspected, but not diagnosed with CNO) who underwent [18F]NaF-PET/CT at our expert clinic. Structural features were compared between patients and controls, and maximal standardized uptake values (SUVmax [g/mL]) were calculated for bone lesions, soft tissue/joint lesions, and reference bone. SUVmax was correlated with clinical disease activity in patients. Structural assessment revealed manubrial and costal sclerosis/hyperostosis and calcification of the costoclavicular ligament as typical features associated with CNO. SUVmax of CNO lesions was higher compared with in-patient reference bone (mean paired difference: 11.4; 95% CI: 9.4-13.5; p < .001) and controls (mean difference: 12.4; 95%CI: 9.1-15.8; p < .001). The highest SUVmax values were found in soft tissue and joint areas such as the costoclavicular ligament and manubriosternal joint, and these correlated with erythrocyte sedimentation rate in patients (correlation coefficient: 0.546; p < .002). Our data suggest that [18F]NaF-PET/CT is a promising imaging tool for adult CNO, allowing for detailed structural evaluation of its typical bone, soft-tissue, and joint features. At the same time, [18F]NaF-PET/CT yields quantitative bone remodeling data that represent the pathologically increased bone turnover and the process of new bone formation. Further studies should investigate the application of quantified [18F]NaF uptake as a novel biomarker for disease activity in CNO, and its utility to steer clinical decision making.

The Effect of Hounsfield Unit Value on the Differentiation of Malignant/Benign Mediastinal Lymphadenopathy and Masses Diagnosed by Endobronchial Ultrasonography.

In cases where standardized maximum uptake (SUVmax) values in positron emission tomography (PET-CT) were not sufficient to differentiate mediastinal lymphadenopathy and masses from malignant or benign, the contribution of Hounsfield unit (HU) values in thorax computed tomography to the diagnosis was evaluated. The study was conducted by evaluating the data of 182 patients between 2019 and 2023. HU values on non-contrast thorax computed tomography and PET-CT SUVmax values of biopsied masses and lymph nodes were compared with histopathological diagnoses. Patients, 58 females (31.9%) and 124 males (68.1%), who underwent EBUS were included in the study. Biopsies were taken from 233 stations (199 lymph nodes, 34 masses) from 182 patients. A total of 135 of the biopsies taken from 233 stations were histopathologically malignant and 98 were benign. While PET-CT SUVmax values of cases with benign histopathology were 4.5 ± 3.5, it was 7.6 ± 4.2 in patients with malignant pathology (p<0.05). The HU value on non-contrast thorax tomography in patients with benign histopathology was 43.1 ± 15.7, and in patients with malignant histopathology it was 40.5 ± 13.7 (p>0.05). When HU was compared according to lung cancer type, it was found to be significantly higher in non-small cell lung cancer (p=0.035). A weak (r=0.182) positive and significant relationship (p<0.01) was found between PET-CT values and HU values in thorax computed tomography. While positron emission tomography maintains its importance in the differentiation of mediastinal lymphadenopathy and masses from malignant to non-malignant, it was concluded that HU values in computed tomography are not sufficient to distinguish malignant/non-malignant.

Value of Molecular Typing Combined with Integrated Positron Emission Tomography/Magnetic Resonance Imaging in Risk Stratification of Endometrial Cancer.

In this study, we investigated the value of molecular typing combined with integrated positron emission tomography (PET)/magnetic resonance imaging (MRI) semi-quantitative indices in endometrial cancer risk stratification. A retrospective study was conducted on 86 patients who were pathologically diagnosed with endometrial cancer and underwent surgical treatment after curettage at the Department of Obstetrics and Gynecology, Xuanwu Hospital, Capital Medical University between January 2017 and March 2023. Prior to surgery, each patient underwent integrated PET/MRI examination. The postoperative samples were subjected to pathological diagnosis, immunohistochemistry, and POLE gene sequencing. The differences in clinicopathological features between the four molecular subtypes and the differences in integrated PET/MRI semi-quantitative indexes (SUV max, ADC min) between the four molecular subtypes were analyzed. The cutoff value of molecular typing combined with integrated PET/MRI semi-quantitative indices for endometrial cancer risk stratification was determined. There were statistically significant differences in pathological types and tumor grades among the four molecular subtypes of endometrial cancer. The values of the four integrated PET/MRI semi-quantitative indices (SUV max and ADC min) of the molecular subtypes were statistically different. The SUV max was greater in the p53abn mutation group than in the POLE mutation group (P < 0.05). The ADC minimum of the POLE mutation group and the MMR-d group was lower than the NSMP group (P <0.05). Molecular typing combined with the integrated PET/MRI semi-quantitative SUV max index can predict the low/medium risk group of endometrial cancer and the medium-high/high risk group, and the cut-off value of SUV max for predicting the risk of early endometrial cancer was 14.72 (sensitivity 66.7%, specificity 68.7%). Molecular typing combined with integrated PET/MRI semi-quantitative indicators is useful to achieve risk stratification in patients diagnosed with endometrial cancer and guide individualized treatment.

Outcomes of liver transplantation for hepatocelluler carcinoma from living donor versus deceased donor within University of Southern California San Francisco criteria: a report from Turkey.

Hepatocellular cancer (HCC) is the most common primary liver cancer with increasing incidence. Liver transplantation (LT) has been accepted as main curative liver cancer treatment. The effectiveness of LDLT as opposed to Deceased Donor Liver Transplant (DDLT) for patients with HCC is still controversial. There is limited data comparing the long-term outcomes of patients undergoing LDLT or DDLT for HCCs that do not meet the Milan criteria. We aimed to compare the perioperative and survival outcomes of LDLT with DDLT in HCC patients.Patients underwent LT between January 2012 and December 2020 were retrospectively analyzed. There were 137 patients who met the UCSF criteria. Of these, 75 patients received LDLT and 62 patients DDLT.The primary end points in the present study were oncologic outcomes such as the recurrence rate, disease-free survival (DFS) and overall survival (OS) of LDLT and DDLT in patients with HCC. PET-CT SUVmax value, the amount of erythrocyte solution (ES) as blood transfusion of red cells given and the tumor recurrence rate were significantly higher among the deceased patients recurrence, ES, PET-CT SUVmax value and tumor differentiation had significant effects on survival. In the multivariate reduced model, cox regression analysis showed significant effects of recurrence, ES, locoregional treatment response and PET-CT on survival.Albeit not significant, the one-year recurrence rate in the LDLT was similar to that in the DDLT, three- and five-year recurrence rates were higher in DDLT compared to LDLT. There is less chance of cold ischemia time and better-quality grafts with minimal fatty changes, lower recurrence rates and similar survival rates can be achieved in LDLT compared to DDLT.

Kontrastlı BT'nin Karaciğer Lezyonlarının Karakterizasyonunda FDG PET'e Katkısı ve Kantitatif Etkileri

Background: The goals of this study was to evaluate the diagnostic capability of enhanced/unenhanced 18F-FDG-PET/CT scans for identifying primary-secondary liver malignancies in terms of size and localization, to decide the quantitative impact of contrast agent on the SUVmax values of liver lesions and normal liver tissue, and to assess the impact in SUVmax metrics following contrast substance administration. Materials and Methods: This was a prospective research that included patients with suspicious primary and secondary hepatic cancers. Patients had non-enhanced &amp;amp; enhanced regional PET/CT examinations. The dimen-sion, position, densities (HU), visually assessment outcome, and SUVmax values for all pathological lesions were recorded, as well as the HU and SUVmax data of normal hepatic tissue. Results: There were 97 liver lesions in total. Visually assessment outcome of lesions, the introduction of a contrast substance considerably enhanced the HU and SUVmax measurements for normal hepatic tissue. The HU measurements for lesions bigger than 1cm increased statistically significantly, as did the SUVmax levels of centralized lesions bigger than 1cm. The attenuation adjustment procedures, resulted in an average inaccuracy in computed SUVmax values at the ratio of %5 for normal liver tissue and %6 for all hepatic pathologies follow-ing the contrast substance delivery. Conclusions: The inclusion of contrast substance increases the identification, localization, and characterization of the liver lesions with PET/CT substantially.

Evaluation of the effect of PET/CT Fluorodeoxyglucose inclusion on mortality and survival in operated thymoma patients.

In recent years, the use of fluorodeoxyglucose PET-computed tomography (PET-CT) has become widespread to evaluate the diagnosis, metabolism, stage and distant metastases of thymoma. In this study, it was aimed to investigate the connection of malignancy potential, survival and maximum standardized uptake value (SUV max ) measured by PET-CT before surgery according to the histological classification of the WHO in patients operated for thymoma. In addition, the predictive value of the Glasgow prognostic score (GPS) generated by C-reactive protein (CRP) and albumin values on recurrence and survival was investigated and its potential as a prognostic biomarker was evaluated. Forty-five patients who underwent surgical resection for thymoma and were examined with PET-CT in the preoperative period between January 2010 and January 2022 were included in the study. The relationship between WHO histological classification, tumor size and SUV max values on PET-CT according to TNM classification of retrospectively analyzed corticoafferents were evaluated. Preoperative albumin and CRP values were used to determine GPS. The cutoff value for SUV max was found to be 5.65 in the patients and the overall survival rate of low-risk (<5.65) and high-risk (>5.65) patients was compared according to the SUV max threshold value (5.65) and found to be statistically significant. In addition, the power of PET/CT SUV max value to predict mortality (according to receiver operating characteristics analysis) was statistically significant ( P = 0.048). Survival expectancy was 127.6 months in patients with mild GPS (O points), 96.7 months in patients with moderate GPS (1 point), and 25.9 months in patients with severe GPS (2 points). PET/CT SUV max values can be used to predict histological sub-type in thymoma patients, and preoperative SUV max and GPS are parameters that can provide information about survival times and mortality in thymoma patients.

Diagnostic value of 18F-PSMA-1007 PET/CT combined with prostate specific antigen derived indicators in gray area prostate cancer.

The incidence of prostate cancer is increasing every year, and precision diagnosis and treatment can help reduce unnecessary prostate punctures for prostate cancer patients in the gray area. This study aims to investigate the diagnostic value of 18F-prostate specific membrane antigen (PSMA) imaging combined with prostate specific antigen (PSA)-derived indicators for gray zone prostate cancer. A total of 107 patients who underwent 18F-PSMA PET/CT imaging for suspicious prostate cancer with tPSA of 4 to 10 μg/L (PSA gray zone) in a hospital were retrospectively included, and were divided into a prostate cancer group and a non-prostate cancer group based on pathological findings. Patients underwent PSA testing, 18F-PSMA, and abdominal ultrasound, and age, tPSA, fPSA, f/tPSA, prostate volume, PSA density (PSAD), maximum standardized uptake value (SUVmax), and molecular imaging prostate specific membrane antigen (miPSMA) score were compared between the 2 groups. Multivariate logistic regression was used to analyze the influencing factors the diagnosis of gray zone prostate cancer. Receiver operating characteristic (ROC) curves were constructed to evaluate the efficacy of PSAD and SUVmax alone and in combination in diagnosing gray zone prostate cancer. The volume of the prostate cancer group [42.00(34.00, 58.00) cm3 vs 49.00(41.27, 60.41) cm3] was smaller than that of the non-prostate cancer group (Z=-2.376, P=0.017), and the PSAD [(0.18±0.06) μg/(L·cm3) vs 0.15±0.05 μg/(L·cm3)] and SUVmax [18.63(8.03, 28.57) vs 9.33(5.90, 13.52)] were higher than those in the non-prostate cancer group (both P<0.05). The percentage of miPSMA score ≥2 in the prostate cancer group was higher than that in the non-prostate cancer group (χ2=40.987, P<0.001). PSAD (OR=22.154, 95% CI 1.430 to 873.751, P=0.042) and SUVmax (OR=1.301, 95% CI 1.034 to 1.678, P=0.009) were independent influential factors for the diagnosis of prostate cancer in the gray zone. The optimal cut-off values of PSAD and SUVmax were 0.22 μg/(L·cm3) and 8.02, respectively, and the AUCs for the diagnosis of prostate cancer in the gray zone alone and in combination were 0.628 (95% CI 0.530 to 0.720, P<0.05) and 0.806 (95% CI 0.718 to 0.876, P<0.05), 0.847 (95% CI 0.765 to 0.910, P<0.05), with sensitivities of 41.03%, 76.92%, and 74.36% and specificities of 79.41%, 89.71%, and 92.65%, respectively. PSAD and SUVmax are increased in patients with gray zone prostate cancer, and the combination of PSAD and SUVmax is of high value in diagnosing gray zone prostate cancer.

Longitudinal imaging of murine atherosclerosis with 2-deoxy-2-[18F]fluoro-D-glucose and [18F]-sodium fluoride in genetically modified Apolipoprotein E knock-out and wild type mice

In a longitudinal design, four arterial segments in mice were followed by positron emission tomography/computed tomography (PET/CT) imaging. We aimed to determine how the tracers reflected the development of atherosclerosis via the uptake of 2-deoxy-2-[18F]fluoro-D-glucose ([18F]FDG) for imaging inflammation and [18F]-sodium fluoride (Na[18F]F) for imaging active microcalcification in a murine model of atherosclerosis. Apolipoprotein E knock-out (ApoE) mice and C57 BL/6NtaC (B6) mice were divided into four groups. They received either normal chow (N = 7, ApoE mice and N = 6, B6 mice) for 32 weeks or a high-fat diet (N = 6, ApoEHFD mice and N = 9, B6HFD mice) for 32 weeks. The mice were scanned with [18F]FDG and Na[18F]F using a dedicated small animal PET/CT scanner at three timepoints. The tracer uptakes in four aortic segments (abdominal aorta, aortic arch, ascending aorta, and thoracic aorta) were measured and reported as SUVmax values. The uptake of [18F]FDG (SUVmax: 5.7 ± 0.5 vs 1.9 ± 0.2, 230.3%, p = < 0.0001) and Na[18F]F (SUVmax: 9.6 ± 1.8 vs 4.0 ± 0.3, 175%, p = 0.007) was significantly increased in the abdominal aorta of ApoEHFD mice at Week 32 compared to baseline abdominal aorta values of ApoEHFD mice. [18F]FDG uptake in the aortic arch, ascending aorta and the thoracic aorta of B6HFD mice at Week 32 showed a robust resemblance to the abdominal aorta uptake whereas the Na[18F]F uptake only resembled in the thoracic aorta of B6HFD mice at Week 32 compared to the abdominal aorta. The uptake of both [18F]FDG and Na[18F]F increased as the disease progressed over time, and the abdominal aorta provided a robust measure across mouse strain and diet. Therefore, it seems to be the preferred region for image readout. For [18F]FDG-PET, both B6 and ApoE mice provide valuable information and either mouse strain may be used in preclinical cardiovascular studies, whereas for Na[18F]F -PET, ApoE mice should be preferred.

68 Ga-Pentixafor PET/CT for in-vivo mapping of CXCR4 receptors as potential radiotheranostic targets in soft tissue and bone sarcoma: preliminary results.

To evaluate the diagnostic utility of 68 Ga-Pentixafor PET/CT for in vivo imaging of CXCR4 receptors in soft tissue/bone sarcoma. Ten (7M: 3F; mean age = 24.7 ± 14.2 years) consecutive patients with clinical and radiological evidence of bone/soft tissue sarcoma were recruited prospectively whole body 68 Ga-Pentixafor PET/CT imaging was performed at 60-min after tracer administration. After performing standard CT, PET acquisition from head to toe was done (3 min/bed position) in a caudocranial direction. PET/CT data was reconstructed and SUV max , SUV mean values, target-to-background ratio (TBR) and active tumor volume (cc) were computed for the tracer avid lesions. Histopathological and IHC analysis was performed on the surgically excised primary tumors. CXCR4 receptors' intensity was evaluated by visual scoring. The mean SUV max and SUV mean values in the primary tumors were 4.80 ± 1.0 (3.9-7.7) and 2.40 ± 0.60 (0.9-4.0). The mean TBR and tumor volume (cc) were 1.84 ± 1.3 and 312.2 ± 285. Diagnosis of osteosarcoma in 7, chondrosarcoma, leiomyosarcoma and synovial sarcoma in 1 patient each was confirmed on HP analysis. Distant metastatic lesions were seen in 3/10 patients. Nuclear CXCR4 receptors' positivity was seen in 5, cytoplasmic in 4 and both pattern seen in 1 patient. The mean CXCR4 receptors' intensity was found to be 7.6 ± 2. The highest SUV max value of 7.7 was observed in the patient having both cytoplasmic and nuclear CXCR4 expression. SUV max was found to be poorly correlated ( r = 0.441) with CXCR4 expression. 68 Ga-Pentixafor PET/CT detects CXCR4 receptors over-expressed in sarcoma, its radio-theranostics potential needs detailed evaluation.

Predictive model for epileptogenic tubers from all tubers in patients with tuberous sclerosis complex based on 18F-FDG PET: an 8-year single-centre study

BackgroundMore than half of patients with tuberous sclerosis complex (TSC) suffer from drug-resistant epilepsy (DRE), and resection surgery is the most effective way to control intractable epilepsy. Precise preoperative localization of epileptogenic tubers among all cortical tubers determines the surgical outcomes and patient prognosis. Models for preoperatively predicting epileptogenic tubers using 18F-FDG PET images are still lacking, however. We developed noninvasive predictive models for clinicians to predict the epileptogenic tubers and the outcome (seizure freedom or no seizure freedom) of cortical tubers based on 18F-FDG PET images.MethodsForty-three consecutive TSC patients with DRE were enrolled, and 235 cortical tubers were selected as the training set. Quantitative indices of cortical tubers on 18F-FDG PET were extracted, and logistic regression analysis was performed to select those with the most important predictive capacity. Machine learning models, including logistic regression (LR), linear discriminant analysis (LDA), and artificial neural network (ANN) models, were established based on the selected predictive indices to identify epileptogenic tubers from multiple cortical tubers. A discriminating nomogram was constructed and found to be clinically practical according to decision curve analysis (DCA) and clinical impact curve (CIC). Furthermore, testing sets were created based on new PET images of 32 tubers from 7 patients, and follow-up outcome data from the cortical tubers were collected 1, 3, and 5 years after the operation to verify the reliability of the predictive model. The predictive performance was determined by using receiver operating characteristic (ROC) analysis.ResultsPET quantitative indices including SUVmean, SUVmax, volume, total lesion glycolysis (TLG), third quartile, upper adjacent and standard added metabolism activity (SAM) were associated with the epileptogenic tubers. The SUVmean, SUVmax, volume and TLG values were different between epileptogenic and non-epileptogenic tubers and were associated with the clinical characteristics of epileptogenic tubers. The LR model achieved the better performance in predicting epileptogenic tubers (AUC = 0.7706; 95% CI 0.70–0.83) than the LDA (AUC = 0.7506; 95% CI 0.68–0.82) and ANN models (AUC = 0.7425; 95% CI 0.67–0.82) and also demonstrated good calibration (Hosmer‒Lemeshow goodness-of-fit p value = 0.7). In addition, DCA and CIC confirmed the clinical utility of the nomogram constructed to predict epileptogenic tubers based on quantitative indices. Intriguingly, the LR model exhibited good performance in predicting epileptogenic tubers in the testing set (AUC = 0.8502; 95% CI 0.71–0.99) and the long-term outcomes of cortical tubers (1-year outcomes: AUC = 0.7805, 95% CI 0.71–0.85; 3-year outcomes: AUC = 0.8066, 95% CI 0.74–0.87; 5-year outcomes: AUC = 0.8172, 95% CI 0.75–0.87).ConclusionsThe 18F-FDG PET image-based LR model can be used to noninvasively identify epileptogenic tubers and predict the long-term outcomes of cortical tubers in TSC patients.

PET/CT with &lt;sup&gt;18&lt;/sup&gt;F-Fluoroestradiol in First Diagnosed Breast Cancer. A Pilot Study

Purpose: To evaluate the informativity of PET/CT with 18F-FES in determining estrogen receptor (ER) positivity in breast tumor tissue, as well as in regional lymph nodes or distant metastatic foci. Material and methods: The data of 30 patients who underwent PET/CT with 18F-FES performed at the stage of primary diagnosis were retrospectively analyzed. The study included patients before the start of specific treatment or on the background of neoadjuvant hormone therapy, with previously determined expression of ER according to the results of IGC. 14 patients underwent 18F-FDG PET/CT with 2–7 days difference between both PET/CT. Results: In our study, the mean SUVmax value in the primary tumor focus was 4.8, the lowest SUVmax = 1.61, and the highest SUVmax = 18.86. 18F-FES accumulation considered suspicious for metastatic lesion in axillary lymph nodes on the affected side was detected in 16 patients (56 %), mean SUVmax = 5.2, lowest SUVmax = 0.99, highest SUVmax = 11.54. On subsequent histological examination, tumor changes in axillary lymph nodes were confirmed in 16/16 patients. Conclusion: PET/CT with 18F-FES is a diagnostic method for noninvasive evaluation of ER expression in tumor foci, which can complement the data of traditional diagnostic methods and has a significant clinical potential. In our study, the results of PET/CT with 18F-FES coincided with the data of immunohistochemical study in 100 % of cases.

Is 18F-fluorodeoxyglucose PET recommended for small lung nodules? CT findings of 18F-fluorodeoxyglucose non-avid lung cancer.

To determine the image characteristics associated with low 18F-FDG (18F-fluorodeoxyglucose) avidity among 8-15 mm solid lung cancer. Patients satisfying the following criteria were included: underwent surgery between January 2014 and December 2019 for lung cancer, presented 8-15 mm nodule without measurable ground glass component on preoperative CT, and underwent 18F-FDG PET before resection. Image characteristics, including air bronchogram, concave shape, pleural attachment, and background emphysema, were evaluated by two board-certified radiologists. The Mann-Whitney U test was used to compare maximum standardized uptake (SUVmax) values from 18F-FDG PET images. The analysis included 235 patients. The SUVmax values of lesions with air bronchogram and concave shape were significantly lower than the SUVmax values of lesions without these features (median: 1.55 vs 2.56 and 1.66 vs 2.45, both P < .001), whereas lesions arising from emphysematous lungs had significantly higher SUVmax values than lesions arising from non-emphysematous lungs (2.90 vs 1.69, P < .001). No significant differences were detected between lesions attached and not attached to pleura. The interobserver agreement was almost perfect for air bronchograms and background emphysema (κ = 0.882 and 0.927, respectively), and 89.7% of lesions with air bronchograms and arising from non-emphysematous lungs showed SUVmax values below 2.5. Among 8-15 mm solid lung cancer, the presence of air bronchograms and concave shape and the absence of background emphysema were associated with low 18F-FDG accumulation. 18F-FDG PET can be misleading in differentiating certain type of small solid lung cancer.

Utility of positron emission tomography for determination of axillary metastasis of breast cancer.

The involvement of axillary lymph nodes plays a key role in breast cancer staging. Positron emission tomography is a promising modality for detecting axillary lymph node metastasis. In addition, nomograms are used to predict the status of axillary lymph nodes. In this study, the role of positron emission tomography in determining axillary metastasis and its correlation with the nomogram was evaluated. The axillary maximum standard uptake value (SUVmax) values of the patients in the preoperative period, the features in the perioperative and postoperative specimen and Memorial Sloan Kettering Cancer Center nomogram data were evaluated. As axillary SUVmax detected by Positron emission tomography in the preoperative period increased, so did the likelihood of lymph node involvement. Axillary SUVmax value were compared with Memorial Sloan Kettering Cancer Center nomogram data but no correlation was found. Age, lymph node number, histopathology results, mass diameter, presence or absence of lymphovascular invasion and/or perineural invasion, tumor type, estrogen receptor status, Ki67 and Cerb-B2 statuses were not correlated. However, axillary SUVmax was inversely correlated with grade and progesterone receptor status. Results from positron emission tomography of axillary lymph nodes in breasts cancer patients showed that SUVmax was only inversely related to cancer grade and progesterone receptor status while not correlating with other accepted parameters for tumor assessment. Thus there is insufficient reliability for the use of axillary SUVmax alone for accurate assessment of tumor characteristics at present.

Predicting Fractures Using Vertebral 18F-NaF Uptake in Prostate Cancer Patients

Background: Patients with prostate cancer tend to be at heightened risk for fracture due to bone metastases and treatment with androgen-deprivation therapy. Bone mineral density (BMD) derived from dual energy X-ray absorptiometry (DXA) is the standard for determining fracture risk in this population. However, BMD often fails to predict many osteoporotic fractures. Patients with prostate cancer also undergo 18F-sodium fluoride (&lt;sup&gt;18&lt;/sup&gt;F-NaF)-positron emission tomography/computed tomography (PET/CT) to monitor metastases. The purpose of this study was to assess whether bone deposition, assessed by &lt;sup&gt;18&lt;/sup&gt;F-NaF uptake in &lt;sup&gt;18&lt;/sup&gt;F-NaF PET/CT, could predict incident fractures better than DXA- or CT-derived BMD in patients with prostate cancer.Methods: This study included 105 males with prostate cancer who had undergone full body &lt;sup&gt;18&lt;/sup&gt;F-NaF PET/CT. Standardized uptake value (SUVmean and SUVmax) and CT-derived Hounsfield units (HU), a correlate of BMD, were recorded for each vertebral body. The average SUVmean, SUVmax, and HU were calculated for cervical, thoracic, lumbar, and sacral areas. The t-test was used to assess significant differences between fracture and no-fracture groups.Results: The SUVmean and SUVmax values for the thoracic area were lower in the fracture group than in the no-fracture group. There was no significant difference in cervical, thoracic, lumbar or sacral HU between the 2 groups.Conclusions: Our study reports that lower PET-derived non-metastatic bone deposition in the thoracic spine is correlated with incidence of fractures in patients with prostate cancer. CT-derived HU, a correlate of DXA-derived BMD, was not predictive of fracture risk. &lt;sup&gt;18&lt;/sup&gt;F-NaF PET/CT may provide important insight into bone quality and fracture risk.

Predictive Value of Pre-Infusion FDG‐PET/CT Parameters for Clinical Outcomes and Toxicities in Relapsed/Refractory (R/R) Large B-Cell Lymphoma (LBCL) Following CAR-T Cell Therapy

Introduction: CD19-targeting chimeric antigen receptor (CAR) T-cell therapy has demonstrated significant efficacy in patients with relapsed/refractory (R/R) non-Hodgkin lymphoma but is associated with serious adverse effects such CRS and ICANS. Pre-infusion disease burden has been investigated as a potential predictor of clinical outcome and toxicity. FDG-PET/CT derived metabolic tumor volume (MTV) and total lesion glycolysis (TLG) are quantitative indicators of this baseline tumor load. We aim to assess the predictive value of pre-CART PET metrics on outcome and toxicity in R/R large B-Cell Lymphoma (LBCL) following CAR-T cell therapy. Method: We conducted a retrospective single site study of 25 consecutive patients with R/R LBCL treated with CAR-T therapy in our institution between May 2020 and October 2022, All patients underwent FDG-PET/CT imaging pre-CAR-T infusion (PET-0) and at day 30 post infusion (PET-1). The images were reviewed by two expert lymphoma PET physicians. Metabolic parameters including MTV, TLG (both calculated using a relative threshold of 40%), SUVmax and Deauville score were calculated. PET-1 was classified as complete metabolic response (CMR, Deauville score 1-3) or non-CMR (Deauville score 4-5) as per the Lugano classification. Results: 25 patients were analyzed , Based on the median MTV (74,6 mL), TLG (379,4), SUVmax (11,8) values, patients were divided into two groups “low” and “high”. The median follow-up was 12 months. Patients with low pre-infusion MTV and TLG had significantly superior day 30 CMR rates (84,6% vs 25%, p= 0.001 &amp; 80% vs 20%, p = 0.001 respectively). Pre-infusion SUVmax ( p = 0.29 ) and Deauville score ( p = 0.103), however, did not predict response to treatment. In our population, pre-infusion PET parameters were not associated with CRS or ICANS . Patients with low pre-infusion MTV and TLG had significantly superior PFS (MTV: p=0.02; TLG: p=0.019) and OS (MTV: p=0.017; TLG: p=0.05), Pre-infusion SUVmax had no statistical significant impact on OS ( p = 0.61) or PFS ( p = 0.37) Conclusion: In our study, pre-infusion quantitative PET metrics, TLG and MTV, predict response and outcomes of CART therapy in R/R LBCL. Our results highlight the importance of adequate disease control before CAR-T administration and the value of pre-infusion FDG-PET/CT as a predictor of outcomes in R/R LBCL patients treated by CAR-T-therapy.

Correlation between Prostate Cancer Positive Cores and 68Ga-PSMA Distribution in Prostate Gland

Introduction: The purpose of our study was to evaluate reliability of ⁶⁸Ga-labeled prostate-specific membrane antigen positron emission tomography (⁶⁸Ga-PSMA PET/CT) and identify appropriate SUV_max cutoff values in order to use for diagnosis, especially in patients remained clinically suspicious for prostate cancer (PCa). Methods: Eighty-four patients applied ⁶⁸Ga-PSMA PET/CT subsequent to transrectal ultrasound-guided prostate biopsy (TRUS-bx) involved in this study retrospectively. ⁶⁸Ga-PSMA PET/CT imagings were analyzed by a nuclear medicine physician, and region of interests were drawn manually in prostate diagrams including 6 segments for each patient. These marked diagrams were analyzed with histopathology reports TRUS-bx. 504 segments were grouped with Gleason scoring system, and all groups were compared with mean SUV_max values. Results: Mean SUV_max value of Gleason grade group 1 (GG1, n: 352 segments) was 6.6 (±4.6) and significantly lower than the other groups (p < 0.001). No significant difference was detected within GG2–5 groups (p > 0.05). According to receiver operating characteristic curve analysis, SUV_max cutoff values were 1.0 (AUC: 0.961) for tumor detection, yielding a sensitivity, specificity, positive predictive value, negative predictive value of 99.4%, 92.1%, 96.5%, 98%, respectively, and 4.2 (AUC: 0.853) for detection of clinically significant PCa with 88.8%, 62.4%, 84.5%, and 71%, respectively. Although tumor percentage of biopsy core and Gleason group were correlated with SUV_max uptake, but patient age was not. Conclusion: ⁶⁸Ga-PSMA PET appears to be a reliable option for diagnosis and disease management in PCa and can be considered especially in discrimination of csPCa, and patients remained suspicious for disease.

Reduced count pediatric whole-body 18F-FDG PET imaging reconstruction with a Bayesian penalized likelihood algorithm.

Advanced positron emission tomography (PET) image reconstruction methods promise to allow optimized PET/CT protocols with improved image quality,decreased administered activity and/or acquisition times. To evaluate the impact of reducing counts(simulating reduced acquisition time) in block sequential regularized expectation maximization (BSREM) reconstructed pediatric whole-body 18F-fluorodeoxyglucose (FDG) PET images, and to compare BSERM with ordered-subset expectation maximization (OSEM) reconstructed reduced-count images. Twenty children (16 male) underwent clinical whole-body 18F-FDG PET/CT examinations using a 25-cm axial field-of-view (FOV) digital PET/CT system at 90s per bed (s/bed) with BSREM reconstruction (β=700). Reduced count simulations with varied BSREM β levels were generated from list-mode data: 60s/bed, β=800; 50s/bed, β=900; 40s/bed, β=1000; and 30s/bed, β=1300. In addition, a single OSEM reconstruction was created at 60s/bed based on prior literature. Qualitative (Likert scores) and quantitative (standardized uptake value [SUV]) analyses were performed to evaluate image quality and quantitation across simulated reconstructions. The mean patient age was 9.0 ± 5.5 (SD) years, mean weight was 38.5 ± 24.5kg, and mean administered 18F-FDG activity was 4.5 ± 0.7 (SD) MBq/kg. Between BSREM reconstructions, no qualitative measure showed a significant difference versus the 90s/bed β=700 standard (all P>0.05). SUVmax values for lesions were significantly lower from 90s/bed, β=700 only at a simulated acquisition time of 30s/bed, β=1300 (P=0.001). In a side-by-side comparison of BSREM versus OSEM reconstructions, 40s/bed, β=1000 images were generally preferred over 60s/bed TOF OSEM images. In children who undergo whole-body 18F-FDG PET/CT on a 25-cm FOV digital PET/CT scanner, reductions in acquisition time or, by corollary, administered radiopharmaceutical activity of >50% from a clinical standard of 90s/bed may be possible while maintaining diagnostic quality when a BSREM reconstruction algorithm is used.

The diagnostic value of quantitative bone SPECT/CT in solitary undetermined bone lesions.

To investigate the diagnostic value of the maximum standard uptake value (SUVmax) of quantitative single-photon emission computed tomography/computed tomography (SPECT/CT) in solitary undetermined bone lesions. In Part I, retrospective study, 167 untreated patients with extra-skeletal malignant tumors by pathology were consecutively enrolled for staging with Tc-99m methyl-diphosphonate (99mTc-MDP) whole-body bone scan (WBS) and quantitative SPECT/CT, and a total of 396 bone lesions with abnormal radioactivity concentration in 167 patients were included from April 2019 to September 2020. The differences in SUVmax among the benign bone lesions, malignant bone lesions, and normal vertebrae were analyzed. The receiver operating characteristic (ROC) curve and cutoff value of SUVmax were obtained. Part II, prospective study, 49 solitary undetermined bone lesions in SPECT/CT in 49 untreated patients with extra-skeletal malignant tumors were enrolled from October 2020 to August 2022. The diagnostic efficacy of SUVmax in solitary undetermined bone lesions was assessed. The final diagnosis was based on follow-up imaging (CT, MRI, or 2-deoxy-2-[18F]fluoro-D-glucose-positron emission tomography/computed tomography) for at least 12 months. In Part I, a total of 156 malignant and 240 benign bone lesions was determined; the SUVmax of malignant lesions (26.49 ± 12.63) was significantly higher than those of benign lesions (13.92 ± 7.16) and normal vertebrae (6.97 ± 1.52) (P = 0.00). The diagnostic efficiency of the SUVmax of quantitative SPECT/CT revealed a sensitivity of 75.00% and a specificity of 81.70% at a cutoff value of 18.07. In Part II, 17 malignant and 32 benign lesions were determined. Using SUVmax ≥18.07 as a diagnostic criterion of malignancy, it has a sensitivity of 82.35%, a specificity of 93.75%, and an accuracy of 89.80%. The SUVmax of quantitative SPECT/CT is valuable in evaluating solitary undetermined bone lesions. Using a cutoff SUVmax value of 18.07, quantitative SPECT/CT demonstrated high sensitivity, specificity, and accuracy in differentiating malignant from benign bone lesions.

Impact of attenuation correction of radiotherapy hardware for positron emission tomography-magnetic resonance in ano-rectal radiotherapy patients.

Positron Emission Tomography-Magnetic Resonance (PET-MR) scanners could improve ano-rectal radiotherapy planning through improved Gross Tumour Volume (GTV) delineation and enabling dose painting strategies using metabolic measurements. This requires accurate quantitative PET images acquired in the radiotherapy treatmentposition. This study aimed to evaluate the impact on GTV delineation and metabolic parameter measurement of using novel Attenuation Correction (AC) maps that included the radiotherapy flat couch, coil bridge and anterior coil to see if they werenecessary. Seventeen ano-rectal radiotherapy patients received a -FluoroDeoxyGlucose PET-MR scan in the radiotherapy position. PET images were reconstructed without ( ) and with ( ) the radiotherapy hardware included. Both AC maps used the same Computed Tomography image for patient AC. Semi-manual and threshold GTVs were delineated on both PET images, the volumes compared and the Dice coefficient calculated. Metabolic parameters: Standardized Uptake Values , and Total Lesion Glycolysis (TLG) were compared using paired t-tests with a Bonferroni corrected significance level of . Differences in semi-manual GTV volumes between and were approaching statistical significance (difference , ), with larger differences in low FDG-avid tumours ( ). The and GTVs were concordant with Dice coefficients (manual) and (threshold). Metabolic parameters were significantly different, with , and TLG differences of ( ), ( ) and ( ) respectively. The TLG difference resulted in 1/8 rectal cancer patients changing prognosis group, based on literature TLG cut-offs, when using rather than . This study suggests that using AC maps with the radiotherapy hardware included is feasible for patient imaging. The impact on tumour delineation was mixed and needs to be evaluated in larger cohorts. However using AC of the radiotherapy hardware is important for situations where accurate metabolic measurements are required, such as dose painting and treatmentprognostication.