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Objectives Positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) are widely used in the diagnosis and follow-up of liver metastases. Both modalities provide anatomical and functional information and have advantages and disadvantages. The objective of this study was to investigate the correlation between apparent diffusion coefficient (ADC) and standardized uptake value (SUV) values in metastatic liver lesions. Methods Abdominal magnetic resonance (MR) scans performed between April 2021 and 2024 using the 3T MR scanner were retrospectively evaluated. Thirty-three patients with liver metastases, less than one month between magnetic resonance imaging (MRI) and PET/CT, no treatment during this period, and lesions larger than 1 cm were included in the study. In each MRI scan, an index lesion was selected for ADC measurement. The radiologist and nuclear medicine specialist measured the same index lesion without the patient being informed of the results. Results The mean age of the 33 patients was 59±12 years, with 17 (51%) men and 16 (49%) women. The mean size of the index lesions was 27±9 mm. In MRI, mean ADCmin: (0.54±0.2) ×10-3mm2/s; ADCmean: (1.02±0.2) ×10-3mm2/s; ADCmax: (1.48±0.44) ×10-3mm2/s; and region of interest area was calculated as 6±4.6 cm2. In PET/CT, mean SUVmean: 5.8±3.3; SUVpeak: 6.8±4.3; SUVmax: 10.7±5.6; and metabolic tumor volume: 12.1 (7.4-20.7) cm3. No statistically significant correlation was found between ADC and SUV values. Conclusion There was no correlation between ADC and SUV values in liver metastases. Prospective studies with a large patient group are needed. Keywords:Liver neoplasms, diffusion magnetic resonance imaging, positron emission tomography computed tomography, apparent diffusion coefficient, standardized uptake value: [ABSTRACT FROM AUTHOR]

Abstract This study aimed to investigate the cutoff values of standardized uptake values (SUVs) and their accuracy using single-photon emission computed tomography–computed tomography (SPECT–CT) for temporomandibular joint (TMJ) osteoarthritis (OA) based on magnetic resonance imaging (MRI) and clinical examination. We included 106 joints of 53 patients with TMJ OA. SUVmax and SUVpeak of each TMJ was measured. SUVref was set as the SUV at the clivus. The diagnostic performance, including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy, were evaluated. SUVmax was 5.15, with a sensitivity of 59.375, specificity of 100.000, PPV of 100.000, NPV of 61.765, and accuracy of 75.472. The cutoff value for SUVpeak was 3.635, with sensitivity of 56.250, specificity of 100.000, PPV of 100.000, NPV of 60.000, and accuracy of 73.585. SUVmax was 3.286 ± 0.780 and 6.623 ± 3.442 in the non-OA and OA groups, respectively (p

Giant cell arteritis is a form of large vessel vasculitis which can present with nonspecific symptoms, and if left untreated can cause significant morbidity and/or death. Early diagnosis and management are therefore paramount. The use of [18F]FDG PET/CT in the evaluation of giant cell arteritis has increased in recent years, with newer generation PET scanners capturing the historically elusive cranial vessel inflammation in active vasculitis. We present a case of giant cell arteritis which was suspected on conventional imaging modalities, and subsequently evaluated with [18F]FDG PET/CT which revealed marked vascular inflammation involving both cranial and other large vessels.

This study aimed to investigate the cutoff values of standardized uptake values (SUVs) and their accuracy using single-photon emission computed tomography–computed tomography (SPECT–CT) for temporomandibular joint (TMJ) osteoarthritis (OA) based on magnetic resonance imaging (MRI) and clinical examination. We included 106 joints of 53 patients with TMJ OA. SUVmax and SUVpeak of each TMJ was measured. SUVref was set as the SUV at the clivus. The diagnostic performance, including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy, were evaluated. SUVmax was 5.15, with a sensitivity of 59.375, specificity of 100.000, PPV of 100.000, NPV of 61.765, and accuracy of 75.472. The cutoff value for SUVpeak was 3.635, with sensitivity of 56.250, specificity of 100.000, PPV of 100.000, NPV of 60.000, and accuracy of 73.585. SUVmax was 3.286 ± 0.780 and 6.623 ± 3.442 in the non-OA and OA groups, respectively (p < 0.001). SUVpeak was 2.324 ± 0.688 and 4.913 ± 2.749 in the non-OA and OA groups, respectively (p < 0.001). SPECT–CT can be helpful for the diagnosis of patients clinically suspected of having OA. It is also recommended that clinicians keep in mind that patients with SUVmax values higher than the cutoff value should be managed with a higher possibility of OA. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to identify a relatively robust SUV for guiding clinical practice through quantitative measurement and comparison of various normalization methods based on the SUV of 99mTc-MDP in the normal spine and pelvis using an integrated SPECT/CT scanner. Methods: Between June 2017 and September 2019, a total of 500 oncology patients (mean age, 60.9; men, 66.0%) who underwent bone SPECT/CT scans with 99mTc-MDP were enrolled in this retrospective study. The mean SUV (SUVmean) of 4962 spinal and pelvic bones was calculated based on the patients' body weight (BW), lean body mass (LBM), bone mineral content (BMC), body surface area (BSA), and body mass index (BMI), defined as SUVbw, SUVlbm, SUVbmc, SUVbsa, and SUVbmi, respectively. The coefficients of variation (CoVs) of the aforementioned parameters were compared, and the correlation and multiple linear regression analyses were used to compare the extent to which these parameters were affected by sex, age, height, weight, BMI, and CT values. Results: The average SUVs in the normal spine and pelvis displayed a relatively wide variability: 4.573 ± 1.972 for SUVbw, 3.555 ± 1.517 for SUVlbm, 0.163 ± 0.071 for SUVbmc, 0.124 ± 0.052 for SUVbsa, and 1.668 ± 0.732 for SUVbmi. In general, SUVbsa had relatively lowest CoV (42.1%) in all vertebrae and pelvis compared with other SUVs. For correlation analyses, all SUVs displayed weak but significant correlations with age and CT values. For regression analyses, SUVbsa was influenced only by age, BMI, and CT values independently. The effects of these variables on SUVbsa were all smaller than those on conventional SUVbw. Conclusions: The SUVs of 99mTc-MDP in normal bone derived from quantitative bone SPECT/CT could serve as a reference for evaluating tumor bone metastasis, but it should be assessed on a site-specific basis. SUVbsa exhibited superior robustness among all the SUV normalization variations, indicating potential clinical applications. [ABSTRACT FROM AUTHOR]

Purpose: Tissue radiotracer activity measured from positron emission tomography (PET) images is an important biomarker that is clinically utilized for diagnosis, staging, prognostication, and treatment response assessment in patients with cancer and other clinical disorders. Using PET image values to define a normal range of metabolic activity for quantification purposes is challenging due to variations in patient-related factors and technical factors. Although the formulation of standardized uptake value (SUV) has compensated for some of these variabilities, significant non-standardness still persists. We propose an image processing method to substantially mitigate these variabilities. Methods: The standardization method is similar for activity concentration (AC) PET and SUV PET images, with some differences, and consists of two steps. The calibration step is performed only once for both AC PET or SUV PET, employs a set of images of normal subjects, and requires a reference object, while the transformation step is executed for each patient image to be standardized. In the calibration step, a standardized scale is determined along with 3 key image intensity landmarks defined on it: the minimum percentile intensity smin, median intensity sm, and high percentile intensity smax. smin and sm are estimated based on image intensities within the body region in the normal calibration image set. The optimal value of the maximum percentile β corresponding to the intensity smax is estimated via an optimization process by using the reference object to optimally separate the highly variable high uptake values from the normal uptake intensities. In the transformation step, the first two landmarks--the minimum percentile intensity pα(I), and the median intensity pm(I)--are found for the given image I for the body region, and the high percentile intensity pβ(I) is determined corresponding to the optimally estimated high percentile value β. Subsequently, intensities of I are mapped to the standard scale piecewise linearly for different segments. We employ three strategies for evaluation and comparison with other standardization methods: (i) comparing coefficient of variation (CVO) of mean intensity within test objects O across different normal test subjects before and after standardization, (ii) comparing mean absolute difference (MDO) of mean intensity within test objects O across different subjects in repeat scans before and after standardization, and (iii) comparing CVO of mean intensity across different normal subjects before and after standardization where the scans came from different brands of scanners. Results: Our data set consisted of 84 FDG-PET/CT scans of the body torso including 38 normal subjects and two repeat-scans of 23 patients. We utilized one of two objects--liver and spleen--as a reference object and the other for testing. The proposed standardization method reduced CVO and MDO by a factor of 3-8 in comparison to other standardization methods and no standardization. Upon standardization by our method, the image intensities (both for AC and SUV) from two different brands of scanners become statistically indistinguishable, while without standardization, they differ significantly and by a factor of 3-9. Conclusions: The proposed method is automatic, outperforms current standardization methods, and effectively overcomes the residual variation left over in SUV and interscanner variations. [ABSTRACT FROM AUTHOR]

Abstract Background Serum bone turnover markers offer limited insight into metabolic activity at the individual vertebra level in osteoporosis. This study introduces a novel image-derived bone turnover marker for individual vertebrae to address this limitation, utilizing volumetric density-adjusted quantitative bone single-photon emission computed tomography/computed tomography (SPECT/CT) with [99mTc]Tc-DPD. This retrospective study included 177 lumbar vertebrae from 55 postmenopausal South Korean women. The mean standardized uptake value (SUVmean, g/cm3) and volumetric bone mineral density (vBMD, mg/cm3) were determined within a 2-cm³ volume of interest in the trabecular portion of each vertebra using quantitative SPECT and CT. The density-adjusted mean standardized uptake value (dSUVmean) was calculated by dividing the SUVmean by the vBMD and multiplying by 1,000. Results SUVmean correlated positively with vBMD (r = 0.60, p

Abstract In 67Ga-citrate scintigraphy (Ga-S), visual assessment is used by evaluating renal-uptake comparison with liver and spine and is simple and objective. We adopted the standardized uptake value (SUV) for 67Ga-citrate and proposed two quantitative indices, active nephritis volume (ANV) and total nephritis uptake (TNU). This study clarified the utility of new Ga-S-based quantitative indices in nephritis management. Before SUV measurement, the Becquerel calibration factor of 67Ga-citrate was obtained using a phantom experiment. Seventy patients who underwent SPECT/CT imaging were studied. SUV, ANV, and TNU were calculated using a quantitative analysis software for bone SPECT. SUVmean, ANV, and TNU were analyzed using the (1) threshold method (set 40%) and constant-value method for (2) vertebral SUVmax, and (3) vertebral SUVmean. ROC analysis was used to evaluate SUV, ANV, and TNU diagnostic abilities to distinguish nephritis presence and absence as well as interstitial nephritis (IN) and non-IN. The area under the curve (AUC) for nephritis presence or absence had a good value (0.80) for SUVmean (1), ANV (3), and TNU (3). The AUC for differentiation between IN and non-IN groups had a good value (0.80) for SUVmean (1). Thus, the new Ga-S-based quantitative indices were useful to evaluate nephritis and distinguish IN and non-IN.

Introduction: Few studies have investigated the prognostic factors for non-adenocarcinoma of the lung. We retrospectively evaluated the prognostic factors on the basis of histological type of non-adenocarcinoma of the lung treated by pulmonary resection. Methods: We enrolled 266 patients with non-adenocarcinoma of the lung in this retrospective study: 196 with squamous cell carcinoma (SCC) and 70 with non-SCC. Results: Relapse-free survival (RFS) did not differ significantly between SCC and non-SCC patients (p = 0.33). For SCC patients, RFS differed significantly between patients who underwent wedge resection and non-wedge resection (p < 0.01) and between patients with Clavien-Dindo grade ≥3a and 0–2 postoperative complications (p < 0.01). For non-SCC patients, RFS rates were significantly different in the groups divided at neutrophil-to-lymphocyte ratio = 2.40 (p = 0.02), maximum standardized uptake value (SUVmax) = 8.39 (p < 0.01), between patients with pathological stage (pStage) 0–I and with pStage more than II (p < 0.01). For SCC patients, male sex (p = 0.04), wedge resection (p = 0.01), and Clavien-Dindo grade ≥3a (p = 0.02) were significant factors for RFS in multivariate analysis. For non-SCC patients, neutrophil-to-lymphocyte ratio >2.40 (p < 0.01), SUVmax >8.39 (p = 0.01), and pStage ≥II (p = 0.03) were significant factors for RFS in multivariate analysis. Conclusion: RFS did not differ significantly differently between SCC and non-SCC patients. It is necessary to perform more than segmentectomy and to avoid severe postoperative complications for SCC patients. SUVmax might be an adaptation criterion of adjuvant chemotherapy for patients with non-adenocarcinoma and non-SCC of the lung. [ABSTRACT FROM AUTHOR]

Background: Serum bone turnover markers offer limited insight into metabolic activity at the individual vertebra level in osteoporosis. This study introduces a novel image-derived bone turnover marker for individual vertebrae to address this limitation, utilizing volumetric density-adjusted quantitative bone single-photon emission computed tomography/computed tomography (SPECT/CT) with [99mTc]Tc-DPD. This retrospective study included 177 lumbar vertebrae from 55 postmenopausal South Korean women. The mean standardized uptake value (SUVmean, g/cm3) and volumetric bone mineral density (vBMD, mg/cm3) were determined within a 2-cm³ volume of interest in the trabecular portion of each vertebra using quantitative SPECT and CT. The density-adjusted mean standardized uptake value (dSUVmean) was calculated by dividing the SUVmean by the vBMD and multiplying by 1,000. Results: SUVmean correlated positively with vBMD (r = 0.60, p < 0.001). Conversely, dSUVmean correlated negatively with vBMD (ρ = −0.66, p < 0.001), highlighting the inverse relationship between bone mass and turnover after density adjustment of SUVmean. Patients with major osteoporotic fractures had lower vBMD (62.5 ± 29.4 vs. 92.3 ± 27.4 mg/cm³, p = 0.001) but higher dSUVmean (100.8 ± 60.7 vs. 62.6 ± 17.5, p = 0.001) compared to those without fractures, reinforcing the association between fracture prevalence, low bone mass, and high bone turnover. Conclusion: Volumetric density-adjusted quantitative bone SPECT/CT offers a novel image-derived bone turnover marker for assessing bone turnover in osteoporosis. This method provides a precise assessment of fragility at the individual vertebra level, which may enhance personalized osteoporosis management. [ABSTRACT FROM AUTHOR]

In 67Ga-citrate scintigraphy (Ga-S), visual assessment is used by evaluating renal-uptake comparison with liver and spine and is simple and objective. We adopted the standardized uptake value (SUV) for 67Ga-citrate and proposed two quantitative indices, active nephritis volume (ANV) and total nephritis uptake (TNU). This study clarified the utility of new Ga-S-based quantitative indices in nephritis management. Before SUV measurement, the Becquerel calibration factor of 67Ga-citrate was obtained using a phantom experiment. Seventy patients who underwent SPECT/CT imaging were studied. SUV, ANV, and TNU were calculated using a quantitative analysis software for bone SPECT. SUVmean, ANV, and TNU were analyzed using the (1) threshold method (set 40%) and constant-value method for (2) vertebral SUVmax, and (3) vertebral SUVmean. ROC analysis was used to evaluate SUV, ANV, and TNU diagnostic abilities to distinguish nephritis presence and absence as well as interstitial nephritis (IN) and non-IN. The area under the curve (AUC) for nephritis presence or absence had a good value (0.80) for SUVmean (1), ANV (3), and TNU (3). The AUC for differentiation between IN and non-IN groups had a good value (0.80) for SUVmean (1). Thus, the new Ga-S-based quantitative indices were useful to evaluate nephritis and distinguish IN and non-IN. [ABSTRACT FROM AUTHOR]

Introduction: It is unclear whether a lower lobe origin is a risk factor for early recurrence of non-small cell lung cancer (NSCLC) in patients who underwent pulmonary resection. Methods: The risk factors for early recurrence, defined as recurrence occurring within 1 year after surgery, were analyzed in 476 patients with NSCLC who underwent pulmonary resection without wedge resection. Results: The proportion of men, Brinkman's index, carcinoembryonic antigen levels, and the maximum standardized uptake value (SUVmax) were significantly higher in patients with early recurrence than in those without early recurrence. Furthermore, the rates of lower lobe origin, extended resection beyond lobectomy, lymphatic invasion, vascular invasion, and advanced-stage disease were significantly higher in patients with early recurrence. Age (odds ratio [OR] = 4.46, p < 0.01), SUVmax (OR = 5.78, p = 0.02), a lower lobe origin (OR = 3.06, p = 0.01), and pathological stage (OR = 3.34, p = 0.01) were risk factors for early recurrence in multivariate analysis. Furthermore, only early recurrence (OR = 3.34, p = 0.01) was a risk factor for overall survival in multivariate analysis, and overall survival outcomes and prognoses significantly differed between patients with and without early recurrence (p < 0.01). Conclusion: Age, SUVmax, a lower lobe origin, and pathological stage are risk factors for early recurrence. These results suggest that for patients with NSCLC who underwent pulmonary resection, SUVmax and a lower lobe origin are important for deciding the indication for adjuvant chemotherapy in addition to pathological stage. [ABSTRACT FROM AUTHOR]

Background: Controversy surrounds the efficacy of adjuvant chemotherapy (ACT) in the treatment of stage I lung adenocarcinoma (LUAD). The objective of this study was to examine the impact of the maximum standardized uptake value (SUVmax) as measured by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) on the efficacy of ACT in patients diagnosed with stage I LUAD. Methods: We scrutinized the medical records of 928 consecutive patients who underwent complete surgical resection for pathological stage I LUAD at our institution. The ideal cut-off value for primary tumor SUVmax in terms of diseasefree survival (DFS) and overall survival (OS) was determined using the X-tile software. The Kaplan–Meier method and Cox regression analysis were used for survival analysis. Results: Based on the SUVmax algorithm, the ideal cutoff values were determined to be 4.9 for DFS and 5.0 for OS. We selected 5.0 as the threshold because OS is the more widely accepted predictive endpoint. In a multivariate Cox regression analysis, SUVmax ≥ 5.0, problematic IB stage, and sublobectomy were identified as independent risk factors for poor DFS and OS. It is noteworthy that patients who were administered ACT had significantly longer DFS and OS than what was observed in the subgroup of patients with pathological stage IB LUAD and SUVmax ≥ 5.0 (p < 0.035 and p ≤ 0.046, respectively). However, there was no observed survival advantage for patients in stages IA or IB who had an SUVmax < 5.0. Conclusion: The preoperative SUVmax of tumors served as an indicator of the impact of ACT in the context of completely resected pathological stage I LUAD. Notably, patients within the Stage IB category exhibiting elevated SUVmax levels emerged as a subgroup experiencing substantial benefits from postoperative ACT. [ABSTRACT FROM AUTHOR]

The objective of present study is to assess the role of the [18Fluorine] 2-Fluoro-2-Deoxy-D-Glucose Positron-Emission-Tomography Computed-Tomography (18F-FDG PET/CT) scan to detect the bone marrow involvement, predict disease free interval (DFI) and histopathological Transformation (HT) in Follicular Lymphoma (FL). Sixty patients were evaluated. Staging 18F-FDG PET/CT scan showed poor sensitivity for bone marrow involvement. Thus, staging 18F-FDG PET/CT cannot replace initial bone marrow biopsy in FL. Maximum standardized uptake value (SUVmax) of lymphomatous lesions in staging 18F-FDG PET/CT scan has no correlation with DFI and HT. Treatment response based on 5-point Deauville Score (5PDS) of interim 18F-FDG PET/CT scan is significantly associated with DFI. Interim 18F-FDG PET/CT scan plays an important role in deciding treatment modification in FL to prevent future recurrence. [ABSTRACT FROM AUTHOR]

Background: Positron emission tomography with computed tomography (PET-CT) using fluorine 18-fluorodeoxyglucose (F-18 FDG) is increasingly used to stage patients with locally advanced breast cancer and for assessing treatment response after neoadjuvant chemotherapy (NACT). Aims and Objectives: The aim of the study was to assess the correlation between PET-CT parameters and pathologic response of breast primary after NACT in breast cancer patients and to devise a grading system called NIMS grading system for response assessment using PET quantitative parameters. Materials and Methods: 55 patients who underwent F-18 FDG PET-CT before starting the therapy and again after completion of therapy were identified and included in the study. The clinical data and the histopathologic findings were recorded. All the patients received chemotherapy followed by surgery with axillary lymph node dissection. The PET-CT results were interpreted both qualitatively by visual analysis and quantitatively by estimating maximum Standardized uptake values(SUVmax) and other parameters – SUVmean, SUL, SUVBSA, Metabolic tumor volume (MTV) and Total lesion glycolysis (TLG). Results: The sensitivity and specificity of F-18 FDG PET-CT to detect the residual disease after neoadjuvant chemotherapy was 75.6% & 92.8% respectively. Differences between complete response and residual disease were significant for ΔSUVmax(p=0.005), ΔSUVmean(p=0.006), ΔSUL (0.005) and ΔSUVBSA(0.004), while ΔMTV and ΔTLG were not significantly different between the two groups. The new NIMS grading system included scoring of ΔSUVmax, ΔSUVBSA, ΔTLG and ΔMTV on scale of 1 to 4 and correlated well with PERCIST criteria. Conclusion: F-18 FDG PET-CT had a good accuracy in the detection of residual disease after completion of NACT. Pre chemotherapy PET-CT is not adequate to predict the response of primary tumour to chemotherapy. However, changes in the values of various PET-CT parameters are a sensitive tool to assess the response to chemotherapy. The new grading system is easy to use and showed good correlation to PERCIST. [ABSTRACT FROM AUTHOR]

Purpose: Standardized uptake values (SUVs) derived from 18F-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography are a crucial parameter for identifying tumors or abnormalities in an organ. Moreover, exploring ways to improve the identification of tumors or abnormalities using a statistical measurement tool is important in clinical research. Therefore, we developed a fully automatic method to create a personally normalized Z-score map of the liver SUV. Methods: The normalized Z-score map for each patient was created using the SUV mean and standard deviation estimated from blood-test-derived variables, such as alanine aminotransferase and aspartate aminotransferase, as well as other demographic information. This was performed using the least absolute shrinkage and selection operator (LASSO)-based estimation formula. We also used receiver operating characteristic (ROC) to analyze the results of people with and without hepatic tumors and compared them to the ROC curve of normal SUV. Results: A total of 7757 people were selected for this study. Of these, 7744 were healthy, while 13 had abnormalities. The area under the ROC curve results indicated that the anomaly detection approach (0.91) outperformed only the maximum SUV (0.89). To build the LASSO regression, sets of covariates, including sex, weight, body mass index, blood glucose level, triglyceride, total cholesterol, γ-glutamyl transpeptidase, total protein, creatinine, insulin, albumin, and cholinesterase, were used to determine the SUV mean, whereas weight was used to determine the SUV standard deviation. Conclusion: The Z-score normalizes the mean and standard deviation. It is effective in ROC curve analysis and increases the clarity of the abnormality. This normalization is a key technique for effective measurement of maximum glucose consumption by tumors in the liver. [ABSTRACT FROM AUTHOR]

Background: Induction chemotherapy (IC) combined with concurrent chemoradiotherapy has become the standard treatment for locoregionally advanced nasopharyngeal carcinoma (LA-NPC). Data on the prognostic value of the lymph node-to-primary tumor ratio (NTR) of positron emission tomography (PET) standardized uptake value (SUV) for patients treated with IC were limited. Objectives: To evaluate the prognostic value of the SUV NTR for patients with LA-NPC treated with IC. Design: In all, 467 patients with pretreatment 18F-fluorodeoxyglucose PET/computed tomography (CT) scans between September 2017 and November 2020 were retrospectively reviewed. Methods: The receiver operating characteristic (ROC) analysis was used to determine the optimal cut-off value of SUV NTR. Kaplan–Meier method was used to evaluate survival rates. The recursive partitioning analysis (RPA) was performed to construct a risk stratification model. Results: The optimal cutoff value of SUV NTR was 0.74. Multivariate analyses showed that SUV NTR and overall stage were independent predictors for distant metastasis-free survival (DMFS) and regional recurrent-free survival (RRFS). Therefore, an RPA model based on the endpoint of DMFS was generated and categorized the patients into three distinct risk groups: RPA I (low risk: SUV NTR < 0.74 and stage III), RPA II (medium risk: SUV NTR < 0.74 and stage IVa, or SUV NTR ⩾ 0.74 and stage III), and RPA III (high risk: SUV NTR ⩾ 0.74 and stage IVa), with a 3-year DMFS of 98.9%, 93.4%, and 84.2%, respectively. ROC analysis showed that the RPA model had superior predictive efficacy than the SUV NTR or overall stage alone. Conclusion: SUV NTR was an independent prognosticator for distant metastasis and regional recurrence in locoregionally advanced NPC. The RPA risk stratification model based on SUV NTR provides improved DMFS and RRFS prediction over the eighth edition of the TNM (Tumor Node Metastasis) staging system. [ABSTRACT FROM AUTHOR]

Objective: Although lung cancer screening trials have showed the efficacy of computed tomography to decrease mortality compared with chest radiography, the two are widely taken as different kinds of clinical practices. Artificial intelligence can improve outcomes by detecting lung tumors in chest radiographs. Currently, artificial intelligence is used as an aid for physicians to interpret radiograms, but with the future evolution of artificial intelligence, it may become a modality that replaces physicians. Therefore, in this study, we investigated the current situation of lung cancer diagnosis by artificial intelligence. Methods: In total, we recruited 174 consecutive patients with malignant pulmonary tumors who underwent surgery after chest radiography that was checked by artificial intelligence before surgery. Artificial intelligence diagnoses were performed using the medical image analysis software EIRL X-ray Lung Nodule version 1.12, (LPIXEL Inc., Tokyo, Japan). Results: The artificial intelligence determined pulmonary tumors in 90 cases (51.7% for all patients and 57.7% excluding 18 patients with adenocarcinoma in situ). There was no significant difference in the detection rate by the artificial intelligence among histological types. All eighteen cases of adenocarcinoma in situ were not detected by either the artificial intelligence or the physicians. In a univariate analysis, the artificial intelligence could detect cases with larger histopathological tumor size (p < 0.0001), larger histopathological invasion size (p < 0.0001), and higher maximum standardized uptake values of positron emission tomography-computed tomography (p < 0.0001). In a multivariate analysis, detection by AI was significantly higher in cases with a large histopathological invasive size (p = 0.006). In 156 cases excluding adenocarcinoma in situ, we examined the rate of artificial intelligence detection based on the tumor site. Tumors in the lower lung field area were less frequently detected (p = 0.019) and tumors in the middle lung field area were more frequently detected (p = 0.014) compared with tumors in the upper lung field area. Conclusions: Our study showed that using artificial intelligence, the diagnosis of tumor-associated findings and the diagnosis of areas that overlap with anatomical structures is not satisfactory. While the current standing of artificial intelligence diagnostics is to assist physicians in making diagnoses, there is the possibility that artificial intelligence can substitute for humans in the future. However, artificial intelligence should be used in the future as an enhancement, to aid physicians in the role of a radiologist in the workflow. [ABSTRACT FROM AUTHOR]

Open in new tab Download slide OBJECTIVES The mean standardized uptake value (SUVmean) and maximum standardized uptake value (SUVmax) on fluorine-18 fluorodeoxyglucose-positron emission tomography are prognostic biomarkers for survival and nodal involvement in non-small-cell lung cancer but their prognostic value in lung neuroendocrine neoplasms (NENs) remains unexplored. In this study, we aimed to examine whether they are also prognostic biomarkers for survival and nodal involvement in lung NENs. METHODS We retrospectively studied patients with typical carcinoid, atypical carcinoid or large cell neuroendocrine carcinoma who had been radically resected at our institution between 2008 and 2020. We measured SUVmean and SUVmax on all primary tumours and lymph nodes that were clinically and/or pathologically involved. We dichotomized the patients into groups of high or low SUVmean and SUVmax of the primary tumour using time-dependent receiver operating characteristic curves and compared their overall survival using Kaplan–Meier curves and Cox models. Lastly, we predicted the patients' pathological nodal status with SUVmean and SUVmax of the lymph nodes using binomial logistic models. RESULTS The study included 245 patients. Patients died earlier if their SUVmean of the primary tumour exceeded 3.9 [hazard ratio 1.97, 95% confidence interval (CI) 1.27–3.04, P  = 0.002] or SUVmax exceeded 5.3 (hazard ratio 1.85, 95% CI 1.20–2.87, P  = 0.006). Likewise, patients had a higher risk of pathological nodal involvement if their SUVmean of the lymph nodes exceeded 3.3 (odds ratio 10.00, 95% CI 2.59–51.01, P  = 0.002) or SUVmax exceeded 4.2 (odds ratio 4.00, 95% CI 1.20–14.65, P  = 0.028). CONCLUSIONS The fluorine-18 fluorodeoxyglucose-positron emission tomography SUVmean and SUVmax are strong prognostic biomarkers for survival and nodal involvement in lung NENs and could be important guides for making treatment decisions. [ABSTRACT FROM AUTHOR]

Background: Neuroendocrine tumours (NETs) are a group of cancers that can produce hormones and other metabolically active compounds. The majority of NETs have specific tissue characteristics, such as the expression of somatostatin receptors (SSTR). Metabolic testing with [99mTc]Tc-EDDA/HYNIC-Tyr3-octreotide ([99mTc]Tc-EDDA/HYNIC-TOC) can be used in patients with NETs to visualise the presence of receptors in different locations of pathological lesions, including the skeletal system. The study aimed to calculate the body weight maximum standardized uptake value (SUVbwmax) of pathological bone lesions and healthy bone tissues, estimate the size of lesions, and identify a relationship between the SUVbwmax of the bone tissues, age and body mass of the study participants. Material and methods: The somatostatin receptor scintigraphies (SRS) with [99mTc]Tc-EDDA/HYNIC-TOC were carried out at the Department of Nuclear Medicine, University Clinical Hospital No. 1, Pomeranian Medical University (PMU) in Szczecin from 2019 to 2022. Whole body and single photon emission computed tomography/computed tomography (SPECT/CT) scans were performed four hours after the injection of 700-800 MBq of [99mTc]Tc-EDDA/HYNIC-TOC in 344 patients with neuroendocrine tumours of various primary lesion locations. In 19 patients, who showed foci of increased radiopharmaceutical accumulation in bone location, the SUVbwmax was measured. The SUVbwmax of pathological bone lesions and healthy tissues were determined on SPECT/CT cross-sectional images using Xeleris 4 software. Results: The total number of foci with increased SSTR expression in bone regions seen on scintigraphic images was 89. Among them, 32 bone lesions were visible on the corresponding CT scans. The mean SUVbwmax of these lesions was 31.39 [standard deviation (SD) 34.31]. For the other 57 lesions that were not visible on corresponding CT scans, the mean SUVbwmax was 19.12 (SD 24.24). The smallest bone lesion detected on the scintigram and visible on the corresponding CT location was 5 mm × 5 mm, measured in cross-section, and was located in the Th8 vertebral body; the largest, measuring 20 mm × 22 mm, was detected in the L3 vertebral body. The SUVbwmax of these lesions was 24.70 and 142.40, respectively. Conclusions: Bone lesions seen on SPECT/CT in [99mTc]Tc-EDDA/HYNIC-TOC scintigraphy can be quantitatively analysed using the SUV index. Even a very small pathological bone lesion can be detected on [99mTc]Tc-EDDA/HYNIC-TOC scintigraphy. It was shown that in cases where bone lesions were visible on CT scans, the SUVbwmax of bone tumour lesions was higher than when lesions were not visible on CT. Body mass does not affect the SUVbwmax of bone lesions. SUVbwmax of healthy bone tissue decreased with age. [ABSTRACT FROM AUTHOR]

Positron Emission Tomography (PET) with 18Ffluorodeoxyglucose (FDG) is an important imaging practice in cancer diagnosis, staging, treatment planning, and response assessment. Accurate interpretation of PET results requires an understanding of FDG uptake in organs. The time activity curve (TAC) and standardized uptake value (SUV) are the two common tools to measure tracer uptake in regions of interest. The TAC provides information on glucose consumption dynamics, while the SUV involves measuring the amount of tracer taken up by a specific region or volume of interest, and then adjusting the measurement by the amount of tracer injected and the subject’s characteristics. In the current study, we measured the TACs and SUVs of the heart, brain, kidney, and muscle in ten mice injected with FDG over a period of 120 minutes. According to the TACs obtained in this study, the brain has a slower uptake than the other organs with a tendency to keep the FDG for a longer period of time. Also, the SUV of the brain showed a rising trend until the middle of the experiment with a sharp falloff afterwards. The pattern of the curves of the other three organs was almost the same. The findings of this study were in agreement with a similar study on humans and are explained by the metabolic activity and physiology of the organs studied.

Positron emission tomography (PET) is a widely used imaging modality in nuclear medicine for a variety of applications. Amongst the methods used for the quantifying and interpretation of PET images, the standardized uptake value (SUV) is a widely-adopted semi-quantitative tool that supplements visual understanding with quantitative information. SUV is used in both clinical and preclinical practices to report the status of various normal organs and tumors under investigation using PET imaging. While the determination of SUVs is typically done manually, which can be tedious, artificial intelligence (AI) can be utilized to enhance the efficiency of the process. In this study, a U-Net-based approach was employed for semi-automated determination of SUV in FDG-PET scans of mice brains. First, a U-Net model was trained using 50 FDG-PET images of six mice to perform the automatic segmentation task. The trained model then delineated the brain of a mouse which was then processed by a short in-house code to extract data and calculate the SUV. The process was also replicated in a manual way for comparison purposes. The comparison of the results from the U-Net-based segmentation method and the conventional manual method at nine different time points revealed that there were errors of less than 4.5% in eight out of the nine-time points. Although our U-Net model’s performance needs improvement, adapting a well-trained AIbased approach for SUV determination, particularly in preclinical studies, can help reduce the workload of organ delineation and minimize associated errors, facilitating SUV determination.

Purpose: Cancer-inflammation prognostic index (CIPI) is calculated by multiplying the concentration of carcinoembryonic antigen by neutrophil-to-lymphocyte ratio. CIPI has been reported as a prognostic factor for colorectal cancer. Although carcinoembryonic antigen and neutrophil-to-lymphocyte ratio have been reported as prognostic factors for non-small cell lung cancer (NSCLC), it has not been investigated whether CIPI is a useful marker. Methods: We analyzed the prognostic factors, including CIPI, in 700 NSCLC patients treated by pulmonary resection. We also analyzed a subgroup of 482 patients with pathological stage I NSCLC. Result: CIPI > 14.59 (P < 0.01), maximum standardized uptake value (SUVmax) > 5.35 (P < 0.01), lymphatic invasion (P = 0.01), and pathological stage (P < 0.01) were significant factors for relapse-free survival (RFS) in multivariate analysis. SUVmax > 5.35 (P < 0.01) and pathological stage (P < 0.01) were revealed as significant factors for overall survival in the multivariate analysis. In the subanalysis, CIPI > 14.88 (P = 0.01) and SUVmax > 5.07 (P < 0.01) were significant factors for RFS of pathological stage I NSCLC in multivariate analysis. Conclusion: CIPI was a significant factor for RFS in NSCLC patients treated surgically, even in those with pathological stage I disease. SUVmax was also a significant factor for RFS and overall survival in NSCLC patients treated surgically, and for RFS in patients with pathological stage I NSCLC. Trial Registration: The Institutional Review Board of Kanazawa Medical University approved the protocol of this retrospective study (Approval Number: I392), and written informed consent was obtained from all patients. [ABSTRACT FROM AUTHOR]

Objective: 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. Methods: 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-glucosepositron emission tomography/computed tomography) for at least 12 months. Results: 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%. Conclusion: 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. [ABSTRACT FROM AUTHOR]

Purpose: The imaging diagnosis of fracture-related infection is often challenging. The aim of this study was to evaluate the value of 18F-FDG PET/CT for the diagnosis of fracture-related infection (FRI) with internal fixation after orthopedic surgery in lower extremities. Methods: A total of 254 consecutive patients who underwent 18F-FDG PET/CT scans with suspected FRI with internal fixation in lower extremities were retrospectively investigated 18F-FDG PET/CT images were semiquantitatively evaluated with multiple metabolic parameters. Additionally, morphological information of the inguinal draining lymph nodes (DLN) with the highest SUV value was also collected and analyzed. Results: Patients were divided into two groups according to final diagnosis: the infected (N=197) and the non-infected group (N=57). The differences in the inguinal DLN-related parameters, including the long diameter, short diameter, maximum cross-sectional area, maximum standardized uptake value (SUVmax), metabolic volume (MV) 60%, MV70%, MV80%, total lesional glycolysis (TLG) 60%, TLG70%, TLG80%, and the infection suspected area related parameters, including SUVmax, MV25%, MV30%, MV35%, MV40%, MV50%, and TLG70%, between the two groups were statistically significant. We then compared the highest area under the curves (AUCs) among the morphological parameters of DLN, metabolic parameters of DLN, and metabolic parameters of the suspected infection area. The result demonstrated that SUVmax of the inguinal DLN showed the best diagnostic performance with an AUC of 0.939 (P<0.05). Conclusion: Semiquantitative analysis (especially SUVmax) of the inguinal DLN in 18F-FDG PET/CT images could be a promising method for the diagnosis of suspected FRI with internal fixation after orthopedic surgery in lower extremities. [ABSTRACT FROM AUTHOR]

The acquisition of in vivo radiopharmaceutical distribution through imaging is time-consuming due to dosimetry, which requires the subject to be scanned at several time points post-injection. This study aimed to generate delayed positron emission tomography images from early images using a deep-learning-based image generation model to mitigate the time cost and inconvenience. Eighteen healthy participants were recruited and injected with [18F]Fluorodeoxyglucose. A paired image-to-image translation model, based on a generative adversarial network (GAN), was used as the generation model. The standardized uptake value (SUV) mean of the generated image of each organ was compared with that of the ground-truth. The least square GAN and perceptual loss combinations displayed the best performance. As the uptake time of the early image became closer to that of the ground-truth image, the translation performance improved. The SUV mean values of the nominated organs were estimated reasonably accurately for the muscle, heart, liver, and spleen. The results demonstrate that the image-to-image translation deep learning model is applicable for the generation of a functional image from another functional image acquired from normal subjects, including predictions of organ-wise activity for specific normal organs. [ABSTRACT FROM AUTHOR]

Abstract Purpose To assess whether the high metabolic region of fluorine-18-fluorode-oxyglucose (18F-FDG) in the primary lesion is the crux for recurrence in patients with nasopharyngeal carcinoma (NPC), to assess the feasibility and rationale for use of biological target volume (BTV) based on 18F-FDG positron emission tomography/computed tomography (18F-FDG-PET/CT). Methods The retrospective study included 33 patients with NPC who underwent 18F-FDG-PET/CT at the time of initial diagnosis as well as the time of diagnosis of local recurrence. Paired 18F-FDG-PET/CT images for primary and recurrent lesion were matched by deformation coregistration method to determine the cross-failure rate between two lesions. Results The median volume of the Vpri (primary tumor volume using the SUV thresholds of 2.5), the Vhigh (the volume of high FDG uptake using the SUV50%max isocontour), and the Vrecur (the recurrent tumor volume using the SUV thresholds of 2.5) were 22.85, 5.57, and 9.98 cm3, respectively. The cross-failure rate of Vrecur∩high showed that 82.82% (27/33) of local recurrent lesions had 20% overlap volume with the primary tumor lesions and the median cross rate was up to 71.74%. Conclusion 18F-FDG-PET/CT may be a powerful tool for automatic target volume delineation, but it may not be the optimal imaging modality for dose escalation radiotherapy based on applicable isocontour. The combination of other functional imaging could delineate the BTV more accurately.

Objective(s): While increased uptake at the bone fractural site gradually decreases over time on bone scans, the rate of change has not been quantitatively evaluated. The purpose of this study was to quantify the extent of bone metabolic changes in fractural lesions on bone SPECT/CT. Methods: We reviewed bone scans acquired by dedicated SPECT/CT and chose those scans in which quantitative SPECT/CT of the same range was acquired twice or more. We set the region of interest on lesions of bone fracture and degeneration, and measured the maximum standardized uptake value (SUVmax). From the SUVmax of lesions and the interval between scans, a value for 30-day change in SUVmax was calculated as DSUVmax30d. The relationship between preSUVmax, SUVmax for the first scan of the comparison, and DSUVmax30d was evaluated utilizing a linear least-squares method. Furthermore, we assessed the ability to differentiate between fracture and degeneration using receiver operating characteristics (ROC) analysis and the Mann-Whitney U test. All cases were then categorized into five groups according to preSUVmax. Values of p

Objective: This study aimed to determine a standardized cut-off value for abnormal 18F-fluorodeoxyglucose (FDG) accumulation in the thyroid gland. Methods: Herein, 7013 FDG–PET/CT scans were included. An automatic thy roid segmentation method using two U-nets (2D- and 3D-U-net) was con structed; mean FDG standardized uptake value (SUV), CT value, and volume of th e thyroid gland were obtained from each participant. The values were categorized by thyroid function into three groups based on serum thyroid-stimulating hormone levels. Thyroid function and mean SUV with increments of 1 were analyzed, and risk for thyro id dysfunction was calculated. Thyroid dysfunction detection ability was examined using a machine learning method (LightGBM, Microsoft) with age, sex, height, weight, CT value, volume, and mean SUV as explanatory variables. Results: Mean SUV was significantly higher in females with hypothyroidi sm. Almost 98.9% of participants in the normal group had mean SUV < 2 and 93.8% participants with mean SUV < 2 had normal thyroid function. The hypothyroidism group h ad more cases with mean SUV ≥ 2. The relative risk of having abnormal thyroid function was 4 .6 with mean SUV ≥ 2. The sensitivity and specificity for detecting thyroid dysfun ction using LightGBM (Microsoft) were 14.5 and 99%, respectively. Conclusions: Mean SUV ≥ 2 was strongly associated with abnormal thyroid function in this large cohort, indicating that mean SUV with FDG–PET/CT can be used as a criterion for thyroid evaluation. Preliminarily, this study shows the pot ential utility of detecting thyroid dysfunction based on imaging findings.

Introduction: Although the consolidation diameter of a tumor on computed tomography (CT) is an adaptation criterion for limited resection in early-stage non-small cell lung cancer (NSCLC), whether the maximum standardized uptake value (SUVmax) is also an adaptation criterion for limited resection has not been evaluated. Methods: In total, 478 NSCLC patients with clinical stage IA disease were analyzed, among whom 383 were used to perform a sub-analysis. Results: Multivariate analysis showed that consolidation diameter (odds ratio [OR]: 3.05, p = 0.01), SUVmax (OR: 10.74, p = 0.02), and lymphatic invasion (OR: 10.34, p < 0.01) were risk factors for lymph node metastasis in clinical stage IA NSCLC patients. Furthermore, age (OR: 2.98, p = 0.03), SUVmax (OR: 13.07, p = 0.02), and lymphatic invasion (OR: 5.88, p = 0.02) were risk factors for lymph node metastasis in clinical stage IA lung adenocarcinoma patients according to multivariate analysis. Conclusion: Consolidation diameter of a tumor on CT, SUVmax, and lymphatic invasion are risk factors for lymph node metastasis. However, SUVmax was a risk factor for lymph node metastasis rather than consolidation diameter on CT in lung adenocarcinoma patients. These results suggest that for early-stage lung adenocarcinoma patients, SUVmax is more important for deciding the indication of limited resection than consolidation diameter of the tumor on CT. [ABSTRACT FROM AUTHOR]

PurposeThe imaging diagnosis of fracture-related infection is often challenging. The aim of this study was to evaluate the value of 18F-FDG PET/CT for the diagnosis of fracture-related infection (FRI) with internal fixation after orthopedic surgery in lower extremities.MethodsA total of 254 consecutive patients who underwent 18F-FDG PET/CT scans with suspected FRI with internal fixation in lower extremities were retrospectively investigated 18F-FDG PET/CT images were semiquantitatively evaluated with multiple metabolic parameters. Additionally, morphological information of the inguinal draining lymph nodes (DLN) with the highest SUV value was also collected and analyzed.ResultsPatients were divided into two groups according to final diagnosis: the infected (N=197) and the non-infected group (N=57). The differences in the inguinal DLN-related parameters, including the long diameter, short diameter, maximum cross-sectional area, maximum standardized uptake value (SUVmax), metabolic volume (MV) 60%, MV70%, MV80%, total lesional glycolysis (TLG) 60%, TLG70%, TLG80%, and the infection suspected area related parameters, including SUVmax, MV25%, MV30%, MV35%, MV40%, MV50%, and TLG70%, between the two groups were statistically significant. We then compared the highest area under the curves (AUCs) among the morphological parameters of DLN, metabolic parameters of DLN, and metabolic parameters of the suspected infection area. The result demonstrated that SUVmax of the inguinal DLN showed the best diagnostic performance with an AUC of 0.939 (P

Abstract Background Although T factor is defined as the size of invasive area rather than total tumor size in the eighth edition of the TNM classification, whether the pathological invasive area to tumor ratio (ITR) is a prognostic factor has not yet been evaluated. Methods In total, 432 lung adenocarcinoma patients were analyzed, among which 266 patients with pathological stage IA were used to perform a subanalysis. Results Smoking status (odds ratio [OR]: 0.43, p = 0.01), neutrophil‐to‐lymphocyte ratio (NLR) (OR: 1.97, p = 0.03), maximum standardized uptake value (SUVmax) (OR: 3.62, p

Abstract Background Although the utility of segmentectomy for early‐stage non‐small cell lung cancer (NSCLC) has been reported, the adaptation criterion for segmentectomy is unclear. Methods In total, 171 NSCLC patients who underwent segmentectomy or lobectomy with a consolidation tumor diameter on computed tomography of ≤20 mm were analyzed. Results Consolidation diameter (p = 0.01), consolidation to tumor ratio (CTR) (p

Background: Lymphoma comprises a histological heterogeneous group of cancers derived from the cells of the immune system manifested as enlargement and proliferation of lymph nodes or secondary lymphoid tissues. Earlier, the imaging evaluation and follow-up of non-Hodgkin's lymphoma patients were based solely on findings at contrast-enhanced CT. Fortunately, 18F-fluorodeoxyglucose (18F -FDG) positron emission tomography (PET)/computed tomography is gaining popularity for evaluating patients with non-Hodgkin lymphomas (NHLs) lymphoma and has proven to be more sensitive and specific than contrast-enhanced CT for evaluating nodal and extranodal lymphomatous involvement. Main body of Abstract: 18 F-FDG PET/CT and the maximum standardized uptake value (SUV max) is currently used for the diagnosis and initial staging of NHLs. The potential usefulness of (SUV max) in NHL cases and the significance of correlations between SUV max and various indicators arc currently unknown. The aim of the current study was to investigate whether the (SUV max) measured by 18 F -FDG PET/CT could discriminate between aggressive and indolent (NHLs) including different pathological subtypes and analyze the correlations between the SUV max and other important parameters. A study was conducted among newly diagnosed 60 adult NHL patients confirmed by biopsy, pretreatment 18F-FDG PET/CT scans, and a complete medical record were retrospectively enrolled in the study including evaluation of various clinical variables; clinical stage, pathological subtype, international Prognostic Index (IPI) score as well as lactate dehydrogenase (LDH) value and then correlated with SUV max of the biopsy site on PET/CT. The area under the ROC curve for examining the accuracy of SUV max regarding distinguishing between aggressive and indolent NHLs was 0.85 and a cutoff value of>7.7 yielded a sensitivity of 90 % and specificity of 73 %. The SUV max mean 6 SD of aggressive NHL was significantly higher than that of the indolent NHL (P<0.001). The SUV max of the biopsy site was strongly positively correlated with IPI score and clinical staging (P=0.001), but it was not significantly correlated with LDH (P>0.05). Short Conclusion: 18F-FDG PET/CT may yield reliable measurements of tumor proliferation, and an SUV max > 7.7 suggesting that SUV max was a useful predictor of diagnosis and may distinguish between aggressive and indolent newly diagnosed NHLs in adults, SUV max correlates with IPI score and clinical staging. SUV max doesn't correlate to LDH. [ABSTRACT FROM AUTHOR]

PurposeTissue radiotracer activity measured from positron emission tomography (PET) images is an important biomarker that is clinically utilized for diagnosis, staging, prognostication, and treatment response assessment in patients with cancer and other clinical disorders. Using PET image values to define a normal range of metabolic activity for quantification purposes is challenging due to variations in patient-related factors and technical factors. Although the formulation of standardized uptake value (SUV) has compensated for some of these variabilities, significant non-standardness still persists. We propose an image processing method to substantially mitigate these variabilities.MethodsThe standardization method is similar for activity concentration (AC) PET and SUV PET images, with some differences, and consists of two steps. The calibration step is performed only once for both AC PET or SUV PET, employs a set of images of normal subjects, and requires a reference object, while the transformation step is executed for each patient image to be standardized. In the calibration step, a standardized scale is determined along with 3 key image intensity landmarks defined on it: the minimum percentile intensity smin, median intensity sm, and high percentile intensity smax. smin and sm are estimated based on image intensities within the body region in the normal calibration image set. The optimal value of the maximum percentile β corresponding to the intensity smax is estimated via an optimization process by using the reference object to optimally separate the highly variable high uptake values from the normal uptake intensities. In the transformation step, the first two landmarks—the minimum percentile intensity pα(I), and the median intensity pm(I)—are found for the given image I for the body region, and the high percentile intensity pβ(I) is determined corresponding to the optimally estimated high percentile value β. Subsequently, intensities of I are mapped to the standard scale piecewise linearly for different segments. We employ three strategies for evaluation and comparison with other standardization methods: (i) comparing coefficient of variation (CVO) of mean intensity within test objects O across different normal test subjects before and after standardization, (ii) comparing mean absolute difference (MDO) of mean intensity within test objects O across different subjects in repeat scans before and after standardization, and (iii) comparing CVO of mean intensity across different normal subjects before and after standardization where the scans came from different brands of scanners.ResultsOur data set consisted of 84 FDG-PET/CT scans of the body torso including 38 normal subjects and two repeat-scans of 23 patients. We utilized one of two objects—liver and spleen—as a reference object and the other for testing. The proposed standardization method reduced CVO and MDO by a factor of 3–8 in comparison to other standardization methods and no standardization. Upon standardization by our method, the image intensities (both for AC and SUV) from two different brands of scanners become statistically indistinguishable, while without standardization, they differ significantly and by a factor of 3–9.ConclusionsThe proposed method is automatic, outperforms current standardization methods, and effectively overcomes the residual variation left over in SUV and inter-scanner variations.

Purpose: Overexpression of the somatostatin receptor (SSTR) has led to adoption of SSTR PET/CT for diagnosis and radiotherapy planning in meningioma, but data on SSTR expression during follow-up remain scarce. We investigated PET/CT quantifiers of SSTR tracers in WHO grade I meningioma following fractionated proton beam therapy (PBT) compared to standard response assessment with MRI. Methods: Twenty-two patients diagnosed with low-grade meningioma treated by PBT were included. Follow-up included clinical visits, MRI, and [68Ga]Ga-DOTATOC PET/CT scans. Radiologic tumor response, MRI and PET volume (VMRI and VPET), maximum and mean standardied uptake value (SUVmax/SUVmean), total lesion activity (TLA), and heterogeneity index (HI) were evaluated. Results: Median follow-up was 35.3 months (range: 6.4–47.9). Nineteen patients (86.4%, p = 0.0009) showed a decrease of SUVmax between baseline and first follow-up PET/CT (median: −24%, range: −53% to +89%) and in 81.8% of all cases, the SUVmax, SUVmean, and TLA at last follow-up were eventually lower than at baseline (p = 0.0043). Ambiguous trends without significance between the timepoints analyzed were observed for VPET. HI increased between baseline and last follow-up in 75% of cases (p = 0.024). All patients remained radiologically and clinically stable. Median VMRI decreased by −9.3% (range 0–32.5%, p < 0.0001) between baseline and last follow-up. Conclusion: PET/CT in follow-up of irradiated meningioma showed an early trend towards decreased binding of SSTR-specific tracers following radiation and MRI demonstrated consistently stable or decreasing tumor volume. Translational research is needed to clarify the underlying biology of the subsequent increase in SSTR PET quantifiers. [ABSTRACT FROM AUTHOR]

Purpose: To assess whether the high metabolic region of fluorine-18-fluorode-oxyglucose (18F-FDG) in the primary lesion is the crux for recurrence in patients with nasopharyngeal carcinoma (NPC), to assess the feasibility and rationale for use of biological target volume (BTV) based on 18F-FDG positron emission tomography/computed tomography (18F-FDG-PET/CT). Methods: The retrospective study included 33 patients with NPC who underwent 18F-FDG-PET/CT at the time of initial diagnosis as well as the time of diagnosis of local recurrence. Paired 18F-FDG-PET/CT images for primary and recurrent lesion were matched by deformation coregistration method to determine the cross-failure rate between two lesions. Results: The median volume of the Vpri (primary tumor volume using the SUV thresholds of 2.5), the Vhigh (the volume of high FDG uptake using the SUV50%max isocontour), and the Vrecur (the recurrent tumor volume using the SUV thresholds of 2.5) were 22.85, 5.57, and 9.98 cm3, respectively. The cross-failure rate of Vrecur∩high showed that 82.82% (27/33) of local recurrent lesions had < 50% overlap volume with the region of high FDG uptake. The cross-failure rate of Vrecur∩pri showed that 96.97% (32/33) of local recurrent lesions had > 20% overlap volume with the primary tumor lesions and the median cross rate was up to 71.74%. Conclusion: 18F-FDG-PET/CT may be a powerful tool for automatic target volume delineation, but it may not be the optimal imaging modality for dose escalation radiotherapy based on applicable isocontour. The combination of other functional imaging could delineate the BTV more accurately. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the clinical significance of 18F-fluorodeoxyglucose positron emission tomography/computed tomography in patients with pancreatic ductal adenocarcinoma who underwent neoadjuvant therapy. Methods: Among 285 consecutive patients who underwent pancreatic resection for pancreatic ductal adenocarcinoma between 2015 and 2021, 86 who underwent preoperative 18F-fluorodeoxyglucose positron emission tomography/computed tomography after completion of neoadjuvant treatment were reviewed. Among preoperative factors, including post-treatment maximum standardized uptake value, predictors of early recurrence and poor prognosis were identified using multivariate analysis for decision making in surgery. Results: Nineteen (22%) patients with pancreatic ductal adenocarcinoma demonstrated high maximum standardized uptake (≥ 4.5). High post-treatment maximum standardized uptake (≥ 4.5) predicted early recurrence within 6 months after surgery and correlated with shorter recurrence-free survival. Elevated post-treatment CA19-9 level (> 37 U/ml) and maximum standardized uptake ≥ 4.5 were independent prognostic factors. Post-treatment, a high maximum standardized uptake value indicated a poorer prognosis than a low maximum standardized uptake value in both patients with elevated CA19-9 and normal CA19-9 levels. The median overall survival in patients with elevated post-treatment CA19-9 and high maximum standardized uptake was only 17 months; 67% experienced early recurrence. Dynamic changes in maximum standardized uptake during neoadjuvant therapy were correlated with pathological response to neoadjuvant therapy, but not with radiological response or change in CA19-9 level. Conclusions: Post-treatment assessment using maximum standardized uptake value is useful for stratifying patients with pancreatic ductal adenocarcinoma who will benefit from surgery. Instead of subsequent curative resection, additional neoadjuvant therapy should be considered in patients with a persistently high maximum standardized uptake value. [ABSTRACT FROM AUTHOR]

Purpose: Adrenal venous sampling (AVS) is a reliable method for lateralization of adrenal hormone secretion, which is important for discriminating between aldosterone-producing adenoma and bilateral adrenal hyperplasia, both of which cause primary aldosteronism (PA). The aim of this study was to evaluate the diagnostic accuracy of the maximum and mean standardized uptake values (SUVmax and SUVmean, respectively) of 131I-6β-iodomethyl-19-norcholesterol (NP-59) single-photon emission computed tomography (SPECT) for PA and its correspondence with AVS. Methods: Adrenal NP-59 scintigraphy was performed in 14 patients with suspected PA, and AVS was also performed in 7 of them. SUVmax and SUVmean of the adrenal lesions on the dominant side and their ratios to the values on the non-dominant side (SUVRmax and SUVRmean, respectively) were calculated on SPECT images using ordered-subset conjugate gradient minimization (OSCGM) and three-dimensional ordered-subset expectation maximization (3D-OSEM) reconstruction algorithms. Results: SUVmax and SUVmean on NP-59 SPECT images were significantly higher for aldosterone-producing adenoma than for bilateral adrenal hyperplasia or non-functioning adenoma and slightly superior to SUVRmax and SUVRmean (P = 0.0475 and P = 0.0447 vs. P = 0.124 and P = 0.132, respectively, with OSCGM). The respective areas under the receiver-operating characteristic curve for SUV and SUVR were 0.933 and 0.725 with OSCGM and 0.844 and 0.750 with 3D-OSEM, while SUVmax and SUVRmax had exactly the same diagnostic accuracy as SUVmean and SUVRmean. SUV and SUVR were associated with the diagnostic features on AVS and consistent with lateralization by AVS in most patients. Conclusion: In this study, SUV on NP-59 SPECT helped in the diagnosis of PA and was consistent with the results of AVS in nearly all cases. [ABSTRACT FROM AUTHOR]

Background: This study aimed to explore the prognostic value of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) metabolic parameters of immune organs and hematological immune-related markers for patients with locally advanced cervical cancer (LACC) undergoing concurrent chemoradiotherapy (CCRT), and to establish prognostic nomograms based on these potential biomarkers., Methods: A total of 180 patients with LACC undergoing CCRT were retrospectively reviewed and randomly divided into training and validation groups at a 7:3 ratio. Cox regression analysis was performed to identify independent prognostic factors for progression-free survival (PFS) and overall survival (OS) from hematological immune-related markers and 18 F-FDG PET/CT metabolic parameters of the primary tumor, spleen, and bone marrow (BM). Nomograms were developed and evaluated using receiver operating characteristic curves, concordance index (C-index), calibration curves, and decision curve analysis (DCA). Spearman correlation analysis was used to assess the relationships among metabolic parameters., Results: Multivariable analysis identified International Federation of Gynecology and Obstetrics (FIGO) stage, neutrophil-to-lymphocyte ratio (NLR), and spleen maximum standardized uptake value (SUV spleen ) as independent prognostic factors for PFS. For OS, the independent prognostic factors were FIGO stage, NLR, metabolic tumor volume, and SUV spleen . The nomograms demonstrated better prognostic performance for PFS (area under curve [AUC]: 0.875 and 0.862; C-index: 0.809 and 0.775) and OS (AUC: 0.858 and 0.814; C-index: 0.828 and 0.792) in the training and validation groups. Calibration curves and DCA indicated that the nomograms have good predictive accuracy and clinical utility. Spearman correlation analysis revealed significant positive correlations among total lesion glycolysis, SUV spleen , SUV BM , and platelet-to-lymphocyte ratio., Conclusion: The nomograms based on metabolic parameters of immune organs and hematological immune-related markers demonstrated high predictive value for patients with LACC undergoing CCRT. The observed correlations between the metabolic parameters of the primary tumor and immune organs suggest a widespread disturbance of systemic immunity caused by the tumor., (© 2025 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.)