Centellografía con fosfonatos para el diagnóstico de la amiloidosis cardíaca por transtirretina / Bone seeking tracers' scintigraphy for the diagnosis of transthyretin cardiac amyloidosis

La amiloidosis cardíaca del subtipo transtirretina (ATTR) es una cardiopatía restrictiva que causa insuficiencia cardíaca en un número considerable de pacientes. Su identificación temprana permitiría brindar tratamientos específicos. Sin embargo, el diagnóstico de ATTR es complejo y requiere métodos invasivos. Los fosfonatos marcados con 99mTecnecio han demostrado ser útiles para el diagnóstico, aunque en Argentina la experiencia es escasa. Nuestro objetivo fue evaluar la utilidad de este método para diagnosticar de forma no invasiva la ATTR. Se estudiaron 46 pacientes entre septiembre de 2016 y enero de 2018 por sospecha de amiloidosis cardíaca. Se evaluó el grado de captación cardíaca con relación al tejido óseo, a la hora, mediante dos métodos: semi-cuantitativo y cuantitativo. El diagnóstico definitivo de amiloidosis y el subtipo específico fue asignado por el centro de miocardiopatías de nuestra institución siguiendo recomendaciones internacionales. Una captación ≥ grado II presentó un valor predictivo positivo del 96% y negativo del 100% para el diagnóstico de amiloidosis cardíaca ATTR. El valor de corte de 1.38 en la relación corazón/pulmón presentó una sensibilidad del 96% y una especificidad del 100% para discriminar entre pacientes con ATTR de aquellos con amiloidosis por cadenas livianas u otras afecciones (área bajo la curva relación corazón/pulmón = 0.95 p < 0.001). La centellografía con fosfonatos marcados demostró ser un método no invasivo útil para diagnosticar ATTR. Dado que además de ser no invasiva, es una herramienta de bajo costo y ampliamente disponible en nuestro medio, su aplicación puede redundar en un beneficio clínico para muchos pacientes.

Transthyretin cardiac amyloidosis (ATTR) is a restrictive cardiomyopathy that leads to heart failure in considerable number of patients. Early diagnosis allows specific treatment options. However, ATTR diagnosis is complex and requires invasive procedures. The utility of 99mTc-phosphate tracers for non-invasive diagnosis is well-known but the experience in Argentina is insufficient. The aim of this work was to assess the utility of 99mTc-phosphate tracers for the diagnosis of ATTR. A total of 46 scintigraphies for detection of cardiac amyloidosis performed between September 2016 and January 2018 were analyzed. Cardiac retention after one hour was assessed in relation to bone uptake using two methods: A semi-quantitative visual score (grade 0 = absent, I = low II = moderate-III = high) and a quantitative method (heart/lung ratio). The final diagnosis and the amyloidosis subtype were carried out by our institution cardiomyopathy team according to international guidelines. The positive and negative predictive values for Grade ≥ II were 96% and 100% respectively for diagnosis of ATTR. Using 1.38 as cut-off value for heart/lung ratio the sensitivity and the specificity were 96% and 100%, respectively for differentiating transthyretin cardiac amyloidosis from light-chain cardiac amyloidosis and other cardiopathies. Scintigraphy with 99mTc-phosphate tracers enable noninvasive diagnosis and subtype classification of cardiac amyloidosis. The use of this non-invasive, inexpensive and widely available tool will result in better patient management.

Size Control of 99mTc-tin Colloid Using PVP and Buffer Solution for Sentinel Lymph Node Detection

Colloidal particle size is an important characteristic that allows mapping sentinel nodes in lymphoscintigraphy. This investigation aimed to introduce different ways of making a 99mTc-tin colloid with a size of tens of nanometers. All agents, tin fluoride, sodium fluoride, poloxamer-188, and polyvinylpyrrolidone (PVP), were mixed and labeled with 99mTc. Either phosphate or sodium bicarbonate buffers were used to adjust the pH levels. When the buffers were added, the size of the colloids increased. However, as the PVP continued to increase, the size of the colloids was controlled to within tens of nanometers. In all samples, phosphate buffer added PVP (30 mg) stabilized tin colloid (99mTc-PPTC-30) and sodium bicarbonate solution added PVP (50 mg) stabilized tin colloid (99mTc-BPTC-50) were chosen for in vitro and in vivo studies. 99mTc-BPTC-50 (100 nm) mainly accumulated in the liver. When a rabbit was given a toe injection, the node uptake of 99mTc-PPTC-30 decreased over time, while 99mTc-BPTC-50 increased. Therefore, 99mTc-BPTC-50 could be a good candidate radiopharmaceutical for sentinel node detection. The significance of this study is that nano-sized tin colloid can be made very easily and quickly by PVP.

Follow-up of a case of subacute thyroiditis with uncommon thyroid 99mTc uptake / Acompanhamento de caso de tiroidite subaguda com absorção incomum de 99mTc pela tiroide

Thyroidal 99mTc uptake in the acute thyrotoxic phase of subacute thyroiditis (SAT) is always inhibited. However, a patient with SAT had signs in the right-side thyroid gland with transient thyrotoxicosis and slightly high 99mTc uptake levels in the right lobe, low 99mTc uptake in the left lobe, and normal overall uptake. Histological examination showed cellular destruction and granulomatous inflammatory changes in the right lobe, with marked interstitial fibrosis in the left lobe. The patient was thyrotrophin-receptor antibody (TRAb) positive. After a short course of prednisolone, SAT-like symptoms and signs improved. TRAb-positivity resolved spontaneously after 22 months, and TSH levels were slightly low for 22 months. Levels then kept normal in the following four years. In conclusion, high 99mTc uptake by the right lobe was due to the combined effects of TRAb and left thyroid gland fibrosis.

A absorção tiroidiana de 99mTc no estado tirotóxico agudo da tireoidite subaguda (SAT) é sempre inibida. Entretanto, um paciente com SAT apresentou sinais na tiroide direita, com tirotoxicose transitória e níveis levemente elevados de 99mTc no lobo direito, baixa absorção de 99mTc no lobo esquerdo e absorção geral normal. O exame histológico mostrou destruição celular e alterações inflamatórias granulomatosas no lobo direito, com fibrose intersticial marcada no lobo esquerdo. O paciente foi positivo para anticorpos antirreceptores da tireotropina (TRAb). Após um curto tratamento com prednisolona, os sintomas e sinais da SAT melhoraram. A positividade para TRAb foi resolvida espontaneamente em 22 meses. Os níveis de TSH permaneceram levemente baixos por 22 meses e, depois, se mantiveram normais nos quatro anos seguintes. Concluiu-se que a alta absorção de 99mTc pelo lobo direito foi devida à combinação entre TRAb e fibrose da tiroide esquerda.

A case of pathological rib fractures: focal osteolysis or osteoporosis? / Un caso de fracturas patológicas de costillas: osteólisis focal u osteoporosis focal?

This paper reports on a unique, previously unreported, successful outcome in the case of a patient with focal osteolytic lesions of the ribs as a first sign of osteoporosis. The lesions were detected by chance after acute cough-induced rib fractures were seen on plain chest radiographs. The diagnosis had to be approached as a diagnosis of exclusion since known causes of the osteolytic process had to be eliminated. The authors describe multiple focal osteolytic lesions with rib fractures appearing in a pattern that could be confused with metastases. Laboratory results were normal. Final diagnosis was based on plain radiography, bone scan and bone densitometry. Pharmacomedical treatments for osteoporosis were applied. The patient was observed between the year 2000 and 2005. Five years later, radiological and bone scintigraphy revealed resolution of the lesion. We conclude that osteoporosis should be included in the differential diagnosis of asymptomatic focal osteolysis of the ribs with rib fractures as a complication of acute cough. The case suggests that focal osteolytic lesions of the ribs may regress over time and become scintigraphically inactive.

Este trabajo presenta la evolución clínica exitosa, única, y no reportada con anterioridad, del caso de un paciente con lesiones osteolíticas focales en las costillas, como primera señal de osteoporosis. Las lesiones fueron detectadas por casualidad, luego que en unas radiografías simples de tórax, se observaran fracturas de las costillas inducidas por tos aguda. El diagnóstico tuvo que ser abordado como diagnóstico de exclusión, ya que las causas conocidas del proceso osteolítico tenían que ser descartadas. Los autores describen las lesiones osteolíticas focales múltiples con fracturas de costilla presentes en un patrón que podría confundirse con metástasis. Los resultados de laboratorio fueron normales. El diagnóstico final se basó en la radiografía simple, escaneo óseo y densitometría ósea. Se aplicaron tratamientos fármaco-médicos para la osteoporosis. El paciente estuvo sujeto a observación entre el año 2000 y el 2005. Cinco años más tarde, la centellografía ósea y radiológica reveló la resolución de la lesión. Concluimos que la osteoporosis debía incluirse en el diagnóstico diferencial de la osteólisis focal asintomática de las costillas con fracturas de costillas, como complicación de la tos aguda. El caso sugiere que las lesiones osteolíticas focales de las costillas pueden experimentar una regresión con el tiempo y hacerse centellográficamente inactivas.

Modificación de la biodistribución de los glóbulos rojos marcados con 99mtc en la anemia ferropénica / Alteration in the biodistribution of 99mTc-RBC in an animal model of ferropenic anemia

Objetivo: Evaluar la biodistribución de 99mTc-GR en un modelo animal de anemia ferropénica. Materiales y métodos: Se utilizaron ratas alimentadas con dietas con diferente contenido de Fe: grupo A (anemia severa, 6.5 ppm), grupo B (anemia moderada, 18 ppm) y grupo C (control, 100 ppm). Se realizó la marcación in vivo de los 99mTc-GR y se evaluó la EBM y su biodistribución a los 30 minutos y a las 24 horas en sangre, hígado, bazo, tracto gastrointestinal, riñones, corazón y pulmones. Los resultados se expresaron como concentración de actividad porcentual (CA por ciento). Resultados: En todos los grupos la EBM fue superior al 98 por ciento. Se observó un aumento de CA por ciento en bazo a las 24 horas en el grupo A, acompañado de una disminución de la CA por ciento del pool sanguíneo posiblemente por aumento del secuestro esplénico de los GR. En los tres grupos hubo un aumento de la CA por ciento en riñón a las 24 horas. Conclusión: La biodistribución de 99mTc-GR se ve modificada en la anemia ferropénica.

Aim: To evaluate the biodistribution of 99mTc-RBC in an animal model of ferropenic anemia. Materials and methods: We used rats which were fed with different iron contents diets: group A (severeanemia, 6.5 ppm), group B (moderate anemia, 18 ppm) and group C (control, 100 ppm). We performed the in vivo labeling of RBC and evaluated the labeling efficiency and the biodistribution at 30 minutes and 24 hours in blood, liver, spleen, gastrointestinal tract, kidneys, heart and lungs. The results were expressed as activity concentration percentage (CA percent). Results: In all groups the labeling efficiency was higher than 98 percent. We observed an increase of CA percent in spleen at 24 hours in the group A, followed by a decrease of CA percent in blood. This could be a consequence of an increase of splenic uptake of RBC. An increase in CA percent in kidney was obtained at 24 hours for all the groups. Conclusion: An alteration in the RBC biodistribution is observed in an animal model of ferropenic anemia.

Adsorption of herbicide [pendimethalin] onto activated carbons developed from date pits

Phosphoric acid-activated carbons PI and P2 were prepared by impregnating crushed date pits with 50 and 75 wt% phosphoric acid followed by carbonization at 500°C in limited air. Zinc chloride-activated carbons Zland Z2 were obtained by impregnating crushed date pits with 100 and 200 wt% zinc chloride followed by carbonization at 600°C in limited air. Steam-activated carbons SI and S2 were obtained by gasifying date pits carbonization product with steam at 950°C to burn-off s = 17 and 48%, respectively. The textural properties of the activated carbons were determined from nitrogen adsorption at 77K and the chemistry of their surfaces were characterized by measuring their surface pH and by determining their acid and base-neutralization capacities. The equilibrium adsorption of pendimethalin at 293, 300, 310 and 320K was studied using different system variables. Generally activated carbons exhibited high adsorption capacities towards pendimethalin. The adsorption data followed Freundlich and Langmuir models. The adsorption of this herbicide decreased with the rise of adsorption temperature and the small values of delta H indicated the loose bonding between adsorbate molecules and adsorbent surface. The negative values of entropy change delta S although small, indicated that the adsorption complex formed was stable

Dynamic esophageal scintigraphy parameters to analize in single liquid bolus swallow

Dynamic esophageal scintigraphy has been widely used since 1972. It received several denominations that reflects a non agreement about terminology. Nonetheless authors do agree that the method is non invasive, physiologic, very simple, ease to perform, low cost, low radiation level, good for follow up. It also is a quantitative and qualitative method; gives information unavailable by other means and can be used as a screening test. The objective of this retrospective study was to analyze dynamic esophageal scintigraphy in patients with esophageal dysmotility employing systematically the following parameters: total transit time, curve pattern and residual activity, stomach entry form, time for initial entry in stomach, presence of chaotic movements and curve variation factor and compare the results with a control group. Population studied was 55 controls and 611 consecutive patients with clinical suspicion or confirmed diagnosis of primary or secondary esophageal motor dysfunction. Results of commom parameters were in accordance with literature. Conclusion: the parameters used could clearly discriminate patients in a very simple way that can be used anywhere. The prevalence of altered parameters increased with the elevation of total transit time. This induced the idea that the alterations were significant not mere physiologic variations. The systematization used permits to compare groups of patients from one institution to another.

Septal endocarditis, bone infection and severe leg ischemia detected in Tc-99m labelled monoclonal anti granulocyte scan

Patient 28 years old has continued to have a persistent fever (39.2°C), despite ten days treatment by specific antibiotics for bacterial endocarditis associated to a recent claudication of the right lower leg. The persistent fever has motivated a 99mTc-labelled monoclonal anti granulocyte scan which has showed an important uptake in the myocardial septum, and other infection locations in temporal bone and in right tibial arteries. Two days after, a nanocolloids-99mTc WBS showed no uptake in the heart area, a total absence of uptake of the nanocolloids in the bone marrow of right tibia b and cranial SPECT views confirmed the infectious site in the right temporal bone. New antibiotic strategy was adopted successfully associated with surgical amputation of the right lower leg.

Valor de la gammagrafía con 99mTc-ciprofloxacina cubana en la detección de las prótesis de cadera infectadas / Value of scintigraphy with Cuban 99mTc-ciprofloxacin in the detection of infected hip prostheses

Con el propósito de determinar la eficacia de la 99mTc-ciprofloxacina cubana en la evaluación de las infecciones bacterianas en las prótesis de cadera, se realizó un estudio de concordancia en 15 pacientes con sospecha de un proceso infeccioso; que se remitieron al departamento de Medicina Nuclear del Complejo Científico Ortopédico Internacional "Frank País", en un período comprendido entre el 1ro. de enero de 2003 hasta el 31 de diciembre de 2004. Se emplearon gammagrafías óseas con 99mTc-metiléndifosfonato y 99mTc-ciprofloxacina a la hora, 4 y 24 h después de la inyección, el cultivo/biopsia se utilizó como criterio de confirmación. Al analizar visualmente todos los pacientes se obtuvo una sensibilidad en el 100 por ciento, una especificidad en el 75 por ciento, una exactitud diagnóstica en el 93,3 por ciento, un valor predictivo positivo en el 91,6 por ciento y un valor predictivo negativo en el 100 por ciento. La relación lesión/sano mostró diferencias significativas entre los pacientes con y sin infección en las diferentes horas de adquisición, con un nivel de significación de a= 0,05. Se demostró la efectividad de la formulación cubana de 99mTc-ciprofloxacina en la evaluación de las infecciones bacterianas de las prótesis de cadera

Sentinel Lymph Node Radiolocalization with 99mTc Filtered Tin Colloid in Clinically Node-Negative Squamous Cell Carcinomas of the Oral Cavity

The objective of this study was to evaluate the feasibility of sentinel lymph node biopsy by using a radiotracer lymphatic mapping technique in patients with squamous cell carcinoma of the oral cavity, and the diagnostic value of this technique. We studied twenty patients with previously untreated squamous cell carcinomas of the oral cavity and N0 necks. After the peritumoral injection of 99mTc filtered tin colloid preop-eratively, lymphoscintigraphy and intraoperative mapping using a gamma detector were performed to localize sentinel nodes. An open biopsy of the sentinel node was followed by complete neck dissection. We identified the sentinel nodes in 19 of 20 patients (95.0%) by lymphoscintigraphy and in all (100%) by intraoperative gamma detector. In all cases, the status of the sentinel node accurately predicted the pathologic status of the neck with the false negative rate being 0%. The negative predictive value for the absence of cervical metastases was 100%. In conclusion, our radio-localization technique of sentinel nodes using 99mTc filtered tin colloid in N0 squamous cell carcinomas of the oral cavity is technically feasible and appears to accurately predict the presence of the occult metastatic disease.

Vanishing bone disease involving the pelvis.

Vanishing bone disease is a rare condition characterized by progressive osteolysis of the bony structures by vascular tissue and their replacement by fibrous, vascular connective tissue. A 38-year-old lady who had a previous history of angioma of the left iliac bone presented with vague symptoms of a limping gait and pain during walking since 2 years duration. The radiologic findings were suggestive of degenerative changes. A possibility of metastatic disease was also considered. However the biopsy and Positron emission tomography (PET) scan ruled out any active disease. Like in most other cases this was possibly a self-limited disease where bone resorption had spontaneously arrested.

Comparison of myocardial perfusion imaging studies with technetium 99' tetrofosmin and coronary angiography findings in non-diabetic and diabetic patients of ischemic heart disease

The main objective of this study was to compare the results of myocardial perfusion imaging studies with Tc99' tetrofosmin and coronary angiography finding in non-diabetic and diabetic patients of ischemic heart disease. This study compared the results of Single Photon Emission Computed Tomographic [SPECT] imaging with technetium-99m tetrofosmin with those of coronary angiography findings in non-diabetic and diabetic patients of ischemic heart disease. Total 35 patients were included in this study and divided in to two groups, the diabetic group and non-diabetic group. Out of 35 patients 18 were were non-diabetics and 17 were diabetics. All the patients underwent stress/rest imaging with technetium tetrofosmin and coronary angiopgraphy. SPECT images were divided in to five segments per patients and >= 70% occlusion of coronary artery were considered to be significant. In comparison with nondiabetic from diabetics, the diabetics have significant number of reversible ischemia in anterior wall [p=0.023] although the angiography findings showed no significant difference in the severity of disease in left anterior descending coronary artery that is the main coronary artery to supply the anterior wall. This shows that due to diffuse disease in diabetics the severity of disease could not be assessed correctly by coronary angiography because due to diffuse nature of disease there is a lack of normal lumen for comparison. Therefore in diabetics myocardial perfusion imaging is more informative as compared to non-diabetics

Gammagrafía de perfusión miocárdica con Tecnecio 99m- MIBI para predecir al año, la evolución de mujeres referidas para evaluación de dolor precordial / Myocardial perfusion scintigraphy with Technetium 99m-MIBI to predict the evolution at one year of women referred for evaluation of precordial pain

Con el propósito de evaluar la capacidad de tecnecio-99m metoxi-isobutil-isonitrilo (Tc99m -MIBI) para predecir la evolución de mujeres enviadas para evaluación de dolor precordial, se estudiaron las tasas de sucesos cardiovasculares al año en un grupo de pacientes con gammagrafía normal (grupo 1: 17 pacientes) y en otro con defectos de perfusión reversible (grupo 2: 17 pacientes). Se aplicó el protocolo de un día para la gammagrafía con Tc99m -MIBI (reposo/estrés), con estrés combinado (bicicleta ergométrica más 0,28 mg/kg de dipiridamol) en los casos en que fue necesario. Se hizo análisis cualitativo y cuantitativo de la captación regional. Las pacientes del grupo 1 eran más jóvenes que las del grupo 2 (edad promedio: 49 vs 55 años, respectivamente, p=0,04); y también tuvieron menos hipercolesterolemia (12 por ciento vs 59 por ciento, respectivamente, p=0,01). Se calcularon las tasas de aparición de sucesos cardiovasculares al año para las pacientes del grupo 2 usando el método de Kaplan.-Meier. Las tasas de aparición de sucesos clínicos (infarto miocárdico y angina inestable) y de necesidad de procedimientos de revascularización (angioplastia coronaria transluminal percutánea y cirugía de bypass aortocoronario) fueron 0,24 en ambos casos. Solo una paciente del grupo 1 presentó angina variante a los 5 meses. No hubo muertes en ninguno de los grupos. El 94 por ciento de las pacientes con gammagrafía de perfusión normal estuvo libre de eventos al año de seguimiento, mientras que solo el 53 por ciento de aquellas con defectos reversibles de perfusión mostraron igual comportamiento. Concluimos que la gammagrafía de perfusión miocárdica con Tc99m -MIBI es un instrumento útil para predecir la evolución al año de mujeres referidas para evaluación de dolor precordial

Visualisation of medullary carcinoma thyroid with locally formulated 99mTC [V] DMS and comparison with 131I-MIBG scintigraphy

Technetium-99m [pentavalent] dimercaptosuccinic acid [99mTc [V] Dms] scintigraphy was performed in one patient with histopathologically confirmed medullary carcinoma thyroid [MCT] using a locally formulated kit. Marked uptake of the tracer by the primary and locally metastatic sites was noted. The same patient was also subjected to Iodine-131-metaiodobenzoilguanidine [131I-Mibg] scintigraphy and the results were found comparable. Better resolution, easy in-house formulation, labelling with 99mTc [V] Dms makes it a better imaging agent as compared to 131I-Mibg for the imaging of the primary and metastatic medullary carcinoma thyroid in our setup. Furthermore, the formulation of 99mTc [V] Dms is simple and convenient procedure. A 52 years old male patient of medullary carcinoma thyroid was diagnosed seventeen years back and successfuly operated for a solitary nodule in the neck at that time. On a routine follow-up visit he was found to have two discrete, firm, palpable nodules in front of his neck. To determine if the nodules were locally metastatic medullary carcinoma thyroid, the patient was prepared for imaging with 99mTc [V] DMS [locally formulated] and 131I-MIBG. The preparation included giving Lugol's iodine in sufficient quantity [10 drops of the solution three times a day for ten days dissolved in water or milk] to block the free pertechnetate uptake in case of 99mTc [V] DMS and 131 I uptake in 131I-MIBG scintigraphy by the thyroid gland. The patient was first subjected to 99mTc [V] DMS and later on to 131I-MIBG scintigraphy. A kit of renal dimercaptosuccinic acid [DMS] supplied by Nuclear Chemistry Division [NCD] Radioisotope Production Group [RIPG], Pakistan Institute of Nuclear Science and Technology [PINSTECH], Islamabad, Pakistan, was taken and 0.2 ml of sterile solution of 7.0% NahCO3 was added and adequately mixed. After that 15 mCi of 99mTc-pertechnetate fresh elute was added into it [upto 150 mCi can be added]. The radio-pharmaceutical [RP] was incubated for fifteen minutes. Quality Control [QC] tests were carried out and labelling efficiency was found to be > 90%. The RP was then injected into the median cubital vein of the forearm of the patient. For 99mTc [V] DMS imaging Toshiba scintillation camera with low-energy-all-purpose [LEAP] collimator was used. A 15% window centred at 140keV g rays energy was set for imaging. After two hours imaging was done for cervico-thoracic region and abdomen. After one week of the 99mTc [V] DMS the patient underwent 131I-MIBG scintigraphy. The 131I-MIBG was formulated at NCD, RIPG, PINSTECH Pakistan with labelling yield of > 90%, the 131I-MIBG was also injected into the median cubital vein by a slow i.v. infusion and having a close look at the vital signs like pulse, blood pressure and respiratory rates. Imaging was done on 1, 2 and 3 postinjection days. Siemens' scintillation gamma camera with large field of view coupled to high-energy-all-purpose [HEAP] parallel hole collimator was employed for imaging. The gamma camera was linked to on-line computer system MicroDelta and Micro Dot imager. The acquisition parameters were as follows: Symmetric energy window was set as 15% centred at the 364 keV Peak energy of 131I. All the images were interpreted by three experienced nuclear physicians in view of the clinical presentation of the patient. Marked uptake of 99mTc [V] DMS was seen in three foci of the neck, corresponding to the palpable nodules in the neck

Comparison between 99m Tc-methoxyisobutyl isonitril and 99m Tc-methylenediphosphonate scintimammography for detection of breast carcinoma

The goal of the study was to assess the values of scintimammography with 99mTc-methoxyisobutyl isonitrile [99mTc-MIBI] and 99mTc-methylenediphosphonate [99mTc-MDP] in detecting breast cancer. A total of 35 women with clinical findings of suspicious breast lesions were studied with both 99mTc-MIBI and 99mTc-MDP scintimammography. All patients underwent surgery within 1 week, and the results of the histopathological diagnosis were obtained. Eighteen of 35 abnormalities of the breast were pathologically confirmed as primary breast cancer and 17 as benign lesions. In this group of patients, the sensitivity, specificity and accuracy of 99mTc-MIBI scintimammography were 77.8, 88.2 and 82.9%, respectively, while those of 99mTc-MDP scintimammography were 72.2, 88.2 and 80.8%, respectively. There was no significant difference between the results of 99mTc-MIBI and 99mTc-MDP scintimammography. This study demonstrated a high diagnostic accuracy of both 99mTc-MIBI and 99mTc-MDP scintimammography in detecting breast cancer. Both radiopharmaceuticals can be used as an adjunct method for the noninvasive assessment of breast cancer prior to surgery. However, 99mTc-MDP is less expensive and more readily available than 99mTc-MIBI

Lymphoscintigraphy in staging and management of breast cancer.

Internal mammary lymphoscintigraphy (IML) is a simple non-invasive and reproducible technique to determine the extent of the parasternal node invasion in patients suffering from breast cancer. A total forty four patients--37 before surgery or any sort of treatment and seven patients after having undergone surgery, chemotherapy and/or radiotherapy were included in this study to assess the potential role of lymphoscintigraphy in the context of the present 'state of the art' of staging and management of breast cancer patients in Bangladesh. The scintigraphic test was done using Technetium 99m (Tc-99m) Antimony sulfide colloid in a dose of 500 microCi injected interstitially into the sub-costal space. Images were obtained after two to three hours on a Gamma Camera and the study findings were then interpreted as normal, abnormal and equivocal. The scintigraphic images obtained in patients who had undergone surgery, chemotherapy and/or radiotherapy were difficult and more challenging to interpret than those images obtained from patients before surgery or other therapy. This was evidenced by the high number (71%) equivocal cases of IML findings in patients after treatment as compared to only 22% equivocal cases in patients studied before surgery or other therapy. Parasternal lymph node involvement was found to occur regardless of the site or size of the primary tumour. Thirty three percent of tumours located in the outer quadrant showed abnormal nodes on IML. When the size was considered, IML was found abnormal in 22.20% patients with tumour size less than 2 cm in diameter. Correlation of IML with clinically palpable lymph nodes showed abnormal scan findings in 18% patients without clinically demonstrable axillary lymph nodes. These findings are in agreement with previously published data and suggests that conventionally classified stage I patients may in effect be in stage II or even in stage III of the disease. In conclusion, when the technique of lymphoscintigraphy is done with a comprehensive overview of the patient, and when the interstitial injection site is correct, it will generally lead to a logical and clinically useful interpretation of the data for more efficient management of the patient with breast cancer.

Role of99m TC-methoxy-isobutyl isonitrile scintimammography in the evaluation of palpable breast masses

99mTc-methoxy-isobutyl-isonitrile [99mTc-MIBI] was utilized as a tumor localizing agent in the evaluation of palpable breast masses. A total of 24 patients with palpable breast masses, along with 8 women with no palpable breast pathology [control population] underwent 99mTc-MIBI scintimammography. Multiple planar views were obtained. Focal area of increased tracer uptake corresponding to the palpable lump was considered as malignant. The scintimammograms indistinguishable from the control population were considered as benign that is no tracer uptake in the palpable mass was considered as benign. All of the 14 breast carcinoma lumps of 13 patients [one case had two lumps in the same breast] were correctly detected using 99mTc-MIBI scintimammography. Twelve of the 14 lumps were correctly diagnosed as benign in 9 patients [one patient had 4 masses and another had 2]. Abnormal focal 99mTc-MIBI uptake was observed only in one fibroade- and one fibrocystic disease patient. The sensitivity and specificity was 100 and 87% espectively. It was concluded that 99mTc-MIBI scintimammography shows a high sensitivity and specificity for carcinoma breast and therefore has the potential to reduce the large number of unnecessary breast biopsies

Somatostatin receptor tumor imaging (Tc 99m P829) in pituitary adenoma.

Technetium 99m P829 (99mTc P829) is a somatostatin like structure labelled with Technetium-99m. Somatostatin receptor positive tumors such as pituitary tumors, neuroendocrine tumors, and lymphomas show positive scintigraphy. Eleven patients suspected of having a pituitary mass (12 studies) were studied with 99mTc P829. Three pituitary adenoma patients (4 studies) showed positive somatostatin receptor tumor imaging. Eight negative somatostatin receptor scintigraphy were one hypothyroid induced pituitary hyperplasia, one craniopharyngioma, one normal pituitary tissue with focal hyperplasia, one ACTH secreting pituitary tumor, one GH, PRL secreting pituitary tumor post transphenoidal partial tumor removal, and no surgery in 3 patients. Finally, somatostatin receptor imaging may be useful as a tumor localizing technique in addition to conventional CT and MRI imaging and identify patients who might potentially benefit from octreotide treatment. In addition, the development of peptide analogs coupling to beta-emitting radiopharmaceutical may lead to a situation in which diagnosis peptide receptor scintigraphy can be followed by radionuclide therapy.

Produçäo de conjuntos reativos liofilizados para obtençäo de L, L-ECD-99mTc / Production of lyophilized kits for labelling L, L-ECD with technetium-99m

Estudos recentes têm demonstrado que o radiofármaco L, L-ECD-99mTc apresenta estabilidade in vitro e características favoráveis para o estudo da perfusäo cerebral. O presente trabalho descreve a obtençäo de conjuntos reativos liofilizados de L, L-ECD para pronta marcaçäo com 99mTc, compostos de 1mg de L,LECD, 0,125 mg de SnCl2.2H2O,24,0 mg de manitol e 0,36 mg de EDTA em pH 2,0-3,0. Os conjuntos reativos estéreis e apirogênicos apresentam estabilidade superior a 4 meses quando estocados em condiçöes ideais, mostrando-se estáveis após a marcaçäo por período superior a 4 h. Os estudos de distribuiçäo biológica em camundongos mostram rápido clareamento sanguíneo e a habilidade do complexo de atravessar a barreira hemato-encefálica. As captaçöes cardíaca e pulmonar säo inexpressivas e o complexo é eliminado pelas vias renal e intestinal. As imagens estáticas planares anterior e lateral mostram uma captaçäo intensa e persistente do complexo no cérebro do cachorro