Whole-body tumour burden on [18F]DCFPyL PET/CT in biochemical recurrence of prostate cancer: association with tumour biology and PSA kinetics.

PURPOSE: The objective was to assess the association between molecular imaging (mi) variables on [18F]DCFPyL-PET/CT with clinical and disease characteristics and prostate specific antigen (PSA) related variables in patients with biochemical recurrence of prostate cancer (BRPC). MATERIAL AND METHODS: We analysed patients with BRPC after radical treatment. We obtained clinical and PSA variables: International Society of Urology Pathology (ISUP) grade group, European Association of Urology (EAU) risk classification, PSA (PSA≤1ng/ml, 12), PSA doubling time (PSAdt) and PSA velocity (PSAvel). All PET/CT scans were reviewed with the assistance of automated Prostate Molecular Imaging Standardized Evaluation (aPROMISE) software and lesions' segmentation in positive scans was performed using this platform. Standardized uptake value (SUV) derived variables; tumour burden variables [whole-body tumour volume (wbTV), whole-body tumour lesion activity (wbTLA) and whole-body mi PSMA (wbPSMA)] and miTNM staging were obtained. Cut-off of PSA and kinetics able to predict PET/CT results were obtained. Associations between disease and mi variables were analysed using ANOVA, Kruskal-Wallis and Spearman's correlation tests. Multivariate analysis was also performed. RESULTS: Two hundred and seventy-five patients were studied. [18F]DCFPyL-PET/CT were positive in 165/275 patients. In multivariate analysis, moment of biochemical recurrence, ISUP group, PSA level and PSAvel showed significant association with the detection rate. miTNM showed significant association with PSA level (p<0.001) and kinetics (p<0.001), being higher in patients with metastatic disease. Both PSA and PSAvel showed moderate correlation with wbTV, wbTLA and wbPSMA (p<0.001). A weak correlation with SUVs was found. Mean wbTV, wbTLA and wbPSMA values were significantly higher in PSA > 2ng/ml, PSAdt ≤ 6 months and PSAvel ≥ 0.2ng/ml/month groups. Also, wbTV (p=0.039) and wbPSMA (p=0.020) were significantly higher in patients with ISUP grade group 5. PSA and PSAvel cut-offs (1.15 ng/ml and 0.065 ng/ml/month) were significantly associated with a positive PET/CT. CONCLUSION: Higher PSA values, unfavourable PSA kinetics and ISUP grade group 5 were robust predictive variables of larger tumour burden variables on [18F]DCFPyL PET/CT assessed by aPROMISE platform.

Analytical performance validation of aPROMISE platform for prostate tumor burden, index and dominant tumor assessment with 18F-DCFPyL PET/CT. A pilot study.

To validate the performance of automated Prostate Cancer Molecular Imaging Standardized Evaluation (aPROMISE) in quantifying total prostate disease burden with 18F-DCFPyL PET/CT and to evaluate the interobserver and histopathologic concordance in the establishment of dominant and index tumor. Patients with a recent diagnosis of intermediate/high-risk prostate cancer underwent 18F-DCFPyL-PET/CT for staging purpose. In positive-18F-DCFPyL-PET/CT scans, automated prostate tumor segmentation was performed using aPROMISE software and compared to an in-house semiautomatic-manual guided segmentation procedure. SUV and volume related variables were obtained with two softwares. A blinded evaluation of dominant tumor (DT) and index tumor (IT) location was assessed by both groups of observers. In histopathological analysis, Gleason, International Society of Urological Pathology (ISUP) group, DT and IT location were obtained. We compared all the obtained variables by both software packages using intraclass correlation coefficient (ICC) and Cohen's kappa coefficient (k) for the concordance analysis. Fifty-four patients with a positive 18F-DCFPyL PET/CT were evaluated. The ICC for the SUVmax, SUVpeak, SUVmean, tumor volume (TV) and total lesion activity (TLA) was: 1, 0.833, 0.615, 0.494 and 0.950, respectively (p < 0.001 in all cases). For DT and IT detection, a high agreement was observed between both softwares (k = 0.733; p < 0.001 and k = 0.812; p < 0.001, respectively) although the concordances with histopathology were moderate (p < 0001). The analytical validation of aPROMISE showed a good performance for the SUVmax, TLA, DT and IT definition in comparison to our in-house method, although the concordance was moderate with histopathology for DT and IT.

Second radioiodine treatment in patients with differentiated thyroid carcinoma: Causes and effects.

INTRODUCTION: Patients with incomplete response to initial therapy of thyroid cancer can be managed with ongoing observation or potentially additional therapies. Our aim was to assess the effect of a second radioactive iodine treatment (RAIT) and its relationship with causes and clinical variables. MATERIAL AND METHODS: Patients undergoing a second RAIT for biochemical or structural incomplete response to initial therapy of DTC were retrospectively included (n=120). They were categorised based on the American Thyroid Association (ATA) classification of response to initial therapy. Patients were reclassified in the following 6-18 months after second RAIT based on imaging findings and measurements of thyroglobulin and antithyroglobulin antibody levels. The associations of a downgrading of response category and progression-free survival (PFS), and the related variables, were evaluated. RESULTS: Sixty-six patients (55%) had a downgrading on ATA response category after second RAIT. A significant interdependence of causes for second RAIT and outcomes was found (χ2=29.400, p=0.001), with patients with neck reoperation showing a higher rate of indeterminate or excellent responses. A significant association between ATA response to second RAIT and absence of structural progression was found (χ2=44.914, p<0.001), with less structural progression in patients with downgrading on ATA response (χ2=30.914, p<0.001). There was also significant interdependence to some clinical variables, such as AJCC stage (χ2=8.460, p=0.015), ATA risk classification (χ2=10.694, p=0.005) and initial N stage (χ2=8.485, p=0.004). CONCLUSIONS: In selected cases, a second RAIT could lead to more robust responses with a potential improvement in prognosis in patients with incomplete response to initial DTC treatment.

Diagnostic and therapeutic impact of PET/CT with 18F-DCFPyL versus 18F-Fluorocholine in initial staging of intermediate-/high-risk prostate cancer: a pilot study.

AIM: To assess the diagnostic and therapeutic impact of PET/CT with 18F-DCFPyL with respect to 18F-Fluorocholine in initial staging of intermediate-/high-risk prostate cancer (PCa). MATERIAL AND METHODS: Patients with recent diagnosis of intermediate-/high-risk PCa without androgen deprivation therapy and previous 18F-Fluorocholine-PET/CT (negative for extraprostatic disease or with oligometastatic disease) were referred to 18F-DCFPyL-PET/CT. Patients' disease characteristic as grade group, D'Amico risk category (intermediate/high), prostate-specific antigen (PSA) closest to PET/CTs and its kinetics were obtained. The overall detection rate (DR) and molecular imaging TNM (miTNM) stage according to the prostate cancer molecular imaging standardized evaluation (PROMISE) criteria were assessed for both radiotracers, and their concordance (Kappa coefficient) was analyzed. The diagnostic and therapeutic impact of 18F-DCFPyL with respect to 18F-Fluorocholine was evaluated. RESULTS: Fifty-eight patients were analyzed (84.5% high-risk). 18F-Fluorocholine showed a higher DR than 18F-DCFPyL of prostate gland involvement (100% versus 93.1%) and pelvic node disease (37.9% versus 31%; k = 0.436, p = 0.001). On the other hand, 18F-DCFPyL-PET/CT showed a higher DR of metastatic disease than 18F-Fluorocholine-PET/CT, 9/58 patients (15.5%): 3 M1a, 5 M1b and 1 M1c) versus 5/58 (8.6%) patients: 1 M1a and 4 M1b), k = 0.426; p = 0.001. No significant association was found between clinical characteristics (grade group, risk category, PSA level and kinetic) and 18F-Fluorocholine or 18F-DCFPyL results. The results of 18F-DCFPyL-PET/CT modified the previously planned treatment compared to 18F-Fluorocholine-PET/CT in 13 patients (22.4%). CONCLUSIONS: 18F-Fluorocholine and 18F-DCFPyL PET/CT showed a similar DR of prostate gland and lymph node involvement, although with moderate concordance for the latter. 18F-DCFPyL was superior to 18F-Fluorocholine in detecting regional and distant metastasis with a therapeutic impact in one of every five patients.

Head-to-Head Comparison of [18F]F-choline and Imaging of Prostate-Specific Membrane Antigen, Using [18F]DCFPyL PET/CT, in Patients with Biochemical Recurrence of Prostate Cancer.

PURPOSE: To analyse diagnostic and therapeutic impact of molecular imaging TNM (miTNM) stage obtained with [18F]DCFPyL versus [18F]F-choline in head-to-head comparison in biochemical recurrence (BCR) of prostate cancer (PCa). MATERIAL AND METHODS: Patients with BCR of PCa after radical treatment with previous [18F]F-choline-PET/CT (negative or oligometastatic disease) were recruited to [18F]DCFPyL-PET/CT. Patients were classified according to: grade group, European Association of Urology classification, PSA, PSA doubling time (PSAdt) and PSA velocity (PSAvel). The overall detection rate (DR) and miTNM stage according to PROMISE criteria were assessed for both radiotracers and also correlated (Kappa). The influence of PSA and kinetics on both PET/CT (DR and miTNM) and predictive value of unfavourable kinetics on miTNM were determined. Cut-off PSA, PSAdt and PSAvel values able to predict PET/CT results were determined. Change in miTNM and treatment derived from [18F]DCFPyL information compared with [18F]F-choline were also evaluated. RESULTS: We studied 138 patients. [18F]DCFPyL showed a higher DR than [18F]F-choline (64.5% versus 33.3%) with a fair agreement. [18F]DCFPyL and [18F]F-choline detected T in 33.3% versus 19.6%, N in 27.5% versus 13.8%, and M in 30.4% versus 8.7%. Both tracers' DR showed significant associations with PSA and PSAvel. Significant association was only found between miTNM and PSA on [18F]F-choline-PET/CT (p = 0.033). For [18F]F-choline and [18F]DCFPyL-PET/CT, a PSAdt cut-off of 4.09 and 5.59 months, respectively, were able to predict M stage. [18F]DCFPyL changed therapeutic management in 40/138 patients. CONCLUSIONS: [18F]DCFPyL provides a higher DR and superior miTNM staging than [18F]F-choline in restaging BCR, especially with high PSA and unfavourable PSA kinetics, showing a fair agreement to [18F]F-choline.

Brain Nocardiosis Defined by 18 F-Fluorocholine PET/CT.

ABSTRACT: Nocardia infection (nocardiosis) is usually acquired by inhalation; so pulmonary nocardiosis is the most common clinical presentation. Extrapulmonary localization occurs through hematogenous dissemination or contiguous spread. Nocardia can involve the central nervous system in a very reduced number of patients, mainly in immunocompromised. We present a case of a 56-year-old woman with a history of aggressive systemic mastocytosis, treated with chemotherapy 1 year ago. Patient reported intense headache, disorientation, and blurry vision without other symptoms being diagnosed with a rare brain nocardiosis by Nocardia cerradoensis . Neither bacteremia nor pulmonary involvement was detected. Brain PET/CT illustrated 18 F-fluorocholine avidity on brain abscesses.

A systematic review about the role of preoperative 18F-FDG PET/CT for prognosis and risk stratification in patients with endometrial cancer.

OBJECTIVE: To analyse the available literature on the prognostic value of preoperative 18F-FDG PET/CT metabolic parameters and their usefulness in risk stratification in patients with endometrial cancer (EC). MATERIAL AND METHODS: Pubmed searches used "(endometr* OR uter*) AND (PET OR FDG)" as keywords from January-2000 to June-2020. References in included articles were checked for possible publications not included in the first search. Studies evaluating the prognostic value of preoperative 18F-FDG PET/CT and its role for risk stratification in patients with EC were included. Non-original articles (reviews, editorials, letters, legal cases, interviews, case reports, etc.) were not included. RESULTS: Twenty-six studies (1918 patients) were selected according to the inclusion criteria in this review. Thirteen studies (939 patients) related to the prognostic role of preoperative 18F-FDG PET/CT and 14 studies (1036 patients) related to its role in risk stratification were included. Parameters such as SUVmax, metabolic tumour volume (MTV) and total lesion glycolysis (TLG) of the primary tumour were analysed. CONCLUSIONS: Preoperative SUVmax is useful for non-invasive diagnosis and for deciding the appropriate therapeutic strategy, as it could be used as an independent prognostic marker for recurrence and survival in EC. In addition, both preoperative VTM and GTL could be independent prognostic factors for predicting recurrence and survival, but there is still insufficient scientific evidence. The usefulness of SUVmax for risk stratification is limited (there is insufficient literature that 18F-FDG PET/CT can replace surgical staging), although VTM and GTL are more accurate and have a valuable role in risk stratification of EC. However, larger multicentre studies with adequate follow-up time are needed to confirm these findings.

18F-Fluoroethyl-L Tyrosine Positron Emission Tomography Radiomics in the Differentiation of Treatment-Related Changes from Disease Progression in Patients with Glioblastoma.

The follow-up of glioma patients after therapeutic intervention remains a challenging topic, as therapy-related changes can emulate true progression in contrast-enhanced magnetic resonance imaging. 18F-fluoroethyl-tyrosine (18F-FET) is a radiopharmaceutical that accumulates in glioma cells due to an increased expression of L-amino acid transporters and, contrary to gadolinium, does not depend on blood-brain barrier disruption to reach tumoral cells. It has demonstrated a high diagnostic value in the differentiation of tumoral viability and pseudoprogression or any other therapy-related changes, especially when combining traditional visual analysis with modern radiomics. In this review, we aim to cover the potential role of 18F-FET positron emission tomography in everyday clinical practice when applied to the follow-up of patients after the first therapeutical intervention, early response evaluation, and the differential diagnosis between therapy-related changes and progression.

Correlation of Global and Regional Amyloid Burden by 18 F-Florbetaben PET/CT With Cognitive Impairment Profile and Severity.

PURPOSE: To assess the correlation between profile and severity deterioration in the neuropsychological assessment and the most affected regions in amyloid PET semiquantification. The influence of vascular risk and other potential confounding factors was also evaluated. METHODS: A retrospective, observational, and multicenter study including all patients referred for amyloid PET in daily practice was conducted. Patients underwent neuropsychological assessment, and cognitive decline severity and domain(s) affected were recorded. The patients were grouped according to cognitive impairment (CI) profile and severity: (A) no CI, single-domain amnestic CI, multiple-domain amnestic CI, and nonamnestic CI; and (B) mild CI, moderate and severe dementia. An adapted Framingham Stroke Risk Profile was calculated for each individual. Depression and parkinsonism were also recorded. Standardized quantitative analysis software was used to obtain standardized uptake value ratio (SUVR) values from PET/CT images. The corresponding associations were assessed with the most appropriate statistical tests. RESULTS: One hundred twenty-nine patients were included (62 men, 67 women; 64.67 ± 7.47 years old). Significant differences in global and regional amyloid load were exclusively found in women between non-CI and moderate dementia ( P = 0.006, for total-cerebellum SUVR). Posterior and anterior cingulates and prefrontal cortex best represented CI severity ( P = 0.003, 0.006, and 0.006, respectively). No relationship between the CI profile and the regional amyloid load was shown. A significantly high positive correlation was found between age and vascular risk and between these variables and amyloid load in nearly all regions, especially in women with moderate dementia. CONCLUSION: Semiquantitative analysis of amyloid PET by SUVR values revealed a significant correlation between amyloid burden and CI severity, although only in women.

A Head-to-Head Comparison of 18F-Fluorocholine PET/CT and Conventional MRI as Predictors of Outcome in IDH Wild-Type High-Grade Gliomas.

(1) Aim: To study the associations between imaging parameters derived from contrast-enhanced MRI (CE-MRI) and 18F-fluorocholine PET/CT and their performance as prognostic predictors in isocitrate dehydrogenase wild-type (IDH-wt) high-grade gliomas. (2) Methods: A prospective, multicenter study (FuMeGA: Functional and Metabolic Glioma Analysis) including patients with baseline CE-MRI and 18F-fluorocholine PET/CT and IDH wild-type high-grade gliomas. Clinical variables such as performance status, extent of surgery and adjuvant treatments (Stupp protocol vs others) were obtained and used to discriminate overall survival (OS) and progression-free survival (PFS) as end points. Multilesionality was assessed on the visual analysis of PET/CT and CE-MRI images. After tumor segmentation, standardized uptake value (SUV)-based variables for PET/CT and volume-based and geometrical variables for PET/CT and CE-MRI were calculated. The relationships among imaging techniques variables and their association with prognosis were evaluated using Pearson's chi-square test and the t-test. Receiver operator characteristic, Kaplan−Meier and Cox regression were used for the survival analysis. (3) Results: 54 patients were assessed. The median PFS and OS were 5 and 11 months, respectively. Significant strong relationships between volume-dependent variables obtained from PET/CT and CE-MRI were found (r > 0.750, p < 0.05). For OS, significant associations were found with SUVmax, SUVpeak, SUVmean and sphericity (HR: 1.17, p = 0.035; HR: 1.24, p = 0.042; HR: 1.62, p = 0.040 and HR: 0.8, p = 0.022, respectively). Among clinical variables, only Stupp protocol and age showed significant associations with OS and PFS. No CE-MRI derived variables showed significant association with prognosis. In multivariate analysis, age (HR: 1.04, p = 0.002), Stupp protocol (HR: 2.81, p = 0.001), multilesionality (HR: 2.20, p = 0.013) and sphericity (HR: 0.79, p = 0.027) derived from PET/CT showed independent associations with OS. For PFS, only age (HR: 1.03, p = 0.021) and treatment protocol (HR: 2.20, p = 0.008) were significant predictors. (4) Conclusions: 18F-fluorocholine PET/CT metabolic and radiomic variables were robust prognostic predictors in patients with IDH-wt high-grade gliomas, outperforming CE-MRI derived variables.

Early Recurrence Detection of Glioma Using 18 F-Fluorocholine PET/CT : GliReDe Pilot Study.

OBJECTIVE: The aim of this study was to analyze the usefulness of 18 F-fluorocholine PET/CT in the early diagnosis of tumor recurrence, increasing the diagnosis confidence of MRI. METHODS: Patients with a previous gross total resection of glioma and the first suspicious or doubtful for recurrence MRI were prospectively included and subjected to 18 F-fluorocholine PET/CT. An independent and combined assessment of 18 F-fluorocholine PET/CT and multimodal MRI was performed classifying the studies as positive or negative for tumor recurrence. Final diagnosis (recurrence or not) was obtained by histological confirmation or clinical and imaging follow-up. The relation of SUV max and tumor-to-background ratio with progression, the diagnostic performance of imaging techniques, and their concordance (κ Cohen) were analyzed. RESULTS: Twenty-four studies on 21 patients were assessed. Recurrence was diagnosed in 20 cases. PET/CT was positive in 23 cases (3 false positive), whereas MRI was positive in 15 cases (1 false positive). MRI was false negative in 6 cases. There was no false negative on 18 F-fluorocholine PET/CT. Accuracy of PET/CT versus MRI was 87.5% and 70.8%, respectively. The combined evaluation of both techniques did not show any advantage with respect to PET/CT results alone. The concordance between both imaging techniques was low (κ = 0.135; P = 0.375). SUV max and tumor-to-background ratio were related to recurrence (areas under the curve of 0.844 [ P = 0.033] and 0.869 [ P = 0.022], respectively). CONCLUSIONS: 18 F-fluorocholine PET/CT was helpful for increasing the diagnostic confidence in the cases of MRI doubtful for recurrence in order to avoid a delayed diagnosis.

Multiple and Diffuse Gliomas by 18F-Fluorocholine PET/CT: Two Sides of the Same Coin.

ABSTRACT: Gliomas are characterized by an inherent diffuse and irregular morphology that prevents defining a boundary between tumor and healthy tissue, both in imaging assessment and surgical field. The effective identification of the extent of the disease in diffuse and multiple gliomas is crucial for their management but doing so by radiological means can be challenging. We present a broad spectrum of diffuse and multiple gliomas using 18F-fluorocholine PET/CT, demonstrating the potential of metabolic imaging in the evaluation of these gliomas, with implications in patient clinical management and outcome.

Increasing the confidence of 18F-Florbetaben PET interpretations: Machine learning quantitative approximation.

AIM: To assess the added value of semiquantitative parameters on the visual assessment and to study the patterns of 18F-Florbetaben brain deposition. MATERIALS AND METHODS: Retrospective analysis of multicenter study performed in patients with mild cognitive impairment or dementia of uncertain origin. 18F-Florbetaben PET scans were visually interpreted by two experienced observers, analyzing target regions in order to calculate the interobserver agreement. Semiquantification of all cortical regions with respect to three reference regions was performed to obtain standardized uptake value ratios (SUVRs). The ability of SUVRs to predict the visual evaluation, the possibility of preferential radiotracer deposition in some target regions and interhemisphere differences were analyzed. RESULTS: 135 patients were evaluated. In the visual assessment, 72 were classified as positive. Interobserver agreement was excellent. All SUVRs were significantly higher in positive PET scans than in negative ones. Prefrontal area and posterior cingulate were the cortical regions with the best correlations with the visual evaluation, followed by the composite region. Using ROC analysis, the SUVRs obtained in same target locations showed the best diagnostic performance. CONCLUSIONS: The derived information from target regions seems to help the visual classification, based on a preferential amyloid ß deposit, allowing machine learning. The amyloid ß deposit, although diffuse in all cortical regions, seems not to be uniform and symmetric.

Prognostic Potential of Postoperative 18F-Fluorocholine PET/CT in Patients With High-Grade Glioma. Clinical Validation of FuMeGA Postoperative PET Criteria.

OBJECTIVE: The aim of this study was to assess the prognostic performance of postoperative 18F-fluorocholine PET/CT in patients with high-grade glioma (HGG). METHODS: Patients with HGG who underwent preoperative and postoperative 18F-fluorocholine PET/CT were prospectively enrolled in the study. Postoperative MRI was classified as complete versus incomplete resection. Postoperative 18F-fluorocholine PET/CT was classified as negative (complete) or positive for metabolic residual tumor (incomplete resection) using a 5-point score system. The correlation of positive locations on PET/CT with the sites of subsequent tumor recurrence was evaluated. The concordance of postoperative imaging techniques (Cohen κ) and their relation with progression-free survival and overall survival were assessed using Kaplan-Meier method and Cox regression analysis. RESULTS: Fifty-one studies, belonging to 47 patients, were assessed. Four patients underwent 2 postoperative 18F-fluorocholine PET/CT scans as they needed a second tumor resection for recurrence. In the follow-up, 42 patients progressed, and 37 died. Concordance between postoperative PET/CT and MRI assessment was poor. Resection grade on MRI did not show any significant association with prognosis. In multivariate analysis, only age and postoperative PET/CT showed significant association with progression-free survival (hazard ratio [HR], 1.03 [1.01-1.06, P = 0.006] and 1.88 [0.96-3.71, P = 0.067], respectively) and overall survival (HR, 1.04 [1.01-1.07, P = 0.004] and 2.63 [1.22-5.68, P = 0.014], respectively). Postoperative positive 18F-fluorocholine PET/CT locations correlated with the sites of subsequent tumor recurrence in 81.82% of cases. CONCLUSION: Postoperative 18F-fluorocholine PET/CT seems superior to postoperative MRI in the outcome prediction of patients with HGG, outperforming it in the identification of the most probable location of tumor recurrence.

Failure of scintigraphy lymphatic mapping in endometrial cancer. Causes and solutions.

AIM: To evaluate the effect of technical problems and patient characteristics on sentinel lymph node (SLN) scintigraphic detection and mapping success in early stages of endometrial cancer (EC). METHODS: Patients with clinical early stage EC (IA-IB) underwent SLN mapping using technetium-99m-nanocolloid, between September 2011 and February 2020 were included. There were excluded cases with technical problems, 92 patients were included for the analysis of the diagnostic performance and the relation of mapping failure (pelvic unilateral or not detected SLN) with patient (age, body mass index, previous pelvic disease or surgery) and disease characteristics (histology, grade, myometrial invasion, lymphovascular space infiltration, tumor size, and lymphatic infiltration risk). RESULTS: The overall detection rate was 79%. Lymph node metastases were diagnosed in 7 patients. Age (P = .01), depth of myometrial invasion ≥50% (P = .04) and high risk of lymphatic infiltration (P = .02) were positively associated with mapping failure. In multivariate analysis, age was significantly associated with mapping failure [odds ratio = 1.63, 95%CI: 1.06-2.50; P = .027]. CONCLUSIONS: Age, depth of myometrial invasion and high risk of lymphatic infiltration were the factors associated with higher mapping failure. An individualized injection technique, optimizing the methodology, could minimize the detection failures.

SUVmax to tumor perimeter distance: a robust radiomics prognostic biomarker in resectable non-small cell lung cancer patients.

OBJECTIVE: The purpose of this study was to evaluate the prognostic value of novel geometric variables obtained from pre-treatment [18F]FDG PET/CT with respect to classical ones in patients with non-small cell lung cancer (NSCLC). METHODS: Retrospective study including stage I-III NSCLC patients with baseline [18F]FDG PET/CT. Clinical, histopathologic, and metabolic parameters were obtained. After tumor segmentation, SUV and volume-based variables, global texture, sphericity, and two novel parameters, normalized SUVpeak to centroid distance (nSCD) and normalized SUVmax to perimeter distance (nSPD), were obtained. Early recurrence (ER) and short-term mortality (STM) were used as end points. Univariate logistic regression and multivariate logistic regression with respect to ER and STM were performed. RESULTS: A cohort of 173 patients was selected. ER was detected in 49/104 of patients with recurrent disease. Additionally, 100 patients died and 53 had STM. Age, pathologic lymphovascular invasion, lymph nodal infiltration, TNM stage, nSCD, and nSPD were associated with ER, although only age (aOR = 1.06, p = 0.002), pathologic lymphovascular invasion (aOR = 3.40, p = 0.022), and nSPD (aOR = 0.02, p = 0.018) were significant independent predictors of ER in multivariate analysis. Age, lymph nodal infiltration, TNM stage, nSCD, and nSPD were predictors of STM. Age (aOR = 1.05, p = 0.006), lymph nodal infiltration (aOR = 2.72, p = 0.005), and nSPD (aOR = 0.03, p = 0.022) were significantly associated with STM in multivariate analysis. Coefficient of variation (COV) and SUVmean/SUVmax ratio did not show significant predictive value with respect to ER or STM. CONCLUSION: The geometric variables, nSCD and nSPD, are robust biomarkers of the poorest outcome prediction of patients with NSCLC with respect to classical PET variables. KEY POINTS: • In NSCLC patients, it is crucial to find prognostic parameters since TNM system alone cannot explain the variation in lung cancer survival. • Age, lymphovascular invasion, lymph nodal infiltration, and metabolic geometrical parameters were useful as prognostic parameters. • The displacement grade of the highest point of metabolic activity towards the periphery assessed by geometric variables obtained from [18F]FDG PET/CT was a robust biomarker of the poorest outcome prediction of patients with NSCLC.

Diagnostic methodology in labelled leukocyte scan for prosthetic / non-prosthetic osteoarticular infection: Visual or semi-quantitative analysis? One- or two-day protocol?

OBJECTIVE: as scarce literature on the topic is available, we aimed to compare diagnostic utility of semi-quantitative versus visual analysis in labelled white blood cell scintigraphy (WBCS) for osteoarticular infection. One-day and two-day protocols were assessed, particularly in orthopaedic devices. MATERIAL AND METHODS: prospective study of 79 consecutive patients with suspected osteoarticular infection. In all patients, WBCS were performed at 30min, 4h, 8h and 24h. Images were analysed by grouping in two protocols: one-day-protocol (experts evaluated 30min, 4h and 8h planar images) and two-day-protocol (experts evaluated 30min, 4h and 24h planar images). Planar images were interpreted qualitative and semiquantitatively and also were compared grouping patients with and without orthopaedic devices. To find which cut-off value of the percentage variation could predict of osteoarticular infection, multiple cut-off values were calculated in both protocols from the Youden index. Three blinded readers analysed the images. RESULTS: Comparing final diagnosis visual analysis of the one-day-protocol provided better results with sensitivity of 95.5%, specificity of 93% and diagnostic accuracy of 93.7% (p<001) than the two-day-protocol with values of 86.4%, 94.7% and 92.4%, respectively (p<001). For semi-quantitative analysis, the one-day-protocol also obtained better results with sensitivity of 72.7%, specificity of 78.9% and accuracy of 77.2% (p<001) than two-day-protocol (no significant results; p=0.14), especially in the group of patients with orthopaedic devices (sensitivity of 100%, specificity of 79.5% and accuracy of 82.7%; p<001). CONCLUSIONS: most accurate approach in the diagnosis of osteoarticular infection corresponded to visual analysis in one-day-protocol that showed greater sensitivity and specificity than semi-quantitative analysis. Semi-quantitative analysis only could be useful when visual analysis is doubtful. In patients with joint prostheses, an increase in percentage variation above 9% obtained maximum sensitivity and negative predictive value.

Interim and end-treatment 18F-Fluorocholine PET/CT and bone scan in prostate cancer patients treated with Radium 223 dichloride.

To assess the predictive and prognostic aim of interim and end-treatment 18F-fluorocholine PET/CT (FCH-PET/CT) and 99mTc-methilen diphosphonate bone scintigraphy (BS) in patients with castration-resistant prostate cancer and bone metastases (CRPC-BM) treated with Radium 223 dichloride (223Ra). Prospective and multicentre ChoPET-Rad study including 82 patients with CRPC-BM. Baseline, after 3 (interim) and 6 doses (end-treatment) BS and FCH PET/CT were performed in patients who meet the study criteria. Clinical variables, imaging and clinical progression were obtained and their association with progression free survival (PFS), and overall survival (OS) was studied. Agreement between BS and FCH PET/CT response was assessed using Kappa (K) analysis. Median of PFS and OS was 3 and 16 months, respectively. Agreement between interim BS and FCH PET/CT was weak (K: 0.28; p = 0.004). No agreement was observed between end-treatment diagnostic studies. Interim and end-treatment FCH PET/CT were related to PFS (p = 0.011 and p < 0.001, respectively). Therapeutic failure and interim BS and FCH PET/CT showed association with OS (p < 0.001, p = 0.037 and p = 0.008, respectively). Interim and end-treatment FCH PET/CT were good predictors of biochemical progression in patients treated with 223Ra. Therapeutic failure and progression in interim BS or FCH PET/CT were adverse factors for OS.

La sinoviortesis radioisotópica en el control de la sinovitis refractaria en Castilla La-Mancha. Una experiencia de 10 años / Radioisotope synoviorthesis in the control of refractory synovitis in Castilla-La Mancha. A 10-year experience

Nuestro hospital es el hospital de referencia en medicina nuclear para la realización de la sinoviortesis radioisotópica para toda Castilla La-Mancha. OBJETIVO: Describir la experiencia en la realización de la sinoviortesis radioisotópica en las artritis refractarias a otros tratamientos en nuestro hospital. METODOLOGÍA: Estudio observacional, descriptivo y transversal protocolizado a través de la revisión de la base de datos de las sinoviortesis radioisotópicas realizadas entre 2007 y 2017. Se recopilaron datos clínicos previos (edad, sexo, proceso patológico, tratamientos previos, infiltración previa y articulación afectada) y evolutivos a los 6 meses tras administrar el isótopo. Se creó una base de datos Excel para un análisis de frecuencias con SPSS 21. RESULTADOS: Se realizaron 30 radiosinoviortesis, siendo las enfermedades más frecuentes, por este orden: sinovitis villonodular pigmentada (40%), artritis reumatoide (23,3%), espondiloartritis (13,3%), osteoartritis (10%) y artritis inespecíficas (6,7%), seguido de lupus eritematoso sistémico y gota. Tras 6 meses un 56,7% de los pacientes mejoraron frente a un 36,7% que seguían igual. Así mismo, ninguno de ellos presentó complicaciones relacionadas con el procedimiento. A un 6,6% de los pacientes se les perdió el seguimiento. DISCUSIÓN Y CONCLUSIONES: En los pacientes con episodios de artritis de repetición con derrame articular asociado en una o 2 articulaciones, refractarias a tratamientos sistémicos, a las infiltraciones locales con corticoides y en aquellos pacientes en los que otros tratamientos puedan estar contraindicados, debemos considerar la posibilidad de realizar una radiosinoviortesis isotópica, pues es una técnica sencilla, segura y con una tasa de éxito superior al 50%

Our hospital is the nuclear medicine referral hospital for radioisotopic synoviorthesis for all of Castilla-La Mancha. OBJECTIVE: To describe the experience in the performance of radioisotopic synoviorthesis for arthritis refractory to other treatments in our hospital. METHODOLOGY: Observational, descriptive and cross-sectional study protocolised through the review of the database of radioisotopic synoviorthesis performed between 2007 and 2017. Previous clinical data were collected (age, sex, pathology, previous treatments, previous infiltration and affected joint), and progress at 6 months after administering the isotope. An Excel database was created for a frequency analysis with SPSS 21. RESULTS: 30 radiosynovitis interventions were performed. The most frequent pathologies in this order were: pigmented villonodular synovitis (40%), rheumatoid arthritis (23.3%), spondyloarthritis (13.3%), osteoarthritis (10%) and nonspecific arthritis (6.7%), followed by systemic lupus erythematosus and gout. After 6 months, 56.7% of the patients improved compared to 36.7% who remained the same. Likewise, none of them presented complications related to the procedure. Six point six percent of the patients were lost to follow-up. DISCUSSION AND CONCLUSIONS: In patients with episodes of recurrent arthritis with associated joint effusion in one or two joints, refractory to systemic treatments, to local infiltrations with corticosteroids and for patients for whom other treatments may be contraindicated, we must consider the possibility of performing an isotope radiosinoviortesis, as it is a simple, safe technique with a success rate of more than 50%