Scintigraphy for detecting tumour necrosis factor-α on the skin of patients with psoriatic arthritis.

OBJECTIVE: This study assessed the use of scintigraphy and magnetic resonance imaging (MRI) in identifying the presence and amount of tumour necrosis factor-α (TNF-α) in the joint or skin of patients with psoriatic arthritis, to guide the course of treatment more efficiently. METHOD: We compared the results of scintigraphy and MRI in two patients with psoriatic arthritis who underwent technetium-99m (99mTc)-anti-TNF-α scintigraphy, and MRI 5 days later. RESULTS: Greater uptake of 99mTc-anti-TNF-α was observed in the left wrist and right second metacarpal in patient 1, and in the left ulnocarpal joint and distal interphalangeal joint of the left first metacarpal in patient 2. These results correlated with the MRI findings. CONCLUSIONS: 99mTc-anti-TNF-α scintigraphy may recognize the molecule involved in the inflammatory process. This may provide crucial information to help physicians make decisions about which drugs to use based on biological evidence, and which are cost-effective and appropriate for the treatment of choice. To the best of our knowledge, this is the first time that TNF-α has been shown in the skin of a patient using diagnostic imaging methods.

Use of (99m)Tc-doxorubicin scintigraphy in females with breast cancer: a pilot study.

OBJECTIVE: Doxorubicin (Eurofarma, São Paulo, Brazil) is an antitumour agent widely used in the treatment of breast cancer and can be used for tumour tracking when labelled with a radionuclide. Here, we present the results obtained with technetium-99m ((99m)Tc)-doxorubicin, using the direct method, to evaluate its uptake in breast cancer. METHODS: Four females with confirmed breast carcinoma diagnosis and breast image reporting and data system Category 5 on mammography underwent whole-body and thorax single-photon emission CT/CT imaging 1 and 3 h after (99m)Tc-doxorubicin administration. RESULTS: We observed increased uptake in breast carcinoma lesions and elimination via renal and hepatic pathways. CONCLUSION: These preliminary results suggest that (99m)Tc-doxorubicin may be a promising radiopharmaceutical for the evaluation of patients with breast cancer. Further studies are ongoing. ADVANCES IN KNOWLEDGE: To our knowledge, this is the first study to evaluate the use of a directly labelled doxorubicin tracer in humans. (99m)Tc-doxorubicin could provide information on the response of tumours to doxorubicin.

Use of 99mTc-doxorubicin scintigraphy in females with breast cancer: a pilot study.

OBJECTIVE:: Doxorubicin (Eurofarma, São Paulo, Brazil) is an antitumour agent widely used in the treatment of breast cancer and can be used for tumour tracking when labelled with a radionuclide. Here, we present the results obtained with technetium-99m (99mTc)-doxorubicin, using the direct method, to evaluate its uptake in breast cancer. METHODS:: Four females with confirmed breast carcinoma diagnosis and breast image reporting and data system Category 5 on mammography underwent whole-body and thorax single-photon emission CT/CT imaging 1 and 3 h after 99mTc-doxorubicin administration. RESULTS:: We observed increased uptake in breast carcinoma lesions and elimination via renal and hepatic pathways. CONCLUSION:: These preliminary results suggest that 99mTc-doxorubicin may be a promising radiopharmaceutical for the evaluation of patients with breast cancer. Further studies are ongoing. ADVANCES IN KNOWLEDGE:: To our knowledge, this is the first study to evaluate the use of a directly labelled doxorubicin tracer in humans. 99mTc-doxorubicin could provide information on the response of tumours to doxorubicin.

A pilot study evaluating 99mTc-anti-TNF-alpha scintigraphy in graves' ophtalmopathy patients with different clinical activity score.

The present study describes the preliminary results of the use of 99mTc-anti-TNF-α scintigraphy as a new diagnostic approach to evaluate patients presenting with Graves' ophthalmopathy (GO). Patients (n=25) presenting at different inflammatory stages of GO and 10 healthy volunteers underwent 99mTc-anti-TNF-α scintigraphy. Images were obtained 15 min after the intravenous injection of 370 MBq (10 mCi) 99mTc-anti-TNF-α. Planar images were obtained in a 256×256 matrix (each lasting 5 min) and single photon emission computed tomography (SPECT) scan lasting 13 min. Regions of interest (ROI) were drawn on the orbit and cerebral hemispheres. The uptake of 99m Tc-anti-TNF-α in these regions was compared and positive scintigraphy established when the ROI was >2.5. In addition, uptake for each positive exam was scored as either slight (2.6-5.1), moderate (5.2-7.6), or high (>7.6). In this pilot study, 69 orbits were evaluated (1 patient had only 1 eye), and 27 had a positive CAS (≥3/7). Scintigraphies were positive in 38 orbits. Comparing the results of the exams with CAS, a high sensitivity and negative predictive values were determined for scintigraphy (96.3% and 96.7%, respectively). However, the specificity and the positive predictive values were 71.4% and 68.4%, respectively, with an accuracy of 81.2%. The exclusion of examinations that were slightly positive from the analysis resulted in an improvement in test accuracy (95.5%). The preliminary results suggest that 99mTc-anti-TNF-α scintigraphy is a promising procedure for the evaluation of active orbital inflammation in GO.

Radioactive synovectomy with (90) yttrium and (153) samarium hydroxyapatite in haemophilic joints: preliminary study on radiation safety.

Most countries still do not achieve 1 IU of factor VIII/capita sufficient for survival. Although primary prophylaxis prevents synovitis, is not universally used. Chronic synovitis is treated with arthroscopy at expense of considerable amount of coagulation factors, and specialized surgeons. Radioactive synovectomy (RS) is a minimally invasive and cost effective alternative to arthroscopy, often considered first the option for persistent synovitis. Even without established causation with cancer, RS is avoided by some, due to this concern. We aim contributing to the understanding of RS safety regarding malignancy, presenting a large number of treated patients, and a single case of cancer. Three centres in Brazil applied RS with (90) Yttrium Citrate, (90) Yttrium hydroxyapatite or (153) Samarium hydroxyapatite in haemophilic joints and performed a survey addressing cancer in these patients. Four hundred and eighty eight patients (ages 3-51) received 1-3 RS (total 842) and follow-up was 6 months to 9 years. One patient aged 14 years presented Ewing sarcoma, 11 months after RS. The tumour was treated successfully with surgery and chemotherapy. Causality of cancer by RS is improbable in this case. Accordingly, latency here is far below minimum 5-10 years for radio-induction of solid tumours. Moreover, ES is not a typically radio-induced tumour, even at high doses. In agreement with others, though recognizing limitations, this study suggests RS is safe regarding cancer induction. Synovitis is a known burden for patients. The decision of making reasonable usage of RS should be outweighed with the risks of leaving synovitis untreated.

9°Yttrium-hydroxyapatite: a new therapeutic option for radioactive synovectomy in haemophilic synovitis.

Recurrent haemarthroses often lead to chronic synovitis in patients with haemophilia and von Willebrand disease. Radioactive synovectomy with yttrium-90 (9°Y) citrate is frequently used to treat this complication, usually with good results. Since 2006, the Nuclear Energy Research Institute (IPEN, Sao Paulo, Brazil) has produced hydroxyapatite particles labelled with 9°Y for radioactive synovectomy. The aim of this study was to compare the results achieved by both forms of 9°Y in the treatment of haemophilic synovitis. We included 221 joints from 136 patients (age range: 6-20 years), treated by one of the two radiopharmaceuticals, at the Hemocenter of Mato Grosso, Brazil. The outcomes analysed were the annual frequency of haemarthrosis, articular pain and joint range of motion before and 1 year after RS. Similar results were achieved regardless of whether 9°Y hydroxyapatite or 9°Y citrate was used, and results were independent of the joint type, age, gender, radiologic stage and presence of inhibitors. 9°Y hydroxyapatite appears to be equivalent to the reference product 9°Y citrate in the treatment of chronic synovitis associated with bleeding disorders.

Intraobserver interpretation of breast ultrasonography following the BI-RADS classification.

PURPOSE: To use the BI-RADS ultrasound classification in an intraobserver retrospective study of the interpretation of breast images. MATERIALS AND METHODS: The study used 40 breast ultrasound images recorded in orthogonal planes, obtained from patients with an indication for surgery. Eight professionals experienced in breast imaging analysis retrospectively reviewed these lesions, in three rounds of image interpretation (with a 3-6 months interval between rounds). Observers had no access to information from medical records or histopathological results, and, without their knowledge, in each new round were assigned the same images previously interpreted by them. Fleiss-modified Kappa measures were the study main concordance index. Besides the BI-RADS, a scale grouping its categories 2-3 and 4-5 was also used. The statistical analysis concerned the intraobserver agreement. RESULTS: Kappa values ranged from 0.37 to 0.75 (original categories) and from 0.73 to 0.87 (grouped categories). Overall, out of the 8 observers, 7 presented moderate to substantial concordance (Kappa values 0.51 to 0.74). CONCLUSION: The BI-RADS is a reporting tool that provides a standardized terminology for US exams. In this study, moderate to substantial concordance in Kappa values was found, in agreement with other studies of the literature.

Bone marrow cell transplant does not prevent or reverse murine liver cirrhosis.

We tested the effect of bone marrow cell (BMC) transplantation in either preventing or reversing cirrhosis on an experimental model of chronic liver disease. Female Wistar rats were fed a liquid alcohol diet and received intraperitoneal injections of carbon tetrachloride (CCl4) over 15 weeks. Ten animals (cell-treated group) received five injections of BMCs during the cirrhosis induction protocol (on the 4th, 6th, 8th, 10th, and 12th weeks) and four animals received the cells after liver injury was established through tail vein. Nine animals (nontreated group) were submitted to the previously described protocols; however, they received vehicle injections. Analyses were performed to verify whether the infusion of cells was effective in preventing the development of cirrhosis in our model of induction, and if the cells could reverse cirrhosis once it was established. Hepatic architecture and fibrotic septa were analyzed in liver slices stained with hematoxilin & eosin and Sirius red, respectively. Fibrosis quantification was measured by Sirius red histomorphometry. Indirect immunofluorescence was performed to detect the amount of tissue transglutaminase 2. Blood analyses were performed to assess liver injury and function by the assessment of alanine aminotransferase and albumin. Ultrasound was performed to analyze the portal vein caliber and presence of ascitis. Cirrhosis features (regenerative nodules and fibrous septa) were observed in histopathology after 15 weeks of continuous hepatic injury in nontreated and cell-treated groups. Collagen content, immunofluorescence analysis, and biochemical and ultrasound parameters were similar in nontreated and cell-treated groups; however, both groups showed significant differences compared to a normal control group. Cell infusions with bone marrow-derived cells seem to be ineffective in improving morphofunctional parameters of the liver when applied to chronic cases either during or after establishment of the hepatic lesion.

Monitoring rheumatoid arthritis synovitis with 99mTc-anti-CD3.

The aim of this study was to investigate the feasibility of using a monoclonal antibody (OKT3) labelled with technetium-99m (99mTc) to monitor disease activity in patients with rheumatoid arthritis. We evaluated 38 patients who were diagnosed with rheumatoid arthritis and classified as Classes II and III after functional assessment (according to the revised criteria specified by the American College of Rheumatology). Two sets of planar anterior images of the patients' wrists, metacarpophalangeal and interphalangeal joints, elbows, shoulders and knees joints were obtained 1 h and 3 h after the injection of 99mTc-OKT3. The scintigraphic findings showed significant correlation (p<0.05) between the radiopharmaceutical accumulation of 99mTc-OKT3 and swollen joints, tender joints and the visual analogue scale. They were able to differentiate patients in remission from patients with active synovitis, according to DAS 28. In contrast, there was no correlation between the radiopharmaceutical accumulation and the patients' age, gender, duration of disease or erythrocyte sedimentation rate. A relatively high disease activity score of 28 joints (4.08+/-1.74) was found in the majority of patients. In conclusion, 99mTc-OKT3 scintigraphy is a reliable and objective method for detecting synovial activity, and can be used to observe disease prognosis.

Radioguided occult lesion localization (ROLL) and excision of breast lesions using technetium-99m-macroaggregate albumin and air injection control.

The aim of this study was to assess the efficiency of the radioguided localization and excision technique using radiopharmaceuticals injected directly or close to occult breast lesions. We studied thirty-two consecutive patients with thirty-six occult breast lesions detected mammographically or ultrasonically categorized as BI-RADS 3, 4 or 5. Macroaggregate Albumin (MAA) labeled with (99m)Tc was administered directly or close to the lesion, guided by mammography or ultrasound, followed by an air injection for radiological control. The excision biopsy was carried out with the aid of a hand-held gamma detecting probe and the entire removal of the lesion was verified by X-ray of the surgical specimens or by intraoperatory frozen section examination. Breast cancer was found in 8.3% of BI-RADS 3 lesions, in 33.3% of the BI-RADS 4 lesions and in 66.6% of the BI-RADS 5 lesions. The radiotracer was correctly positioned in 97.2% of the specimens (35/36) allowing the removal of 97.2%. Xray confirmed the entire removal in 27 lesions (75%), intraoperatory frozen section study in 19.4% (7/36) and by both methods in 5.5% (2/36). Radioguided surgery turned out to be an important tool in the removal of non-palpable breast lesions, as a simple, fast and feasible method that can be implemented in the clinical routine of patients with non-palpable breast lesions.

Failure predictors of the sentinel lymph node in patients with breast cancer using Tc-99m sulfur colloid and periareolar injection.

AIM: As sentinel lymph node (SLN) experience rises, it is important to identify factors that can limit lymphoscintigraphic mapping. METHODS: A prospective study was conducted with breast cancer patients that were submitted to sentinel node mapping by lymphoscintigraphy between October 2003 and January 2005. The analyzed factors were: patients' age, body mass index, tumor size, previous breast surgeries, time between a previous biopsy and the radiotracer injection and their impact on preoperative SLN identification. RESULTS: Two hundred and three breast cancer patients were injected with (99m)Technetium-sulfur colloid and submitted to lymphoscintigraphy scan for SLN biopsy. One hundred and eighty-four of these patients (90.64%) had a successfully identified SLN and 19 (9.36%) had a mapping failure. The median age of the successful group was 55.6 years and in the failure group was 57.1 years (P=0.002). The median body mass index was 25.3 and 27.6, respectively (P=0.024). The tumor size did not show any significant difference between the patients with successful mapping and failure (P=0.07). Previous breast surgery was an important limiting factor for SLN mapping (P=0.017). The mean time from biopsy to SLN detection was 23.6 days on the successfully marked patients and 17.4 days in the failure group (P<0.0001). All the 184 successfully mapped patients had the SLN identified. Only one patient of the failure group had the SLN identified using blue dye. CONCLUSION: Advanced age, elevated body mass index, previous breast surgery and a shorter period of time after a breast biopsy are causes for SLN identification failure. The tumor size was not a limiting factor.

Assessment of takotsubo (ampulla) cardiomyopathy using iodine-123 metaiodobenzylguanidine scintigraphy.

PURPOSE: To evaluate the role of cardiac sympathetic innervation in patients whose clinical features consisted of chest pain, transient ST-segment elevation, left ventricular apical akinesis, minimal elevation of cardiac enzymes, and onset of symptoms shortly after a severe stress condition. MATERIAL AND METHODS: Five female patients, mean age 67+/-14 years, underwent thoracic 123I-MIBG (planar and SPECT) and 67Ga citrate (planar) scans within 5 days after the onset of symptoms. The 123I-MIBG myocardial washout rate between early (30 min) and delayed (3 hours) planar images was calculated. All patients presented findings consistent with takotsubo-like syndrome. Echocardiograms showed the characteristic wall motion pattern of significant apical dysfunction. Acute-phase coronary angiographies revealed a non-obstructive pattern. A peculiar apical akinesis and basal normokinesis were observed on the ventriculograms. RESULTS: Impairment of cardiac neuronal uptake of 123I-MIBG based on a reduction of the heart-to-mediastinum uptake ratio was observed in all patients, while the washout rate was raised in four patients. All patients presented an apical uptake defect in the 123I-MIBG SPECT and planar images and a normal 67Ga scintigraphy. CONCLUSION: Our data indicate that ampulla cardiomyopathy (AC) is associated with a cardiac sympathetic innervation deficit characterized by a reduced global 123I-MIBG uptake and an apical uptake defect. The lack of 67Ga uptake in the acute phase of this syndrome indicates that AC is probably not associated with an inflammatory process.

Use of 99mTc-mononuclear leukocyte scintigraphy in nosocomial fever.

PURPOSE: To determine the overall diagnostic accuracy of mononuclear leukocyte- 99mTc scintigraphy in the routine detection of infectious lesions and fever of unknown origin (FUO) in inpatients. MATERIAL AND METHODS: The use of mononuclear leukocyte 99mTc scintigraphy is presented in 87 patients who fulfilled the Durack and Street diagnostic criteria of nosocomial FUO; 66 patients were suspected of having infectious lesions (myocarditis, endocarditis, infected catheters, diabetic foot, and osteomyelitis) and 21 patients presented with unknown causes of FUO. Scans were carried out 1, 3, and 24 h after injection of labeled leukocytes. RESULTS: In three cases (3/27) where scintigraphs were negative, biopsies were positive. There were two (2/87) false-positive scintigrams. We found a 95.8% sensitivity and 92.3% specificity. PPV was 93.8%, PPN 94.7%, and accuracy 94.2%. CONCLUSION: Mononuclear leukocyte 99mTc scintigraphy showed high sensitivity, specificity, positive and negative predictive values in patients with nosocomial FUO. These results suggest an important role for nuclear medicine in the management of patients with infection/inflammation.

Oesophageal dysmotility in systemic sclerosis: comparison of HRCT and scintigraphy.

The aim of this study was to compare oesophageal abnormalities observed in high-resolution CT with radionuclide transit in patients with systemic sclerosis. 76 patients with systemic sclerosis were evaluated by high-resolution CT and oesophageal transit scintigraphy. Residual activity > or =20% (in relation to peak activity) at 15 s after the beginning of the swallow of the labelled liquid (in supine position) was considered indicative of oesophageal dysfunction. Supra-aortic and infra-aortic oesophageal coronal diameters were measured in high-resolution CT. Oesophageal dilatation was deemed present when the diameters exceeded 10 mm. 19 patients (25%) had supra-aortic oesophageal dilatation and 48 patients (63.1%) had infra-aortic dilatation. The prevalence of radionuclide transit delay was 77.6%. All patients (19/19) with supra-aortic dilatation had oesophageal dysfunction, compared with 70.2% (40/57) of the patients with no supra-aortic dilatation (p = 0.004). Oesophageal dysfunction was present in 97.9% (47/48) of patients with infra-aortic dilatation, compared with 42.9% (12/28) in patients without it (p < 0.001). Receiver operating characteristic (ROC) curves have demonstrated that the supra-aortic and infra-aortic diameters had good discriminatory capacity for oesophageal dysfunction in systemic sclerosis (area under the curve, 95% confidence interval: 0.80, 0.70-0.89 and 0.92, 0.86-0.98, respectively). There is a clinically significant association between oesophageal dysmotility and high-resolution CT findings of oesophageal coronal dilatation. The evaluation of infra-aortic oesophageal coronal diameter can provide additional useful information about the functional and anatomic conditions of the oesophagus in systemic sclerosis.

Sentinel node identification by scintigraphic methods in cutaneous melanoma.

In melanoma patients lymph node metastasis is an important prognostic factor that indicates the need for therapeutic lymph node dissection. Preoperative lymphoscintigraphy mapping associated with radioguided sentinel lymph node biopsy has become a well established procedure for cutaneous melanoma patients without clinically detectable lymph node metastases (stage I, II). This technique is a versatile way of characterizing the lymphatic basin at risk for metastases and identifying involved lymph nodes. The purpose of the present study was to examine the reproducibility of lymphoscintigraphy and sentinel lymph node biopsy in detecting micro metastases in cutaneous melanoma. The study was a single-institution prospective analysis of 74 melanoma patients, with primary tumors having Breslow thickness > 0.7 mm, who underwent lymphoscintigraphies between May 2002 and September 2003. Technetium-99m sulfur colloid was injected intradermally at the primary tumor site and dynamic images were obtained for 40 minutes. Two observers evaluated the images. One to two weeks after the first lymphoscintigraphy, radioguided lymph node biopsy was performed. For the biopsy, technetium-99m sulfer colloid was injected intradermally in the same manner as performed before. Lymph nodes were identified and removed with the aid of a gamma ray detecting probe (GDP), and were submitted to histopathological analysis. The histopathological analysis of the sentinel lymph nodes collected during surgery was performed in a sequential manner. First, frozen sections were analyzed during surgery. The lymph nodes considered negative by frozen section were analyzed by H&E staining. Subsequently, the slides considered negative with H&E were sent for immunohistochemical analysis. Lymphoscintigraphy identified at least one sentinel lymph node in all patients. Sentinel node biopsy detected metastases in 20 patients (27.2%). In all cases the lymph node basins identified during lymphoscintigraphy were found to have at least one sentinel lymph node during surgery. Frozen section analysis of the lymph node was only able to identify the disease in 35% of the patients eventually found to have micrometastases with H&E and immunohistochemistry. Two lymph nodes were negative with H&E and positive with immunohistochemical analysis. In conclusion, lymphoscintigraphy is a simple procedure that is well tolerated by patients. It is useful in locating sentinel lymph nodes in patients with melanoma and is an important tool in the clinical practice of oncology. We recommend performing H&E, and if necessary, immunohistochemical analysis of all sentinel lymph nodes because of the high rate of false negative results with frozen sections alone.

Preliminary results of [99mTc]OKT3 scintigraphy to evaluate acute rejection in renal transplants.

Allograft rejection can be classified as humoral or cellular mechanisms. Accurate diagnosis of acute rejection remains a formidable challenge in renal transplantation. The need to avoid unnecessary immunosuppressive therapy to treat this complication has led to a continued search for improved diagnostic methods to evaluate and identify postoperative episodes. Here we evaluated the use of [(99m)Tc]OKT3 scintigraphy to diagnose acute rejection in renal transplants. Among 22 patients undergoing renal transplant, we observed an increased [(99m)Tc]OKT3 kidney uptake with the passage of time in patients with rejecting allografts. These findings agreed with those of biopsies. We suggest the [(99m)Tc]OKT3 scans may be useful for the monitoring of renal transplants to detect acute rejection.

Diagnosis of renal allograft rejection and acute tubular necrosis by 99mTc-mononuclear leukocyte imaging.

One hundred kidney transplant recipients were evaluated on the first and fifth days after transplantation by Tc-99m mononuclear cell scintigraphy. We have developed a quantitative method to diagnose rejection and acute tubular necrosis (ATN) by comparing regions of interest drawn on allograft scintigraphs at different times after endovenous administration of the labeled cells. We suggest that the use of Tc-99m-WBC may be useful for the early diagnosis of rejection and the differential diagnosis of ATN.

Identification of sentinel node in breast cancer: comparison between peritumoral and periareolar injection of the radiopharmaceutical contrast medium.

Axillary node status is the most important prognostic factor for patients with primary breast carcinoma. The sentinel node biopsy (SN) technique has received much attention as a possible alternative to axillary lymph node dissection. The aim of this study is to identify the sentinel node by periareolar and subdermal injection of the radiopharmaceutical in four points, independent of tumor topography and the presence of biopsies and/or previous surgery. The peritumoral injection technique was carried out for comparison purposes. This study was performed on 115 patients, divided into 2 groups: Group A (25 patients, peritumoral injection) and Group B (90 patients, injection in four points). All the SN biopsies were studied by both imprint cytology and H&E staining. Control axillary lymph-node dissection was followed in all patients from Group A and in these positive cases from Group B. Twenty-two out of the twenty-five (88%) SNs were identified in Group A. There was no false negative; the sensitivity and specificity were 100%. Eighty-two of the ninety (91.1%) SNs were identified in Group B. Lymphoscintigraphy showed radiopharmaceutical migration to axilla in 93.7% of the cases. Hotspot area was 10 to 100 times the intensity of the background radiation. Among the 92 cases with negative sentinel nodes at intraoperative examination (TP), the SN histopathology confirmed the absence of cancer cells in 89 patients, whereas 3 were positive for metastatic cells. This study shows that periareolar injection in four points seems to be a good lymphatic mapping method for SN identification. We suggest standardizing this site of injection to identify the SNs. More studies to confirm these findings are ongoing.

Identification of sentinel node in breast cancer.

Axillary lymphadenectomy is a very important procedure in the staging of breast cancer patients. However, it is associated with a significant morbidity rate. On the other hand, using early diagnosis we can see a high number of cases where the lymph nodes are negatives. With the intention of avoiding unnecessary axillary dissection, the possibility of evaluating a single node has been studied. This lymph node, defined as "sentinel node", would be the first to receive tumoral lymphatic drainage. The aim of this study is to evaluate: (i) the efficacy of the methods to identify the sentinel nodes, (ii) estimate the predictability of the histological examination of the sentinel node in comparison to other nodes of the axilla, (iii) compare the efficacy of the frozen section regarding the definitive histological examination of the same node. This study was performed in 29 patients, and the sentinel node was identified in all of them. It was metastatic in 7 (24.1%). Out of the 22 patients where the node was negative, 15 were submitted to complete dissection. Out of these 15, there was one case (6.7%) where one lymph node of the first level was positive. All 7 patients with the positive sentinel node were submitted to axillary dissection. When comparing the histological examination of the sentinel node with other nodes, we got a sensitivity of 87.5%, specificity of 100%, predictive positive value of 100%, predictive negative value of 93% and efficacy of 95%. The intra-operative examination was made in 24/29 cases (82.7%). The correlation between both examinations was 95.8%. This study shows that the technique of the sentinel node will be a reliable method to avoid radical axillary dissection in breast cancer patients with early diagnosis.

Comparison of Tc-99m THY and Tc-99m MIBI scans for diagnosis of breast lesions.

Mammoscintigraphy has recently become a useful method for breast cancer diagnosis, mainly in patients whose X-ray mammography is affected by technical problems. Tc-99m MIBI has been used for this purpose. A noninvasive, improved technique to select those who would most benefit from biopsy of the breast and reduce the number of negative biopsies is clearly of value and still desired. Here, we describe the use of Tc-99m THY in breast carcinoma and show the comparative results with Tc-99m MIBI in 29 patients. We studied a total of 39 women, 32 were patients and 7 healthy volunteers. Of the 32 patients, 3 had bilateral pathology. In addition, mammography imaging and histopathologic findings were presented. Twenty three malignant lesions were taken up by labeled thymine. Of the 12 benign cases there was one false-positive uptake with Tc-99m THY. There was no thymine uptake in the breasts of the healthy volunteers. Of the 30 cases treated with both radiopharmaceuticals there were 4 false-positives and 1 false-negative uptake with Tc-99m MIBI. The results confirm that Tc-99m THY breast imaging has a high specificity of 94.73% (18/19), an accuracy of 97.61% (41/42) and a positive predictive value of 95.83% (23/24) when compared with Tc-99m MIBI specificity of 71.42% (10/14), an accuracy of 86.48% (32/37) and a positive predictive value of 84.61% (22/26) in detection of breast carcinoma. Scintimammography using Tc-99m THY could influence the therapeutic strategy and reduce the number of mammographically recommended surgical biopsies that yield benign results.