Maximum Standardized Uptake Value Research Articles

Does FDG PETCT have a predictive value for neoadjuvant chemotherapy response in nonmetastatic breast cancer?

A pathological complete response (pCR) rate after neoadjuvant chemotherapy (NAC) is important for the prognosis of early-stage breast cancer. The prediction of an NAC response plays a key role in managing neoadjuvant treatment. The aim of this study is to investigate the predictive value of the baseline PETCT FDG (F-18 fluoro-deoxy-glucose (FDG) positron emission tomography/computed tomography) SUVmax (the maximum standardized uptake value) for pCR after NAC in early-stage breast cancer. The patients who performed PETCT before NAC were included in this retrospective study. The basal PETCT SUVmax values were divided into two categories based on the cutoff points of ≥ 8.77 or < 8.77, namely the low SUV max group and the high SUV max group. These two groups were compared according to the general characteristics. The impact of the PETCT SUVmax values on pCR was determined with logistic regression analyses. One hundred forty-eight patients who performed PETCT before NAC were included in this retrospective study. Eighty-one patients were in the low SUV max group and 67 patients were in the high SUVmax group. The pCR trended toward a higher rate in the high SUVmax group than in low SUVmax group but it was not statistically significant (p = 0.052). The baseline PETCT SUVmax value was an independent predictive factor for pCR. (p = 0.025). PETCT SUVmax may be a factor for the predicting complete response to neoadjuvant treatment in early-stage breast cancer.

Comparative analysis of metabolic characteristics and prognostic stratification of HER2-low and HER2-zero breast cancer using 18F-FDG PET/CT imaging

BackgroundRecent advancements in novel anti-human epidermal growth factor receptor 2 (HER2) antibody-drug conjugates (ADCs) have highlighted the emerging HER2-low breast cancer subtype with promising therapeutic efficacy. This study aimed to comparatively analyze the metabolic characteristics and prognostic stratification of HER2-low and HER2-zero breast cancer using baseline fluorine-18 fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) imaging.MethodsConsecutive patients with newly diagnosed breast cancer who underwent 18F-FDG PET/CT prior to therapy in our hospital were retrospectively reviewed. The relationship between metabolic parameters (maximum standardized uptake value (SUVmax), tumor-to-liver SUV ratio (TLR), total lesion glycolysis (TLG), and metabolic tumor volume (MTV)) in primary lesions and HER2 expression was analyzed. The survival analyses were performed to identify the prognostic factors for disease-free survival (DFS) in patients with HER2-negative (HER2-low versus -zero).ResultsIn total, 258 patients (mean age: 54 ± 12 years) were included. In hormone receptor (HR)-positive subgroup, SUVmax and TLR were significantly higher in HER2-low than in HER2-zero (P = 0.045 and 0.03, respectively). But in HR-negative subgroup, there was no significant metabolic difference between HER2-low and HER2-zero (All P > 0.05). The four metabolic parameters were significant predictors of DFS in HER2-negative patients (All P < 0.01), but there was no significant difference in DFS between HER2-low and -zero, regardless of tumor metabolism. Moreover, in HER2-zero patients, the DFS of patients with high metabolism was significantly shorter than that of patients with low metabolism (PSUVmax = 0.002, PMTV = 0.03, PTLG= 0.005, PTLR < 0.001, respectively), but without a similar finding in HER2-low patients.ConclusionOur study demonstrated the HR-positive HER2-low breast cancer exhibited a particularity in glucose metabolic profile. Additionally, HER2-zero patients with elevated metabolism were associated with inferior prognosis and warranted careful attention in clinical evaluations.

Desmoplastic Small Round Cell Tumor: a study of CT, MRI, PET/CT multimodal imaging features and their correlations with pathology

PurposeExploring the computed tomography (CT), magnetic resonance imaging (MRI), and fluorodeoxyglucose positron emission tomography (FDG-PET)/CT Multimodal Imaging Characteristics of Desmoplastic Small Round Cell Tumor (DSRCT) to enhance the diagnostic proficiency of this condition.MethodsA retrospective analysis was performed on clinical data and multimodal imaging manifestations (CT, MRI, FDG-PET/CT) of eight cases of DSRCT. These findings were systematically compared with pathological results to succinctly summarize imaging features and elucidate their associations with both clinical and pathological characteristics.ResultsAll eight cases within this cohort exhibited abdominal-pelvic masses, comprising six solitary masses and two instances of multiple nodules, except for one case located in the left kidney, the remaining cases lacked a clear organ source. On plain images, seven cases exhibited patchy areas of low density within the masses, four cases showed calcification within the masses. Post-contrast imaging displayed mild-to-moderate, uneven enhancement. Larger masses displayed patchy areas without significant enhancement at the center. In the four MRI examinations, T1-weighted images exhibited uneven, low signal intensity, while T2-weighted images demonstrated uneven high signal intensity. Imaging unveiled four cases of liver metastasis, four cases of ascites, seven cases of lymph node metastasis, three cases of diffuse peritoneal thickening, and one case involving left ureter invasion with obstruction. In the FDG-PET/CT examinations of seven cases, multiple abnormal FDG accumulations were observed in the abdominal cavity, retroperitoneum, pelvis, and liver. One postoperative case revealed a new metastatic focus near the colonic hepatic region. The range of maximum standardized uptake values (SUVmax) for all lesions are 6.62–11.15.ConclusionsDSRCT is commonly seen in young men, and the imaging results are mostly multiple lesions with no clear organ source. Other common findings include intratumoral calcification, liver metastasis, ascites, peritoneal metastasis, and retroperitoneal lymph node enlargement. The combined use of CT, MRI and FDG-PET/CT can improve the diagnostic accuracy and treatment evaluation of DSRCT. However, it is imperative to underscore that the definitive diagnosis remains contingent upon pathological examination.

Gemcitabine-Loaded Microbeads for Transarterial Chemoembolization of Rabbit Renal Tumor Monitored by 18F-FDG Positron Emission Tomography/X-Ray Computed Tomography Imaging

Background/Objectives: The purpose of this study was to develop the gemcitabine-loaded drug-eluting beads (G-DEBs) for transarterial chemoembolization (TACE) in rabbit renal tumors and to evaluate their antitumor effect using 2-deoxy-2-[(18)F]fluoro-D-glucose positron emission tomography/X-ray computed tomography (18F-FDG PET/CT). Methods: DEBs were prepared by polyvinyl alcohol-based macromer crosslinked with N-acryl tyrosine and N,N′-methylenebis(acrylamide). Gemcitabine was loaded through ion change to obtain G-DEBs. Their particle size and drug release profile were characterized. VX2 tumors were implanted in the right kidney of rabbits to establish the renal tumor model. The tumor-bearing rabbits received pre-scan by 18F-FDG PET/CT, followed by targeted transarterial injection of G-DEBs under digital subtraction angiography (DSA) guidance. The rabbits received another 18F-FDG PET/CT scan 10 or 14 days after the treatment. The therapeutic effect was further validated by histopathological analysis of the dissected tumors. Results: The average particle size of the microspheres was 58.06 ± 0.50 µm, and the polydisperse index was 0.26 ± 0.002. The maximum loading rate of G-DEBs was 18.09 ± 0.35%, with almost 100% encapsulation efficiency. Within 24 h, GEM was eluted from G-DEBs rapidly and completely, and more than 20% was released in different media. DSA illustrated that G-DEBs were delivered to rabbit renal tumors. Compared with the untreated control group with increased tumor volume and intense 18F -FDG uptake, the G-DEBs group showed significant reductions in tumor volume and maximum standard uptake value (SUVmax) 10 or 14 days after the treatment. Histopathological analysis confirmed that the proliferating area of tumor cells was significantly reduced in the G-DEBs group. Conclusions: Our results demonstrated that G-DEBs are effective in TACE treatment of rabbit VX2 renal tumors, and 18F-FDG PET/CT provides a non-invasive imaging modality to monitor the antitumor effects of TACE in renal tumors.

68Ga-PSMA PET CT/MRI in the initial diagnosis and staging of prostate cancer: A review

Prostate-specific membrane antigen-positron emission tomography (PSMA-PET) imaging has demonstrated potential in addressing prostate cancer (PCa) diagnostic difficulties. According to current guidelines, gallium-68 (68Ga)-PSMA-PET is used as an adjunct to traditional imaging modalities in patients with primary PCa. The purpose of this review, conducted using Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines, is to give an overview of studies that have examined the role of 68Ga-PSMA in the initial diagnosis of PCa, its performance in TNM staging, its correlation with prostate-specific antigen (PSA) levels, targeted biopsies, and the International Society of Urological Pathology (ISUP) scores using computed tomography (CT) or magnetic resonance imaging (MRI). The findings demonstrate that, in addition to MRI alone, combining 68Ga-PSMA-PET with MRI-targeted biopsy improves the initial identification of clinically significant prostate cancer (csPCa), particularly for ambiguous prostate imaging-reporting and data system (PI-RADS) three lesions. 68Ga-PSMA-PET/CT is useful when MRI results for csPCa are uncertain, but consistent techniques are required. Regarding risk assessment and therapy planning, 68Ga-PSMA-PET has a strong correlation with both PSA levels and ISUP scores. It accurately detects primary PCa lesions, making it suitable for high-risk patients. In 68Ga-PSMA-PET, higher maximum standardized uptake value (SUVmax) readings are linked to more aggressive illness. For N and M staging, 68Ga-PSMA-PET/CT is more sensitive and specific than conventional imaging; however, for T-staging, multiparametric MRI (mpMRI) provides better accuracy. 68Ga-PSMA-PET/MRI shows improved accuracy for primary PCa detection compared to mpMRI alone. Challenges include the lack of standardized SUVmax cutoff values. 68Ga-PSMA-PET is useful for the initial diagnosis and staging of PCa, complementing MRI, although further research is needed to standardize imaging techniques and interpretations.

Quantitative assessment of volume-based metabolic parameters in early-stage invasive ductal breast cancer: Impact of different standardized uptake value thresholds on prognostic factors - A comprehensive analysis.

This study compares volume-based metabolic parameters in early-stage invasive ductal breast cancer using different standardized uptake value (SUV) thresholds and examines their association with immunohistochemical factors. A retrospective analysis included 135 patients with early-stage invasive ductal breast cancer who underwent preoperative fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scans. Metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were derived using absolute SUV threshold methods and fixed % maximum tumor SUV threshold methods. Associations with immunohistochemical factors were explored, and receiver operating characteristic curves were generated. Metabolic tumor volume 2.5 and TLG 2.5 showed stronger correlations with maximum tumor SUV values. Metabolic tumor volume 2.0 and TLG 2.0 had superior area under the curve (AUC) values in predicting estrogen and progesterone receptor negativity. Metabolic tumor volume 2.0 and TLG 2.0 were superior in distinguishing low and high-grade tumors. Absolute SUV threshold methods with a threshold of 2.0 are recommended for calculating volume-based metabolic parameters due to their strong correlation with immunohistochemical factors in invasive ductal breast cancer.

Analysis of the relationship between 18F-FDG PET/CT and ultrasound BI-RADS classification and their combined application in the diagnosis of breast diseases.

To analyze the relationship between fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) and ultrasound breast imaging reporting and data system (BI-RADS) classification, and to evaluate the diagnostic value of their combined application in breast diseases. A retrospective analysis was conducted on the 18F-FDG PET/CT images and ultrasound BI-RADS classification data of 110 patients with suspected breast cancer treated at our hospital from July 2020 to May 2022. Pearson correlation analysis was used to assess the relationship between the maximum standardized uptake value (SUVmax) and BI-RADS classification. Using pathology or long-term follow-up results as the "gold standard," the diagnostic value of 18F-FDG PET/CT, ultrasound BI-RADS classification, and their combined application in breast diseases was analyzed. Based on the "gold standard" of pathology or long-term follow-up, of the 110 patients with suspected breast cancer, 49 were benign, and 61 were malignant. The SUVmax levels of malignant lesions were significantly higher than those of benign lesions (P<0.05). Pearson correlation analysis indicated a low correlation between SUVmax and ultrasound BI-RADS classification (r=0.458, P<0.05). Receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of the combined application of SUVmax and ultrasound BI-RADS classification was higher than that of either method alone, both for breast tumors and for patients classified as BI-RADS category 3 to 4. The correlation between SUVmax and ultrasound BI-RADS classification is low (r=0.458), indicating that these two methods assess different biological aspects of breast tumors. However, the combined use of SUVmax and BI-RADS classification significantly enhances diagnostic accuracy, particularly for patients with BI-RADS 3 to 4 lesions. Although this combination improves diagnostic efficacy, 18F-FDG PET/CT should not be used as a primary screening tool but rather as a complementary method in specific clinical scenarios where imaging findings are inconclusive or suspicion of malignancy is high.

Accidental renal cell carcinoma detected on 68Ga-Pentixafor PET/MR.

The value of gallium-68 (68Ga)-Pentixafor positron emission tomography/magnetic resonance (PET/MR) image in renal carcinoma is unknown. Herein, we reported 68Ga-Pentixafor PET/MR findings in a 47-year-old man with accidental renal carcinoma. Gallium-68-Pentixafor PET/MR showed a small nodule in the left kidney with iso-signal on T1WI and low signal on T2WI. This lesion had intense 68Ga-Pentixafor uptake with a maximum standardized uptake value (SUVmax) of 7.05. This case suggested the potential of 68Ga-Pentixafor PET/MR in the image evaluation of renal carcinoma.

Analysis of the diagnostic effect of 18F-FDG PET/CT in IIM patients and its relationship with disease severity.

To analyze the diagnostic effect of fluorine-18-fluorodeoxyglucose (18F-FDG) positron emission tomography/computed tomography (PET/CT) in patients with idiopathic inflammatory myopathies (IIM) and its relationship with disease severity. A retrospective analysis was conducted on the clinical and imaging data of 31 IIM patients treated in our hospital from April 2020 to April 2024, who were included in the lesion group. Additionally, 30 patients without muscle disease during the same period were selected as the control group. The maximum standardized uptake value (SUVmax) of the proximal limb girdle muscles was measured in both groups and compared. A receiver operating characteristic (ROC) curve was plotted to analyze the diagnostic value of SUVmax for IIM using 18F-FDG PET/CT. Spearman rank correlation was used to analyze the relationship between muscle SUVmax in IIM patients and relevant laboratory indicators, including creatine kinase (CK), creatine kinase-MB (CK-MB), C-reactive protein (CRP), serum ferritin (SF), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT). The SUVmax level of the lesion group (2.94±0.58) was significantly higher than that of the control group (1.17±0.23) (t=15.568, P<0.05). A receiver operating characteristic curve analysis indicated that the optimal cut-off value of SUVmax for distinguishing the lesion group from the control group was 2.16g/mL, with a diagnostic sensitivity of 100%, specificity of 91.8%, and an area under the curve (AUC) of 0.952. Correlation analysis showed a positive correlation between SUVmax and CK (r=0.659), CK-MB (r=0.523), AST (r=0.458), and LDH (r=0.437) (P<0.05), but no significant correlation with CRP (r=0.219), SF (r=0.348), or ALT (r=0.237). Fluorine-18-FDG PET/CT demonstrates an ideal diagnostic effect for IIM patients, and its semi-quantitative parameter, SUVmax, holds good auxiliary diagnostic value for IIM. It can reflect the activity and severity of the disease to a certain extent.

Analysis of the application value of SUV in quantitative SPECT/CT for diagnosing benign and malignant bone lesions.

To analyze the application value of standardized uptake value (SUV) in quantitative single-photon emission computed tomography/computed tomography (SPECT/CT) based on the maximum expectation reconstruction algorithm for diagnosing benign and malignant bone lesions. A retrospective analysis was conducted on the clinical data of 83 patients suspected of bone metastasis who underwent quantitative SPECT/CT bone scans in our hospital from September 2023 to July 2024. A total of 91 high-metabolic bone lesions were outlined for SUV measurement, while the spinal SUV of patients with normal bone metabolism were outlined as the control group (46 vertebral bodies). The maximum SUV (SUVmax), mean SUV (SUVmean), and minimum SUV (SUVmin) of benign lesions (benign group), malignant lesions (malignant group), and the control group were measured and compared. Receiver operating characteristic (ROC) curves were plotted to analyze the diagnostic value of SUV in differentiating benign and malignant bone lesions using quantitative SPECT/CT. Based on the final diagnosis determined by pathology and/or imaging follow-up for 6-12 months or more, 50 malignant bone lesions and 41 benign bone lesions were identified. The levels of SUVmax, SUVmean, and SUVmin in the malignant and benign groups were higher than those in the control group, with the malignant group showing higher levels than the benign group (P<0.05). Receiver operating characteristic curve analysis showed that the areas under the curves for SUVmax, SUVmean, and SUVmin were 0.867, 0.909, and 0.896, respectively. The optimal cut-off value for SUVmax was 26.58g/mL, with a specificity of 100% and a sensitivity of 65.27%; for SUVmean, the optimal cutoff value was 12.75g/mL, with a sensitivity of 78.36% and a specificity of 93.54%; for SUVmin, the optimal cut-off value was 9.13g/mL, with a sensitivity and specificity of 81.42% and 89.87%, respectively. The diagnostic detection rate of quantitative SPECT/CT fusion imaging combined with SUVmean analysis (91.21%) was higher than that of conventional SPECT/CT fusion imaging qualitative analysis (74.73%) (P<0.05). Standardized uptake value in quantitative SPECT/CT to some extent supplements the qualitative analysis of tumor bone metastasis and benign bone lesions, offering a higher accuracy in diagnosing tumor bone metastasis and differentiating between benign and malignant lesions compared to conventional SPECT/CT bone fusion imaging.

Serial positron-emission tomography after induction therapy as a predictor of prognostic outcomes for patients with thymic carcinoma.

To investigate the role of 18F-fluorodeoxy glucose-positron emission tomography/computed tomography (FDG-PET/CT) to assess pathological response and prognosis after induction therapy in patients with thymic carcinoma. The subjects of this retrospective study were 18 patients with thymic carcinoma who underwent FDG-PET, before and after induction therapy. We measured the maximum standardized uptake value (SUVmax) of the tumor and analyzed the correlation between the change in SUVmax and pathological response or recurrence. Induction therapy led to a reduction in both the tumor size and SUVmax in most patients. A strong correlation (Pearson coefficient = 0.90, p < 0.0001) was observed between the changes in tumor size and SUVmax. Although the SUVmax and tumor size showed no association with the pathological response, an SUVmax change > 50% predicted lower recurrence rates (p = 0.03). Changes in the SUVmax following induction therapy may serve as a valuable predictor of recurrence in patients with thymic carcinoma. This finding highlights the potential of FDG-PET as a tool for patient monitoring and prognostication of this rare subset of carcinomas. Further studies are warranted to validate these results and standardize the FDG-PET protocols for optimal clinical use.

Characterization of malignant kidney tumors in childhood by 18F-FDG PET/CT.

To evaluate the role of semiquantitative parameters derived from 18F-FDG PET/CT in characterizing pediatric malignant kidney tumors. 54 children with pathologically confirmed renal malignancies who underwent pretreatment 18F-FDG PET/CT were retrospectively reviewed. Association between PET-derived semiquantitative parameters, including maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG), and tumor histology, disease stage, and loss of heterozygosity were analyzed. Of the 54 patients, 43 had Wilms tumor (WT), 4 had clear cell sarcoma of the kidney (CCSK), 3 had rhabdoid tumor of kidney, 2 had renal cell carcinoma, and 2 had congenital mesoblastic nephroma. 18F-FDG PET/CT detected all primary renal tumors, with SUVmax ranging from 1.2 to 14.5. PET-derived parameters showed no significant differences among different tumor types, except for CCSK, which exhibited lower FDG uptake compared to WT (SUVmax 3.60 ± 1.02 vs. 6.10 ± 2.25, p = 0.034). Higher MTV, TLG, and lactate dehydrogenase were associated with stage IV disease. ROC analysis showed that TLG had the highest AUC (0.931) for predicting stage IV disease in the whole cohort, while SUVmax had the highest AUC (0.867) for predicting stage IV and V in WT. Furthermore, Children with 1q gain exhibited higher MTV in WT (447 ± 354 vs. 207 ± 189, p = 0.041). PET-derived semiquantitative parameters highly associated with disease stage both in the overall cohort of renal malignancies and specifically in the WT group. Additionally, volumetric metabolic indices might provide further insights into loss of heterozygosity in children with WT.

The role of FDG PET assessment in patients with advanced breast cancer treated with cyclin-dependent kinase 4/6 inhibitors in the second-line setting.

Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have demonstrated a survival benefit in the second-line treatment of patients with hormone receptor-positive human epidermal growth factor receptor 2-negative advanced breast cancer. However, identifying prognostic biomarkers remains a challenge. Thus, we aimed to assess the prognostic value of 18F-fluorodeoxyglucose positron emission tomography-computed tomography (FDG-PET-CT) performed before CDK4/6 inhibitors initiation. This single-center retrospective analysis comprised patients treated with CDK4/6 inhibitors in the second-line setting between 2018 and 2024, with FDG-PET-CT performed before CDK4/6 inhibitor initiation. The study included 39 patients with a median age of 63 years (IQR 50 -71). Among them, 12 had de novo metastatic disease (30.8%), and 13 had oligometastatic disease (33.3%). Treatment distribution was as follows: 15 patients received palbociclib (38%), 19 ribociclib (49%), and five abemaciclib (13%). Most patients received fulvestrant (31 patients, 79%), whereas eight patients (21%) were treated with letrozole. The median progression-free survival (PFS) in all studied patients was 25.8 months. Notably, baseline SUVmax (maximum standardized uptake value) showed statistically and clinically significant differences. Patients in the low SUVmax group had a median PFS of 30.7 months, compared to 13.0 months for those in the high SUVmax group (p = 0.038). The 2-year PFS was 76.2% [95% CI 51.8% - 89.4%] for the low SUVmax group, contrasting with 22.3% [95% CI 4.0% - 49.9%] for the high SUVmax group. High SUVmax, poor performance status, and de novo metastatic disease were independent prognostic factors for PFS. FDG-PET-CT performed before cyclin-dependent kinase 4/6 inhibitor commencement is a valuable prognostic tool in hormone receptor-positive human epidermal growth factor receptor 2-negative advanced breast cancer. Patients with SUVmax less than 8.4 experienced extended progression-free survival compared to those with higher SUVmax.

Predictive value of 18F-fluorodeoxyglucose uptake for axillary lymph node metastasis in operable breast cancer: impact of molecular subtypes.

To evaluate the predictive value of standardized uptake value (SUV) in both primary tumors and axillary lymph nodes (ALNs) using FDG PET/CT for lymph node metastasis in breast cancer patients, and to assess the influence of molecular subtypes on this predictive performance. This retrospective study included 287 patients with invasive ductal carcinoma (IDC) who underwent FDG PET/CT prior to surgery between September 2016 and December 2019. The maximum standardized uptake value (SUVmax)of primary tumors (SUV-B) and ALNs (SUV-LN) were analyzed. Molecular subtypes were classified as hormone receptor-positive, HER2-positive, and triple-negative breast cancer (TNBC). Receiver operating characteristic (ROC) curve analysis was performed to assess and compare the diagnostic performance of SUV-B and SUV-LN for predicting ALN metastasis. Among the 287 patients, 62 (21.6%) had confirmed ALN metastasis. The median SUV-LN was significantly higher in patients with metastasis compared to those without metastasis(1.5 vs. 0.9; P < 0.001). SUV-LN demonstrated good discriminative performance for ALN metastasis (AUC: 0.796), whereas SUV-B did not show significant predictive value (AUC: 0.536). The SUV_LN demonstrated significantly lower predictive performance for ALN metastasis in the hormone-positive group (AUC: 0.796) compared to the excellent discriminative performance in the HER2-positive (AUC: 0.923, P = 0.018) and TNBC (AUC: 0.940, P = 0.004) groups. Hormone receptor-positive tumors also exhibited lower FDG uptake in metastatic lymph nodes compared to HER2-positive and TNBC subtypes (P = 0.031). FDG PET/CT SUV-LN effectively predicts ALN metastasis in HER2-positive and TNBC subtypes. Hormone receptor-positive breast cancers show lower FDG uptake in metastatic ALNs, reducing diagnostic accuracy. This finding may aid in selecting the most appropriate diagnostic modality based on tumor characteristics in the era of personalized medicine.

Diagnostic Ability of Quantitative Parameters of Whole-Body Bone SPECT/CT Using a Full-Ring 360° Cadmium-Zinc-Telluride Camera for Detecting Bone Metastasis in Patients with Prostate Cancer

Background/Objectives: This study aimed to assess the diagnostic capability of quantitative parameters from whole-body bone single-photon emission computed tomography/computed tomography (SPECT/CT) in detecting bone metastases in prostate cancer patients; Methods: We retrospectively analyzed 82 prostate cancer patients who underwent staging bone scintigraphy with a full-ring 360° Cadmium-Zinc-Telluride (CZT) SPECT/CT system. From the SPECT/CT images, we measured the maximum (SUVmax) and mean (SUVmean) standardized uptake values at six normal bone sites (skull, humerus, thoracic spine, lumbar spine, iliac bone, and femur), and the SUVmax for both metastatic and benign bone lesions. Ratios of lesion SUVmax-to-maximum and mean uptake values at the skull, humerus, and femur were computed for each lesion; Results: SUVmax and SUVmean at the skull and femur exhibited significantly lower variance compared to those at the thoracic spine, lumbar spine, and iliac bone, and revealed no significant differences between patients with and without bone metastasis. In receiver operating characteristic curve analysis for detecting bone metastasis among 482 metastatic lesions, 132 benign bone lesions, and 477 normal bone sites, the lesion-to-femur mean uptake ratio demonstrated the highest area under the curve value (0.955) among SPECT/CT parameters. Using a cut-off value of 5.38, the lesion-to-femur mean uptake ratio achieved a sensitivity of 94.8% and a specificity of 86.5%; Conclusions: The bone lesion-to-femur mean uptake ratio was the most effective quantitative bone SPECT/CT parameter for detecting bone metastasis in prostate cancer patients. Quantitative analysis of bone SPECT/CT images could thus play a crucial role in diagnosing bone metastasis.

Deep learning-based low count whole-body positron emission tomography denoising incorporating computed tomography priors.

Deep-learning-based denoising improves image quality and quantification accuracy for low count (LC) positron emission tomography (PET). Conventional deep-learning-based denoising methods only require single LC PET image input. This study aims to propose a deep-learning-based LC PET denoising method incorporating computed tomography (CT) priors to further reduce the dose level. Fifty patients who underwent their routine whole-body 2-deoxy-2-[18F]fluoro-D-glucose (18F-FDG) PET/CT scans in March 2022 were retrospectively and non-consecutively recruited. For full count (FC) PET, patients were injected with 3.7 MBq/kg FDG and scanned for 5 bed positions with 2 min/bed. LC PET of 1/10 (LC-10) and 1/20 (LC-20) count levels of FC PET were obtained by randomly down-sampling the FC list mode data, which were then paired with FC PET for training U-Net (U-Net-1) and cGAN (cGAN-1). Networks incorporated CT images as input (U-Net-2 and cGAN-2) were also implemented. Quantitative analysis of physical and clinical indices was performed and statistically assessed with Wilcoxon sign-rank test with Bonferroni correction. Mean square error and structural similarity index were the best for cGAN-2, followed by U-Net-2, cGAN-1 and U-Net-1. The errors of mean standardized uptake value (SUV) and maximum SUV were lowest for cGAN-2, followed by cGAN-1, U-Net-2 and U-Net-1. For cGAN-2, image quality and lesion detectability scores were 3.71±0.94 and 4.25±0.83 for LC-10, 3.57±0.79 and 3.61±1.21 for LC-20, while they were 3.49±0.92 and 4.42±0.08 for FC. Notably, some small lesions were "masked out" on cGAN/U-Net-1 but can be retrieved on cGAN/U-Net-2 denoised PET for LC-20. Deep-learning-based LC PET denoising incorporating CT priors is more effective than conventional deep-learning-based denoising with single LC PET input, especially at lower dose levels.

Radiology–pathology correlation of hormonal subtypes of breast cancer based on mammography, ultrasound, and PET imaging

BackgroundBreast cancer is one of the most common cancers among the female population globally and a major cause of death due to cancers among women. It has been classified into histopathological, hormonal, and molecular subtypes based on hormone receptor status. Their management involves a multidisciplinary approach depending on these subtypes, TNM staging, tumour size, and site. The purpose of this study was to assess the correlation between ultrasound and mammography characteristics and the maximum standardized uptake value on PET with hormonal subtypes of breast cancer.MethodsIt was a retrospective study from a single-centre data available for 8 months. In this study, 5 hormonal subtypes were considered; Luminal A, Luminal B, Luminal HER2-positive subtype, HER2-enriched subtype, and triple-negative subtype. The morphology of the lesions analysed on mammography and sonography and the SUV max value on PET were considered for analyses. The prediction performance of these features for the hormonal subtypes of breast cancers was then analysed.ResultsLuminal A and B subtypes of breast cancer had indistinct margins with posterior acoustic shadowing on ultrasound. Triple-negative subtypes were well-circumscribed lesions with posterior acoustic enhancement on ultrasound. HER2-positive lesions characteristically had pleomorphic microcalcifications with mixed posterior acoustic features on mammography. On PET, HER2-enriched cases had the highest SUV, and the Luminal A subtype had the lowest SUV.ConclusionAccording to our observations, there are certain typical morphological imaging characteristics for each hormonal subtype of breast cancer. These imaging modalities may help radiologists and clinicians in stratifying their patients for prognostication and better management.

Comparison of Different Diagnostic Criteria of 68Ga-Pentixafor PET/CT for the Classification of Primary Aldosteronism.

68Ga-Pentixafor positron emission tomography/computed tomography (PET/CT) is an emerging method for the classification diagnosis primary aldosteronism (PA). However, the diagnosis criteria are still controversial. To compare the accuracy of different criteria of 68Ga-Pentixafor PET/CT in the classification diagnosis of PA. This was a retrospective study at a tertiary hospital in China. Patients with PA who had undergone PET/CT and had classification diagnosis of unilateral PA (UPA) or bilateral PA (BPA) based on surgery or adrenal venous sampling were included. Area under the receiver operating characteristic curve (AUC), specificity, and sensitivity were used to analyze the accuracy of the lateralization index (LI) based on adrenal maximum standardized uptake value (SUVmax), dominant side SUVmax adjusted by liver, dominant side of SUVmax, and visual analysis. A total of 208 patients with PA (including 128 UPA and 80 BPA) were analyzed. The AUCs for diagnosing UPA using LI and visual analysis were both 0.82, higher than that of the dominant side of SUVmax (0.72) and dominant side SUVmax adjusted by liver (0.71). Visual analysis showed a sensitivity of 0.73 and a specificity of 0.88. The LI cutoff of 1.50 resulted in the highest Youden index of 0.59, with a sensitivity of 0.68 and a specificity of 0.91. When the LI cutoff was increased to 1.65, the sensitivity reduced to 0.61, while the specificity increased to 0.96. Both LI and visual analysis could be used for interpretation the results of 68Ga-Pentixafor PET/CT; nevertheless, visual analysis is more sensitive, and LI is more advantageous in specificity.

Prognostic Role of Pretreatment Tumor Burden and Dissemination Features From 2-[18F]FDG PET/CT in Advanced Mantle Cell Lymphoma.

Mantle cell lymphoma (MCL) is an aggressive non-Hodgkin lymphoma with poor prognosis. The usefulness of fluorine-18-fluorodeoxyglucose positron emission tomography/computed tomography (2-[18F]FDG PET/CT) and its parameters in the evaluation of treatment response and prognosis is not yet clear. The aim of this study was to investigate the prognostic role of tumor burden and tumor dissemination features derived by 2-[18F]FDG PET/CT in advanced MCL. We retrospectively included 120 patients with advanced MCL who underwent baseline 2- 2-[18F]FDG PET/CT and end-of-treatment (eot) PET/CT. The baseline-PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value body weight (SUVbw), lean body mass (SUVlbm), body surface area (SUVbsa), metabolic tumor volume (MTV), total lesion glycolysis (TLG) and dissemination features (Dmax and Dmax-bsa). EotPET/CT was judged according to the Lugano classification. Progression-free survival (PFS) and overall survival (OS) were plotted according to the Kaplan-Meier method. At a median follow-up of 59months, relapse/progression occurred in 68 patients while death in 38 patients with a median PFS and OS of 27.2 and 57.6months, respectively. MIPI score, Bulky disease, Ki-67 index, metabolic response, pretreatment MTV and TLG were significantly associated with PFS at univariate analysis, but only metabolic response, MTV and TLG were confirmed to be independent prognostic factors. Considering OS, only dissemination features were demonstrated to be prognostic features. In conclusions, metabolic response and metabolic tumor burden parameters (MTV and TLG) are strongest predictor of PFS, while dissemination features may have a significant role for predicting OS.

Evaluating the diagnostic performance of [18F]ALF-NOTA-FAPI-04 PET/CT in gastric cancer: a comparative study with [18F]FDG PET/CT.

To compare the diagnostic value of [18F]ALF-NOTA-FAPI-04 positron emission tomography/computed tomography (PET/CT) and 18F-fluorodeoxyglucose (FDG) PET/CT in gastric cancer. This single-center retrospective analysis included 65 patients with gastric cancer who received both [18F]FDG and [18F]ALF-NOTA-FAPI-04 PET/CT for initial staging or restaging. Histopathological manifestations, typical imaging manifestations, follow-up imaging, and comprehensive clinical assessment were used as reference criteria. The uptakes of [18F]FDG and [18F]ALF-NOTA-FAPI-04 PET were compared using the Wilcoxon signed-rank test. McNemar's test was employed to compare the diagnostic performance of the two imaging techniques. A total of 65 patients were included (26 male and 39 female; mean age, 54.03 ± 10.41 years), Among them, 10 were newly diagnosed, 46 underwent radical gastrectomy, and 9 received only chemotherapy prior to the study. Compared with [18F]FDG PET/CT, [18F]ALF-NOTA-FAPI-04 PET/CT showed higher sensitivity in primary or recurrent tumors (100% vs. 64.52%, p < 0.001)), lymph node metastases (88.89% vs. 38.89%, p = 0.006), distant metastases (91.18% vs. 50%, p < 0.001). From the semi-quantitative evaluation, the Maximum standardized uptake value (SUVmax) and target-to-background ratio of [18F]ALF-NOTA-FAPI-04 PET/CT were significantly higher than that of [18F]FDG PET/CT in primary or recurrent tumors, lymph node metastases, and distant metastases (all p < 0.001). Our study results indicate that [18F]ALF-NOTA-FAPI-04 PET/CT outperforms [18F]FDG PET/CT in the detection of primary or recurrent tumors, lymph node metastasis, and distant metastasis in gastric cancer. Question Early diagnosis and precise staging of gastric cancer are crucial for patient prognosis; however, current imaging techniques still face significant limitations. Findings [18F]ALF-NOTA-FAPI-04 PET/CT demonstrated significantly higher sensitivity than [18F]FDG PET/CT in detecting primary or recurrent tumors and metastases in patients with gastric cancer. Clinical relevance [18F]ALF-NOTA-FAPI-04 PET/CT is an advanced imaging diagnostic technique that significantly enhances the diagnostic accuracy for gastric cancer and its metastatic lesions. This technology provides robust support for clinical decision-making, thereby improving the management of patients with gastric cancer.