18F-DCFPyL PET/CT guidelines.

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 18F-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 18F-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.

Assessment of 68Ga-PSMA-11 PET positivity predictive factors in prostate cancer. / Valoración de factores predictivos de positividad en PET con 68Ga-PSMA-11 en el cáncer de próstata.

PURPOSE: Positron emission tomography (PET) studies with 68Ga-PSMA-11 (68Ga-HBED-CC-PSMA) have earned the attention of researchers, due to overexpression of PSMA in the tumoral tissues of prostate cancer. Our aim was to analyse the potential benefit of this radiotracer in the biochemical relapse of prostate cancer. MATERIAL AND METHODS: This retrospective analysis included 53 studies, performed on 50 male prostate cancer patients referred due to biochemical recurrence. In all cases, previous imaging techniques were negative or inconclusive. RESULTS: Of the 53 studies, 36 (68%) were positive. Significant differences were found between the positive and negative PET groups in Gleason's scale, PSA levels, PSAdt, late acquisition and the administration of androgen deprivation therapy during treatment (P<.05). Regarding PSA levels, 10 (48%) of the 21 patients with PSA<1ng/ml, obtained a pathological PET result. When the PSAdt was below six months, 86.7% of the patients obtained an abnormal PET. In the multivariate analysis, only Gleason's scale was associated independently with an abnormal PET result. CONCLUSIONS: 68Ga-PSMA-11 PET shows a high disease detection rate in patients where other techniques showed negative or doubtful images. Almost 50% of patients with prostate cancer biochemical recurrence and low PSA levels (<1ng/ml) have active disease on 68Ga-PSMA-11 PET, precisely where other radiotracers lack sensitivity.

Validación del renograma con estímulo diurético inmediato / Validation of the renogram with immediate diuretic stimulus

Objetivo El objetivo de este estudio es determinar la fiabilidad diagnóstica del renograma con estímulo diurético a la vez que la administración de la dosis comparando dos grupos de 59 pacientes cada uno (F0 y F+10) para identificar a aquellos pacientes susceptibles de ser tratados con cirugía. Material y métodos Estudio retrospectivo de dos grupos de 59 pacientes cada uno a los que se les efectuó renograma con estímulo diurético (furosemida) por sospecha de obstrucción ureteropiélica o ureterovesical, utilizando 99mTc-mercaptoacetylglicina. En el primero se aplicó el estímulo diurético a los 600 s de la administración de la dosis del radiotrazador (F+10). En el segundo se efectuó simultáneamente a la administración de la dosis (F0). Para la interpretación se valoró el análisis visual de las imágenes, los parámetros de las curvas y el porcentaje de eliminación tras modificación con la gravedad y micción. Se realizó análisis estadístico de los datos. Resultados El renograma F+10 muestra una sensibilidad del 96,7%, especificidad del 96,1%, valor predictivo positivo del 90,6% y valor predictivo negativo del 98,6%. El renograma F0 muestra una sensibilidad del 95,2%, especificidad del 98,9%, valor predictivo positivo del 95,2% y valor predictivo negativo del 98,9%. Conclusión La realización de renograma mediante la administración de estímulo diurético al mismo tiempo que la administración del radiofármaco es un método útil y cómodo en pacientes de edad pediátrica, y no supone una merma significativa en los parámetros de eficacia de la prueba en la selección de pacientes para intervención quirúrgica(AU)

Objective The aim of this study is to determine the diagnostic reliability of the renogram with diuretic stimulus simultaneously at the administration of the dose, comparing two groups of 59 patients each one (F0 and F+10), to select patients for surgery. Material and Methods This is an retrospective study about two groups of 59 patients to whom the diuretic renogram was carried out by stimulus (furosemide), by suspicion of ureteropelvic or vesicoureteral obstruction, using 99mTc-Mercaptoacetylglicine. In the first one, the study was conducted applying the diuretic stimulus 600 seconds after the administration of the dose of the radiotracer (F+10). In the second one it was carried out simultaneously to the administration (F0). For the interpretation there was used the visual analysis, the parameters of the curves and the percentage of elimination after modification by the severity and micturition. Statistical analysis of the information was made. Results The F+10 renogram shows a sensitivity of 96,7%, specificity of 96,1%, positive predictive value of 90,6%, and a negative predictive value of 98,6%. The F0 renogram shows a sensitivity of 95,2%, specificity of 98,9%, positive predictive value of 95,2%, and a negative predictive value of 98,9%. Conclusion The performance of renogram by means of the administration of diuretic stimulus at the same time as the administration of the radiotracer is a useful and comfortable method in paediatric patients, not supposing a significant wastage in the parameters of efficiency of the test in the patients selection for surgery(AU)

[Diagnostic accuracy of FP-CIT SPECT in patients with parkinsonism]. / Utilidad diagnóstica de la SPECT con FP-CIT en el estudio de pacientes con parkinsonismo.

OBJECTIVE: To determine the diagnostic accuracy of FP-CIT SPECT in entities with and without presynaptic involvement of the nigral-striatal dopaminergic pathway in a large group of patients with movement disorders, evaluating the usefulness of quantitative analysis. MATERIALS AND METHODS: A group of 183 consecutive patients clinically diagnosed as either having or not having degenerative Parkinsonism. These results were then contrasted with those of FP-CIT SPECT to determine the diagnostic accuracy of the procedure. The specific binding index was evaluated with ROC curves. RESULTS: FP-CIT SPECT was highly accurate in the diagnosis of neurodegenerative Parkinsonism (sensitivity: 95 %, specificity: 90 %). Most of the false positive results arose in patients with vascular Parkinsonism and the false negative results in patients with Parkinson disease. ROC curve analysis of semiquantitative evaluation had a sensitivity of 83 % and specificity of 82 % with an optimal cut-off of 1.44. The area under the curve was not significantly different between patients 60 years (0.899 vs 0.884) of age. CONCLUSIONS: FP-CIT SPECT has a high degree of diagnostic accuracy for striatal dopaminergic involvement. No significant changes in diagnostic accuracy were seen with respect to patient age.

Pacientes tratados por carcinoma diferenciado de tiroides con rastreos de 131I negativos y niveles de tiroglobulina elevada. Una evolución posible / Patients treated for differentiated thyroid cancer with negative 131i whole-body scanning and elevated thyroglobulin levels. A possible course

Objetivo. Constatar la existencia de pacientes con carcinoma diferenciado de tiroides (CDT) tratados que en el seguimiento presentan rastreos negativos con tiroglobulina (Tg) elevada y evolucionan hacia la normalización sin otras actuaciones terapéuticas.Material y métodos. Revisión retrospectiva de los exámenes periódicos de 725 pacientes con CDT, analizando los niveles de Tg sérica determinados con IRMA anualmente en tratamiento hormonal y cada 1-5 años en ausencia de tratamiento hormonal, previo a rastreos con 131I. Seguimiento mínimo de 2 años. Se seleccionaron y se analizaron las características de aquellos que presentaron en su evolución niveles elevadosde Tg (>3 ng/ml), rastreos negativos y otras pruebas de imagen negativas en los que se normalizó la cifra de Tg sin tratamiento médico-quirúrgico específico (grupo I), y de aquellos en los que no se normalizó la cifra de Tg (grupo II). Resultados. Se encontraron 130 pacientes (17,93 %) con niveles elevados de Tg y rastreos negativos. Grupo I: 31 pacientes (4,28 %), 11 hombres y 20 mujeres; edad media en el momento del diagnóstico de 33,4 años (rango: 5-60 años); seguimiento medio: 12,4 años (+/-7,4). Histología: 27 tumores papilares, 4 foliculares. Dosis media de ablación 3,260 GBq (88,1 mCi); dosis total media de 131I 6,850 GBq (185,13 mCi). Normalización de la Tg en una media de 8,2 años. Grupo II: 99 pacientes (13,65 %), 27 hombres y 72 mujeres; edad media de 40,4 años (rango 7-76); seguimiento medio: 9,8 años (rango 2-28 años). Histología: 86 tumores papilares y 13 tumores foliculares. Dosis media de ablación de 3,266 GBq (88,28 mCi) y dosis total media de 9,363 GBq (253,06 mCi). Dos de los pacientes del grupo I presentaron fluordesoxiglucosa-F18 (PETFDG) negativo. Se detectaron 13 pacientes en los que se constató un descenso progresivo de los niveles de Tg sin llegar a la normalización con PET-FDG negativo. Conclusiones. En pacientes con CDT irradiado, es posible la normalización diferida de los niveles de la Tg. Los tratamientos empíricos no pueden ser considerados como único factor que contribuye a este resultado

Objective. To verify the existence of patients with treated differentiated thyroid cancer (DTC) with negative 131I whole-body scanning (WBS) and high serum thyroglobulin (Tg) in the follow-up who evolve towards normalization without other therapy interventions. Material and methods. Retrospective revision of the periodic examinations established in the protocol for patients with DTC, analyzing the levels of Tg found with IRMA annually in those with hormonal treatment and every 1-5 years in absence of previous hormonal treatment to WBS. Minimum surveillance of 2 years. Those who had elevated levels of Tg and WBS and other negative imaging tests in their course were selected. The characteristics of the patients selected were analysed in those whose Tg levels evolved to normalization without specific medical or surgical treatment (Group I) and those who did not reach normalization of Tg (Group II). Results. A total of 130 patients (17.93 %) with high levels of Tg and negative WBS were detected. Group I: 31 patients (4.28 %), 11 men and 20 women; average age at the moment of the diagnosis of 33.4 years (rank: 5-60); average surveillance: 12.4 years (+/-7.4). Histology: 27 papillary and 4 follicular carcinoma. Average ablation dose: 3.260 GBq (88,1 mCi); average total I131 dose: 6.850 GBq (185.13 mCi). Tg normalization average time: 8.2 years. Group II: 99 patients (13.65 %), 27 men and 72 women. Average age of 40.4 years (rank: 7-76). Average surveillance: 9.8 years. Histology: 86 papillary and 13 follicular carcinoma. Average ablation dose: 3.266 GBq (88.28 mCi); average total 131I dose: 9.363 GBq (253,06 mCi). Two of the patients in group I had negative PET-FDG. There were 13 patients in whom progressive reduction of the levels of thyroglobulin without reaching normalization with negative PET-FDG was detected. Conclusions. In patients with radiated DTC, deferred normalization of the levels of the serum thyroglobulin is possible. Empirical treatments cannot be considered the only factor that contributes to this result, which can occur without the administration of high-doses of 131I

[Patients treated for differentiated thyroid cancer with negative 131I whole-body scans and elevated thyroglobulin levels: a possible course]. / Pacientes tratados por carcinoma diferenciado de tiroides con rastreos de 131I negativos y niveles de tiroglobulina elevada. Una evolución posible.

OBJECTIVE: To verify the existence of patients with treated differentiated thyroid cancer (DTC) with negative 131I whole-body scanning (WBS) and high serum thyroglobulin (Tg) in the follow-up who evolve towards normalization without other therapy interventions. MATERIAL AND METHODS: Retrospective revision of the periodic examinations established in the protocol for patients with DTC, analyzing the levels of Tg found with IRMA annually in those with hormonal treatment and every 1-5 years in absence of previous hormonal treatment to WBS. Minimum surveillance of 2 years. Those who had elevated levels of Tg and WBS and other negative imaging tests in their course were selected. The characteristics of the patients selected were analysed in those whose Tg levels evolved to normalization without specific medical or surgical treatment (Group I) and those who did not reach normalization of Tg (Group II). RESULTS: A total of 130 patients (17.93 %) with high levels of Tg and negative WBS were detected. Group I: 31 patients (4.28 %), 11 men and 20 women; average age at the moment of the diagnosis of 33.4 years (rank: 5-60); average surveillance: 12.4 years (+/- 7.4). HISTOLOGY: 27 papillary and 4 follicular carcinoma. Average ablation dose: 3.260 GBq (88,1 mCi); average total I131 dose: 6.850 GBq (185.13 mCi). Tg normalization average time: 8.2 years. Group II: 99 patients (13.65 %), 27 men and 72 women. Average age of 40.4 years (rank: 7-76). Average surveillance: 9.8 years. HISTOLOGY: 86 papillary and 13 follicular carcinoma. Average ablation dose: 3.266 GBq (88.28 mCi); average total 131I dose: 9.363 GBq (253,06 mCi). Two of the patients in group I had negative PET-FDG. There were 13 patients in whom progressive reduction of the levels of thyroglobulin without reaching normalization with negative PET-FDG was detected. CONCLUSIONS: In patients with radiated DTC, deferred normalization of the levels of the serum thyroglobulin is possible. Empirical treatments cannot be considered the only factor that contributes to this result, which can occur without the administration of high-doses of 131I.