The role of 18FDG, 18FDOPA PET/CT and 99mTc bone scintigraphy imaging in Erdheim-Chester disease.

Erdheim-Chester disease (ECD) is a rare non-Langerhans cell histiocitosis, characterized by multisystemic xanthogranulomatous infiltration by foamy histiocytes that stain positively for CD68 marker but not express CD1a and S100 proteins. Etiology and pathogenesis are still unknown and only about 500 cases are related in the literature. Multisystemic involvement leads to a wide variety of clinical manifestations that results in a poor prognosis although recent advances in treatment. We present the clinical, nuclear medicine findings and therapeutic aspects of a serie of 6 patients with histopathological diagnosis of ECD, who have undergone both bone scintigraphy (BS) and 18F-fluorodeoxyglucose (18FDG)-PET/CT scans in our institution. A complementary 18F-fluorodopa (18FDOPA)-PET/CT was performed in one case. Three different presentations of the disease were observed in our casuistic: most indolent form was a cutaneous confined disease, presented in only one patient. Multifocal involvement with central nervous system (CNS) preservation was observed in two patients. Most aggressive form consisted in a systemic involvement with CNS infiltration, presented in three patients. In our experience neurological involvement, among one case with isolate pituitary infiltration, was associated with mortality in all cases. 18FDG-PET/CT and BS were particularly useful in despite systemic involvement; locate the site for biopsy and the treatment response evaluation. By our knowledge, 18FDOPA-PET/CT not seems useful in the initial staging of ECD. A baseline 18FDG-PET/CT and BS may help in monitoring the disease and could be considered when patients were incidentally diagnosed and periodically 18FDG-PET/CT must be performed in the follow up to evaluate treatment response.

123I-MIBG, 18F-DOPA y 18F-FDG en una paciente con síndrome de neoplasia endocrina múltiple tipo 2 y recidiva de feocromocitoma / 123I-MIBG, 18F-DOPA and 18F-FDG in a patient with MEN2 syndrome and recurrent pheochromocytoma

El feocromocitoma es un tumor poco frecuente localizado en la médula de la glándula adrenal y caracterizado por una elevada síntesis de catecolaminas. La cirugía es el tratamiento de elección y es potencialmente curativa si se diagnostica y reseca adecuadamente. Los métodos de diagnóstico por imagen, tanto morfológica como funcional, son de gran importancia en la evaluación prequirúrgica. Se presenta el caso de una paciente con síndrome de neoplasia endocrina múltiple tipo 2 con suprarrenalectomía bilateral por sendos feocromocitomas y elevación progresiva de la metanefrina urinaria. En la resonancia magnética realizada se observó una imagen nodular en la fosa suprarrenal derecha, por lo que se remitió a nuestra unidad con el objetivo de confirmar la sospecha de recidiva. Dada la ausencia de hallazgos patológicos en la gammagrafía con 123I-MIBG y ante la alta sospecha de recidiva se realizaron estudios PET/TAC con 18F-DOPA y 18F-FDG que confirmaron el diagnóstico(AU)

Pheochromocytoma is a rare tumor located in the medulla of the adrenal gland that is characterized by high catecholamine synthesis. Surgery is the treatment of choice and is usually curative if appropriately diagnosed and excised. Imaging methods, both morphological and functional, are of great importance in presurgical evaluation. We report the case of a female patient with multiple endocrine neoplasia syndrome type 2, with bilateral adrenalectomy due to two pheochromocytomas and progressive elevation of urinary metanephrine. Magnetic resonance imaging showed a nodular image in the right adrenal fossa. The patient was referred to our unit in order to confirm suspicion of recurrence. Due to the absence of pathological findings in the 123I-MIBG scintigraphy and high suspicion of recurrence, PET/CT imaging with 18F-DOPA and 18F-FDG were performed, and the diagnosis was confirmed(AU)

123I-MIBG, 18F-DOPA and 18F-FDG in a patient with MEN2 syndrome and recurrent pheochromocytoma.

Pheochromocytoma is a rare tumor located in the medulla of the adrenal gland that is characterized by high catecholamine synthesis. Surgery is the treatment of choice and is usually curative if appropriately diagnosed and excised. Imaging methods, both morphological and functional, are of great importance in presurgical evaluation. We report the case of a female patient with multiple endocrine neoplasia syndrome type 2, with bilateral adrenalectomy due to two pheochromocytomas and progressive elevation of urinary metanephrine. Magnetic resonance imaging showed a nodular image in the right adrenal fossa. The patient was referred to our unit in order to confirm suspicion of recurrence. Due to the absence of pathological findings in the (123)I-MIBG scintigraphy and high suspicion of recurrence, PET/CT imaging with (18)F-DOPA and (18)F-FDG were performed, and the diagnosis was confirmed.

[Unsuspected bronchial carcinoid tumor detected in a somatostatin receptor scintigraphy in a patient with multiple endocrine neoplasia syndrome type 1 and hypergastrinemia]. / Hallazgo incidental de un tumor carcinoide bronquial en gammagrafía de receptores de somatostatina de paciente con síndrome de neoplasia endocrina múltiple tipo 1 e hipergastrinemia.

Multiple Endocrine Neoplasia type 1 syndrome (MEN1) is characterized by the presence of tumors in parathyroid glands, anterior pituitary gland, endocrine pancreas and duodenum. However, other tumors may also occur. One of them is the carcinoid tumor, which in this context, is more common in the gastrointestinal tract. Less common is the presence of carcinoid tumors of bronchial origin, which with histologic confirmation, may occur in 5-8% of cases and that appears more frequently in patients with hypergastrinemia. We report a patient with MEN1 syndrome, hypergastrinemia and an incidental finding in a somatostatin receptor scintigraphy of an unsuspected bronchial carcinoid tumor that was confirmed histologically.

[Evaluation of efficacy and clinical impact of 18F-FDG-PET in the diagnosis of recurrent medullary thyroid cancer with increased calcitonin and negative imaging test]. / Evaluación de la eficacia y del impacto clínico de la PET-18F-FDG en el diagnóstico de recurrencia del carcinoma medular de tiroides con calcitonina elevada y pruebas de imagen negativas.

AIM: To evaluate the efficacy and clinical impact of the FDG-PET in the diagnosis of suspicion of recurrence of medullary thyroid cancer (MTC) in patients with elevated serum calcitonin and negative imaging test. MATERIAL AND METHODS: We performed a retrospective study of 31 consecutive cases from february 2001 to october 2007 of 17 women and 14 men, mean age 56.2 years (range: 26-88), with anatomical-pathology diagnosis of medullary thyroid cancer and suspicion of recurrence due to abnormal elevation of calcitonin and negative imaging tests. All of the patients underwent whole body FDG-PET scan with a dedicated PET or PET-CT 60 minutes after intravenous injection of 333-434 MBq of (18)F-FDG. Results were confirmed by pathology study in 45.2% of the patients and by clinical follow-up with a mean of 4 years (range: 16 m-8 years) RESULTS: Sensitivity was 88%, specificity 84.6%, positive predictive value 88%, negative predictive value 84.6% and diagnostic accuracy 87%. The results of the FDG PET modified the therapeutic strategy in 14 cases (45.2%). A comparison was made of the mean values of calcitonin using the Student's "t" test between positive PET studies for the disease and negative ones. No significant differences were found (P=.3). CONCLUSIONS: In patients with MTC and suspected recurrence with elevated calcitonin and negative imaging test, the FDG is the best test for the diagnosis of occult recurrence in MTC with elevated calcitonin and negative imaging techniques with elevated clinical impact. It facilitates the therapeutic management of the patients with MTC recurrence, and should be included in the diagnosis algorithm in these patients.

Value of the negative PET-FDG in the middle term follow-up of differentiated thyroid cancer in patients with negative 131 I-Na scan and elevated thyroglobulin serum levels.

OBJECTIVE: This study has aimed to analyze the evolution of patients diagnosed with differentiated thyroid carcinoma (DTC) with a negative (131)I-Na whole body scan (WBS), high levels of serum thyroglobulin (Tg) and negative (18F)fluorodeoxyglucose positron emission tomography (PET-FDG) study. MATERIAL AND METHODS: Twenty-three patients diagnosed and treated for DTC were studied retrospectively. Patients were aged between 23 and 83 and had shown, between January 2001 and December 2002, negative WBS, Tg values in a range of suspected recurrence or metastasis (Tg>2 ng / mL with thyroid hormone withdrawal) and a negative PET-FDG study. The patients were monitored clinically, radiologically and analytically for a minimum period of 4 years. After this, a new evaluation was made of their state of disease with a control WBS, also observing the evolution of Tg. All WBS were performed with a 185 MBq diagnostic dose of (131)I-Na. RESULTS: In 18/23 patients, Tg decreased and in 5 it increased. Four patients (17%) were free of active disease (negative WBS Tg<2 ng / mL). A total of 16 patients (70%) were free of disease according to the WBS but had elevated Tg. Three patients (13%) had disease and high levels of Tg, two of them with positive WBS and the third with (99m)Tc-MIBI scan and CT positive. CONCLUSIONS: Most patients with a negative WBS, high Tg serum levels and negative FDG PET had good evolution, with descending Tg levels, normal levels even being reached in a significant percentage of them.

[Clinical impact of FDG-PET in patients with suspected recurrent ovarian cancer]. / Impacto clínico de la PET-FDG en pacientes con sospecha de recurrencia de cáncer de ovario.

AIM: To evaluate the efficacy and clinical impact of FDG-PET in patients with suspected recurrent ovarian cancer. METHODS: Between October 2001 and October 2006, we retrospectively studied 49 FDG-PET performed in 40 women (age: 52.4 +/- 12.2 years) with ovarian cancer, who had suspicion of recurrent disease by positive morphologic imaging tests (MIT) or increased tumour markers and negative MIT. All patients underwent whole body FDG-PET after the injection of 370-434 MBq of (18)FDG. The results were confirmed by histology in 31 cases, and by clinical-radiological follow-up in 18. RESULTS: Prevalence of disease was 79.6 %. We obtained a global sensitivity and positive predictive value of 87.2 % and 87.2 %, and an accuracy of 79.6 %. Results led to a change in the patient's management in 25 cases (51 %). Subgroup results were: Sensitivity of 81.8 % in patients with increased tumour markers and negative MIT, and 89.3 % in patients with operable malignant lesions. CONCLUSIONS: FDG-PET has high sensitivity and clinical impact in patients with suspicion of recurrent ovarian cancer. Better results were obtained in patients with increased tumour markers and negative MIT.

Impacto clínico de la PET-FDG en pacientes con sospecha de recurrencia de cáncer de ovario / Clinical impact of FDG-PET in patients with suspected recurrent ovarian cancer

Objetivo. Evaluar la eficacia y el impacto clínico de la PET-18FDG en las pacientes con sospecha de recidiva de cáncer de ovario. Método. Entre octubre de 2001 y octubre de 2006, estudiamos de forma retrospectiva 49 exploraciones PET-FDG realizadas a 40 mujeres (edad: 52,4 ± 12,2 años) diagnosticadas de carcinoma de ovario, en las que se sospechaba recurrencia de su enfermedad bien por técnicas morfológicas (medios diagnósticos convencionales [MDC]), bien por elevación de marcadores tumorales (MMTT) con MDC negativas. A todas se les realizó PET corporal tras la inyección de 370-434 MBq de 18FDG. Los resultados se confirmaron por anatomía patológica en 31 pacientes y por seguimiento clínico/radiológico en 18. Resultados. La prevalencia de enfermedad en la muestra estudiada fue del 79,6 %. Se obtuvieron una sensibilidad y un valor predictivo positivo globales del 87,2 y 87,2 %, y una exactitud diagnóstica del 79,6 %. Los resultados de los estudios indujeron un cambio en el manejo terapéutico en 25 casos (51 %). La sensibilidad fue del 81,8 % en el subgrupo de pacientes con elevación de MMTT y MDC negativas, y del 89,3 % en el de pacientes con lesiones susceptibles de cirugía con intención curativa. Conclusiones. La PET-18FDG tiene una alta sensibilidad e impacto clínico en la sospecha de recurrencia de carcinoma de ovario, obteniéndose los mejores resultados en el subgrupo de pacientes con MMTT elevados y MDC negativos

Aim. To evaluate the efficacy and clinical impact of FDG-PET in patients with suspected recurrent ovariancancer. Methods. Between October 2001 and October 2006, we retrospectively studied 49 FDG-PET performed in 40 women (age: 52.4 ± 12.2 years) with ovarian cancer, who had suspicion of recurrent disease by positive morphologic imaging tests (MIT) or increased tumour markers and negative MIT. All patients underwent whole body FDG-PET after the injection of 370-434 MBq of 18FDG. The results were confirmed by histologyin 31 cases, and by clinical-radiological follow-up in 18. Results. Prevalence of disease was 79.6%. We obtained a global sensitivity and positive predictive value of 87.2 % and 87.2 %, and an accuracy of 79.6 %. Results led to a change in the patient’s management in 25 cases (51 %). Subgroup results were: Sensitivity of 81.8 % in patients with increased tumour markers and negative MIT, and 89.3 % in patients with operable malignant lesions. Conclusions. FDG-PET has high sensitivity and clinical impact in patients with suspicion of recurrent ovarian cancer. Betterresults were obtained in patients with increased tumourmarkers and negative MIT

[Bone metastases from unknown primary. FDG-PET detection of two synchronous tumors]. / Metástasis óseas de tumor primario desconocido. Detección mediante PET-FDG de dos tumores sincrónicos.

A 60-year-old woman presented with noncardiac chest pain over months and negative laboratory findings. Conventional imaging methods and bone scintigraphy detected bone lesions suggesting metastatic disease from an unknown primary tumor. An 18FDG-PET scan performed to orient the search for the primary tumor found focal lesions suggesting lymphoma and identified a focal thyroid lesion and a cervical lymph node accessible for biopsy. The biopsy of this lymph node incidentally detected a papillary differentiated thyroid cancer (DTC), since the existence of a non-Hodgkin's lymphoma was confirmed after a new biopsy. After confirming the presence of a lymphoma, 18FDG-PET enabled the initial staging of the tumor, the evaluation of the response to treatment, and follow-up for detection of recurrence. On the other hand, 18FDG-PET incidentally detected a DTC.

Metástasis óseas de tumor primario desconocido. Detección mediante PET-FDG de dos tumores sincrónicos / Bone metastases from unknown primary. Fdg-pet detection of two sincronic tumors

Paciente mujer de 60 años con dolor torácico características mecánicas de meses de evolución y determinaciones analíticas dentro de la normalidad. Los estudios morfológicos y la gammagrafía ósea detectaron lesiones óseas sugestivas de afectación metastásica de un tumor de origen desconocido, por lo que se solicitó una exploración con tomografía por emisión de positrones con 2-18F-fluoruro-2-deoxi- D-glucosa (PET-FDG) con el objetivo de orientar la búsqueda del tumor primario. El estudio se informó como lesiones hipermetabólicas sugestivas de linfoma, mencionando la presencia de una lesión tiroidea hipermetabólica y de una adenopatía cervical accesible para la toma de biopsia. Dicha adenopatía detectó de forma incidental un cáncer diferenciado de tiroides (CDT) papilar, ya que posteriormente se confirmó la existencia de un linfoma no-Hodgkin tras la toma de una nueva biopsia. La PET-FDG, tras confirmar la existencia de un linfoma, permitió su estadificación inicial, así como valorar la respuesta al tratamiento y realizar su seguimiento. Por otro lado, detectó de forma incidental la existencia de un CDT

A 60-year-old woman presented with noncardiac chest pain over months and negative laboratory findings. Conventional imaging methods and bone scintigraphy detected bone lesions suggesting metastatic disease from an unknown primary tumor. An 18FDG-PET scan performed to orient the search for the primary tumor found focal lesions suggesting lymphoma and identified a focal thyroid lesion and a cervical lymph node accessible for biopsy. The biopsy of this lymph node incidentally detected a papillary differentiated thyroid cancer (DTC), since the existence of a non-Hodgkin’s lymphoma was confirmed after a new biopsy. After confirming the presence of a lymphoma, 18FDG-PET enabled the initial staging of the tumor, the evaluation of the response to treatment, and follow-up for detection of recurrence. On the other hand, 18FDG-PET incidentally detected a DTC