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The objective of this guide is to provide to nuclear medicine physicians a tool based on scientific evidence and prepared by consensus of experts, to perform the 18 F-DCFPyL PET/CT procedure with safely and efficiently for patients with prostate cancer who present PSMA overexpression. For them, some recommendations will be established for 18 F-DCFPyL PET/CT examination: reconstruction parameters, presentation of the images and their interpretation. The possible false positives of the procedure will be analysed, how to interpret them and how to avoid them. Finally, all exploration should lead to the preparation of a report that answers the clinician's question. For this, it is recommended to prepare a structured report that includes the PROMISE criteria as well as the classification of the findings according to PSMA-RADS parameters., (Copyright © 2023 Sociedad Española de Medicina Nuclear e Imagen Molecular. Published by Elsevier España, S.L.U. All rights reserved.)

Bone metastatic disease is the main cause of morbidity / mortality in patients with prostate cancer, presenting frequently as bone pain, pathological fractures or spinal cord compression, which requires early and timely therapy. Although, for the moment, the therapeutic window for its use has not been definitively established, radium-223 ( 223 Ra), an alpha particle emitter, has proved to be an effective therapeutic tool, pre or post-chemotherapy, in patients with castration-resistant prostate cancer with symptomatic bone metastases and absence of visceral metastases, significantly modifying the prognosis of the disease. It is therefore imperative to define the ideal scenarios and the correct protocol for the use of this therapy and thus offer the greatest possible clinical benefit to the patient., (Copyright © 2018 Sociedad Española de Medicina Nuclear e Imagen Molecular. Publicado por Elsevier España, S.L.U. All rights reserved.)

Positron emission tomography/computed tomography (PET/CT) with 68 Ga-PSMA is a non-invasive diagnostic technique to image prostate cancer with increased prostate-specific membrane antigen (PSMA) expression. PSMA is a transmembrane protein present in all prostatic tissues. Increased PSMA expression is seen in several malignancies, although prostate cancer is the tumour where it presents higher concentrations. Almost all prostate adenocarcinomas show PSMA expression in most of lesions, primary and metastatic. Immunohistochemistry has demonstrated that the expression of PSMA increases in patients with de-differentiated, metastatic or hormone-refractory tumours. Moreover, the expression level of PSMA has a prognostic value for disease outcome. PET measures the three-dimensional distribution of 68 Ga-PSMA, producing semi-quantitative images that allow for non-invasive assessment of PSMA expression., (Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.)

Objective: To compare sensitivity, specificity and predictive value of Deauville score (DS) vs. ΔSUVmax in interim-treatment PET (iPET) and end-treatment PET (ePET), in patients with diffuse large B cell lymphoma (DLBCL), Hodgkin lymphoma (HL), and follicular lymphoma (FL)., Method: Retrospective longitudinal multicentre study including 138 patients (46 DLBCL, 46 HL, 46 FL), on whom 3 18 F-FDG PET/CT were performed: baseline, iPET, and ePET. Visual (DS) and semi-quantitative (ΔSUVmax) parameters were determined for iPET and ePET. Predictive value was determined in relation to disease-free interval., Results: Statistical analysis. iPET for DLBCL, HL, and FL: 1) sensitivity of DS: 76.92/83.33/61.53%; specificity: 78.78/85/81.81%; 2) sensitivity of ΔSUVmax: 53.84/83.33/61.53%; specificity: 87.87/87.50/78.78%. ePET for DLBCL, HL and FL: 1) sensitivity of DS: 61.53/83.33/69.23%; specificity: 90.90/85/87.87%; 2) sensitivity of ΔSUVmax: 69.23/83.33/69.23%; specificity: 90.90/87.50/84.84%. Predictive assessment. iPET study: in DLBCL, DS resulted in 10.3% recurrence of negative iPET, and 17.1% in ΔSUVmax at disease-free interval; in HL, both parameters showed a 2.8% recurrence of negative iPET; in FL, DS resulted in 15.6% recurrence of negative iPET, and 16.1% in ΔSUVmax, with no statistical significance. ePET study: in DLBCL, DS resulted in 14.3% recurrence of negative ePET, and 11.8% in ΔSUVmax at disease-free interval; in HL and FL, both methods showed 2.8 and 12.5% recurrence in negative ePET, respectively., Conclusion: DS and ΔSUVmax did not show significant differences in DLBCL, HL and FL. Their predictive value also did not show significant differences in HL and FL. In DLBCL, DS was higher in iPET, and ΔSUVmax in ePET., (Copyright © 2017 Elsevier España, S.L.U. y SEMNIM. All rights reserved.)

Purpose: The detection of occult cancer in patients suspected of having a paraneoplastic neurological syndrome (PNS) poses a diagnostic challenge. The aim of our study was to perform a systematic review and meta-analysis to assess the diagnostic performance of FDG PET for the detection of occult malignant disease responsible for PNS., Methods: A systematic review of the literature (MEDLINE, EMBASE, Cochrane, and DARE) was undertaken to identify studies published in any language. The search strategy was structured after addressing clinical questions regarding the validity or usefulness of the test, following the PICO framework. Inclusion criteria were studies involving patients with PNS in whom FDG PET was performed to detect malignancy, and which reported sufficient primary data to allow calculation of diagnostic accuracy parameters. When possible, a meta-analysis was performed to calculate the joint sensitivity, specificity, and detection rate for malignancy (with 95% confidence intervals [CIs]), as well as a subgroup analysis based on patient characteristics (antibodies, syndrome)., Results: The comprehensive literature search revealed 700 references. Sixteen studies met the inclusion criteria and were ultimately selected. Most of the studies were retrospective (12/16). For the quality assessment, the QUADAS-2 tool was applied to assess the risk of bias. Across 16 studies (793 patients), the joint sensitivity, specificity, and detection rate for malignancy with FDG PET were 0.87 (95% CI: 0.80-0.93), 0.86 (95% CI: 0.83-0.89), and 14.9% (95% CI: 11.5-18.7), respectively. The area under the curve (AUC) of the summary ROC curve was 0.917. Homogeneity of results was observed for sensitivity but not for specificity. Some of the individual studies showed large 95% CIs as a result of small sample size., Conclusions: The results of our meta-analysis reveal high diagnostic performance of FDG PET in the detection of malignancy responsible for PNS, not affected by the presence of onconeural antibodies or clinical characteristics.

Objective: To evaluate (18)F-fluorocholine positron-emission tomography (PET)/computed tomography (CT) in restaging patients with a history of prostate adenocarcinoma who have biochemical relapse after early radical treatment, and to correlate the technique's disease detection rate with a set of variables and clinical and pathological parameters., Patients and Methods: This was a retrospective multicentre study that included 374 patients referred for choline-PET/CT who had biochemical relapse. In all, 233 patients who met the following inclusion criteria were analysed: diagnosis of prostate cancer; early radical treatment; biochemical relapse; main clinical and pathological variables; and clinical, pathological and imaging data needed to validate the results. Criteria used to validate the PET/CT: findings from other imaging techniques, clinical follow-up, treatment response and histological analysis. Different statistical tests were used depending on the distribution of the data to correlate the results of the choline-PET/CT with qualitative [T stage, N stage, early radical prostatectomy (RP) vs other treatments, hormone therapy concomitant to choline-PET/CT] and quantitative [age, Gleason score, prostate-specific antigen (PSA) levels at diagnosis, PSA nadir, PSA level on the day of the choline-PET/CT (Trigger PSA) and PSA doubling time (PSADT)] variables. We analysed whether there were independent predictive factors associated with positive PET/CT results., Results: Choline-PET/CT was positive in 111 of 233 patients (detection rate 47.6%) and negative in 122 (52.4%). Disease locations: prostate or prostate bed in 26 patients (23.4%); regional and/or distant lymph nodes in 52 (46.8%); and metastatic bone disease in 33 (29.7%). Positive findings were validated by: results from other imaging techniques in 35 patients (15.0%); at least 6 months of clinical follow-up in 136 (58.4%); treatment response in 24 (10.3%); histological analysis of lesions in 17 (7.3%); and follow-up plus imaging results in 21 (9.0%). The statistical analysis of qualitative variables, corresponding to patients' clinical characteristics, and the positive/negative final PET/CT results revealed that only whether or not early treatment with RP was done was statistically significant (P < 0.001), with the number of positive results higher in patients who did not undergo a RP. Among the quantitative variables, Gleason score, Trigger PSA and PSADT clearly differentiated the two patient groups (positive and negative choline-PET/CT: P = 0.010, P = 0.001 and P = 0.025, respectively). A Gleason score of <5 or ≥ 8 clearly differentiated positive from negative PET. Trigger PSA: mean of 8 ng/mL for positive PET/CT vs 2.8 ng/mL for negative PET/CT; PSADT: mean of 8 months for positive vs 12.6 months for negative. The optimal threshold values were: 3 ng/mL for Trigger PSA level and 6 months for PSADT (Youden index/receiver operating characteristic curve). Analysing these two variables together showed that PSADT was more conclusive in patients with lower Trigger PSA levels. Analysing variables by location showed that only PSADT was able to differentiate between those with disease confined to the prostate compared with the other two locations (lymph nodes and bone), with shorter PSADT in these two, which was statistically significant (P < 0.002). In the patient group with a PSA level of <1.5 ng/mL, 30.8% had the disease, 7% of whom had metastatic bone disease. In the multivariate logistic regression, the risks factors that were clearly independent for those with positive PET/CT were: PSA level of >3 ng/mL, no early RP, and Gleason score of ≥ 8., Conclusion: Our results support the usefulness of (18)F-fluorocholine PET/CT in biochemical relapse of prostate cancer after radical treatment, with an overall disease detection rate close to 50%, and it can be recommended as first-line treatment. As mentioned above, besides Trigger PSA levels, there are other clinical and pathological variables that need to be considered so as to screen patients properly and thus minimise the number of nodular lesions and increase the diagnostic accuracy of the examination., (© 2014 The Authors. BJU International © 2014 BJU International.)

Background and Aim: currently it is recognized the usefulness of 18F-FDG PET in assessing response to therapy with imatinib (Gleevec®) in the gastrointestinal tract sarcomas (GIST). To facilitate the follow-up of these studies is important to know the patterns of metastatic spread. The aim of this paper is to describe patterns observed in the 18F-FDG PET/CT., Method: retrospective study included 29 patients who underwent 18F-FDG PET/CT after being diagnosed with unresectable or metastatic GIST. In total, 87 PET/CT studies were performed (1-6 controls per patient) with a mean time of follow-up 6-36 months. We analyzed the location of the lesions evidenced in PET, CT and fusion. Images were evaluated visually and semiquantitatively (SUV). In cases in which has been considered necessary, additional images have been undertaken: PET delayed imaging, intravenous contrast CT and inspiratory chest CT., Results: the most common primary site was the stomach (41%), small bowel (35%), and rectum (24%). Significant changes in the location of metastatic disease between pre-treatment and the monitoring were observed, with the appearance of more extra-abdominal disease., Conclusions: individualization of protocol studies and interpretation of PET, CT and fused images were required for evaluation of treatment response to imatinib. Hybrid 18F-FDG PET/CT provides an accurate determination of the extent of GIST. While the most common metastatic site is the liver and peritoneum, in the following cases are common extra-abdominal disease.

We present the case of a 57-year old woman diagnosed of papillary thyroid carcinoma and treated with thyroidectomy followed by radioiodine (I-131) on two occasions. Follow-up radioiodine scan showed disease in right cervical region, confirmed by fine needle aspiration (FNA) and treated with lymphadenectomy. Due to thyroglobulin elevation, I-131 scan negative and inconclusive cervical ultrasonography/CT scan, we conducted a CT/PET study that confirmed cervical disease. An additional CT scan that was performed on maximum-inspiration showed four micro-nodules, one of which was not detected by the CT scan on shallow breathing (CT/PET). Post-treatment (I-131) scan confirmed uptake in these localizations. Good fusion between PET and CT images that avoids the errors of attenuation correction, especially in the lung bases, is necessary for correct image interpretation of the CT/PET study. Shallow breathing is necessary in order to obtain optimal image fusion with the CT/PET study, although this is not the best to evaluate pulmonary parenchyma in which an additional inspiratory CT scan improves detection of the pulmonary nodules.

Introduction: Gastrointestinal stromal tumors (GISTs) account for almost 4 % of all gastrointestinal neoplasms. Recently, a new type of tyrosine kinase inhibitor (Glivec), has been successfully used in patients with metastasic or unresectable disease. The aim of the study is to show the utility of PET in the staging, recurrence and treatment response to Glivec in GIST tumors., Materials and Methods: 48 whole body FDG-PET studies in 27 patients with GIST (19 men/mean age = 56 y) were evaluated for initial staging (n = 13), recurrence (n = 15) or treatment response to Glivec (n = 20). Images were acquired in a whole body 2D mode using attenuation correction on an Advance Nxi G.E.MS camera and were evaluated visually and quantatively using SUV analysis. Results were compared with radiological findings, hystological confirmation or follow-up., Results: In the initial staging evaluation, FDG-PET shows a more extensive disease than suspected in 3/10 patients. In other 3 patients PET ruled out mesenteric or peritoneal disease. In the evaluation of treatment response to Glivec, FDG-PET showed a good response in eleven patients (complete response in seven and partial response in four). In this group a sixty percent decrease of the SUV max was assessed. Two patients showed no response to Glivec at doses of 400 mg or 800 mg, showing a stable SUV value and/or increased in some abdominal lesions. PET detected recurrence in one patient., Conclusions: This study show how FDG-PET is accurate in the early treatment response to Glivec. PET could be helpful in the staging and recurrence of GIST tumors.

A 34-year-old male was seen with severe right hip pain, rapidly worsening in 1 to 2 weeks, with no history of trauma. There was no fever and laboratory studies were normal. Bone scan showed markedly increased uptake in the femoral head. Magnetic resonance imaging showed bone marrow edema. The patient became asymptomatic with conservative therapy, confirmed by returning toward normal on bone scintigraphy 5 months later. He was readmitted 4 months later because the patient developed similar symptoms on the opposite side. A bone scan showed demineralization of the left femoral head. He recovered on conservative therapy and there was a normal bone scan one year after the initial admission.

We present here results on the labelling of red blood cells with 99mTc-HMPAO as an alternative method to the usual in vitro technique. Anticoagulant agents, the labelling medium with plasma, and the lapse of time between 99mTc-HMPAO preparation and labelling are the main factors which affect the efficiency of the procedure. A 93.9 +/- 2.3% labelling yield was obtained with freshly prepared 99mTc-HMPAO. In vitro (tracer elution of 4.3 +/- 1.2% at 60 mins) and in vivo (percentage of plasma activity at 60 mins, 7.8 +/- 2.8%) stability of the label, as well as image quality, qualify 99mTc-HMPAO labelled red blood cells as a suitable agent for clinical use.