Aumento de la confianza en la interpretación del PET con 18F-Florbetaben: “machine learning” basado en la aproximación cuantitativa / Increasing the confidence of 18F-florbetaben PET interpretations: Machine learning quantitative approximation

Objetivo: Determinar el valor a-adido de los parámetros semicuantitativos en el análisis visual y estudiar los patrones del depósito cerebral de 18F-Florbetaben. Material y métodos: Análisis retrospectivo de pacientes con deterioro cognitivo leve o demencia de origen incierto procedentes de un estudio multicentrico. Los PET con 18F-Florbetaben fueron interpretados de forma visual por dos observadores independientes, analizando las regiones “diana” con la finalidad de calcular el acuerdo interobservador. Se realizó análisis semicuantitativo de todas las regiones corticales con respecto a tres regiones de referencia para obtener índices de captación (SUVRs). Se analizó la capacidad de los SUVRs para predecir el resultado de la interpretación visual, la posibilidad de depósito preferencial del radiotrazador en algunas regiones “diana” así como las diferencias interhemisféricas. Resultados: Se evaluaron 135 pacientes. En la valoración visual, 72 estudios se clasificaron como positivos. El acuerdo interobservador fue excelente. Todos los SUVRs fueron significativamente superiores en pacientes con PET positivos con respecto a los negativos. Las regiones corticales correspondientes al área prefrontal y al cingulado posterior mostraron la mejor correlación con la evaluación visual, seguidas por la valoración integrada cortical. Usando análisis de ROC, los SUVRs obtenidos en las mismas regiones “diana” mostraron la mejor capacidad diagnóstica. Conclusiones: La información obtenida de las regiones “diana” parece ser de ayuda en la clasificación visual, basado en un depósito preferencial de amiloide, lo que permitiría el “machine learning”. El depósito de amiloide, aunque difuso en todas las regiones corticales, parece no ser uniforme ni simétrico (AU)

Aim: To assess the added value of semiquantitative parameters on the visual assessment and to study the patterns of 18F-Florbetaben brain deposition. Materials and methods: Retrospective analysis of multicenter study performed in patients with mild cognitive impairment or dementia of uncertain origin. 18F-Florbetaben PET scans were visually interpreted by two experienced observers, analyzing target regions in order to calculate the interobserver agreement. Semiquantification of all cortical regions with respect to three reference regions was performed to obtain standardized uptake value ratios (SUVRs). The ability of SUVRs to predict the visual evaluation, the possibility of preferential radiotracer deposition in some target regions and interhemisphere differenceswere analyzed. Results: 135 patients were evaluated. In the visual assessment, 72 were classified as positive. Interobserver agreement was excellent. All SUVRs were significantly higher in positive PET scans than in negative ones. Prefrontal area and posterior cingulate were the cortical regions with the best correlations with the visual evaluation, followed by the composite region. Using ROC analysis, the SUVRs obtained in same target locations showed the best diagnostic performance. Conclusions: The derived information from target regions seems to help the visual classification, based on a preferential amyloid deposit, allowing machine learning. The amyloid deposit, although diffuse in all cortical regions, seems not to be uniform and symmetric (AU)

Basal (18)F-FDG PET/CT in follicular lymphoma: A comparison of metabolic and clinical variables in the prognostic assessment.

AIM: To analyze the relationship of clinical variables related to prognosis and tumor burden, with metabolic variables obtained in the staging (18)F-FDG PET/CT, and their value in the prognosis in follicular lymphoma (FL). METHODS: 82 patients with FL, a (18)F-FDG PET/CT at diagnosis and a follow-up for a minimum of 12 months, were retrospectively enrolled in the present study. Clinical variables (Tumor grade, Follicular Lymphoma International Prognostic Index (FLIPI) and Tumor burden) were evaluated. Metabolic variables such as SUVmax in the highest hypermetabolic lesion, extralymphatic locations, number of involved lymph node locations, bone marrow (BM) involvement, PET stage and diameter of the biggest hypermetabolic lesion, were analyzed in order to establish a PET score and classify the studies in low, intermediate and high metabolic risk. Clinical and metabolic variables (included metabolic risk) were compared. The relation among all variables and disease-free survival (DFS) was studied. RESULTS: The 28% of patients had a high-grade tumor. The 30.5% had FLIPI risk low, 29.3% intermediate y 40.2% high. The 42.7% presented a high tumor burden. The PET/CT was positive in 94% of patients. The tumor grade did not show significant relation with metabolic variable. FLIPI risk and tumor burden showed statistical relations with the SUV max and the PET score (p<0.008 and p=0.003 respectively). With respect to DFS, significant differences were detected for the PET stage and FLIPI risk (p=0.015 and p=0.047 respectively). FLIPI risk was the only significant predictor in Cox regression analysis, with a Hazard Ratio of 5.13 between high risk and low risk. CONCLUSION: The present research highlights the significant relation between metabolic variables obtained with FDG PET/CT and clinical variables although their goal as an independent factor of prognosis was not demonstrated in the present work.

Incidental pathologic extracardiac uptake of (99m)Tc-tetrofosmin in myocardial perfusion imaging: Importance of patient background evaluation.

(99m)Tc-tetrofosmin single photon emission computed tomography ((99m)Tc-tetrofosmin SPECT) has an important role in the assessment of coronary artery disease. Despite being its main indication, this study does not only evaluate myocardial perfusion, but much more. Moreover, during the SPECT acquisition, the field area covered includes many important organs of the thorax and abdomen, so extracardiac abnormalities can be observed. The correct etiologic diagnosis of them is only possible if we understand how (99m)Tc-tetrofosmin works and make a comprehensive investigation of the clinical history of the patient.

Positron emission tomography/computed tomography exam request form under review. Is it effective?

AIM: Our objective was to analyze all the rejected PET/CT-request forms (rf), its primary question to be answered and the impact of not performing the PET/CT studies for the management of the patients. MATERIAL AND METHODS: We retrospectively reviewed all the cancelled PET/CT-rf received in our department from January 2007 to June 2011. The reasons for cancelling were patient clinical status, request from referring physician, patient request and criteria of nuclear medicine physician. PET/CT-rf were classified according to the primary question to be answered. The clinical evolution of patients was followed up for 6 months after PET/CT was requested. RESULTS: Thirty-nine studies were cancelled due to the patient clinical situation (mainly advanced state of neoplastic disease), 46 due to request from referring physician, 18 by patient request and 74 PET/CT-rf were rejected due to nuclear medicine physician criteria. Thirty-four patients with a rejected PET/CT had known neoplastic history. The more prevalent primary questions to be answered were: evaluation of pulmonary (20) and bone lesions (13). Regarding pulmonary nodules, only 4 patients had previous neoplastic disease and their size was less than 5mm. The rejection of PET/CT studies did not cause any impact in the natural evolution of the disease of the patients. CONCLUSION: This procedure avoided unnecessary PET/CT scans reducing expenses and radiation without any detriment in the patients.

[Implementation of a quality management system according to the UNE-UN-ISO 9001:2008 standard in a nuclear medicine department]. / Implantación de un sistema de gestión de calidad según norma UNE-UN-ISO 9001:2008 en un servicio de medicina nuclear.

OBJECTIVE: To describe the process of implementing a quality management system according to UNE-EN-ISO 9001:2008 standard in a Nuclear Medicine Department. MATERIAL AND METHOD: In February 2008, the committee on internal quality of the Department was established, naming a responsible physician. The general operating plan was drawn up, following the requirements established by the ISO 9001:2008 standard. It defined the scope of the standard, defining, preparing and transcribing the various activities of our Department. Four training sessions were carried out. RESULTS: A total of nine general and two specific procedures were documented in which all the activities performed in our Department were included. Personnel records of each worker were created, including their profiles and training plan. A record of the equipment and service providers was created, as well as issues with the latter. Satisfaction surveys were obtained from external (patients) and internal customers (faculty applicants). Targets for improvement and activity markers were established. Two audits were performed to complete the process, one internal and one external. The Department was accredited in April 2010. CONCLUSION: The quality accreditation process is a tool that requires reflection on how we do things and how they can be improved. It makes it possible to measure what we do, to analyze and introduce improvement measures, and therefore, to achieve a higher level of quality in the service we provide our customers. The involvement of the Department workers with a commitment to team performance was essential.

[Analysis of cost-effectiveness in the diagnosis of fever of unknown origin and the role of (18)F-FDG PET-CT: a proposal of diagnostic algorithm]. / Análisis de costo-efectividad en el diagnóstico de fiebre de origen desconocido y el papel de la (18)F-FDG PET-TC: propuesta de algoritmo diagnóstico.

AIM: To analyze the costs of Fever of Unknown Origin (FUO) prior to the PET-CT study. To determine the effectiveness of PET-CT in the diagnosis of FUO. A proposal of diagnostic algorithm. MATERIAL AND METHODS: A retrospective study was performed that included 20 patients who had been studied between January 2007 and January 2011, with a mean age of 57.75 years and FUO diagnosis. All underwent a PET-CT study with (18)F-FDG. Individual and mean costs of FUO in these patients were assessed, including hospitalization days and complementary tests prior to the PET-CT study. The effectiveness of the PET-CT study in the diagnosis of FUO was analyzed. Costs of the FUO process were determined, including those of the PET-CT study, and if it had been done earlier in the diagnostic process. RESULTS: Mean hospital stay per patient until the PET-CT study was 28 days. The cost per hospitalization day was 342 €. Average cost per patient in complementary tests was 1395 €. Total cost of the FUO process until the PET-CT study was around 11167 € per patient. The PET-CT study showed a 78% sensitivity, 83% specificity, 92% PPV and 62% NPV. If PET-CT had been performed earlier in the FUO process, assuming the same effectiveness, 5471 € per patient would have been saved. CONCLUSION: The PET-CT study could be cost-effective in the FUO process if used at an early stage, helping to establish an early diagnosis, reducing hospitalization days due to diagnostic purposes and the repetition of unnecessary tests.

Is a selective brain (18)F-FDG PET/CT study profitable in patients with small cell lung cancer?

AIM: To evaluate the diagnostic yield of a selective brain (18)F-FDG PET/CT in neurologically asymptomatic patients with small cell lung cancer. MATERIAL AND METHODS: Twenty-one neurologically asymptomatic patients referred to our service between July 2008 and December 2009 for staging of small cell lung cancer were included in the study. All underwent a standard (18)F-FDG PET/CT study followed by a selective brain PET/CT. The neurological findings were confirmed by CT scan with intravenous contrast, MRI or minimum clinical follow-up of 6 months. The brain PET/CT was considered positive if any alteration was observed in the FDG distribution that was not related with previously known benign lesion in the CT image. RESULTS: Brain metastases were detected in 5 of the 21 patients (23.8%), these being correctly classified in 3 of them by the selective brain PET/CT. The stage was upgraded in one of them with the selective brain study. Only one patient showed a hypermetabolic lesion in the PET images in relationship to the lesions observed in the CT images. Sensibility, specificity, positive predictive value and negative predictive value were 60, 100, 100 and 88.89%, respectively. CONCLUSION: Hypometabolic areas in the cerebral parenchyma are frequently associated to metastatic lesions in patients with small cell lung cancer. The selective brain PET/CT in these patients allows correct staging and early treatment of unsuspected metastasis.

[Prevalence of micrometastases and isolated tumor cells in the sentinel node at early stage breast cancer]. / Prevalencia de micrometástasis y células aisladas en el ganglio centinela en estadios iniciales del cáncer de mama.

AIM: To analyze the prevalence of isolated tumor cells (ITC) and micrometastases in the sentinel node of early stage breast cancer. MATERIAL AND METHODS: A total of 234 patients diagnosed of breast cancer, stages T1 or T2, with no axillary involvement detected by palpation or ultrasound-FNA, were studied. The sentinel node (SN) was identified by lymphoscintigraphy and removed in the operating room. Serial sections and immunohistochemical staining were then performed, classifying them as negative (SN-), negative with ITC (SN-ITC), positive with micrometastases (SN+mic) and positive with macrometastases (SN+mac). A complete axillary lymphadenectomy (CAL) was carried out in those cases with micro- or macrometastases, the former being classified as negative (CAL-), positive with micrometatases (CAL+mic), and positive with macrometastases (CAL+mac). The follow-up ranged from 6-71 months. RESULTS: ITC were found in 12 patients (5.1%) and micrometastases in 24 (10.3%). Thus, a total of 36 patients were affected by some of these conditions (15.4%). In the group with micrometastases, the result of CAL was CAL- in 19/24 (79.1%), CAL+mic in 2 (8.3%) and CAL+mac in 3 (12.5%). No axillary recurrences have occurred up to date. CONCLUSIONS: ITC and micrometastases were found in the sentinel node in a significant percentage of patients in the early stages of breast cancer. The low percentage of further axillary invasion in the group of micrometastases may open up the possibility of avoiding CAL in favor of other adjuvant treatments (chemotherapy, radiotherapy).

[Utility of PET-CT on radiotherapy planning of head and neck cancer. Our initial experience]. / Utilidad de la PET-TAC en la planificación radioterápica en el cáncer de cabeza y cuello. Nuestra experiencia inicial.

OBJECTIVE: To describe the methods used for the incorporation of FDG-PET-CT on radiotherapy planning of patients with head and neck cancer and also to evaluate the impact of FDG-PET-CT on staging and tumor volume definition. MATERIAL AND METHODS: A prospective study in which 20 patients with head and neck tumor submitted for radiotherapy treatment were included. All underwent a whole body PET- CT (GE DSTE 16) for staging and restaging, also acquiring an additional 3h delayed PET image with diagnostic CT parameters for planning. A CT scan with diagnostic protocol, tabletop available for radiotherapy treatment and the same personalized head-shoulder mask were used in the latter. Lymph node involvement and/or distant involvement were evaluated, considering the changes in staging. We also evaluated the differences in volumes obtained between the different techniques. The threshold value used for delineating PET gross tumor volume (GTV) was empirically established and ranged from 20-40% of the maximum SUV. RESULTS: Radiotherapy planning was performed with PET-CT in 20 patients between October 2007 to September 2008. A total of 29 lesions (18 primary lesions because 2 patients were excluded as no tumor was observed on the PET CT images, and 11 nodes). The most frequent location was oropharynx (5 patients). Mean maxSUV of the 29 lesions was 14.4 (range 5.0 and 26.4). No statistically significant differences were found between the GTV PET and GTV CT (mean 21.9cm³ and 19.3cm³, respectively). PET-CT modified the staging in 20% of the patients, with a diagnostic and therapeutic impact of 50 and 25%, respectively. CONCLUSION: The incorporation of PET-CT in routine radiotherapy planning is a promising technique that requires close collaboration between the nuclear medicine and radiotherapy oncology departments. PET-CT achieves better staging in patients and has a significant diagnostic and therapeutic impact. The use of the hybrid technique avoids problems arising from co-registry as well as a second examination for planning with the consequent advantage for the patient. Nonetheless, more prospective and randomized studies with pathology specimens are needed to evaluate the real impact in the tumor volume definition.

[Diagnostic and therapeutic impact of 18F-FDG-PET/CT in patients with suspected breast cancer recurrence]. / Impacto diagnóstico y terapéutico de la (18)F-FDG-PET/TAC en pacientes con sospecha de recidiva de cáncer de mama.

Breast cancer is a tumor with high prevalence in our environment. Thus, it is essential to make an early diagnosis in both the primary disease and its recurrence, given the high mortality of the cases with the advanced disease. Our study has aimed to evaluate the impact of (18)F-FDG-PET/CT in patients with suspected breast cancer recurrence and their therapeutic management. This study analyzed the PET/CT of 70 patients with a background of breast cancer and suspicion of recurrence, either because of elevation of tumor markers (n=28), doubtful findings on other imaging techniques (n=56) and/or suspicious symptoms (n=1). All the patients underwent a standard FDG-PET study acquired in combination with low-dose CT. The studies were considered pathological in 34 of the 70 patients, with 29 true positive, 32 true negative, 5 false positive and 4 false negative results. The final diagnosis was established either by histopathologic confirmation (n=17), other imaging techniques (n=26) and/or clinical radiological follow-up (n=27, mean 12.7 months). The sensitivity, specificity, positive predictive value and negative predictive values obtained were 87.8%, 86.4%, 85.2% and 88.8%, respectively. Therapeutic management was modified in 41% of the patients. In conclusion, PET/CT is a technique with high diagnostic yield in patients with suspected breast cancer recurrence.

[Micrometastasis in the sentinel node and axillary lymph node macro-metastasis in breast cancer]. / Micrometástasis en el ganglio centinela y macrometástasis ganglionares axilares en el cáncer de mama.

AIM: The study of the sentinel node has made it possible to obtain more comprehensive knowledge about the extent of axillary involvement in breast cancer. It has also decreased the surgical morbidity associated to the surgical examination of the axilla. The systematic use of immunohistochemical staining and molecular biology techniques improves the ability to detect the presence of micrometastasis or isolated tumor cells in a significant number of cases when this is the only sign of the lymph node extension of the disease. The possibility of avoiding complete axillary lymphadenectomy in those patients who are only affected by micrometastasis is proposed because of the low incidence of further involvement of the remaining lymph nodes. MATERIAL AND METHOD: 159 patients diagnosed of stage T1 or T2 breast cancer, in which the sentinel node had been identified by scintigraphy and intraoperative localization, were included in the study. Complete axillary lymphadenectomy was performed when micro- or macrometastases were found in the sentinel node, in order to determine the degree of axillary involvement. RESULTS: A total of 40 patients (25%) showed infiltration of the sentinel node. This infiltration was only by micrometastasis in 17 of them (10.7%). Of these 17 patients, only 2 (11.8%) showed macro-metastasis in the lymphadenectomy. In the remaining subjects, the final staging reached after the sentinel node study was not modified. CONCLUSION: It is possible to speculate that, in the future, axillary dissection can be avoided in those patients diagnosed of micrometastasis in the sentinel node, pending the conclusions of the on-going multicenter studies.

(18)F-FDG PET-CT respiratory gating in characterization of pulmonary lesions: approximation towards clinical indications.

AIM: To evaluate the effect of the 18F-FDG PET-CT respiratory gating (4D) study in the correct documentation of pulmonary lesions with faint uptake in standard PET-CT. METHODS: Forty-two pulmonary lesions with a low or no detectable uptake of FDG (SUV(max) < 2.5) in 3D PET-CT were prospectively evaluated in 28 patients (19 males and 9 females), mean age 66.5 years (41-81). 22 patients had neoplastic background. A conventional PET-CT (3D) total body scan was performed approximately 60 min after iv injection of a mean dose of 370 MBq. Furthermore, a 4D PET-CT (synchronized with respiratory movement) thorax study was acquired. SUV(max) was determined for each lesion in both studies. For the 4D studies, we selected the SUV(max) in respiratory period with the highest uptake ("best bin"). We calculated the SUV(max) percentage difference between 3D and 4D PET-CT (% difference = SUV(max) 4D - SUV(max) 3D/SUV(max) 3D x 100) and the relation of this value with the size and locations of the lesions. In 4D study, any lesion with SUV(max) > or = 2.5 was classified as malignant. We assessed the changes of lesion classification (from benign to malignant) applying the 4D technique. The final diagnosis was obtained by histological assessment or clinical and radiological follow-up longer than 12 months. RESULTS: Forty out of 42 lesions showed an increase of SUV(max) in the 4D study with respect to 3D. The mean SUV(max) in the 3D and 4D PET-CT studies were 1.33 (+/-0.59) and 2.26 (+/-0.87), respectively. The SUV(max) percentage difference mean between both techniques was 83.3% (+/-80.81).The smaller the lesion the greater was the SUV(max) percentage difference (P < 0.05). No differences were observed depending on the location of the lesion. In 40% of cases, there was a change in the final classification of lesions from benign to malignant. In the final diagnosis, 24 lesions were malignant. 4D PET-CT diagnosed correctly the 52% of them. CONCLUSIONS: The 4D PET-CT study permitted a better characterization of malignant lung lesions compared with the standard PET-CT, because of its higher sensitivity. 4D PET-CT is a recommendable technique in the early diagnosis of malignant lesions.

[(18)F-FDG PET-CT and respiratory synchronization: effect in the detection and catalogation of pulmonary lesions]. / (18)F-FDG PET-TAC y sincronización respiratoria: efecto en la detección y catalogación de lesiones pulmonares.

UNLABELLED: The respiratory movement reduces the sensitivity in the detection of pulmonary lesions. The synchronized acquisition of PET with respiratory movement (4D) can reduce this inconvenient. Our objective was assess the effect of 4D PET-CT in the metabolic activity of (18)F FDG and final classification of pulmonary lesions. MATERIAL AND METHODS: 12 patients with 18 pulmonary lesions with sizes within 0.8-4cm were assessed. The maximum SUV was obtained in the imaging acquired in standard conditions (3D) and the obtained in the respiratory period with higher metabolic activity in 4D images. The difference of percentage between both values was calculated. Moreover were evaluated the changes of the classification of pulmonary nodes (benign or malignant) obtained from the assessment of 4D and 3D PET images. RESULTS: 17/18 pulmonary lesions showed an increase in the SUV(max) value in the 4D with respect to 3D image. 5 lesions showed SUV(max) values >2.5 in 4D image and <2.5 in 3D image. From these 3 were correctly catalogued as malignant with 4D although the number of false positive increased to 2. CONCLUSION: (18)F-FDG 4D PET-CT shows values of metabolic activity more realistic allowing the correct classification reducing the false negative although increasing the false positive.

[PET-CT with intravenous contrast in the evaluation of patients with lymphoma. Contribution to diagnostic indications]. / PET-TAC con contraste intravenoso en la valoración de pacientes con linfoma. Aproximación hacia las indicaciones diagnósticas.

AIM: To define the utility of intravenous contrast administration in the PET-CT (PET-CTc) in patients with lymphoma in order to determine its possible indications. MATERIAL AND METHODS: 78 patients with lymphoma were prospectively evaluated. All underwent simultaneous PET-CTc scans in a hybrid system for staging (8), evaluation of response to treatment (29), suspicion of recurrence (9) and complete remission control (48). The PET scan was acquired by a conventional method and the diagnostic CT scan was performed according to radiological protocol. Both examinations were evaluated blinded and independently, analyzing 28 anatomical locations in order to determine the degree of agreement. Final diagnosis was established by the clinician based on the histological study, results of other diagnostic techniques or clinical follow-up. RESULTS: The final result of both techniques were concordant in 87/94 studies (92.5%). A total of 158 (36 FP) pathological locations were detected with PET-CT and 189 (71 FP) with CTc, with 72 locations being discordant between both techniques. Global sensitivity, specificity, PPV and NPV were 93%, 98%, 77% and 99%; and 94%, 97%, 62% and 99%, respectively. CONCLUSIONS: Administration of intravenous contrast does not seem to provide any advantage in the determination of nodal and extranodal disease in lymphoma patients. The low prevalence of disease probably accounts for the limited PPV of both techniques. An increase of our sample size, with a greater homogeneity of the groups, should offer more reliable results.

[Usefulness of ventricular function values obtained using post-stress gated-SPECT in a diabetic population with clinical suspicion of ischaemic heart disease]. / Utilidad de los valores de función ventricular obtenidos mediante gated-SPECT post-estrés en población diabética con sospecha clínica de cardiopatía isquémica.

OBJECTIVE: To assess the clinical usefulness of left ventricular function values obtained using post-stress myocardial perfusion gated-SPECT in diabetic patients with suspected ischaemic heart disease (IHD). MATERIALS AND METHODS: Sixty-one patients with diabetes mellitus (DM), with clinical suspicion of IHD and no previous history of heart disease were studied. Ergometric or pharmacological post-stress myocardial perfusion gated-SPECT was performed on all patients. The relationship between the ejection fraction values and ventricular volumes, and the perfusion study results, final diagnosis, severity of the perfusion defects and the clinical evolution was studied. The mean follow-up time was 14 months. RESULTS; All the ventricular function values independently showed significant differences between the groups with a normal and pathological perfusion study, and between groups with a final diagnosis of IHD and non-IHD. After multivariate logistic regression, the end-diastolic volume (EDV) was the only value which showed a statistical association with the pathological perfusion study, its severity and the final diagnosis of IHD. No statistical association was observed between the ventricular function values and the occurrence of cardiac events. CONCLUSIONS: All the ventricular function values obtained by gated-SPECT added diagnostic information to the post-stress myocardial perfusion study in the diabetic population with suspected IHD; however, only EDV showed a statistical association with the pathological perfusion study, severity of defects and the final diagnosis of IHD.

[Value of 99mTc-labelled red cells in the detection of pulmonary haemorrhage]. / Valor de la gammagrafía con hematíes marcados con 99mTc en la detección de hemorragia pulmonar.

The use of 99mTc-labelled red cells is very extensive in the detection of haemorrhages of gastrointestinal origin. However, not only is it useful in haemorrhages in this location, but it may also be of use in other locations such as pulmonary haemorrhage. We should not forget that this is a non-invasive diagnostic method, useful in localising possible pulmonary bleeding which causes symptoms of haemoptysis, without having to resort to invasive tests such as angiography, or prior to this, to have approximate knowledge of the location of the bleeding area. We present the case of a patient with a haemoptysis picture where the use of scintigraphy with labelled red cells detected the location of the bleeding site, directing towards subsequent surgery, and a final diagnosis of haemoptysis due to pulmonary carcinoma.

[Study of physician satisfaction as a quality criterion in Nuclear Medicine]. / Estudio de satisfacción de facultativos como criterio de calidad en Medicina Nuclear.

OBJECTIVE: To determine the perception and satisfaction level of referring physicians requesting scans as final users of the Nuclear Medicine Department. MATERIAL AND METHODS: A self-administered questionnaire was designed; it was composed of 10 closed questions (5 categorised and 5 with numerical scale) and 3 open questions. The indicators evaluated were: physician's information about available tests, test indications and diagnostic information, accessibility, delay in the examination and reception of the diagnostic report, usefulness of diagnostic information and overall satisfaction with the department. Two hundred and fifteen questionnaires were sent. RESULTS: Seventy eight questionnaires were returned, so the response index was 36.3 %. The 44.6 % of physicians surveyed considered that they had sufficient information about the tests and 59.5 % were satisfied with the indications and diagnostic information. The accessibility was 7 or more out of 10 for 78.5 %. The 64.9 % of physicians considered the delay in performing examinations to be correct but the satisfaction was lower in the delay between performance and reception of the diagnostic report. The diagnostic information was considered useful by 81.9 % and relevant in the management of patients by 70.5 % of the participants surveyed. The overall satisfaction was > or = 7 out of 10 in 86.8 %. CONCLUSIONS: Overall satisfaction was high, although the level of knowledge about available tests and the delay between test performance and report reception could be improved.

[Are bone scintigraphy examinations requested in oncologic patients according to established indications?]. / Se solicitan las gammagrafías óseas en pacientes oncológicos según criterios clínicos reconocidos?

OBJECTIVE: To determine the percentage of bone scintigraphy examinations (BS) requested according to established indications and to assess the clinical impact of the scintigraphic results. MATERIAL AND METHODS: A retrospective study was performed including BS in 117 patients (70 women and 47 men) carried out in our department during the year 2001. All patients had a primary extraosseous malignancy. The correctness of the indication of each study requested was analyzed according to established criteria from the literature. BS results were classified as positive, negative, and equivocal for metastatic disease. RESULTS: 96 out of the 117 BS were performed in patients affected with the most prevalent primary malignancies: breast (57), prostate (21), and lung (18). The remaining studies were included in a miscellaneous group (gynecological [3], colorectal [4], oropharyngeal [4], and renal malignancies [4]; lymphoma [2], melanoma [2], hemangioendothelioma [1]; and cancer of the bladder [1] or pancreas [1]). Ninety-nine (85 %) of the 117 BS performed met the criteria for appropriate indication. The indication was correct in 75 % of breast, 90 % of prostate (19/21), and 100 % of lung cancers. The indication was correct in 90 % of the cases in the miscellaneous group. BS were positive in 21 patients (20 of which were confirmed). BS were equivocal in 24 patients (in 5 of whom bone metastases were confirmed). BS were negative in 72 patients (one of whom had bone metastases). The BS findings changed staging in 9 % (9/99) of the correctly indicated cases. CONCLUSION: Most BS (85 %) were indicated according to the established criteria and the clinical impact was greater in this group.

[Patient satisfaction as quality indicator in a nuclear medicine department]. / La satisfacción del usuario como indicador de calidad en un servicio de Medicina Nuclear.

OBJECTIVE: To assess patient satisfaction and dissatisfaction with a Nuclear Medicine department. MATERIAL AND METHODS: A questionnaire was designed with 9 closed questions, 1 with a numerical scale (1-10) and 1 with an open question for suggestions. The questions included different quality dimensions of the department related with waiting time for the scan, information, facilities, attention manner with department staff and global satisfaction (numerical scale, 1-10). Dissatisfaction was determined by analyzing the written complaints for the last 6 years. RESULTS: A total of 671 questionnaires were obtained, 58 % of those surveyed being women. The mean age of patients was 56.5 (+/- 16.26). The information provided was correct in 81.7 % of cases. Equipment and facilities were correct for 74.5 % of patients. Waiting list and waiting time were correct for 70 % and 66.4 % respectively. The attention manner of the department staff was the most satisfactory dimension (98.7 %). Global satisfaction was positive (> or = 7 out of 10) in 82.8 % of the patients. 29 complaints were received. Most of them were based on waiting list (12) and disagreement with assistance (9). CONCLUSIONS: Global satisfaction was high in most of patients. Waiting time was the dimension with the lowest level of satisfaction and subsidiary of improvement plans. The primary spontaneous complain by our patients was due to the waiting list.

[Clinical and prognostic value of X-ray based attenuation correction in post-stress myocardial perfusion SPECT]. / Valor clínico y pronóstico de la corrección de atenuación con rayos X en la SPECT de perfusión miocárdica post-estrés.

OBJECTIVE: The purpose of the study was to validate the X-ray-based attenuation correction technique applied to post-stress myocardial perfusion single photon emission computed tomography (SPECT). MATERIALS AND METHODS: Fifty-six patients with clinically suspected ischemic heart disease and no history of myocardial infarction or coronary revascularization were studied. All patients underwent a myocardial perfusion SPECT after exercise (38) or pharmacological stress (18). Mean clinical follow-up time was 18.6 months. Studies were assessed after reconstruction using the filtered back projection technique and after application of the X-ray-based attenuation correction technique, and the results obtained were related to the final clinical diagnosis. RESULTS: Eleven uncorrected studies were normal, while 45 studies showed perfusion defects. After attenuation correction, absence of significant perfusion defects was observed in 24 cases (42.9 % of all cases), and ischemic heart disease was finally ruled out in 22 cases. A greater study normalization rate was seen in men (p = 0.048; odds ratio = 2,923), but this fact was not shown to be significantly correlated to the following variables: pre-test probability of ischemic heart disease, body mass index greater than 30, presence of cardiovascular risk factors or otherwise, and age. CONCLUSIONS: Application of the X-ray-based attenuation correction technique would have allowed for obviating the conduct of a resting perfusion study in 42.9 % of patients without apparently changing the diagnostic safety of the test. This fact was seen more frequently in men. This method seems to be both safe and time- and cost-effective.