El cáncer de próstata resistente a la castración metastásico (CPRCm) representa un importante desafío clínico en oncología, tanto por su complejidad biológica como por su impacto en la calidad de vida y la supervivencia de los pacientes. La incorporación de [177Lu]Lu-PSMA-617 en la práctica clínica plantea oportunidades relevantes, pero exige una adecuada coordinación multidisciplinar, protocolos claros de selección de los pacientes y un manejo cuidadoso de los aspectos logísticos y de seguridad radiológica. La variabilidad en la disponibilidad de recursos y en la experiencia entre centros hace especialmente valiosa la elaboración de unas guías prácticas adaptadas a la realidad asistencial. A diferencia de las guías internacionales, centradas principalmente en aspectos técnicos y regulatorios, este documento pretende ofrecer recomendaciones prácticas adaptadas a la realidad asistencial del Sistema Nacional de Salud español para la implantación de la terapia con [177Lu]Lu-PSMA-617 en pacientes con CPRCm. Ha sido elaborado por un panel de especialistas en medicina nuclear con experiencia en terapias con radioligandos, a partir de una revisión no sistemática de la literatura (ensayos de registro, guías de procedimiento internacionales EANM y SNMMI, criterios PROMISE V2y PCWG4, y documentación regulatoria aplicable), de la práctica clínica de los autores y de un proceso iterativo de discusión y consenso del panel mediante reuniones de trabajo. La guía aborda los criterios de indicación y selección de los pacientes (incluyendo las restricciones de financiación del Sistema Nacional de Salud), el procedimiento terapéutico estandarizado, el seguimiento clínico, el manejo de las toxicidades, las cuestiones prácticas del día a día y las áreas de incertidumbre. Su objetivo es facilitar la toma de decisiones clínicas y contribuir a la armonización de protocolos entre centros.
OBJECTIVE:The gastrointestinal tract is one of the systems most frequently involved in systemic sclerosis (SSc). The objective was to analyze gastrointestinal functional involvement by means of total gastrointestinal transit scintigraphy in patients with established SSc and in the early stages (VEDOSS), comparing both groups and evaluating the relationship between scintigraphic findings and general clinical and pulmonary functional variables. MATERIALS AND METHODS:Prospective study with 30 patients (21 with VEDOSS and 9 with SSc). Clinical, laboratory, imaging and pulmonary function parameters were evaluated. The scintigraphic study included esophageal transit, gastric emptying of solids and liquids, small bowel transit and colonic transit up to 72 h. Progression was analyzed by means of quantitative regional transit parameters, including the colonic geometric center. RESULTS:The study was abnormal in 85.7% of patients with VEDOSS and in 88.8% of patients with SSc. The most frequent abnormalities were observed in the esophagus (60% of cases), colon (56.7%) and solid gastric emptying (30%). No statistically significant differences were observed between the two groups under study. A total of 46.7% of patients presented altered patterns in several segments. A significant correlation was found between disease duration and quantitative esophageal transit values, with no association between scintigraphic findings and pulmonary function tests. CONCLUSIONS:Gastrointestinal involvement in SSc was highly prevalent, heterogeneous and detectable from the early stages of the process. Total gastrointestinal transit scintigraphy provided a global and regional evaluation, facilitating the early diagnosis of dysmotility and optimizing personalized patient follow-up.
OBJECTIVE:To create a non-invasive model for forecasting microsatellite instability (MSI) status in colorectal cancer (CRC) using preoperative 18F-FDG PET/CT metabolic parameters, guiding personalized treatment. METHODS:A total of 156 pathologically confirmed CRC patients who underwent 18F-FDG PET/CT at Mindong Hospital affiliated to Fujian Medical University (November 2023 - August 2025) were retrospectively enrolled. Twenty-one parameters (demographic, clinical, pathological, PET/CT metabolic and heterogeneity indices) were collected. MSI status was determined by immunohistochemistry (IHC) for four mismatch repair (MMR) proteins (MLH1, MSH2, MSH6, PMS2). After variable selection by LASSO regression and collinearity elimination through correlation analysis, a nomogram model was constructed using multivariate logistic regression. Model performance was evaluated by ROC, calibration, and decision curves, with internal validation using LOOCV, 5-fold cross-validation, and bootstrapping. RESULTS:Among patients, 28 (17.95%) were microsatellite instability-high (MSI-H, deficient mismatch repair, dMMR) and 128 (82.05%) were microsatellite stable (MSS, proficient mismatch repair, pMMR). Independent predictors included mucinous component, lymph node metastasis, differentiation grade, tumor size, and metabolic tumor volume (MTV). The model's AUC was 0.883 (95% CI: 0.820-0.945), with a sensitivity of 0.789 and a specificity of 0.857. Calibration curves and the Hosmer-Lemeshow test (χ² = 8.641, P = 0.3734) indicated good calibration of the model, and decision curve analysis showed that the model provided high net benefit. The AUCs of internal validation ranged from 0.801 to 0.857, which confirmed the good stability of the model. CONCLUSION:The integrated model established in this study is expected to assist in the non-invasive evaluation of MSI in CRC and may provide certain reference value for individualized clinical decision-making.
INTRODUCTION AND OBJECTIVE:The optimal radiotracer for detecting infection and inflammation remains uncertain due to limited direct comparative data. This systematic review and network meta-analysis (NMA) aimed to evaluate and rank the diagnostic performance of various positron emission tomography (PET) and conventional nuclear medicine tracers in bone and soft tissue. METHODS:PubMed, Embase, Cochrane Library, and ClinicalTrials.gov were systematically searched through February 2026 for studies comparing at least two radiotracers for infection or inflammation detection. The outcome was the DR. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were estimated using a frequentist random-effects NMA with 67Ga-citrate as the reference node. RESULTS:Thirteen studies involving 558 subjects and lesions were included, forming a network of 10 radiotracers (three PET and seven conventional scintigraphy probes). Relative to 67Ga-citrate, 68Ga-FAPI had the highest estimated DR (RR 1.94; 95% CI, 0.88-4.30), followed by 18F-FDG (RR 1.63; 95% CI, 0.81-3.26), however, neither difference reached statistical significance. Among conventional agents, 99mTc-DMSA(V) and 99mTc-HMPAO-WBC ranked highest, whereas 99mTc-nanocolloid yielded a lower DR than the reference (RR 0.69; 95% CI, 0.48-0.99). 99mTc-MDP had the lowest DR in the network (RR 0.64; 95% CI, 0.38-1.07). The third PET tracer, 68Ga-citrate, ranked seventh - below several conventional scintigraphy agents. CONCLUSION:Our findings suggest that 68Ga-FAPI and 18F-FDG may offer the highest estimated DRs for bone and soft tissue infection and inflammation, while 99mTc-HMPAO-WBC appears to perform best among scintigraphy probes. The observation that 68Ga-citrate ranked below several conventional tracers suggests that detection performance may depend not only on the imaging platform but also on the biological targeting mechanism of the radiopharmaceutical. Given the limited number of studies, these rankings should be interpreted with caution and warrant further validation in large-scale comparative trials.
INTRODUCTION:Radioiodine treatment in differentiated thyroid carcinoma requires elevated TSH levels to optimize the uptake of [131I]NaI. Levothyroxine suspension is the usual strategy for inducing endogenous TSH elevation, although the optimal duration of this suspension remains controversial. OBJECTIVE:To evaluate the effect of the duration of levothyroxine suspension on TSH levels achieved prior to radioiodine treatment. MATERIALS AND METHODS:Retrospective cohort study that included 104 patients with differentiated thyroid carcinoma treated at a reference university center. Patients were classified according to the time of discontinuation of levothyroxine prior to radioiodine treatment: three weeks (group A, n = 21) and four weeks (group B, n = 83). TSH levels between groups and their distribution by categories (<30, 30-49, 50-69, 70-99 y ≥100 mIU/L) were analyzed. The proportion of patients who reached the recommended TSH threshold (≥30 mIU/L) was also evaluated. RESULTS:The mean age (SD) was 46.7 (10.3) years and 87 patients were women. The mean TSH was 70.9 mIU/L (95% CI: 54.5-87.2) in group A and 88.7 mIU/L (95% CI: 84.8-92.6) in group B. The proportion of patients who achieved TSH ≥ 30 mIU/L was significantly higher in group B (100% vs 76.2%; p < 0.001). The distribution of TSH levels by category differed significantly between both groups (p < 0.001). On the other hand, the proportion of patients with TSH ≥ 100 mIU/L did not show significant differences (60.2% vs 47.6%; p = 0.42). In multivariate analysis adjusted for age, sex, and radioiodine dose, levothyroxine discontinuation time was not independently associated with the likelihood of TSH ≥ 100 mIU/L. CONCLUSIONS:Three weeks of levothyroxine suspension allowed TSH levels ≥30 mIU/L to be reached in most patients, although a proportion did not reach the recommended threshold. Four weeks were associated with adequate TSH elevation in all patients in this cohort. TSH monitoring during preparation could allow for more individualized strategies that optimize thyroid stimulation, minimizing unnecessary exposure to hypothyroidism.
OBJECTIVE:To propose a model to facilitate the surgical localization and excision of the sentinel lymph node in gynecological tumors. METHODOLOGY:This was an observational, cross-sectional, retrospective, and descriptive study incorporating data from patients who underwent sentinel lymph node biopsy for gynecological tumors between May 2020 and August 2025. RESULTS:The assumptions of linearity, normality, independence, and homoscedasticity of residuals were verified. Subsequently, a simple linear regression analysis model was performed, yielding a predictive equation for surgical count rates: Y = 26.918 + 0.056 × SPECT/CT Counts (R2 = 0.925). This equation demonstrated applicability in a small sample of patients. CONCLUSIONS:The SPECT/CT counts helps estimate the surgical count rate using a predictive equation. However, studies with larger sample sizes are needed to obtain a more precise equation with greater clinical applicability.
PURPOSE:Long COVID, also known as post-acute sequelae of SARS-CoV-2 infection (PASC), is characterized by persistent symptoms. Fibroblast activation protein (FAP), expressed on activated fibroblasts during tissue remodeling, can be visualized with [⁶⁸Ga]Ga-FAPI PET/CT. This study investigated lung and muscle fibroblastic activity in patients with post-acute sequelae of COVID-19 (PASC) following moderate-to-severe COVID-19 pneumonia more than two years after the acute infection, using [⁶⁸Ga]Ga-FAPI PET/CT. METHODS:In this pilot prospective observational study, we enrolled patients with PASC following severe acute COVID-19 requiring high-flow nasal cannula or mechanical ventilation and age- and sex-matched controls without pulmonary pathology between September 2023 and February 2024. PASC patients underwent high-resolution CT (HRCT), pulmonary function tests (PFTs), and [⁶⁸Ga]Ga-FAPI PET/CT. SUVmax and SUVmean were measured for each lung lobe. HRCT abnormalities were scored using a semi-quantitative scale (0-20) and categorized as ground-glass opacities, reticulations, parenchymal bands, traction bronchiectasis, or subpleural cysts. These findings were statistically compared and correlated with PET parameters, PFTs, and clinical symptoms. In addition, [⁶⁸Ga]Ga-FAPI uptake in the paravertebral muscles was assessed at the level of the L3 vertebra. RESULTS:Twenty patients with PASC and 10 control subjects were included (median ages: 64 and 58.5 years, respectively). The mean interval between hospitalization for acute COVID-19 and study imaging was 25 ± 4.5 months. PASC patients exhibited significantly increased [⁶⁸Ga]Ga-FAPI uptake in the lungs compared with controls. Lung [⁶⁸Ga]Ga-FAPI uptake was markedly increased in patients with traction bronchiectasis. No correlations were observed between lung [⁶⁸Ga]Ga-FAPI SUVmax and PFTs or symptom burden. However, lung [⁶⁸Ga]Ga-FAPI SUVmean demonstrated moderate inverse correlation with DLCO (r = -0.455, p = 0.044). In addition, [⁶⁸Ga]Ga-FAPI SUVmax in muscle was significantly higher in PASC patients than in controls, with particularly elevated uptake observed in patients with a history of mechanical ventilation. CONCLUSIONS:[⁶⁸Ga]Ga-FAPI PET/CT demonstrated increased lung tracer uptake in patients with PASC more than two years after moderate to severe COVID-19, supporting persistent fibroblast-related tissue activity. Limited associations between lung SUVmean and DLCO suggest a potential link between tracer uptake and functional impairment. Increased muscle [⁶⁸Ga]Ga-FAPI uptake was also observed as an exploratory finding requiring further functional and histopathological validation.
Objetivo El tracto gastrointestinal es uno de los sistemas más frecuentemente comprometidos en la esclerosis sistémica (ES). El objetivo fue analizar la afectación funcional digestiva mediante gammagrafía de tránsito gastrointestinal total en pacientes con ES establecida y en fases tempranas (VEDOSS), comparando ambos grupos y evaluando la relación entre hallazgos gammagráficos y variables clínicas generales y funcionales pulmonares. Material y métodos Estudio prospectivo con 30 pacientes (21 con VEDOSS y nueve con ES). Se evaluaron parámetros clínicos, analíticos, pruebas de imagen y función pulmonar. El estudio gammagráfico incluyó tránsito esofágico, vaciamiento gástrico de sólidos y líquidos, tránsito del intestino delgado y tránsito colónico hasta las 72 horas. La progresión se analizó mediante parámetros cuantitativos del tránsito regional, incluyendo el centro geométrico colónico. Resultados El estudio fue anormal en el 85,7% de pacientes con VEDOSS y en el 88,8% de pacientes con ES. Las alteraciones más frecuentes se apreciaron en esófago (60% de casos), colon (56,7%) y vaciamiento gástrico de sólidos (30%). No se observaron diferencias estadísticamente significativas entre ambos grupos en estudio. Un 46,7% de pacientes presentó patrones alterados en varios segmentos. Se encontró correlación significativa entre duración de la enfermedad y valores cuantitativos del tránsito esofágico, sin asociación entre hallazgos gammagráficos y pruebas de función pulmonar. Conclusiones La afectación gastrointestinal en la ES fue muy prevalente, heterogénea y detectable desde fases iniciales del proceso. La gammagrafía de tránsito gastrointestinal total proporcionó una evaluación global y regional, facilitando el diagnóstico precoz de la dismotilidad y optimizando un seguimiento personalizado del paciente.
