99mTC-white blood cell scintigraphy with SPECT/CT in the diagnosis of vascular graft infection. / Gammagrafía con leucocitos marcados y SPECT/TC en el diagnóstico de infección de prótesis vasculares.

AIM: Vascular graft infection is a rare complication with a high morbidity and mortality. Early diagnosis is essential to establish an adequate treatment. We assess the accuracy of 99mTc-WBC scintigraphy with SPECT/CT in the diagnosis of vascular graft infection. MATERIALS AND METHODS: We retrospectively analyzed thirty 99mTc-WBC scintigraphies with SPECT/CT performed in thirty patients with suspicion of vascular prosthesis infection. Studies were considered positive for graft infection if the intensity of activity involving the graft was greater than the liver or bone marrow activity (spine and pelvis). RESULTS: Final diagnosis of infection was established in 10 patients, based on Fitzgerald criteria. Scintigraphy was positive in 11 patients. No false negatives were obtained. The values of sensitivity and specificity were 100% and 95%, respectively, with a PPV of 91% and a NPV of 100%. Twenty five patients had a CT performed prior to scintigraphy, in 9 cases the result was positive and in the remaining 16 was negative. CT sensitivity and specificity obtained in our study were 62.5% and 76% respectively, with a PPV of 55.6% and a NPV of 81.3%. Diagnosis of infection led to prosthesis exeresis in 8 cases (all of them had a positive microbiological study of the extracted material), while the remaining 2 patients were treated with antibiotic therapy alone due to high surgical risk. CONCLUSION: Our results suggest a high accuracy for 99mTc-WBC scintigraphy with SPECT/CT in the assessment of clinically suspected arterial graft infection.

[Complete hormonal and metabolic response after iodine-131 metaiodobenzylguanidine treatment in a patient diagnosed of malignant pheochromocytoma]. / Respuesta hormonal y metabólica completa tras el tratamiento con yodo-131 metayodobencilguanidina en un caso de feocromocitoma maligno.

Radiolabeled metaiodobenzylguanidine is an analogue of norepinephrine used to localize tumors that express the neurohormone transporters, specifically those derived from the neural crest having a neuroendocrine origin. It is also used to treat non-surgical metastases derived from them. A review of the literature revealed symptomatic improvements associated to a decrease in hormone levels in a significant percentage of patients after (131)I-MIBG treatment. However, complete tumor remission has been described only in very few cases and hardly ever when bone metastases exist. We present a case of a patient diagnosed of malignant pheochromocytoma who achieved complete hormonal and metabolic response after (131)I-MIBG treatment (600 mCi) in spite of the presence of bone metastases.

Pancreatic and thyroid metastases detected with 18F-FDG PET/CT in patient with colorectal cancer.

A 53-year-old woman with diagnosis of colorectal cancer, who received surgical treatment and chemotherapy. After 5-years of complete remission, she showed an atypical oncological evolution. The utility of (18)F-FDG PET/CT scan has been fundamental to detect suspected and unsuspected recurrence and to monitor response to treatment.

[Iodine uptake in the chest in the follow-up of well-differentiated thyroid cancer]. / Captación torácica de (131)I en el seguimiento del cáncer diferenciado de tiroides.

Differentiated thyroid cancer is a disease having a very good prognosis when treated adequately. Ablation treatment with (131)I is frequently adjunct to surgery in these patients since it improves survival. Radioiodine whole-body scan is one of the imaging modality of choice in the follow-up of patients with this kind of pathology. After ablation treatment of the thyroid gland, any radioiodine accumulation in a non-physiological location usually means the presence of functioning metastasis. Recognition of potential false-positives is essential to avoid unnecessary exposure to further radiation from repeated therapeutic doses of radioactive iodine. We report a case of uptake in the chest due to bronchiectasis, potentially masquerading as pulmonary metastasis.

[Non-invasive diagnosis of posttraumatic thoracic splenosis]. / Diagnóstico no invasivo de la esplenosis torácica postraumática.

Intrathoracic splenosis is a generally asymptomatic entity incidentally diagnosed after the completion of an Rx, CT scan or MRI for another reason. The performance of scintigraphy with (99m)Tc-labelled heat-denatured erythrocytes allows the noninvasive diagnosis of this entity and avoids more aggressive diagnostic techniques such as FNAP or thoracotomy. Because this splenic tissue may be partially or fully functioning and therefore may have some beneficial immune function for the patient, the management of this entity should be conservative. Radioisotopic scintigraphy with (99m)Tc labelled heat-denatured erythrocytes is the technique with the greatest specificity in the demonstration of splenic tissue. The presence of subpleural pulmonary nodules, associated or not with intra-abdominal nodules, together with the existence of previous partial or total splenectomy, traumatic or not, with or without associated rupture of the diaphragm, should raise suspicion of the presence of intrathoracic splenosis.

Gammagrafía con leucocitos marcados y SPECT/TC en el diagnóstico de infección de prótesis vasculares / 99mTC-white blood cell scintigraphy with SPECT/CT in the diagnosis of vascular graft infection

OBJETIVO: La infección de las prótesis vasculares es una complicación temible por su alta morbimortalidad, en la que el diagnóstico precoz es imprescindible. Evaluamos la utilidad de la gammagrafía con leucocitos marcados con 99mTc-HMPAO y SPECT/TC (GLM-SPECT/TC) en el diagnóstico de esta patología. MATERIALES Y MÉTODOS: Analizamos retrospectivamente 30 GLM-SPECT/TC realizadas en pacientes con sospecha de infección de prótesis vasculares. Se consideró como resultado positivo la captación del radiofármaco en el área protésica con una intensidad superior a la del hígado o la médula ósea de raquis y pelvis. RESULTADOS: El diagnóstico final de infección, basado en los criterios de Fitzgerald, se estableció en 10pacientes, siendo la gammagrafía positiva en 11. No se obtuvieron falsos negativos. Los valores de sensibilidad y especificidad fueron 100% y 95%, respectivamente, con un VPP del 91% y un VPN del 100%. Veinticinco pacientes contaban también con un TC previo a la gammagrafía, que en 9 de los casos fue positivo (4FP). Los resultados de sensibilidad y especificidad del TC fueron del 62,5% y del 76%, con un VPP del 55,6% y un VPN del 81,3%. El diagnóstico de infección conllevó la exéresis del material protésico en 8 casos (todos ellos con confirmación microbiológica), mientras que los 2 restantes fueron tratados únicamente con antibioterapia debido a un alto riesgo quirúrgico. CONCLUSIONES: La GLM-SPECT/TC es una prueba de gran utilidad que presenta una alta precisión diagnóstica en la sospecha de infección de prótesis vasculares

AIM: Vascular graft infection is a rare complication with a high morbidity and mortality. Early diagnosis is essential to establish an adequate treatment. We assess the accuracy of 99mTc-WBC scintigraphy with SPECT/CT in the diagnosis of vascular graft infection. MATERIALS AND METHODS: We retrospectively analyzed thirty 99mTc-WBC scintigraphies with SPECT/CT performed in thirty patients with suspicion of vascular prosthesis infection. Studies were considered positive for graft infection if the intensity of activity involving the graft was greater than the liver or bone marrow activity (spine and pelvis). RESULTS: Final diagnosis of infection was established in 10 patients, based on Fitzgerald criteria. Scintigraphy was positive in 11 patients. No false negatives were obtained. The values of sensitivity and specificity were 100% and 95%, respectively, with a PPV of 91% and a NPV of 100%. Twenty five patients had a CT performed prior to scintigraphy, in 9 cases the result was positive and in the remaining 16 was negative. CT sensitivity and specificity obtained in our study were 62.5% and 76% respectively, with a PPV of 55.6% and a NPV of 81.3%. Diagnosis of infection led to prosthesis exeresis in 8 cases (all of them had a positive microbiological study of the extracted material), while the remaining 2 patients were treated with antibiotic therapy alone due to high surgical risk. CONCLUSION: Our results suggest a high accuracy for 99mTc-WBC scintigraphy with SPECT/CT in the assessment of clinically suspected arterial graft infection

Clinical significance of abdominal scintigraphy using 99mTc-HMPAO-labelled leucocytes in patients with seronegative spondyloarthropathies.

Abdominal scintigraphy shows silent gut inflammation in patients with spondyloarthropathies (Sp) without clinical evidence of gut inflammation. Abdominal scintigraphy images are different than those obtained in patients with ulcerative colitis or Crohn's disease and are not related to the anti-inflammatory drugs administered. The aim of this study was to examine the clinical associations of findings on abdominal scintigraphy in patients with Sp. A total of 204 Sp patients (European Spondylarthropathy Study Group 1991 criteria) and 54 non-Sp controls receiving non-steroidal anti-inflammatory drugs were studied. Abdominal scintigraphy images were obtained at 30 and 120 min after injection of technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO)-labelled leucocytes. 99mTc-HMPAO-labelled leucocyte scans were positive in 104 Sp patients (50.9%) and in six non-Sp controls (2.9%) (P<0.001; OR=8.32; 95% CI=3.23-22.67). Silent gut inflammation was not associated with any of the following: age of onset, duration of evolution, sex, family history of Sp or psoriasis, articular manifestations, extra-articular manifestations, radiological findings or HLA-B27 positivity. Positive abdominal scintigraphy was associated with active disease (P < 0.0001; OR=52.7; 95% CI=19-145.6) and an increase in the C-reactive protein (P < 0.005; OR = 3.4; 95% CI = 1.5-7.4). It is concluded that (a) abdominal scintigraphy using 99mTc-HMPAO-labelled leucocytes is of value in detecting the silent gut inflammation in Sp patients, and (b) silent gut inflammation is related to the clinical activity, but is not associated with any particular type of illness or with HLA-B27.

Clinical significance of abdominal scintigraphy using (99m)Tc-HMPAO-labelled leucocytes in patients with seronegative spondyloarthropathies.

Abdominal scintigraphy shows silent gut inflammation in patients with spondyloarthropathies (Sp) without clinical evidence of gut inflammation. Abdominal scintigraphy images are different than those obtained in patients with ulcerative colitis or Crohn's disease and are not related to the anti-inflammatory drugs administered. The aim of this study was to examine the clinical associations of findings on abdominal scintigraphy in patients with Sp. A total of 204 Sp patients (European Spondylarthropathy Study Group 1991 criteria) and 54 non-Sp controls receiving non-steroidal anti-inflammatory drugs were studied. Abdominal scintigraphy images were obtained at 30 and 120 min after injection of technetium-99m hexamethylpropylene amine oxime ((99m)Tc-HMPAO)-labelled leucocytes. (99m)Tc-HMPAO-labelled leucocyte scans were positive in 104 Sp patients (50.9%) and in six non-Sp controls (2.9%) (P<0.001; OR=8.32; 95% CI=3.23-22.67). Silent gut inflammation was not associated with any of the following: age of onset, duration of evolution, sex, family history of Sp or psoriasis, articular manifestations, extra-articular manifestations, radiological findings or HLA-B27 positivity. Positive abdominal scintigraphy was associated with active disease (P<0.0001; OR=52.7; 95% CI=19-145.6) and an increase in the C-reactive protein (P<0.005; OR=3.4; 95% CI=1.5-7.4). It is concluded that (a) abdominal scintigraphy using (99m)Tc-HMPAO-labelled leucocytes is of value in detecting the silent gut inflammation in Sp patients, and (b) silent gut inflammation is related to the clinical activity, but is not associated with any particular type of illness or with HLA-B27.

Respuesta hormonal y metabólica completa tras el tratamiento con yodo-131 metayodobencilguanidina en un caso de feocromocitoma maligno / Complete hormonal and metabolic response after iodine-131 metaiodobenzylguanidine treatment in a patient diagnosed of malignant pheochromocytoma

La metayodobencilguanidina radiomarcada es un análogo de la norepinefrina que se utiliza en la localización de tumores que expresan transportadores de dicha neurohormona, especialmente los derivados de la cresta neural y de origen neuroendocrino, y en el tratamiento de sus metástasis cuando estas no son quirúrgicas. En la literatura revisada se encuentran mejorías sintomáticas, asociadas a un descenso de los niveles hormonales, en un porcentaje no despreciable de casos tras el tratamiento con 131I-MIBG. Sin embargo, la remisión tumoral completa se ha descrito en muy pocas ocasiones y casi nunca en presencia de metástasis óseas. Presentamos un caso de feocromocitoma maligno que tras el tratamiento con 131I-MIBG (600 mCi) alcanzó una respuesta hormonal y metabólica completa a pesar de la existencia de metástasis óseas (AU)

Radiolabeled metaiodobenzylguanidine is an analogue of norepinephrine used to localize tumors that express the neurohormone transporters, specifically those derived from the neural crest having a neuroendocrine origin. It is also used to treat non-surgical metastases derived from them. A review of the literature revealed symptomatic improvements associated to a decrease in hormone levels in a significant percentage of patients after 131I-MIBG treatment. However, complete tumor remission has been described only in very few cases and hardly ever when bone metastases exist. We present a case of a patient diagnosed of malignant pheochromocytoma who achieved complete hormonal and metabolic response after 131I-MIBG treatment (600 mCi) in spite of the presence of bone metastases (AU)

Metástasis pancreática y tiroidea detectadas con 18F-FDG PET/TAC en paciente con cáncer colorrectal / Pancreatic and thyroid metastases detected with 18F-FDG PET/CT in patient with colorectal cancer

Mujer de 53 años diagnosticada de cáncer colorrectal, quien recibió tratamiento quirúrgico y quimioterápico, tras 5 años de remisión completa presenta una evolución atípica de su patología oncológica. La utilidad de la PET/TAC con 18F-FDG ha sido fundamental para la detección de las recidivas, sospechadas y no sospechadas, y para la monitorización de la respuesta al tratamiento(AU)

A 53-year-old woman with diagnosis of colorectal cancer, who received surgical treatment and chemotherapy. After 5-years of complete remission, she showed an atypical oncological evolution. The utility of 18F-FDG PET/CT scan has been fundamental to detect suspected and unsuspected recurrence and to monitor response to treatment(AU)

Diagnóstico no invasivo de la esplenosis torácica postraumática / Non-invasive diagnosis of posttraumatic thoracic splenosis

La esplenosis intratorácica es una entidad generalmente asintomática que se diagnostica de forma incidental tras la realización de una radiografía, TAC o RM por otro motivo. La realización de una gammagrafía con hematíes desnaturalizados marcados con 99mTc permite el diagnóstico no invasivo de esta entidad y evita técnicas de diagnóstico más agresivas. Dado que este tejido esplénico puede ser parcial o totalmente funcionante, y por tanto tener cierta función inmunológica beneficiosa para el paciente (suficiente para brindar protección frente a la sepsis postesplenectomía), el manejo de esta entidad debe ser conservador. La técnica radioisotópica de gammagrafía con hematíes desnaturalizados marcados con 99mTc es la que presenta mayor especificidad para la demostración de tejido esplénico. La presencia de nódulos pulmonares subpleurales, asociados o no a nódulos intraabdominales, junto con la existencia de antecedentes de esplenectomía parcial o total, traumática o no, deben hacer sospechar la presencia de una esplenosis intratorácica(AU)

Intrathoracic splenosis is a generally asymptomatic entity incidentally diagnosed after the completion of an Rx, CT scan or MRI for another reason. The performance of scintigraphy with 99mTc-labelled heat-denatured erythrocytes allows the noninvasive diagnosis of this entity and avoids more aggressive diagnostic techniques such as FNAP or thoracotomy. Because this splenic tissue may be partially or fully functioning and therefore may have some beneficial immune function for the patient, the management of this entity should be conservative. Radioisotopic scintigraphy with 99mTc labelled heat-denatured erythrocytes is the technique with the greatest specificity in the demonstration of splenic tissue. The presence of subpleural pulmonary nodules, associated or not with intra-abdominal nodules, together with the existence of previous partial or total splenectomy, traumatic or not, with or without associated rupture of the diaphragm, should raise suspicion of the presence of intrathoracic splenosis(AU)

Captación torácica de 131I en el seguimiento del cáncer diferenciado de tiroides / Iodine uptake in the chest in the follow-up of well-differentiated thyroid cancer

El cáncer diferenciado de tiroides es una enfermedad con muy buen pronóstico si se trata adecuadamente. El tratamiento ablativo con 131I frecuentemente se asocia al tratamiento quirúrgico en estos pacientes ya que mejora la supervivencia, y el rastreo corporal total con 131I es una de las modalidades de diagnóstico de elección en el seguimiento de esta enfermedad. Tras tratamiento ablativo del tejido tiroideo, cualquier depósito del radiotrazador en una localización no fisiológica representa habitualmente la presencia de metástasis. Así pues, será fundamental el reconocimiento de cualquier posible falso positivo con el fin de evitar la radiación innecesaria debida a tratamientos inadecuados. Presentamos un caso clínico de captación torácica por bronquiectasias que puede malinterpretarse como metástasis pulmonar(AU)

Differentiated thyroid cancer is a disease having a very good prognosis when treated adequately. Ablation treatment with 131I is frequently adjunct to surgery in these patients since it improves survival. Radioiodine whole-body scan is one of the imaging modality of choice in the follow-up of patients with this kind of pathology. After ablation treatment of the thyroid gland, any radioiodine accumulation in a non-physiological location usually means the presence of functioning metastasis. Recognition of potential false-positives is essential to avoid unnecessary exposure to further radiation from repeated therapeutic doses of radioactive iodine. We report a case of uptake in the chest due to bronchiectasis, potentially masquerading as pulmonary metastasis(AU)