Clinical utility of (18)F-fluorocholine positron-emission tomography/computed tomography (PET/CT) in biochemical relapse of prostate cancer after radical treatment: results of a multicentre study.

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.

Controversy in the initial nodal staging of rectal cancer (MRI or PET/CT?).

OBJECTIVE: To compare the usefulness of MRI and PET/CT in nodal staging (N) of patients with locally advanced rectal cancer (LARC). MATERIAL AND METHODS: Retrospective study of patients with LARC, who completed their initial staging with PET/CT, between January-20 and March-23. Regional nodes were assessed, and N was determined using both techniques according to TNM criteria. Concordance between MRI and PET/CT was analyzed. The accuracy of both techniques was calculated for those patients who underwent direct surgery. Non-regional pelvic lymph nodes were evaluated by both modalities. RESULTS: Among the 73 patients, 48 were ultimately diagnosed with a locally advanced stage. Of these, 39 underwent neoadjuvant treatment (chemoradiotherapy) followed by surgery, and 9 direct surgery. In 25, the PET/CT extension study revealed distant disease, leading to systemic treatment. Weak concordance was observed between MRI and PET/CT in determining N (k=0.286; p<0.005). Out of 73 patients, 31(42%) exhibited concordance, and 42(58%) showed discordance. In 83% of the discordant cases, MRI overstaged compared to PET/CT, with 17 cases indicating nodal involvement (N+) by MRI and N0 by PET/CT. Diagnostic accuracy was 78% for both techniques. Sensitivity, specificity, positive predictive value, and negative predictive value were 80%, 75%, 80%, and 75% for MRI, and 60%, 100%, 100%, and 67%, for PET/CT. PET/CT identified pelvic metastatic adenopathies in 8 patients that were not visible/doubtful by MRI. CONCLUSIONS: In the initial nodal staging of rectal cancer MRI overstages relative to PET/CT. Both modalities are complementary, PET/CT offers higher specificity and MRI higher sensitivity.

Prognostic 18F-FDG Radiomic Features in Advanced High-Grade Serous Ovarian Cancer.

High-grade serous ovarian cancer (HGSOC) is an aggressive disease with different clinical outcomes and poor prognosis. This could be due to tumor heterogeneity. The 18F-FDG PET radiomic parameters permit addressing tumor heterogeneity. Nevertheless, this has been not well studied in ovarian cancer. The aim of our work was to assess the prognostic value of pretreatment 18F-FDG PET radiomic features in patients with HGSOC. A review of 36 patients diagnosed with advanced HGSOC between 2016 and 2020 in our center was performed. Radiomic features were obtained from pretreatment 18F-FDGPET. Disease-free survival (DFS) and overall survival (OS) were calculated. Optimal cutoff values with receiver operating characteristic curve/median values were used. A correlation between radiomic features and DFS/OS was made. The mean DFS was 19.6 months and OS was 37.1 months. Total Lesion Glycolysis (TLG), GLSZM_ Zone Size Non-Uniformity (GLSZM_ZSNU), and GLRLM_Run Length Non-Uniformity (GLRLM_RLNU) were significantly associated with DFS. The survival-curves analysis showed a significant difference of DSF in patients with GLRLM_RLNU > 7388.3 versus patients with lower values (19.7 months vs. 31.7 months, p = 0.035), maintaining signification in the multivariate analysis (p = 0.048). Moreover, Intensity-based Kurtosis was associated with OS (p = 0.027). Pretreatment 18F-FDG PET radiomic features GLRLM_RLNU, GLSZM_ZSNU, and Kurtosis may have prognostic value in patients with advanced HGSOC.

[Bone microarchitecture and other body composition parameters in patients with overweight or obesity grouped by glucose metabolism disorders]. / Microarquitectura ósea y otros parámetros de composición corporal en pacientes con sobrepeso u obesidad agrupados según alteraciones del metabolismo hidrocarbonado.

INTRODUCTION: Introduction: obesity and DM-2 decrease trabecular bone mass even though cortical bone increase may coexist. Another common finding is presarcopenia/sarcopenia, possibly due to insulin resistance and oxidative stress. It remains to be clarified whether these changes depend on either early (prediabetes) or late (established DM) glucidic alterations, or rather they would be linked predominantly by excess fat mass in obese patients Objectives: to evaluate and compare body composition parameters (bone, muscle and adipose-visceral tissues) in overweight/obese patients grouped by whether or not they present glucidic metabolism disorders. Analyze if there are differences between FRAX vs FRAX adjusted to trabecular bone score TBS in both groups. Methods: sixteen overweight/obese patients were included. In all of them clinical-anthropometric evaluation, bioimpedance, DXA and analysis were performed. They were grouped by glycemia as: a) normal; b) impaired fasting glycemia (IFG); and c) DM-2. Non-parametric tests were performed. Results: no statistically significant differences were found among groups regarding bone microarchitecture, muscle mass or visceral fat. The IFG group showed the highest average muscle mass and visceral fat. Then, patients were reclassified in only two groups, normal glycemia in group 1 and altered glycemia in group 2 (IFG and DM-2), and statistically significant differences were found at the expense of lower trabecular bone microarchitecture in group 2 (p = 0.031) and phosphorus lower levels in group 1 (p = 0.042). Conclusions: in our study, the bone microarchitecture is impaired in patients with altered glycemia and obesity. Studies with larger sample size are needed to establish when these changes take place in the natural evolution of diabetes.

INTRODUCCIÓN: Introducción: la obesidad y la diabetes mellitus tipo 2 (DM-2) disminuyen el entramado trabecular óseo aun cuando puede coexistir aumento del hueso cortical. Otro hallazgo en común es la presarcopenia/sarcopenia secundaria posiblemente a la insulinorresistencia y el estrés oxidativo. Queda por aclarar si estos cambios dependen fundamentalmente de las alteraciones glucídicas precoces (pre DM-2) o tardías (DM-2 establecida), o más bien estarían vinculadas de forma predominante por el exceso de masa grasa en individuos obesos. Objetivos: evaluar y comparar parámetros de composición corporal (compartimentos óseo, muscular y adiposo-visceral) en pacientes con sobrepeso/obesidad agrupados según presenten o no alteraciones glucídicas. Analizar si existen diferencias comparando FRAX vs. FRAX ajustado a trabecular bone score (TBS) en ambos grupos. Métodos: se incluyeron 16 pacientes con sobrepeso/obesidad. A todos se les realizó evaluación clínica-antropométrica, bioimpedanciometría, absorciometría de rayos X de energía dual o densitometría ósea (DXA) y análisis, y se les agrupó según glucemia en tres grupos: a) normal; b) glucemia basal alterada en ayunas (GBA); y c) DM-2. Para el análisis estadístico empleamos pruebas no paramétricas. Resultados: no se encontraron diferencias estadísticamente significativas en los grupos respecto a microarquitectura ósea, masa muscular o grasa visceral. El grupo GBA mostró el mayor promedio de masa muscular y grasa visceral. Tras reclasificar en solo dos grupos, glucemia normal en el grupo 1 y glucemia alterada en el grupo 2 (GBA y DM-2), encontramos diferencias estadísticamente significativas con detrimento de la microarquitectura ósea trabecular en el grupo 2 (p = 0,031) y cifras de fósforo con niveles inferiores en el grupo 1 (p = 0,42). Conclusiones: en nuestro estudio, la microarquitectura ósea está deteriorada en pacientes con glucemia alterada y obesos. Hacen falta estudios con mayor tamaño muestral para establecer en qué momento se instauran estos cambios en la evolución natural de la diabetes.

[Use of positron emission tomography in assessing hidden extrathoracic metastasis in non small cell lung cancer]. / Utilidad de la tomografía por emisión de positrones en la detección de metástasis ocultas extratorácicas en el carcinoma broncogénico no células pequeñas.

INTRODUCTION: Positron emission tomography combined with computed axial tomography (PET/CT) is used for staging non small cell lung cancer (NSCLC). This study aims to describe PET/CT findings of unsuspected extrathoracic metastasis when used in mediastinal evaluation of patients with apparently resectable NSCLC. PATIENTS AND METHOD: Prospective and concurrent study including all NSCLC patients between June 2004 and November 2006 who underwent PET/CT after considering them as candidates for surgery, with resectable disease after bronchoscopy, thorax and abdominal CT, brain CT and bone gammagraphy evaluation, if metastasis at these locations were suspected. Metastasis were confirmed histopathologically or assumed when they had a compatible evolution. RESULTS: A total of 91 patients with NSCLC underwent PET/CT. In 24 of them (26%) at least one suspicious extrathoracic uptake was seen. In 7 patients (7.7%) those uptakes were NSCLC extrathoracic metastasis hidden from conventional staging. In 3 of these cases (13.1%) extrathoracic uptakes corresponded to metacrhonous tumours or pre-malignant conditions. Benign lesions were found in 12 patients (13.1%), and in 2 cases (2.2%) the uptake origins were undetermined. CONCLUSIONS: PET/CT is a complementary diagnosis method for assessing hidden metastases which could modify the therapeutical approach in patients otherwise suitable for surgery.