The scintigraphic index spleen/liver at 30 minutes predicts the success of splenectomy in persistent and chronic primary immune thrombocytopenia.

UNLABELLED: Splenectomy is considered the second-line of treatment in patients with chronic primary immune thrombocytopenia (ITP) in whom glucocorticoids have failed. Some patients do not respond to splenectomy or they have postoperative complications. Based on our previous experience using kinetic and scintigraphic parameters, we did a retrospective study with the aim of comparing all these parameters as a means of predicting the success of splenectomy in persistent and chronic primary ITP. Forty-one consecutive patients with chronic primary ITP refractory to prednisone, who had been splenectomized, were included in the study. The response to splenectomy was assessed by evaluating bleeding and platelet counts before and at different times after surgery. A complete platelet kinetic study was performed before the splenectomy using autologous (111) In-labeled platelets. The scintigraphic parameters measured included different indices between spleen/heart, liver/hearth, and spleen/liver. Thirty-six patients gave a complete response after splenectomy and five patients did not respond. A statistically significant difference between both groups was found with initial platelet recovery and with some scintigraphic indices which also showed a variable prediction value for the success of splenectomy. Among these indices, the spleen/liver at 30 minutes demonstrated a predictive value with a 100% of sensitivity and a 100% of specificity. CONCLUSION: some platelet kinetic parameters and scintigraphic indices, in particular the spleen/liver at 30 minutes, were useful to predict the outcome of splenectomy in persistent and chronic primary ITP and, therefore, they should be taken into account when deciding whether or not to perform a splenectomy.

Guidelines for the labelling of leucocytes with (99m)Tc-HMPAO. Inflammation/Infection Taskgroup of the European Association of Nuclear Medicine.

We describe here a protocol for labelling autologous white blood cells with (99m)Tc-HMPAO based on previously published consensus papers and guidelines. This protocol includes quality control and safety procedures and is in accordance with current European Union regulations and International Atomic Energy Agency recommendations.

Guidelines for the labelling of leucocytes with (111)In-oxine. Inflammation/Infection Taskgroup of the European Association of Nuclear Medicine.

We describe here a protocol for labelling autologous white blood cells with (111)In-oxine based on previously published consensus papers and guidelines. This protocol includes quality control and safety procedures and is in accordance with current European Union regulations and International Atomic Energy Agency recommendations.

Characterization of radiologically indeterminate lung lesions: 99mTc-depreotide SPECT versus 18F-FDG PET.

AIM: To evaluate the diagnostic accuracy of 99m Tc-depreotide vs PET-18FDG scans in patients with suspicion of lung cancer. MATERIAL AND METHODS: Prospective study in 29 patients (age: 38-80 years) diagnosed of inderteminate lung lesions. Diagnosis was established by histology based on samples of surgical resection, fine needle aspiration (FNA) or broncoalveolar lavage (BAL). Within a maximum of 10 days, without pre-established fixed order the following exams were performed: 1) Whole body and chest SPECT-CT with Tc-depreótide (DEP-SPECT) and 2) PET-CT study with F-FDG (PET-FDG). Every exam was evaluated by Nuclear Medicine especialist blinded to patient data. RESULT: Malignancy was confirmed in 20 patients. PET-FDG was positive in all cases. DEP-SPECT was positive in 17 and falselly negative in 3, one carcinoid tumor, one undifferentiated non-small cell adenocarcinoma, and a moderately differentiated adenocarcinoma. In the remaining 9 patients benignancy was confirmed; both studies were normal in 8 and falselly positive in one case of non-specific inflammatory lung process. In 9 out of the 20 cases with malignancy extrapulmonar uptake was seen, with a total number of 19 lesions. In two cases the extrapulmonar uptake were non ganglionar metastasis (bone and adrenal) and in 7 due to mediastinic ganglionar involvement. ROC analysis using peak SUV FDG (cut-off point of 3.5) uptake and target/background depreotide uptake (cut-off point of 1.3) provided, sensitivity and specificity values of 95% and 89% of 84% and 88% for PET and SPECT respectively. It does not exist statistically significant differences between both methods (Z-test SPSS). In summary, FDG-PET has a greater sensitivity and diagnostic accuracy for assessing malignancy of indeterminate lung lesions, and for detection of extrapulmonary involvement, DEP-SPECT represents a good diagnostic alternative for centers where PET is not available.

Succinylated gelatine: an alternative to hydroxyethyl starch for labelling leukocytes with 99mTc-HMPAO.

BACKGROUND: Hydroxyethyl starch (HES) is the most used plasma expander in the sedimentation of the erythrocytes during the radiolabelling procedure for leukocytes in vitro. AIM: To evaluate the usefulness of succinylated gelatine (GEL), another colloidal plasma expander, as an alternative to HES in this process. METHODS: Two identical blood samples were obtained from 30 patients referred to white blood cell scintigraphy. The first sample was used to label leukocytes with Tc-HMPAO using the routine procedure, with HES. The other sample was used to label leukocytes with Tc-HMPAO using the same procedure, with GEL. The cell concentration of the leukocyte-platelet-rich plasma (LPRP) achieved after blood sedimentation was analysed. Labelling efficiency was calculated and the eosin Y viability and red cell/leukocyte ratio were evaluated from the final labelled cell suspension. RESULTS: Leukocytes and platelets recovered in LPRP were not statistically different between both HES and GEL samples (leukocytes: 8.10x10/microl+/-3.82 and 7.80x10/microl+/-3.47; platelets: 411x10/microl+/-182 and 406x10/microl+/-172, respectively). There were no significant differences between both agents on the labelling efficiency (HES: 80.3%+/-6.6%; GEL: 80.1%+/-6.3%), the eosin Y viability (HES: 99.2%+/-1.3%; GEL: 99.3%+/-1.1%) and the red cell/leukocyte ratio (HES: 1.21+/-0.7; GEL: 0.9+/-0.5). CONCLUSION: These results show that succinylated gelatine can be used instead of hydroxyethyl starch in the labelling of leukocytes with Tc-HMPAO.

Comparación del citrato de galio-67 de los leucocitos marcados con exametazina-tecnecio-99m y de la inmunoglobulina G marcada con DTPA-indio-111 en el diagnóstico de infecciones óseas y articulares / Comparison between 67-gallium citrate of exametazine-T-99m labelled leucocites and the DTPA-indio-111 labelled G immunoglobuline in the diagnosis of bone and articular infections

El objetivo de este estudio ha sido comparar la capacidad de la gammagrafia con citrato de Gálio-67 (67Ga), de los leucocitos marcados con Tc-99m (99mTc-leucocitos) y de la inmunoglobulina G marcada con In-111 (111In-IgG) en el diagnóstico de infecciones óseas y articulares. Han sido estudiados 56 pacientes. En todos ellos se indicó una gammagrafia ósea (99mTc-MDP). Los pacientes han sido aleatoriamente asignados para estudios con 67Ga (Grupo 1 - 22 pacientes) o con la administración simultánea de 99mTc-leucocitos y con 111In-IgG.(Grupo 2 - 34 pacientes). Para los grupos 1 y 2 han sido confirmadas 12/26 y 11/34 lesiones sépticas respectivamente. La gammagrafia con 67Ga mostró 6 verdadero-positivos, 9 verdadero-negativos, 5 falso-positivos y 6 falso-negativos. Con los 99mTc-leucocitos, los resultados han sido 8, 18, 5 y 3, respectivamente. Con la 111In-IgG, 7, 17, 6 y 4, respectivamente. La sensibilidad, especificidad y precisión han sido respectivamente del 50 por ciento, 64,3 por ciento y 57,7 por ciento para el 67Ga, 72,7 por ciento, 78,2 por ciento y 76,4 por ciento para los 99mTc-leucocitos y 63,6 por ciento, 73,9 por ciento y 70,6 por ciento para la 111In-IgG. En este estudio, la gammagrafia con los leucocitos marcados presentó mayor precisión que con 67Ga y con 111In-IgG en el diagnóstico de infecciones óseas y articulares. Sin embargo, en el diagnóstico de infecciones en prótesis articulares los resultados han sido menos fiables