Development of a leakage monitoring system in isolated limb perfusion with portable gamma camera. / Desarrollo de un protocolo de monitorización de fuga en perfusión de miembro aislado con gammacámara portátil.

Isolated limb perfusion (ILP) is a method for treating unresectable lesions of limbs in patients with melanoma or sarcoma by using high doses of tumor necrosis factor alpha and melphalan. These high doses can result in high systemic toxicity if there is a drug leak from the isolated circulation of the limb to the systemic. This makes it imperative to monitor the leakage rate (F[%]) during the infusion, currently performed with radiotracers. The objective of this work was to develop a leakage monitoring protocol as accurate as possible to ensure safe ILP. MATERIAL AND METHOD: We built a phantom with 3compartments (body, limb and precordial area) and a high sensitivity collimator fitted to a portable gammacamera. We simulate ILP with scheduled leaks every 10minutes from 1% to 9% (theorical F[%]). We mesured F(%) using 2equation: one is the proposed in the literature and another corrected by decay of the radioisotope. We test the optimal radiopharmaceutical doses to minimize the detector dead time error and compare F(%) mesured by both equations regarding the theoretical F(%). The leakage monitoring protocol was used in 17 ILP of 16 patients and an analysis of the recorded data was performed. RESULTS: We found significant differences between F(%) mesured using the first equation and theoretical F(%), obtaining results very adjusted to the theorical after applying the decay correction. CONCLUSIONS: The decay correction of the radioisotope is a simple manner to carry out the procedure more safely, reducing the error in the calculation of F(%).

Bone scintigraphy as cornerstone in the diagnosis of Erdheim-Chester disease.

The Erdheim-Chester disease (ECD) is an extremely rare form of non-Langerhans cell histiocytosis. The main difficulty for its diagnosis lies in the wide variety of non-specific symptoms and signs that can occur in the disease process, leading, therefore, to there being no clear-cut algorithm as a guide for an optimal biopsy to confirm the diagnosis. An 81-year-old male with history of diabetes insipidus was admitted due to non-specific respiratory signs. Imaging techniques revealed osteoblastic lesions in the lumbar spine. Whole-body bone-scintigraphy (BS) was performed, in which lesions involving the axial and appendicular skeleton, with different rates of osteoblastic activity, were observed. This highlighted a symmetrical severely intense uptake in the knees, leading to an accurate biopsy specimen that enabled making the definitive diagnosis. BS is a widely available, safe, and inexpensive technique that shows a characteristic pattern of uptake for ECD, thus its use is highly recommended for screening and guiding biopsy if clinical suspicion exists. Furthermore, when the scintigraphy pattern is incidentally observed, biopsy of increased uptake areas (tibia preferably) is mandatory in order to rule out the disease.

[Detection by SPECT-CT scan with (99m)Tc-(V) DMSA of bone metastases in patient with medullary thyroid cancer]. / Detección mediante SPECT-TAC con (99m)Tc-(V) DMSA de metástasis óseas en paciente con cáncer medular de tiroides.

Multiple endocrine neoplasia syndrome, type 2B (MEN 2B), is a rare entity characterized by the presence of medullary thyroid cancer in 100% of the cases. The phenotype of this syndrome consists in the presence of marfanoid features and mucocutaneous neuromas. We describe the case of a male patient with MEN 2B syndrome who was diagnosed with medullary thyroid cancer after lung metastases was found. We analyze the role of DMSA-V and the new hybrid SPECT-CT scan systems in the extension study and monitoring of medullary thyroid cancer.

[Confirmation of cortical lesions of progressive prosopagnosia by cerebral SPECT]. / Confirmación de lesiones corticales de la prosopagnosia progresiva mediante la SPECT cerebral.

We present the case of a 78 year old man admitted to the hospital with progressive memory disorder. Neuropsychological examination showed inability to recognize familiar faces (prosopagnosia). MRI documented cortical atrophy, which did not explain the neurological deficit. CT did not show abnormalities. Most patients with prosopagnosia present brain atrophy, as they are more than 65 years old. Scanning by SPECT revealed hypoperfusion in the right parietotemporal region, which was worse in a later examination.

[When should a brain scan with HMPAO be performed to diagnose brain death?]. / ¿Cuando realizar una gammagrafía cerebral con HMPAO en el diagnóstico de muerte encefálica?

INTRODUCTION: Current Spanish law defines the criteria to be met in the case of brain death (BD) and the complementary tests to confirm it, although they do not always need to be carried out. In Spain one of the most frequently used methods is the electroencephalogram (EEG), which has its shortcomings in patients who are under sedation with barbiturates. Transcranial Doppler (TCD) offers a number of advantages in the diagnosis of BD, but it also has certain limitations. In these cases, a cerebral perfusion scan (CPS) with HMPAO can be very useful. CASE REPORTS: We describe the case of two patients who were admitted to the Intensive Care Unit with serious traumatic brain injuries. Progress was unfavourable and the findings of the clinical exploration were compatible with BD. Since we were dealing with patients under barbiturate therapy, the EEGs were complex and difficult to interpret. TCD was difficult to perform in both cases because of loss of brain matter and displacement of intracranial structures, respectively. CPS, however, allowed us to confirm the diagnosis of BD. CONCLUSION: Although it has obvious advantages, TCD cannot always be performed to confirm BD diagnosis. In these cases, CPS can be an extremely valuable tool

[SPECT study of a group of patients with severe recurrent depression]. / Estudio con la SPECT de un grupo de pacientes con depresión recurrente grave.

OBJECTIVE: In this work with the SPECT we tried to define the most possible the disfuntions that could exist in a group of patients with severe recurrent depression. MATERIAL AND METHOD: The sample is compound for fifteen patients (2 men and 13 woman) diagnosed of recurrent depression according CIE-10 with equal distribution between melancholic depressions and depressions with psychotic symptoms congruents and not congruents with the state of mood. The mean age of the group is of 55.4 years. All the patients have been studied with de SPECT (Tc-HMPAO) during the first week of hospitalization. The severity of the depressive syndrome was studied with the questionnaire for depression of Beck and the state of anxiety was studied with the questionnaire of anxiety of Spielberger. All the patients were severes depressives and anxious according to the questionnaires. RESULTS: We appreciated disfunction, hypocaptation, in frontoorbital zones, well bilateral (mainly in recurrent depressions with psychotic symptoms) or only in the left frontal side (areas of Brodmann 10 and 11) mainly in recurrent melancholies. We also found that in almost all the patients existed hypocaptation in the left angular circunvolution (areas of Brodmann 37 and 39). In the recurrent melancholies the localization of the hypocaptation is fundamentally posterior parietotemporal in the left side. CONCLUSIONS: In the recurrent serious depressions the hypocaptation is located to prefrontal level with tendency to bilateral being and/or posterior parietotemporal left side, that in the melancholies the localization of the hypocaptation is fundamentally posterior parietotemporal in the left side and it could imply that when the severity clinic gets complicated with psychotic symptoms the hypocaptation is located in a bigger number of places (prefrontal and left posterior parietotemporal) in relation to what it happens in the melancholic depressions. It seems to exist relationship between depressive and anxious severity and localization of the hypocaptation.