The role of positron emission tomography/computed tomography imaging with radiolabeled choline analogues in prostate cancer.

INTRODUCTION: prostate cancer is the most frequent solid malignant tumor in Western Countries. Positron emission tomography/x-ray computed tomography imaging with radiolabeled choline analogues is a useful tool for restaging prostate cancer in patients with rising prostate-specific antigen after radical treatment (in whom conventional imaging techniques have important limitations) as well as in the initial assessment of a selected group of prostate cancer patients. For this reason a literature review is necessary in order to evaluate the usefulness of this imaging test for the diagnosis and treatment of prostate cancer. EVIDENCE ACQUISITION: a MEDLINE (PubMed way) literature search was performed using the search parameters: «Prostate cancer¼ and «Choline-PET/CT¼. Other search terms were «Biochemical failure¼ and/or «Staging¼ and/or «PSA kinetics¼. English and Spanish papers were selected; original articles, reviews, systematic reviews and clinical guidelines were included. CONCLUSIONS: according to available data, radiolabeled choline analogues plays an important role in the management of prostate cancer, especially in biochemical relapse because technique accuracy is properly correlated with prostate-specific antigen values and kinetics. Although is an emerging diagnostic technique useful in treatment planning of prostate cancer, final recommendations have not been submitted.

Falso negativo de la gammagrafía con 99mTc-sestamibi en un carcinoma paratiroideo con tumores pardos asociados. Aportaciones de la PET/TAC-18F-FDG / False negative of the scintigraphy with 99mTc-sestamibi in parathyroid carcinoma with associated brown tumors. Contributions of the 18F-FDG-PET/CT

El carcinoma paratiroideo (CPT) es un tumor poco frecuente que suele ser hiperfuncionante, produciendo un exceso de hormona paratiroidea. El hiperparatiroidismo produce trastornos del metabolismo óseo, como osteopenia y en ocasiones tumores pardos. Los tumores pardos son lesiones óseas benignas, pero localmente destructivas, cuyo diagnóstico diferencial con metástasis u otros tipos de tumores primarios puede ser complicado. La técnica habitual para la detección de patología paratiroidea es la gammagrafía con 99mTc-sestamibi, con una sensibilidad del 85–100% y una especificidad cercana al 100% en adenomas paratiroideos, presentando cifras muy similares en la detección del CPT. Presentamos el caso de un paciente diagnosticado de hiperparatiroidismo de origen tumoral con lesiones óseas asociadas en el que la gammagrafía con 99mTc-sestamibi presentó un falso negativo en la detección de patología paratiroidea. Sin embargo, la PET/TAC-18F-FDG detectó el CPT y ayudó en el diagnóstico diferencial de las lesiones óseas asociadas, que fueron finalmente tumores pardos(AU)

Parathyroid carcinoma (PTC) is a rare malignant disease that is usually hyperfunctioning, which produces an excess of parathyroid hormone. Hyperparathyroidism causes bone metabolism disorders, as osteopenia and sometimes brown tumors. Brown tumors are benign but locally aggressive bone lesions, whose differential diagnosis with metastases or other primary malignancies may be complicated. 99mTc-Sestamibi scan is the usual procedure for the detection of parathyroid pathology, with a sensitivity of 85–100% and specificity close to 100% in parathyroid adenomas, it having similar percentages in the detection of PTC. We present the case of a patient diagnosed of a malignant hyperparathyroidism associated with bone lesions in which the 99mTc-Sestamibi scan showed a false negative result in the detection of parathyroid condition. However, 18F-FDG-PET/CT detected the PTC and helped in the differential diagnosis of associated bone lesions, which were finally confirmed as brown tumors(AU)

[False negative of the scintigraphy with 99mTc-sestamibi in parathyroid carcinoma with associated brown tumors. Contributions of the 18F-FDG-PET/CT]. / Falso negativo de la gammagrafía con 99mTc-sestamibi en un carcinoma paratiroideo con tumores pardos asociados. Aportaciones de la PET/TAC-18F-FDG.

Parathyroid carcinoma (PTC) is a rare malignant disease that is usually hyperfunctioning, which produces an excess of parathyroid hormone. Hyperparathyroidism causes bone metabolism disorders, as osteopenia and sometimes brown tumors. Brown tumors are benign but locally aggressive bone lesions, whose differential diagnosis with metastases or other primary malignancies may be complicated. (99m)Tc-Sestamibi scan is the usual procedure for the detection of parathyroid pathology, with a sensitivity of 85-100% and specificity close to 100% in parathyroid adenomas, it having similar percentages in the detection of PTC. We present the case of a patient diagnosed of a malignant hyperparathyroidism associated with bone lesions in which the (99m)Tc-Sestamibi scan showed a false negative result in the detection of parathyroid condition. However, (18)F-FDG-PET/CT detected the PTC and helped in the differential diagnosis of associated bone lesions, which were finally confirmed as brown tumors.

Displasia fibrosa ósea. Aportación de la Medicina Nuclear al diagnóstico de sospecha de degeneración sarcomatosa / Fibrous dysplasia of the bone. Contribution of Nuclear Medicine in the diagnosis of suspicion of sarcomatous degeneration

La displasia fibrosa (DF) es una enfermedad benigna del hueso relativamente frecuente, en la que existe un trastorno de la maduración del mesénquima óseo con sustitución del tejido lamelar de la cavidad medular de los huesos por un tejido fibroso anómalo. Su diagnóstico a menudo es un hallazgo casual al realizar estudios radiológicos o gammagráficos óseos por otros motivos ya que normalmente es asintomática. En ocasiones puede presentar complicaciones como deformidades, fracturas patológicas y excepcionalmente transformación maligna. El diagnóstico diferencial entre DF y neoplasia maligna puede ser complicado y llevar a un diagnóstico tardío de cuando ya existe degeneración sarcomatosa. En este contexto, la tomografía de positrones con 18F-fluorodesoxiglucosa (PET-FDG) puede ser de utilidad en el seguimiento de esta patología. Presentamos 2 casos de pacientes diagnosticadas de DF con sospecha de malignización de sus lesiones y a las que se les solicitaron estudios complementarios de medicina nuclear(AU)

Fibrous dysplasia (FD) is a relatively frequent benign disease of the bone in which there is a maturation disorder of the bone-forming mesenchyme where the lamellar bone marrow is replaced with abnormal fibrous tissue. Its diagnosis is often an accidental finding when X-ray studies or bone scans are performed for other reasons since it is usually asymptomatic. There may be complications such as deformities, pathological fractures and exceptionally malignant transformation. The differential diagnosis between malignancy and FD can be complicated and lead to late diagnosis when sarcomatous degeneration already exists. In this context, the positron tomography with 18F-fluorodeoxyglucose (FDG-PET) may be useful in the monitoring of this condition. We present two cases of patients diagnosed of FD with suspicion of malignization of their bone lesions who were referred to Nuclear Medicin(AU)

[Perivascular epithelioid tumors: Utility of the positron emission tomography with 18F-fluorodesoxyglucose (PET-TAC FDG) in their staging and follow-up]. / Tumor epitelioide perivascular uterino. Utilidad de la tomografía por emisión de positrones con (18)F-fluordesoxiglucosa en su estadificación y seguimiento.

Perivascular epithelioid tumors (PEComas) are a rare group of mesenchymal neoplasms with an unpredictable natural history and uncertain malignant potential. Uterine involvement and their association with tuberous sclerosis are typical for these tumors. We present a case of a 40-year old patient who was incidentally diagnosed of a uterine PEComa and serial studies of PET-CT with FDG were performed for staging and therapeutic response assessment. FDG PET-CT proved to be a valuable tool for detecting unsuspected pulmonary metastases and defining the reassessment of the patient after chemotherapy. The findings suggest that since this is a rare tumor, which does not always have benign behaviour, PET-CT may be a useful diagnostic imaging procedure for staging and clinical monitoring of patients who suffer this type of tumors.

[Fibrous dysplasia of the bone. Contribution of nuclear medicine in the diagnosis of suspicion of sarcomatous degeneration]. / Displasia fibrosa ósea. Aportación de la Medicina Nuclear al diagnóstico de sospecha de degeneración sarcomatosa.

Fibrous dysplasia (FD) is a relatively frequent benign disease of the bone in which there is a maturation disorder of the bone-forming mesenchyme where the lamellar bone marrow is replaced with abnormal fibrous tissue. Its diagnosis is often an accidental finding when X-ray studies or bone scans are performed for other reasons since it is usually asymptomatic. There may be complications such as deformities, pathological fractures and exceptionally malignant transformation. The differential diagnosis between malignancy and FD can be complicated and lead to late diagnosis when sarcomatous degeneration already exists. In this context, the positron tomography with (18)F-fluorodeoxyglucose (FDG-PET) may be useful in the monitoring of this condition. We present two cases of patients diagnosed of FD with suspicion of malignization of their bone lesions who were referred to Nuclear Medicin.