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PURPOSE: Theranostic approaches combining prostate-specific membrane antigen (PSMA)-PET/CT or PET/MRI with PSMA-targeted radionuclide therapy have improved clinical outcomes in patients with prostate cancer (PCa) especially metastatic castrate resistant prostate cancer. Dural metastases in PCa are rare but can pose a diagnostic challenge, as meningiomas, a more common dural based lesions have been shown to express PSMA. The aim of this study is to compare PSMA PET parameters between brain lesions classified as dural metastases and meningiomas in prostate cancer patients. METHODS: A retrospective analysis of PSMA PET/CT scans in patients with PCa and intracranial lesions was conducted. Brain lesions were categorized as dural metastases or meningiomas based on MRI characteristics, longitudinal follow-up, and histopathological characteristics. Standardized uptake values (SUVmax) of each brain lesion were measured, along with SUV ratio referencing parotid gland (SUVR). SUVs between lesions classified as metastases and meningiomas, respectively, were compared using Mann-Whitney-test. Diagnostic accuracy was evaluated using ROC analysis. RESULTS: 26 male patients (median age: 76.5 years, range: 59-96 years) met inclusion criteria. A total of 44 lesions (7 meningiomas and 37 metastases) were analyzed. Median SUVmax and SUVR were significantly lower in meningiomas compared to metastases (SUVmax: 2.7 vs. 11.5, p = 0.001; SUVR: 0.26 vs. 1.05, p < 0.001). ROC analysis demonstrated AUC 0.903; the optimal cut-off value for SUVR was 0.81 with 81.1 % sensitivity and 100 % specificity. CONCLUSION: PSMA PET has the potential to differentiate meningiomas from dural-based metastases in patients with PCa, which can optimize clinical management and thus improve patient outcomes.
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Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias de la Próstata , Humanos , Masculino , Anciano , Persona de Mediana Edad , Estudios Retrospectivos , Anciano de 80 o más Años , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/secundario , Glutamato Carboxipeptidasa II/metabolismo , Sensibilidad y Especificidad , Radiofármacos , Neoplasias Meníngeas/diagnóstico por imagen , Neoplasias Meníngeas/secundario , Meningioma/diagnóstico por imagen , Meningioma/patología , Meningioma/secundario , Antígenos de Superficie/metabolismo , Imagen por Resonancia Magnética/métodosRESUMEN
BACKGROUND: Recent data support 18F-FDG PET-CT for the management of infections in immunocompromised patients, including invasive fungal infection (IFI). However, its role is not well established in clinical practice. We performed an international survey to evaluate the knowledge of physicians about the usefulness of 18F-FDG PET-CT in IFI, in order to define areas of uncertainty. METHODS: An online survey was distributed to infectious diseases working groups in December 2023-January 2024. It included questions regarding access to 18F-FDG PET-CT, knowledge on its usefulness for IFI and experience of the respondents. A descriptive analysis was performed. RESULTS: 180 respondents answered; 60.5% were Infectious Diseases specialists mainly from Spain (52.8%) and Italy (23.3%). 84.4% had access to 18F-FDG PET-CT at their own center. 85.6% considered that 18F-FDG PET-CT could be better than conventional tests for IFI. In the context of IFI risk, 81.1% would consider performing 18F-FDG PET-CT to study fever without a source and around 50% to evaluate silent lesions and 50% to assess response, including distinguishing residual from active lesions. Based on the results of the follow-up 18F-FDG PET-CT, 56.7% would adjust antifungal therapy duration. 60% would consider a change in the diagnostic or therapeutic strategy in case of increased uptake or new lesions. Uncovering occult lesions (52%) and diagnosing/excluding endocarditis (52.7%) were the situations in which 18F-FDG PET-CT was considered to have the most added value. There was a great variability in responses about timing, duration of uptake, the threshold for discontinuing treatment or the influence of immune status. CONCLUSION: Although the majority considered that 18F-FDG PET-CT may be useful for IFI, many areas of uncertainty remain. There is a need for protocolized research to improve IFI management.
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Fluorodesoxiglucosa F18 , Infecciones Fúngicas Invasoras , Tomografía Computarizada por Tomografía de Emisión de Positrones , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Infecciones Fúngicas Invasoras/tratamiento farmacológico , Infecciones Fúngicas Invasoras/diagnóstico por imagen , Infecciones Fúngicas Invasoras/diagnóstico , Encuestas y Cuestionarios , Huésped Inmunocomprometido , España , ItaliaRESUMEN
The aim of this study was to establish and validate the precision of a novel radiomics approach that integrates 18Fluorine-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)-computed tomography (CT) scan data with clinical information to improve the prognostication of survival rates in patients diagnosed with stage III Non-Small Cell Lung Cancer (NSCLC) who are not candidates for surgery. We evaluated pretreatment 18F-FDG PET-CT scans from 156 individuals diagnosed with stage III inoperable NSCLC at Shandong Cancer Hospital. These individuals were divided into two groups: a training set comprising 110 patients and an internal validation set consisting of 46 patients. By employing random forest classifier and cox proportional hazards model , we identified and utilized relevant features to create predictive models and a nomogram. The effectiveness of these models was assessed through the use of the receiver operating characteristics(ROC) curves, Kaplan-Meier (KM) curves, and the application of the nomogram. Our findings showed that the combined model, which integrates both clinical and radiomic data, outperformed those based solely on clinical or radiomic features in predicting 3-year overall survival(OS). Furthermore, calibration plots revealed a high level of agreement between predicted and actual survival times. The research successfully established a predictive radiomics model that integrates 18F-FDG PET/CT imaging with clinical indicators to enhance survival predictions for patients with stage III inoperable NSCLC.
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Carcinoma de Pulmón de Células no Pequeñas , Fluorodesoxiglucosa F18 , Neoplasias Pulmonares , Estadificación de Neoplasias , Nomogramas , Tomografía Computarizada por Tomografía de Emisión de Positrones , Humanos , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Carcinoma de Pulmón de Células no Pequeñas/patología , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Masculino , Femenino , Persona de Mediana Edad , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/mortalidad , Neoplasias Pulmonares/patología , Anciano , Pronóstico , Curva ROC , Adulto , Estimación de Kaplan-Meier , Modelos de Riesgos Proporcionales , RadiómicaRESUMEN
BACKGROUND: Prostate tuberculosis (TB) is a rare and often underdiagnosed condition due to its nonspecific symptoms and imaging features, which can mimic malignancies on 18F-fluorodeoxyglucose positron emission tomography (PET) scans. This resemblance poses a challenge in differentiating TB from prostate cancer, especially in patients with preexisting tumors such as diffuse large B-cell lymphoma. The purpose of this study is to highlight the importance of considering TB in the differential diagnosis of patients with atypical imaging findings, even in the presence of known malignancies. CASE: We present a case of a 60-year-old man with diffuse large B-cell lymphoma who was initially misdiagnosed with a prostate tumor based on 18F-fluorodeoxyglucose PET/computed tomography scans. The subsequent ultrasound-guided prostate biopsy confirmed the presence of prostate TB, not malignancy. CONCLUSIONS: This case report underscores the critical role of considering TB as a potential diagnosis in patients with hematological tumors and atypical imaging results. It serves as a reminder for clinicians to exercise caution when interpreting PET/computed tomography scans and to incorporate TB into their differential diagnoses, thereby avoiding misdiagnosis and inappropriate treatment.
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Fluorodesoxiglucosa F18 , Linfoma de Células B Grandes Difuso , Tomografía Computarizada por Tomografía de Emisión de Positrones , Radiofármacos , Humanos , Masculino , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Persona de Mediana Edad , Linfoma de Células B Grandes Difuso/diagnóstico por imagen , Linfoma de Células B Grandes Difuso/diagnóstico , Diagnóstico Diferencial , Neoplasias de la Próstata/diagnóstico por imagen , Tuberculosis de los Genitales Masculinos/diagnóstico por imagen , Tuberculosis de los Genitales Masculinos/diagnóstico , Errores Diagnósticos , Próstata/diagnóstico por imagen , Próstata/patologíaRESUMEN
We observed at our university-based imaging centers that when prostate-specific membrane antigen (PSMA) PET/CT became available for staging and restaging prostate cancer, the volume of bone scanning on patients with prostate cancer (BS-P) markedly decreased. We aimed to study use patterns of PSMA PET/CT and BS-P at our imaging centers during the 4-y period around U.S. Food and Drug Administration approval of PSMA PET/CT in December 2020. We tested the hypothesis that the rate of decline of BS-P accelerated after U.S. Food and Drug Administration approval, as physicians planned for use of PSMA PET/CT in their patients. Methods: Our clinical report system was searched for BS-P and PSMA PET/CT scans from January 2019 through June 2023. Numbers of scans were tabulated by quarter and year. Quantitative and statistical analyses were performed. Results: Annualized average monthly BS-P peaked at 53.7 scans/mo in 2021 and then decreased over time. There were 552 BS-Ps performed in 2019, 503 in 2020, 614 in 2021, 481 in 2022, and 152 in the first half of 2023. BS-P monthly averages declined by 22% from 2021 to 2022 and by 36% from 2022 to 2023, whereas monthly PSMA PET/CT scan averages increased by 1,416% from 2021 to 2022 and by 69% from 2022 to 2023. There was a significantly greater decline in BS-Ps from 2022 to 2023 than from 2021 to 2022 (36% vs. 22%, P < 0.0001). There were 30 PSMA PET/CT scans performed in 2021, 455 in 2022, and 384 in the first half of 2023. The greatest quarterly increase in these scans (400%) occurred at the outset of PSMA PET/CT implementation in quarter 4 of 2021. In quarter 2 of 2023, the percentage of total studies was higher for PSMA PET/CT than for BS-P (74% vs. 26%, P < 0.0001). Conclusion: At our university-based imaging centers, use of BS-P has declined in correlation with the timing of U.S. Food and Drug Administration approval and implementation of PSMA PET/CT. This study illustrates one instance of workflow changes that occur in the nuclear medicine clinic when new agents are introduced and affect clinical management options.
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Antígenos de Superficie , Glutamato Carboxipeptidasa II , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias de la Próstata , Humanos , Masculino , Antígenos de Superficie/metabolismo , Huesos/diagnóstico por imagen , Neoplasias Óseas/diagnóstico por imagen , Glutamato Carboxipeptidasa II/metabolismo , Hospitales Universitarios , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Neoplasias de la Próstata/diagnóstico por imagenRESUMEN
OBJECTIVE: To evaluate the potential utility of 18F-FDG PET/CT to assess response to neoadjuvant immunochemotherapy in patients with resectable NSCLC, and the ability to screen patients who may benefit from neoadjuvant immunochemotherapy. METHODS: Fifty one resectable NSCLC (stage IA-IIIB) patients were analyzed, who received two-three cycles neoadjuvant immunochemotherapy.18F-FDG PET/CT was carried out at baseline(scan-1) and prior to radical resection(scan-2). SULmax, SULpeak, MTV, TLG, T/N ratio, ΔSULmax%,ΔSULpeak%, ΔMTV%, ΔTLG%,ΔT/N ratio% were calculated. 18F-FDG PET/CT responses were classified using PERCIST. We then compared the RECIST 1.1 and PERCIST criteria for response assessment.With surgical pathology of primary lesions as the gold standard, the correlation between metabolic parameters of 18F-FDG PET/CT and major pathologic response (MPR) was analyzed. All metabolic parameters were compared to treatment response and correlated to PFS and OS. RESULTS: In total of fifty one patients, MPR was achieved in 25(49%, 25/51) patients after neoadjuvant therapy. The metabolic parameters of Scan-1 were not correlated with MPR.The degree of pathological regression was negatively correlated with SULmax, SULpeak, MTV, TLG, T/N ratio of scan-2, and the percentage changes of the ΔSULmax%, ΔSULpeak%, ΔMTV%,ΔTLG%,ΔT/N ratio% after neoadjuvant therapy (p < 0.05). According to PERCIST, 36 patients (70.6%, 36/51) showed PMR, 12 patients(23.5%, 12/51) had stable metabolic disease(SMD), and 3 patients(5.9%, 3/51) had progressive metabolic disease (PMD). ROC indicated that all of scan-2 metabolic parameters and the percentage changes of metabolic parameters had ability to predict MPR and non-MPR, SULmax and T/N ratio of scan-2 had the best differentiation ability.The accuracy of RECIST 1.1 and PERCIST criteria were no statistical significance(p = 0.91). On univariate analysis, ΔMTV% has the highest correlation with PFS. CONCLUSIONS: Metabolic response by 18F-FDG PET/CT can predict MPR to neoadjuvant immunochemotherapy in resectable NSCLC. ΔMTV% was significantly correlated with PFS.
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Carcinoma de Pulmón de Células no Pequeñas , Fluorodesoxiglucosa F18 , Neoplasias Pulmonares , Terapia Neoadyuvante , Tomografía Computarizada por Tomografía de Emisión de Positrones , Radiofármacos , Humanos , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/patología , Carcinoma de Pulmón de Células no Pequeñas/terapia , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Masculino , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/patología , Neoplasias Pulmonares/terapia , Neoplasias Pulmonares/tratamiento farmacológico , Femenino , Terapia Neoadyuvante/métodos , Persona de Mediana Edad , Anciano , Pronóstico , Inmunoterapia/métodos , Adulto , Estudios RetrospectivosRESUMEN
PURPOSE: The purpose was to evaluate the pathological nature of focal thyroid uptake seen in 11C-Choline PET/CT performed for prostate cancer. MATERIAL AND METHODS: The study was IRB-approved. All 11C-Choline PET/CT exam reports for studies performed between January 01, 2018, and July 30, 2021, in male patients with prostate cancer in our institution were retrospectively reviewed. Exams with "focal thyroid uptake" on their final report were selected. Patients with surgery or ablation in the thyroid prior to the PET/CT, proven parathyroid adenomas or absent thyroid ultrasound were excluded. Repeated PET/CT exams of same patient were excluded. PET images were analyzed visually and semi-quantitatively by measuring the maximum standardized uptake value (SUVmax) of the focal thyroid uptake. Available thyroid ultrasound images, cytology and pathology reports were reviewed. Statistical analyses were performed. RESULTS: Out of 10,047 sequential 11C-Choline PET/CT studies, 318 reports included "focal thyroid uptake." About 128 of these studies were repeat exams and were excluded. Additional 87 patients were excluded, because the uptake was determined to be adjacent, rather than confined to the thyroid gland. Out of the remaining 103 patients, 74 patients had focal thyroid uptake and concurrent thyroid sonographic evaluation. Out of the 74 focal uptakes evaluated with ultrasound, 21 were presumed benign thyroid nodules based on the ultrasound and 53 had further evaluation with biopsy. Sixty three nodules were benign (21 presumed benign on ultrasound and 42 cytology or surgical pathology-proven), 9 nodules were malignant and 2 remained indeterminate. There was no significant difference between the SUVs of the benign and malignant groups (P > .3). CONCLUSION: In this retrospective study of patients with prostate cancer who underwent 11C-Choline PET/CT, we identified a group of patients who underwent thyroid ultrasound for incidental finding of focal 11C-Choline thyroid uptake. Incidence of malignancy in this group was 12%. Therefore, further investigation with ultrasound and possibly ultrasound-guided biopsy may be warranted when a choline avid thyroid nodule is found incidentally on choline PET.
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Radioisótopos de Carbono , Colina , Hallazgos Incidentales , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias de la Próstata , Nódulo Tiroideo , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Masculino , Nódulo Tiroideo/diagnóstico por imagen , Nódulo Tiroideo/patología , Colina/farmacocinética , Estudios Retrospectivos , Anciano , Persona de Mediana Edad , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Neoplasias de la Tiroides/diagnóstico por imagen , Neoplasias de la Tiroides/patología , Neoplasias de la Tiroides/diagnóstico , Ultrasonografía/métodos , Anciano de 80 o más Años , Glándula Tiroides/diagnóstico por imagen , Glándula Tiroides/patología , Radiofármacos/farmacocinéticaRESUMEN
The role of torso computed tomography (CT) in evaluating body composition has been unexplored. This study assessed the potential of low-dose torso CT from positron emission tomography (PET)/CT for analyzing body composition and its relation to muscle strength. We retrospectively recruited 384 healthy Korean adults (231 men, 153 women) who underwent torso 18F-FDG PET/CT, bioelectrical impedance analysis (BIA), and muscle strength tests (handgrip strength [HGS] and knee extension strength [KES]). CT images were segmented into three compartments: torso volumetric, abdominal volumetric, and abdominal areal. Muscle amounts from each compartment were indexed to height (m2). BIA and HGS served as reference standards, with correlation coefficients (r) calculated. Torso muscle volumetric index (TorsoMVI) had the strongest correlations with BIA-derived values (r = 0.80 for men; r = 0.73 for women), surpassing those from the abdominal compartments. TorsoMVI was also correlated significantly with HGS (r = 0.39, p < 0.01) and differentiated between normal and possible sarcopenia in men (n = 225, 5960 ± 785 cm3/m2 vs. n = 6, 5210 ± 487 cm3/m2, p = 0.02). In women, KES correlated more strongly with muscle parameters than HGS. Despite gender-specific variations, torso CT-derived parameters show promise for evaluating body composition and sarcopenia.
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Composición Corporal , Impedancia Eléctrica , Fuerza Muscular , Tomografía Computarizada por Tomografía de Emisión de Positrones , Torso , Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Fuerza Muscular/fisiología , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Torso/diagnóstico por imagen , Torso/fisiología , Estudios Retrospectivos , Anciano , Sarcopenia/diagnóstico por imagen , Sarcopenia/fisiopatología , Músculo Esquelético/diagnóstico por imagen , Músculo Esquelético/fisiologíaRESUMEN
Introduction: prostate cancer recurrence after definitive therapy for organ-confined disease often manifests as rising prostate-specific antigen (PSA) levels without clinically overt disease. 68Gallium prostate-specific membrane antigen, positron emission tomography/computed tomography (68GaPSMA PET/CT) imaging plays a major role in the management of recurrent prostate cancer. The purpose of this study was to assess the positivity rate of 68Ga PSMA PET/CT scans in cases of prostate cancer recurrence, and to compare the results with existing international literature. Methods: a retrospective analysis of 177 68Ga PSMA PET/CT scans of patients with biochemically proven disease recurrence was performed. The possible association of a positive PSMA PET/CT with the PSA level and Gleason score were analyzed. Results: a total of 177 68Ga PSMA PET/CT scans were performed in 163 patients (median age 66 years). Of these, 117 (66%) scans detected the site of disease recurrence. Among patients with PSA 0.2-0.99 ng/ml, 23/49 (47%, p<0.0001) were positive, and 20/35 (57%, p<0.0005) were positive in the group of patients with PSA 1.00-1.99. When PSA values were further categorized into PSA <2 ng/ml and PSA ≥2 ng/ml, detection rates were 49% and 86% respectively (p <0.0001). The scans were positive in 65% of patients with Gleason score of <7, 62% with Gleason score of =7 and 68% with Gleason score >7 (p=0.745). Conclusion: there was an increase in the detection rate with an increase in the PSA. Gleason score was not a predictor of a positive 68Ga PSMA PET/CT scan. 68Ga-PSMA PET/CT should be prioritized in patients with biochemical recurrence with PSA levels >0.2 ng/ml.
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Isótopos de Galio , Radioisótopos de Galio , Clasificación del Tumor , Recurrencia Local de Neoplasia , Tomografía Computarizada por Tomografía de Emisión de Positrones , Antígeno Prostático Específico , Neoplasias de la Próstata , Humanos , Masculino , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Estudios Retrospectivos , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Anciano , Antígeno Prostático Específico/sangre , Persona de Mediana Edad , Anciano de 80 o más Años , Ácido Edético/análogos & derivados , Ácido Edético/administración & dosificación , Radiofármacos/administración & dosificación , Radiofármacos/farmacologíaRESUMEN
This study aimed to evaluate the dose in different protocols of 18F-2-fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (PET/CT) procedure. The retrospective study involves 207 patients with confirmed malignancies who underwent PET/CT. Effective dose (E) from PET was estimated based on injected activity and dose coefficient as per International Commission on Radiation Protection (ICRP) 128. Estimation of E from CT was done utilizing the dose length product (DLP) method and conversion factors as per ICRP 102. There was a significant statistical difference observed in E between different PET/CT protocols (P < .001). E of PET in the whole body (WB) was found to be 4.9 ± 0.9 mSv, whereas mean volume computed tomography dose indexvol, DLP, and E of CT in WB were 7.0 ± 0.2 mGy, 674.3 ± 80.7 mGy.cm, and 10.1 ± 1.2 mSv, respectively. No linear correlation was seen between the size-specific dose estimate and E of CT (r = -0.003; P = .978). The total mean E in WB PET/CT was 17.0 ± 1.7 mSv. CT dose was contributing more than PET dose in all protocols except brain PET/CT. Optimization strategies can be evaluated only if monitored periodically.
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Fluorodesoxiglucosa F18 , Tomografía Computarizada por Tomografía de Emisión de Positrones , Dosis de Radiación , Radiofármacos , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Masculino , Femenino , Estudios Retrospectivos , Persona de Mediana Edad , Adulto , Anciano , Neoplasias/diagnóstico por imagen , Neoplasias/radioterapia , Adulto Joven , Anciano de 80 o más Años , Imagen de Cuerpo Entero/métodosRESUMEN
PURPOSE: Gliomas account for 75 % of primary malignant CNS tumors. High-grade glioma (CNS WHO grades 3 and 4) have an unfavorable treatment response and poor outcome. CXCR4 is a G protein-coupled receptor that plays an important part in the signaling pathway between cancer cells and tumor microenvironment. CXCR4 overexpression has been shown in a variety of cancers. In this study, we evaluate the potential value of [68Ga]Ga-Pentixafor as a PET/CT CXCR4-probe for in vivo assessment of CXCR4 expression in patients with high-grade glioma and its correlation with tumor grade. MATERIALS AND METHODS: [68Ga]Ga-CXCR4 PET/CT was performed in the prospective single-center study in treatment-naïve biopsy-proven patients with high-grade glioma. The acquired images were analyzed qualitatively and semi-quantitatively. RESULT: A total of 26 patients (mean age: 53.3±14.4 years, 11 women, 15 men) were enrolled. CNS WHO grade 3 pathology was seen in 19 % (5/26) of the sample. The patient-based sensitivity of 68Ga-CXCR4 was 96.2 %. Overall, 28 pathologic lesions were detected, leading to a lesion-based sensitivity of 96.4 %. The median (IQR) SUVmax of grade 4 lesions was substantially greater than the grade 3(3.03(2.5-3.7) vs. 1.51(1.2-1.8), p = 0.0145).). The highest tracer activity of organs -beside bladder as the main excretion reservoir-was in lymphoid tissue of Waldeyer's ring (mean SUVmax: 7.41), and spleen (mean SUVmax: 6.62). CONCLUSION: In conclusion, this new application for [68Ga]Ga-Pentixafor PET tracer exhibits excellent visual and semi-quantitative diagnostic properties. Further studies are warranted.
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Neoplasias Encefálicas , Glioma , Tomografía Computarizada por Tomografía de Emisión de Positrones , Radiofármacos , Receptores CXCR4 , Humanos , Receptores CXCR4/metabolismo , Femenino , Masculino , Glioma/diagnóstico por imagen , Glioma/metabolismo , Glioma/patología , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Persona de Mediana Edad , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/metabolismo , Radiofármacos/farmacocinética , Estudios Prospectivos , Radioisótopos de Galio , Clasificación del Tumor , Sensibilidad y Especificidad , Péptidos Cíclicos , Adulto , Anciano , Complejos de CoordinaciónRESUMEN
OBJECTIVES: To discriminate between post-treatment changes and tumor recurrence in patients affected by glioma undergoing surgery and chemoradiation with a new enhancing lesion is challenging. We aimed to evaluate the role of ASL, DSC, DCE perfusion MRI, and 18F-DOPA PET/CT in distinguishing tumor recurrence from post-treatment changes in patients with glioma. MATERIALS AND METHODS: We prospectively enrolled patients with treated glioma (surgery plus chemoradiation) and a new enhancing lesion doubtful for recurrence or post-treatment changes. Each patient underwent a 1.5T MRI examination, including ASL, DSC, and DCE PWI, and an 18F-DOPA PET/CT examination. For each lesion, we measured ASL-derived CBF and normalized CBF, DSC-derived rCBV, DCE-derived Ktrans, Vp, Ve, Kep, and PET/CT-derived SUV maximum. Clinical and radiological follow-up determined the diagnosis of tumor recurrence or post-treatment changes. RESULTS: We evaluated 29 lesions (5 low-grade gliomas and 24 high-grade gliomas); 14 were malignancies, and 15 were post-treatment changes. CBF ASL, nCBF ASL, rCBV DSC, and PET SUVmax were associated with tumor recurrence from post-treatment changes in patients with glioma through an univariable logistic regression. Whereas the multivariable logistic regression results showed only nCBF ASL (p = 0.008) was associated with tumor recurrence from post-treatment changes in patients with glioma with OR = 22.85, CI95%: (2.28-228.77). CONCLUSION: In our study, ASL was the best technique, among the other two MRI PWI and the 18F-DOPA PET/CT PET, in distinguishing disease recurrence from post-treatment changes in treated glioma.
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Neoplasias Encefálicas , Dihidroxifenilalanina , Glioma , Recurrencia Local de Neoplasia , Tomografía Computarizada por Tomografía de Emisión de Positrones , Radiofármacos , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Masculino , Glioma/diagnóstico por imagen , Glioma/terapia , Recurrencia Local de Neoplasia/diagnóstico por imagen , Femenino , Persona de Mediana Edad , Estudios Prospectivos , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/terapia , Adulto , Dihidroxifenilalanina/análogos & derivados , Anciano , Diagnóstico Diferencial , Imagen por Resonancia Magnética/métodos , Medios de ContrasteRESUMEN
Nuclear medicine is an important tool for use in molecular imaging of important biological processes. Methods for intravenous delivery of radiotracers remains a challenge, with tail vein injections demonstrated to be technically difficult and lacking in reproducibility. Other intravenous methods include jugular vein (JV) injection, which requires a more invasive and precise microsurgical technique. Although the retroorbital (RO) sinus drains directly into the JV, and RO injections are minimally invasive and simpler to perform, they remain underutilized, perhaps due to a lack of studies demonstrating their performance. This study provides a comprehensive comparison of dynamic tissue biodistribution of three categories of commonly utilized radiopharmaceuticals between JV and RO injection methods in prostate tumor-bearing mice using PET-CT imaging. Results show that JV and RO injections have equivalent dynamic tissue biodistributions across the three categories of radiopharmaceuticals used: (1) small molecule measuring tumor metabolism (18F-flurodeoxyglucose [FDG]); (2) peptide-based probe measuring angiogenesis (64Cu-NOTA-PEG4-cRGD2); and (3) dextran-based nanocarrier (64Cu-NOTA-D20). Although RO injections present with some limitations such as type of injectate and difficulty for measuring acute, dynamic pharmacokinetics, this study demonstrates that RO injections are a viable, minimally invasive or stressful, and efficient alternative intravenous delivery technique for molecular imaging.
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Venas Yugulares , Neoplasias de la Próstata , Radiofármacos , Animales , Ratones , Masculino , Venas Yugulares/diagnóstico por imagen , Venas Yugulares/metabolismo , Distribución Tisular , Radiofármacos/farmacocinética , Radiofármacos/administración & dosificación , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/metabolismo , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Tomografía de Emisión de Positrones/métodos , Inyecciones Intravenosas , Línea Celular TumoralRESUMEN
Cerebral atrophy is a key finding in patients with dementia and usually determined on MRI. We tested whether cerebral atrophy can be imaged with FDG PET by applying deformation-based morphometry (DBM). We retrospectively identified 26 patients with a biomarker-supported clinical diagnosis of Alzheimer's disease (AD) who had received FDG PET on a fully-digital PET/CT system and structural MRI and compared them to 13 healthy elderly controls (HEC). We performed DBM with FDG PET data (FDG-DBM). As a reference standard for determining atrophy we used voxel-based morphometry of MRI data (MRI-VBM). For conventional analysis of hypometabolism, scaled FDG PET scans (reference: brain parenchyma) were compared between groups. Receiver operating characteristic (ROC) analyses were performed. ROI read-outs were tested for associations with cognitive test performance. FDG-DBM showed abnormalities in AD mainly in the bilateral hippocampi. Similarly, MRI-VBM showed hippocampal atrophy. By contrast, conventional FDG PET analysis revealed reduced bilateral temporo-parietal FDG uptake (all p < 0.05, FWE-corrected). FDG-DBM measures of the hippocampus significantly separated AD from HEC with an AUC of 0.81; MRI-VBM achieved an AUC of 0.87; the difference between the two ROC curves was not significant (p = 0.40). Whereas FDG uptake of the hippocampus did not separate AD from HEC, FDG uptake of the Landau Meta-ROI achieved an AUC of 0.88. Verbal memory was significantly associated with FDG-DBM measures of the hippocampus (p = 0.009), but not of the Landau Meta-ROI (p > 0.1). The opposite held true for conventional FDG uptake (p > 0.1 and p = 0.001, respectively). Hippocampal atrophy in AD can be detected by applying DBM to clinical, fully-digital FDG PET. It correlates with cognitive performance and might constitute a biomarker of neurodegeneration that is complementary to conventional FDG PET analysis of regional hypometabolism.
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Enfermedad de Alzheimer , Atrofia , Fluorodesoxiglucosa F18 , Hipocampo , Imagen por Resonancia Magnética , Tomografía de Emisión de Positrones , Humanos , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/patología , Enfermedad de Alzheimer/metabolismo , Hipocampo/diagnóstico por imagen , Hipocampo/patología , Hipocampo/metabolismo , Masculino , Anciano , Femenino , Atrofia/patología , Tomografía de Emisión de Positrones/métodos , Imagen por Resonancia Magnética/métodos , Estudios Retrospectivos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Anciano de 80 o más Años , Persona de Mediana Edad , Curva ROCRESUMEN
In up to two thirds of prostate-specific membrane antigen (PSMA) PET scans, unspecific bone uptake has been described. The aim of this study was to estimate the diagnostic accuracy of [68Ga]Ga-PSMA-11 PET/CT for bone metastases and the occurrence of equivocal lesions. Methods: We analyzed retrospectively 118 patients who underwent a [68Ga]Ga-PSMA-11 PET/CT for initial staging or recurrence evaluation. Lesions were interpreted according to the PSMA reporting and data system (PSMA-RADS) and the prostate cancer molecular imaging standardized evaluation (PROMISE) criteria. The SUVmax and the localization of each lesion were recorded. A combination of prior or follow-up examinations was used as a reference standard to categorize benign and malignant lesions. Correlation between the final diagnosis and imaging or clinicobiochemical parameters was tested. The diagnostic accuracy was calculated for different cutoffs of PSMA-RADS criteria, for PROMISE criteria, and the sequential combination of both. Results: In total, 265 bone abnormalities were identified in 70 of 118 patients. Among these, 148 (55.8%) lesions in 50 (42.4%) patients were classified as PSMA-RADS-3B. There were no PSMA-RADS-3D lesions in our cohort. Equivocal lesions were more frequent on the ribs (30.6%) followed by the pelvis (26.5%), but in the ribs, such an uptake was malignant in 33.3% of cases versus 66.7% in the pelvis. A significant association was found between the final diagnosis and the SUVmax, prostate-specific antigen (PSA), PSA doubling time, International Society of Urological Pathology score, and the number of foci. The sensitivity and specificity were 100% and 63.6% for the PSMA-RADS-3B cutoff, respectively; 40.5% and 100% for the PSMA-RADS-4 cutoff, respectively; and 89.3% and 96.6% for both the PROMISE criteria and the sequential PSMA-RADS/PROMISE strategy, respectively. In the sequential method, the number of equivocal lesions was reduced from 147 to 2. We found that 53% of PSMA-RADS-3B lesions were malignant; 95.5% of lesions classified positive by the sequential method were true positives, whereas 32.6% were false negatives. Conclusion: [68Ga]Ga-PSMA-11 PET/CT has high accuracy for the diagnosis of bone metastases. Equivocal lesions constitute nearly half of the lesions seen on PSMA PET. The sequential combination of PSMA-RADS and PROMISE criteria reduces the number of lesions classified as equivocal. PSMA-RADS-3B lesions which are positive according to the PROMISE criteria should be considered highly suggestive of malignancy.
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Neoplasias Óseas , Ácido Edético , Isótopos de Galio , Radioisótopos de Galio , Oligopéptidos , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias de la Próstata , Humanos , Masculino , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/patología , Neoplasias Óseas/secundario , Neoplasias Óseas/diagnóstico por imagen , Anciano , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Ácido Edético/análogos & derivados , Persona de Mediana Edad , Estudios Retrospectivos , Anciano de 80 o más Años , Estándares de ReferenciaRESUMEN
Background Intravenous prostate-specific membrane antigen (PSMA)-targeted radioligand therapy improves survival in men with metastatic castration-resistant prostate cancer. Yet, the impact of selective prostatic arterial administration on primary tumor uptake is unclear. Purpose To compare gallium 68 (68Ga)-PSMA-11 uptake using dynamic PET/CT in prostatic tumoral volumes of interest (VOIs) during intravenous and selective prostatic arterial infusions for individuals with untreated, high-risk prostate cancer. Materials and Methods In this prospective, intraindividual comparative study conducted at an academic medical center, five men aged 58, 61, 64, 66, and 68 years with treatment-naive prostate cancer were enrolled between January 2022 and February 2023 and underwent two dynamic 68Ga-PSMA-11 PET/CT examinations 1 week apart. During the first examination, the radiotracer was administered intravenously. During the second administration, the radiotracer was delivered into either the right or left prostatic artery through an angiographically placed microcatheter. The primary outcome was maximum standardized uptake value (SUVmax) in prostatic tumoral VOIs. The secondary outcomes included mean SUV (SUVmean) in prostatic tumoral VOIs and area under the SUVmean curves (AUC). Longitudinal mixed-effects models were used to compare dynamic SUVmax and SUVmean time-activity curves (TACs), and paired t tests were used for the remaining data. Results The mean SUVmax within tumoral VOIs was 14 (range, 3-43) for venous sessions and 938 (range, 460-1436) for arterial sessions (P = .008). The SUVmean within VOIs was greater during arterial sessions (P < .001) overall and 46-fold and 19-fold greater at peak uptake and final time points, respectively. The mean AUC was greater on arterial TACs than on venous TACs at 14600 SUV × min (range, 8353-20025 SUV × min) and 240 SUV × min (range, 69-622 SUV × min), respectively (P = .002). Conclusion Selective prostatic arterial infusion resulted in greater 68Ga-PSMA-11 tumoral SUV than intravenous infusion. Further study of local-regional, intra-arterial delivery of a PSMA-targeted theranostic agent is warranted in high-risk prostate cancer. ClinicalTrials.gov identifier: NCT04976257 © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Civelek in this issue.
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Radioisótopos de Galio , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias de la Próstata , Humanos , Masculino , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Anciano , Estudios Prospectivos , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/metabolismo , Persona de Mediana Edad , Radioisótopos de Galio/farmacocinética , Próstata/diagnóstico por imagen , Próstata/irrigación sanguínea , Isótopos de Galio , Radiofármacos/farmacocinética , Infusiones Intravenosas , Adenocarcinoma/diagnóstico por imagen , Adenocarcinoma/metabolismoRESUMEN
Background Lutetium 177 [177Lu]Lu-PSMA-617 (177Lu-PSMA-617) is a prostate-specific membrane antigen (PSMA)-targeted radioligand therapy for metastatic castration-resistant prostate cancer (mCRPC). Quantitative PSMA PET/CT analysis could provide information on 177Lu-PSMA-617 treatment benefits. Purpose To explore the association between quantitative baseline gallium 68 [68Ga]Ga-PSMA-11 (68Ga-PSMA-11) PET/CT parameters and treatment response and outcomes in the VISION trial. Materials and Methods This was an exploratory secondary analysis of the VISION trial. Eligible participants were randomized (June 2018 to October 2019) in a 2:1 ratio to 177Lu-PSMA-617 therapy (7.4 GBq every 6 weeks for up to six cycles) plus standard of care (SOC) or to SOC only. Baseline 68Ga-PSMA-11 PET parameters, including the mean and maximum standardized uptake value (SUVmean and SUVmax), PSMA-positive tumor volume, and tumor load, were extracted from five anatomic regions and the whole body. Associations of quantitative PET parameters with radiographic progression-free survival (rPFS), overall survival (OS), objective response rate, and prostate-specific antigen response were investigated using univariable and multivariable analyses (with treatment as the only other covariate). Outcomes were assessed in subgroups based on SUVmean quartiles. Results Quantitative PET parameters were well balanced between study arms for the 826 participants included. The median whole-body tumor SUVmean was 7.6 (IQR, 5.8-9.9). Whole-body tumor SUVmean was the best predictor of 177Lu-PSMA-617 efficacy, with a hazard ratio (HR) range of 0.86-1.43 for all outcomes (all P < .001). A 1-unit whole-body tumor SUVmean increase was associated with a 12% and 10% decrease in risk of an rPFS event and death, respectively. 177Lu-PSMA-617 plus SOC prolonged rPFS and OS in all SUVmean quartiles versus SOC only, with no identifiable optimum among participants receiving 177Lu-PSMA-617. Higher baseline PSMA-positive tumor volume and tumor load were associated with worse rPFS (HR range, 1.44-1.53 [P < .05] and 1.02-1.03 [P < .001], respectively) and OS (HR range, 1.36-2.12 [P < .006] and 1.04 [P < .001], respectively). Conclusion Baseline 68Ga-PSMA-11 PET/CT whole-body tumor SUVmean was the best predictor of 177Lu-PSMA-617 efficacy in participants in the VISION trial. Improvements in rPFS and OS with 177Lu-PSMA-617 plus SOC were greater among participants with higher whole-body tumor SUVmean, with evidence for benefit at all SUVmean levels. ClinicalTrials.gov identifier: NCT03511664 Published under a CC BY 4.0 license. Supplemental material is available for this article.
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Dipéptidos , Isótopos de Galio , Radioisótopos de Galio , Compuestos Heterocíclicos con 1 Anillo , Lutecio , Tomografía Computarizada por Tomografía de Emisión de Positrones , Neoplasias de la Próstata Resistentes a la Castración , Radiofármacos , Humanos , Masculino , Neoplasias de la Próstata Resistentes a la Castración/diagnóstico por imagen , Neoplasias de la Próstata Resistentes a la Castración/radioterapia , Neoplasias de la Próstata Resistentes a la Castración/patología , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Lutecio/uso terapéutico , Compuestos Heterocíclicos con 1 Anillo/uso terapéutico , Anciano , Dipéptidos/uso terapéutico , Radiofármacos/uso terapéutico , Persona de Mediana Edad , Resultado del Tratamiento , Radioisótopos/uso terapéutico , Ácido Edético/análogos & derivados , Ácido Edético/uso terapéutico , Antígeno Prostático EspecíficoRESUMEN
INTRODUCTION: The pulmonary Hot Clot artifact (HCa) on 18F-FDG PET/CT is a poorly understood phenomenon, corresponding to the presence of a focal tracer uptake without anatomical lesion on combined CTscan. The hypothesis proposed in the literature is of microembolic origin. Our objectives were to determine the incidence of HCa, to analyze its characteristics and to identify associated factors. METHODS: All 18F-FDG PET/CT retrieved reports containing the keywords (artifact/vascular adhesion/no morphological abnormality) during the period June 2021-2023 at Brest University Hospital were reviewed for HCa. Each case was associated with 2 control patients (same daily work-list). The anatomical and metabolic characteristics of HCa were analyzed. Factors related to FDG preparation/administration, patient and vascular history were investigated. Case-control differences between variables were tested using Chi-2 test and OR (qualitative) or Student's t-test (quantitative). RESULTS: Of the 22,671 18F-FDG PET/CT performed over 2 years, 211 patients (0.94%) showed HCa. The focus was single in 97.6%, peripheral in 75.3%, and located independently in the right or left lung (51.1% vs. 48.9%). Mean ± SD values for SUVmax, SUVmean, MTV and TLG were 11.3 ± 16.5, 5.1 ± 5.0, 0.3 ± 0.3 ml and 1.5 ± 2.1 g respectively. The presence of vascular adhesion (p < 0.001), patient age (p = 0.002) and proximal venous access (p = 0.001) were statistically associated with the presence of HCa. CONCLUSION: HCa is a real but rare phenomenon (incidence around 1%), mostly unique, intense, small in volume (< 1 ml), and associated with the presence of vascular FDG uptake, confirming the hypothesis of a microembolic origin due to probable vein wall trauma at the injection site.
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Artefactos , Fluorodesoxiglucosa F18 , Tomografía Computarizada por Tomografía de Emisión de Positrones , Radiofármacos , Humanos , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Femenino , Masculino , Persona de Mediana Edad , Estudios de Casos y Controles , Anciano , Factores de Riesgo , Adulto , Estudios Retrospectivos , Embolia Pulmonar/diagnóstico por imagen , Embolia Pulmonar/etiología , Embolia Pulmonar/epidemiología , Anciano de 80 o más Años , Trombosis/diagnóstico por imagen , Trombosis/etiología , Trombosis/epidemiologíaRESUMEN
Objective.Target volumes for radiotherapy are usually contoured manually, which can be time-consuming and prone to inter- and intra-observer variability. Automatic contouring by convolutional neural networks (CNN) can be fast and consistent but may produce unrealistic contours or miss relevant structures. We evaluate approaches for increasing the quality and assessing the uncertainty of CNN-generated contours of head and neck cancers with PET/CT as input.Approach.Two patient cohorts with head and neck squamous cell carcinoma and baseline18F-fluorodeoxyglucose positron emission tomography and computed tomography images (FDG-PET/CT) were collected retrospectively from two centers. The union of manual contours of the gross primary tumor and involved nodes was used to train CNN models for generating automatic contours. The impact of image preprocessing, image augmentation, transfer learning and CNN complexity, architecture, and dimension (2D or 3D) on model performance and generalizability across centers was evaluated. A Monte Carlo dropout technique was used to quantify and visualize the uncertainty of the automatic contours.Main results. CNN models provided contours with good overlap with the manually contoured ground truth (median Dice Similarity Coefficient: 0.75-0.77), consistent with reported inter-observer variations and previous auto-contouring studies. Image augmentation and model dimension, rather than model complexity, architecture, or advanced image preprocessing, had the largest impact on model performance and cross-center generalizability. Transfer learning on a limited number of patients from a separate center increased model generalizability without decreasing model performance on the original training cohort. High model uncertainty was associated with false positive and false negative voxels as well as low Dice coefficients.Significance.High quality automatic contours can be obtained using deep learning architectures that are not overly complex. Uncertainty estimation of the predicted contours shows potential for highlighting regions of the contour requiring manual revision or flagging segmentations requiring manual inspection and intervention.
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Aprendizaje Profundo , Neoplasias de Cabeza y Cuello , Procesamiento de Imagen Asistido por Computador , Tomografía Computarizada por Tomografía de Emisión de Positrones , Humanos , Neoplasias de Cabeza y Cuello/diagnóstico por imagen , Tomografía Computarizada por Tomografía de Emisión de Positrones/métodos , Incertidumbre , Procesamiento de Imagen Asistido por Computador/métodos , Estudios Retrospectivos , Fluorodesoxiglucosa F18 , Redes Neurales de la Computación , AlgoritmosRESUMEN
PURPOSE: This retrospective study evaluates the value of 68Ga-DOTATATE PET/CT in the diagnosis and localization of insulinomas, whether sporadic, malignant or MEN-1 associated insulinoma. METHOD: The study included 43 patients, having clinical (symptomatic hypoglycemia) and/or laboratory suspicion of having insulinoma (72 h fasting test with serum insulin ≥18 pmol/L), with available pre-operative 68Ga-DOTATATE PET/CT and CE-CT, and diagnosed with insulinoma confirmed by post-operative histopathology. Preoperative imaging was retrospectively analyzed by two radiologists who were blinded to the final diagnosis and to the results of other imaging modalities. Histopathology of specimen was considered the reference standard, and head-to-head comparison of preoperative CE-CT and PET imaging findings. Findings were classified as true positive (TP), true negative (TN), false positive (FP), and false negative (FN) for each modality. Based on these results, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of CE-CT, and 68Ga-DOTATATE PET/CT for the detection of insulinoma were calculated. RESULTS: 43 patients (N = 43 patients, L = 56 lesions), out of these, 37 patients had benign sporadic insulinoma (N = 37, L = 42), only 3 patients had malignant sporadic insulinoma (N = 2, L = 9), and 3 patients had MEN-1 syndrome associated insulinoma (N = 3, L = 5). There was no significant statistical difference in sensitivity (P = 0.3058) and PPV (P = 0.5533) for insulinoma localization in the overall cohort with 68Ga-DOTATATE PET/CT (87.5 %, 90.74 %) compared to CE-CT (80.36 %, 93.75 %). CONCLUSION: 68Ga-DOTATATE PET/CT is a non-invasive imaging modality that can identify most insulinomas. Still, it offers limited additional information when the tumor is localized by other anatomic imaging studies, so should be used as an adjunct when imaging studies fail to localize the tumor in insulinoma patients, especially when minimally invasive surgical is intended.