PET/CT of cranial arteries for a sensitive diagnosis of giant cell arteritis.

OBJECTIVES: To investigate the performance of cranial PET/CT for the diagnosis of GCA. METHODS: All patients with a suspected diagnosis of GCA were prospectively enrolled in this study and had a digital PET/CT with evaluation of cranial arteries if they had not started glucocorticoids >72 h previously. The diagnosis of GCA was retained after at least 6 months of follow-up if no other diagnosis was considered by the clinician and the patient went into remission after at least 6 consecutive months of treatment. Cranial PET/CT was considered positive if at least one arterial segment showed hypermetabolism similar to or greater than liver uptake. RESULTS: For cranial PET/CT, sensitivity (Se), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) were 73.3%, 97.2%, 91.7% and 89.7%, respectively. For extracranial PET/CT, diagnostic performance was lower (Se = 66.7%, Sp = 80.6%, PPV = 58.8%, NPV = 85.3%). The combination of cranial and extracranial PET/CT improved overall sensitivity (Se = 80%) and NPV (NPV = 90.3%) while decreasing overall specificity (Sp = 77.8%) and PPV (PPV = 60%). CONCLUSION: Cranial PET/CT can be easily combined with extracranial PET/CT with a limited increase in examination time. Combined cranial and extracranial PET/CT showed very high diagnostic accuracy for the diagnosis of GCA. TRIAL REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov, NCT05246540.

[18F]DCFPyL PET/CT versus [18F]fluoromethylcholine PET/CT in Biochemical Recurrence of Prostate Cancer (PYTHON): a prospective, open label, cross-over, comparative study.

PURPOSE: Primary objective was to compare the per-patient detection rates (DR) of [18F]DCFPyL versus [18F]fluoromethylcholine positron emission tomography/computed tomography (PET/CT), in patients with first prostate cancer (PCa) biochemical recurrence (BCR). Secondary endpoints included safety and impact on patient management (PM). METHODS: This was a prospective, open label, cross-over, comparative study with randomized treatment administration of [18F]DCFPyL (investigational medicinal product) or [18F]fluoromethylcholine (comparator). Men with rising prostate-specific antigen (PSA) after initial curative therapy were enrolled. [18F]DCFPyL and [18F]fluoromethylcholine PET/CTs were performed within a maximum time interval of 12 days. DR was defined as the percentage of positive PET/CT scans identified by 3 central imaging readers. PM was assessed by comparing the proposed pre-PET/CT treatment with the local treatment", defined after considering both PET/CTs. RESULTS: A total of 205 patients with first BCR after radical prostatectomy (73%; median PSA = 0.46 ng/ml [CI 0.16;27.0]) or radiation therapy (27%; median PSA = 4.23 ng/ml [CI 1.4;98.6]) underwent [18F]DCFPyL- and/or [18F]fluoromethylcholine -PET/CTs, between July and December 2020, at 22 European sites. 201 patients completed the study. The per-patient DR was significantly higher for [18F]DCFPyL- compared to [18F]fluoromethylcholine -PET/CTs (58% (117/201 patients) vs. 40% (81/201 patients), p < 0.0001). DR increased with higher PSA values for both tracers (PSA ≤ 0.5 ng/ml: 26/74 (35%) vs. 22/74 (30%); PSA 0.5 to ≤ 1.0 ng/ml: 17/31 (55%) vs. 10/31 (32%); PSA 1.01 to < 2.0 ng/ml: 13/19 (68%) vs. 6/19 (32%);PSA > 2.0: 50/57 (88%) vs. 39/57 (68%) for [18F]DCFPyL- and [18F]fluoromethylcholine -PET/CT, respectively). [18F]DCFPyL PET/CT had an impact on PM in 44% (90/204) of patients versus 29% (58/202) for [18F]fluoromethylcholine. Overall, no drug-related nor serious adverse events were observed. CONCLUSIONS: The primary endpoint of this study was achieved, confirming a significantly higher detection rate for [18F]DCFPyL compared to [18F]fluoromethylcholine, in men with first BCR of PCa, across a wide PSA range. [18F]DCFPyL was safe and well tolerated.

Whole Spinal Cord FDG Uptake at PET/CT Caused by H3K27-Altered Diffuse Midline Glioma in an Adult Patient.

ABSTRACT: Diffuse midline glioma, H3K27-altered, is a relatively new entity, characterized by H3K27M histone mutation. This rare pediatric disease with severe prognosis has recently been identified as a new subtype of diffuse astrocytoma due to major breakthrough in histopathological and molecular characterization of gliomas. We report a case of H3K27-altered diffuse midline glioma in a 30-year-old woman.

Performance of [18F]FDG-PET/CT Imaging in First Recurrence of Invasive Lobular Carcinoma.

BACKGROUND: Invasive lobular carcinoma accounts for 10 to 15% of all breast cancers. The first objective of this retrospective study was to assess the diagnostic performance of FDG-PET/CT scanning in women previously treated for invasive lobular carcinoma with suspected first recurrence. The secondary objectives were to evaluate the impact of PET/CT in a change in treatment and its prognostic value on specific survival. METHODS: Patients in whom a PET/CT scan was performed from January 2011 to July 2019 in our Cancer Research Center were enrolled. Recurrence was suspected based on clinical symptoms, abnormal findings on conventional imaging, and/or elevated tumor markers. The diagnosis of recurrence was established by the oncologist after integration of all clinical, biological, histological, imaging, and follow-up data. Prognostic factors of recurrence as predicted by PET were determined using univariate logistic regression. KI67, mitotic index, or grade of mitosis were tested. Survival curves were compared using the log-rank test. Sixty-four patients (mean age: 60.3; SD = 12.4 years) were enrolled. The average time from initial diagnosis of the primary tumor to suspicion of recurrence was 5.2 ± 4.1 years. Forty-eight patients (75%) were judged to have recurrence by the oncologist: 7 local and 41 metastatic, with mainly bone (n = 24), lymph node (n = 14) and liver (n = 10) metastases. RESULTS: Sensitivity, specificity, and positive and negative predictive values of PET/CT to predict recurrence were, respectively: 87%, 87%, 95%, and 70%. SUVmax at recurrence sites was generally high (mean: 6.4; SD = 2.9). False negative PET/CT results occurred with local (n = 2), peritoneal (n = 2), meningeal (n = 1), or bladder (n = 1) recurrences. In 40 patients with available histopathological data from suspected sites of recurrence, 30 PET/CT were true positive. In four patients, primary lung (n = 1) or gastric (n = 1) tumors or lymphomas (n = 2) were found. The detection of a recurrence resulted in a change in treatment in 44/48 patients (92%). No association between recurrence predicted by PET and biological biomarkers was found. Median specific survival appears shorter in patients with metastatic recurrence versus patients with local or no recurrence on PET/CT (p = 0.067). CONCLUSIONS: FDG-PET/CT is an effective and reliable tool for the detection of invasive lobular carcinoma recurrence, although certain recurrence sites specific to this histological type can impair its diagnostic performance.

Unusual uptakes on 18F-fluorocholine positron emission tomography/computed tomography (PET/CT): a retrospective study of 368 prostate cancer patients referred for a biochemical recurrence or an initial staging.

BACKGROUND: 18F-fluorocholine positron emission tomography/computed tomography (F-choline PET/CT) is considered a cornerstone in the staging and restaging of patients with prostate cancer (PCa). The aim of this study was to retrospectively assess unusual uptakes in patients who underwent a F-choline PET/CT for the initial staging or for the restaging of a relapsing PCa. METHODS: Three hundred and sixty-eight PCa patients were staged or restaged using F-choline PET/CT. Unusual uptakes were defined as uptakes occurring outside the usual paths of diffusion of PCa or as uptake in bone with a clear morphological evidence of nonmetastatic lesion. RESULTS: We found unusual uptakes in 47/368 patients (12.8%). Among them, 41/47 presented with benign F-choline uptake, usually within lymph nodes, due to inflammatory processes (22/47). Other benign processes were found in: thyroid (3/47), adrenal gland (3/47), brain (2/47), liver (1/47), bowel (3/47), frontal sinus (1/47), lungs (4/47), parotid gland (1/47) and bone (1/47). The six remaining patients presented with a second cancer, including lymphoma (1/47), non-small cell lung cancer (4/47) and neuroendocrine tumor (1/47). CONCLUSIONS: unusual uptakes on F-choline PET/CT are quite frequent and should be explored since they may correspond to non-PCa.

[Factors influencing platelets labelling with indium-111 oxine]. / Facteurs influençant le marquage des plaquettes à l'oxinate d'indium-111.

Autologous indium-111 labelled platelets can be used for kinetic studies in patients with autoimmune thrombocytopenic purpura [AITP]. The objective of this study was to evaluate some biological and clinical factors influencing the labeling efficiency. METHODS: We studied incubation media (Plasma media [MP] or dry media [MS]), platelet concentration [NP], mean platelet volume [VPM], hemoglobin level and pathology associated with AITP. RESULTS: This was a retrospective study of 93 platelets labelling (43 in MS and 50 in MP), 38 primary AITP (41%) and 55 secondary AITP (59%). The labeling efficiency was 72% (78% in MS versus 53% in MP; p < 0.0001). The labeling efficiency was correlated with VPM (p = 0.0004), NP (p = 0.03), hemoglobin level (p = 0.037) and type of AITP (p = 0.0036). The incubation medium, hemoglobin level and type of the AITP have an independent predictive value on the labeling efficiency. CONCLUSION: These data confirm the influence of the incubation medium on the labeling efficiency and identify two other predictive criteria, hemoglobin level and type of AITP.

[Effect of obesity, age and gender on glomerular filtration rate measured in normal adults]. / Influence de l'obésité, de l'âge et du sexe sur le débit de filtration glomérulaire mesuré chez l'adulte normal.

The aims of this study were to assess the dependence of glomerular filtration rate (GFR) on age and gender and to produce reference data for the interpretation of 51Cr-EDTA GFR measurements in adults. METHODS: This was a retrospective study of 120 live kidney donors (75 females, 45 males). GFR was evaluated from 51Cr-EDTA plasma clearance using blood samples taken at 3, 4 and 5 hours. The slope-intercept GFR was corrected for body surface area using the Dubois & Dubois and for the fast exponential using the Brochner-Mortensen equation. Scatter plot of DFG against age in live kidney donors was plotted and the 98% range limits have been defined. RESULTS: The median GFR obtained for kidney donors was 88 mL/min/1.73 m2 [68-130]. No significant difference with gender was found. 51Cr-EDTA clearance was strongly correlated with patient age (r = - 0.62, P < 0,0001). GFR decreased by approximately 8 mL/min/1.73 m2 per decade. Based on these results, a nomogram for GFR is presented. CONCLUSION: The interpretation of GFR requires age-adjusted normal values. These standards need not be adjusted to the patient's sex or BMI.

FDG PET/CT in a Pregnant Woman With Breast Cancer.

This 37-year-old woman was diagnosed with breast cancer during pregnancy. After multidisciplinary meeting, she was referred to our department for an FDG PET/CT for staging, and chemotherapy with weekly infusion of paclitaxel was initiated before childbirth. We estimated the fetal dose from the PET/CT procedure, and our results show that, if deemed necessary, this examination can reasonably be performed during pregnancy. The patient gave birth vaginally at term to an apparently healthy girl.

[Effect of 99mTc elution in vivo from red cells on red cell volumes measured using autologous 99mTc-labeled red cells: comparison with 51Cr method]. / Effet de l'élution in vivo du technétium sur les volumes globulaires mesurés à l'aide d'hématies autologues marquées au 99mTc : comparaison avec la technique au 51Cr.

The purpose of this work was to compare the measured red-cell volume (RCV) using sodium pertechnétate [RCV-99mTc] compared to the reference technique using sodium radiochromate [RCV-51Cr] and to assess the influence of technetium-99 elution on the RCV-99mTc value. Ten patients had simultaneous measurements of RCV-99mTc and RCV-51Cr. Elution of Tc-99m from red blood cells was 2.9% and led to an average overestimation of RCV-99mTc of 3.7%. The introduction of individual tracer elution rates in the RCV-99mTc calculation corrects this overestimation.

An enlarged left adrenal gland is an indirect sign of infection on 18F-FDG PET/CT.

OBJECTIVES: To determine whether hypermetabolisms of the spleen and bone marrow and an enlarged adrenal gland are significant indirect signs of infection on fluorine-18-fluorodeoxyglucose (F-FDG) PET/CT performed in patients with known or suspected infectious disease. PATIENTS AND METHODS: Potential indirect signs of infection were as follows: (i) investigated in a retrospectively selected group of patients referred to F-FDG PET/CT for a known or suspected infectious disease and among whom the presence or absence of infectious foci was ascertained in 43 and 12 cases, respectively, and (ii) further validated in groups prospectively constituted of 12 patients with severe sepsis and of 39 control patients with no sign of any infectious disease. Standardised uptake values were determined on left adrenal gland, spleen and bone marrow, whereas the size of left adrenal gland was assessed by its maximal surface on unenhanced axial computed tomography (CT) slices. RESULTS: Only the maximal surface of the left adrenal gland was a predictor in the initial study group (infection: 2.72±0.99 cm vs. no infection: 1.85±0.76 cm, P=0.004) and further validation groups (sepsis: 2.79±0.83 cm vs. controls: 1.91±0.67 cm, P=0.001). Patients with a greater than 1.8 cm maximal surface had more than two-fold higher infection rate than the other patients in the initial study group [88 (36/41) vs. 36% (4/11), P=0.001], even when only considering the subgroup with no evident infectious focus on F-FDG PET/CT [76 (16/21) vs. 30% (3/10), P=0.02]. CONCLUSION: An enlarged left adrenal gland is a significant sign of infection on F-FDG PET/CT, even in the absence of any evident infectious focus on F-FDG PET/CT images.

Bilateral Huge Incidentalomas of Isolated Adrenal Metastases From Unknown Primary Melanoma Revealed by 18F-FDG PET/CT.

FDG PET/CT has high sensitivity and specificity for the detection of distant metastases from cutaneous melanoma. Imaging is recommended for patients with clinical suspicion of metastasis and should be considered for those with confirmed sentinel lymph node metastasis. Metastatic melanoma bears a poor prognosis. Only a complete resection improves survival, which explains the need to detect potentially unresectable disease, and most metastatic patients are ineligible for a curative surgical procedure. Here, FDG PET/CT demonstrated isolated bilateral adrenal metastases from melanoma of unknown primary. The patient underwent curative surgery, with no sign of recurrence at 48 months after surgery.

Brain Perfusion Before and After Surgical Treatment of Moyamoya Disease.

Moyamoya disease is characterized by bilateral progressive terminal internal carotid arteries steno-occlusion. In this patient, the disease affected middle cerebral arteries and was disclosed after a left frontal cerebral infarction. Brain HMPAO perfusion scintigraphy with acetazolamide challenge, obtained before surgical treatment, demonstrates an extended bilateral frontal hypoperfusion with a vascular steal phenomenon. The same examination obtained after surgical treatment demonstrates a frank improvement in basal brain vascularization, with nearly complete correction of vascular steal phenomenon. HMPAO brain scintigraphy is a very useful tool in the assessment of moyamoya disease severity before surgery and for the evaluation of treatment efficiency.

FDG Brain PET/CT Revealing Bilateral Thalamostriatal Activation During a Symptomatic Episode in a Patient With Kleine-Levin Syndrome.

We report the case of a 14-year-old girl with clinically diagnosed Kleine-Levin syndrome. Electroencephalogram and brain MRI were unremarkable. An FDG PET/CT scan was acquired during a symptomatic episode, while she was asleep, and another PET scan was obtained when she was asymptomatic, awake, and quiet. Comparison of both examinations demonstrated a bilateral activation of thalami, caudate nuclei, and lenticular nuclei. These findings may be linked to the implication of thalamostriatal structures in the regulation of sleep and wakefulness.

Aneurysmal angiosarcoma associated with vascular graft revealed by 18F-FDG-PET imaging.

We report a rare case of vascular graft-associated aneurysmal angiosarcoma by 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET). An 81-year-old male patient, with a prior history of graft interposition 1 year previously, was referred to 18F-FDG-PET because of an inflammatory syndrome of unknown origin. FDG-PET images revealed a particular pattern of intense circular uptake within the arterial wall (SUVmax = 10) in a popliteal aneurysm and, additionally, a large hypermetabolic mass centered by the graft. Remote hypermetabolisms in lung nodules and pleural thickenings were also detected. The diagnosis of angiosarcoma was ascertained through histopathological analysis of surgical samples. Development of an aneurysmal angiosarcoma at the site of a vascular graft is a rare entity, often misdiagnosed. 18F-FDG-PET appears to be useful in its detection with a PET pattern of intense circular uptake within the arterial wall. Such finding should lead to the search for distant metastasis.