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Sentinel node mapping reduces surgical morbidity and allows the use of more accurate tumour staging techniques. Radionuclide studies are preferentially performed using small colloids, which have limited availability in our country. The possibility of using phytate for sentinel node mapping was raised because of the similarity between its biodistribution and that of nanocolloids in the reticulo-endothelial system. In this paper we evaluated the use of 99mTc-phytate for sentinel node mapping, correlating the histopathological results with the status of the rest of the lymph node chain in different malignant tumours. A total of 100 patients were studied. group 1 consisted of 62 patients with breast cancer, group 2 of 20 patients with melanoma and group 3 of 18 patients with vulvar carcinoma. Lymph node scintigraphy was carried out after injecting 99mTc-phytate subdermally, and the sentinel node projection was marked on the skin. After 18-24 h, intraoperative sentinel node localisation was performed using a gamma probe (combined with visual localisation using patent blue dye) in 75 patients, and lymph node dissection was then carried out. Radionuclide scintigraphy identified the sentinel node in 98% of all studies. Intraoperative detection using the gamma probe was equally efficient: group 1=93% (38/41), group 2=95% (18/19) and group 3=100% (15/15). The sentinel node was involved in 41%, 31% and 20% of cases in groups 1, 2 and 3, respectively. Among the patients with positive nodes, the sentinel node was the only one affected in 53% of group 1, 50% of group 2 and 67% of group 3 cases. The method's negative predictive value was 91% in group 1 and 100% in the other groups. One false-negative study occurred in a patient who had a multifocal tumour and an intraparenchymatous lymph node; another occurred in a patient with a macroscopically affected node found during surgery. There were no side-effects related to the 99mTc-phytate. It is concluded that scintigraphic and intraoperative sentinel node identification was satisfactorily performed using 99mTc-phytate. The results were comparable to those previously described in the literature using other radiopharmaceuticals. Easy availability and low cost justify the use of phytate in our practice.

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We studied vertebral morphometry and its relation to bone mineral density (BMD) in normal Brazilian women (n = 605). All women (age 22-97 years) were ambulatory and healthy. A lateral spine scan was done for morphometric X-ray absorptiometry using an imaging densitometer. In 429 of these women, BMD of the spine and proximal femur also were measured using dual-energy X-ray absorptiometry. All women were white with mean (+/- 1 SD) age of 53.7 (+/- 9.5) years. About 21% of the women over 50 years had a T score for spine BMD lower than -2.5 SD, and 7% had a femoral neck BMD below this osteoporosis threshold. Vertebral heights (anterior, HA; middle, HM; and posterior, HP) and ratios (HA/HP and HM/HP) were assessed. There was no systematic difference between younger (20-49 years) and older (50+ years) women in heights or ratios. The vertebral heights were normalized for those observed in each individual case for the L2-L4 sequence. This normalization was adequate for all vertebral heights; the Z score averaged about +0.1. The average Z score for HA/HP was +0.01, but that for the HM/HP was -0.72, indicating that the latter ratio might differ from the reference population used (white American and European women). We observed a small positive correlation between vertebral heights and spine or femur BMD, but this was due entirely to the influence of body size on BMD. On a group basis, the HM/HP showed a significant association with axial BMD; the 1 SD difference between the lowest and highest quartile was associated with a difference of 8-15% (0.5-1.0 SD) in axial BMD.

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OBJECTIVE: To evaluate bone mineral density and bone mineral content of skeleton and lumbar spine of pre-pubertal children and to correlate results thus found with sex, bone age, body weight, height and insulin-like growth factor 1 serum level. METHODS: 26 boys and 12 girls aged between 7 and 8 years old, students from a São Paulo public school, were studied. They all presented weight and height between 2.5 and 97.5 percentiles of the Brazilian childrens curve, lack of secondary sex characteristics, no reports on chronic diseases and normal physical examination. Bone age was determined from radiograms of the left hand and wrist. Serum levels of insulin-like growth factor 1 were measured by radioimmunoassay. Bone mineral density and bone mineral content were measured in skeleton and lumbar spine using a dual X-ray absorptiometry equipment. RESULTS: The mean values of skeleton bone mineral density found were 0.812 -/+ 0.057 g/cm(2) in the girls and 0.839 -/+0.053 g/cm(2) in the boys, while the respective mean lumbar values were 0.649 -/+ 0.092 g/cm(2) and 0.657 -/+ 0.062 g/cm(2). The mean values of skeleton bone mineral content found were 840 -/+ 181g in the girls and 919 -/+ 133 g in the boys, while the respective lumbar values were 13.3 -/+ 3,0g and 14.5 -/+ 2,4. It was found that the bone mass of children at this age corresponds to about 50% of the bone mass pick found in the young adult. No significant bone mass differences between sexes were found. No correlation was found between bone mass and insulin-like growth factor 1 serum levels. Positive correlations between bone mass and body weight and bone age were found. CONCLUSIONS: In pre-pubertal children (1) the analysis of bone mass should be interpreted mainly as a function of body weight and (2) bone mineral density of the lumbar spine and skeleton correlate with bone age and may represent an additional parameter of skeleton maturation.

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Objetivo. Estudar a densidade mineral óssea (BMD) vertebral (L2-L4) e femoral (colo do fêmur) de mulheres brancas, normais. Material e Método. Mediu-se o BMD de 724 mulheres (40-79 Kg; 20-69 anos de idade) por dual-energy x-ray absorptiometry e analisaram-se os dados em funçao da idade e peso corporal (PC). Resultados. As mulheres mais leves (40-49 Kg) atingiram o BMD maximo (BMDm) vertebral e femoral aos 30-39 anos de idade, enquanto as mais pesadas (60-79 Kg) apresentaram BMDm aos 20 anos. No fêmur, houve uma correlaçao significativa entre BMDm e PC (r=0,97, p<0,001; slope=0,72 por cento/Kg). Em L2-L4, apenas as mulheres com 40-49Kg apresentaram BMDm menor do que as demais(p<0,001). A diminuiçao do BMD vertebral foi mais intensa (-8,3 vs. -5,7 por cento/década) e iniciou mais cedo (quarta vs. quinta década) nas mulheres pesando 40-59Kg do que nas pesando 60-79Kg. A diminuiçao do BMD femoral iniciou logo após o BMDm ser atingido e, até os 69 anos, as mulheres mais pesadas apresentaram um decréscimo 5,3 por cento menor do que aquelas pesando 40-49Kg. O BMD vertebral das mulheres brasileiras foi praticamente o mesmo de uma populaçao norte-americana previamente descrita. Conclusoes. 1) O BMD vertebral e femoral das brasileiras estudadas comportou-se, em funçao da idade, de forma semelhante a de outras populaçoes brancas; 2) havendo o cuidado de corrigir o PC, o BMD das mulheres brasileiras é comparavel ao de mulheres norte-americanas; e 3) o PC é importante na aquisiçao e diminuiçao da massa óssea, além de influenciar a relaçao BMD-idade.

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OBJECTIVE: To study the vertebral (L2-L4) and femoral (neck) bone mineral density (BMD) of normal white women. MATERIAL AND METHOD: We measured the BMD of 724 women (40-79 kg; 20-69 years-age) by dual-energy X-ray absorptiometry. Data were analysed as a function of age and body weight (BW). RESULTS: Thinner women (40-49 kg) attained maximal vertebral and femoral BMD (mBMD) at ages between 30-39 years, while heavier women (60-79 kg) already had the mBMD by the age of 20. At the femur, there was a significant mBMD-BW correlation (r = 0.97; p < 0.001; slope = 0.72%/kg). At the spine, only the 40-49 Kg women exhibited lower mBMD when compared to the others (p < 0.001). The decrease of the vertebral BMD was more intense (-8.3 vs. -5.7%/decade) and started earlier (fourth vs. fifth decade) in women weighting 40-59 kg, as compared to those weighting 60-79 kg. The decrease of the femoral BMD was initiated just after mBMD was achieved and, at the age of 69, heavier women showed a decrease that was 5.3% lower than those weighting 40-49 kg. The vertebral BMD of the Brazilian women was practically the same as reported for a North-American population. CONCLUSIONS: (i) Vertebral and femoral BMD of this Brazilian population varied with age similarly to other white female populations; (ii) provided that appropriate corrections are made for BW, the BMD of Brazilian women is comparable to the BMD of North-Americans; and (iii) the BW is important both in acquisition and decline of bone mass, as it influences the relation BMD-age.

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AIMS: To investigate the influence of body weight (BW), fat mass (FM) and lean mass (LM) on the bone mineral density (BMD) of several areas of the skeleton. PARTICIPANTS: Sixty one white postmenopausal women (50.1 +/- 4.8 years). MEASUREMENTS: Measurement of BMD by dual energy x-ray absorptiometry. The results were analyzed by linear regression and the slopes of each curve were compared. RESULTS: The results showed that the correlations between BW, FM and LM to BMD were positive, whilst the correlations between age and years since menopause to BMD were negative. LM was the main factor that influence BMD in almost all areas. CONCLUSIONS: FM and LM present a positive effect on BMD, although LM is the main determinant of bone mass. Moreover, higher values of LM and FM present a protective effect against the reduction of BMD combined with menopause. Therefore postmenopausal women with low BW, especially low LM, present serious risk for developing osteoporosis.

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Osteoporosis is often diagnosed after fracture occurrence, when therapy is less effective. The dual photon densitometry has been the proposed method for osteoporosis early diagnosis. In the present study is presented our experience on the lumbar vertebral and femoral neck bone mass measurement by utilizing a Lunar DP-3 densitometer in normal young 82 volunteers and 103 women with radiologically and clinically diagnosed osteoporosis. The values found in osteoporotical patients were significantly lower when compared to those normals either in lumbar vertebrae (L2-L4) or in the femoral neck. The method's coefficient of variation was less than 0.5%, when determinated with a synthetic phantom aid and less than 1.5% repeating the exam in 10 normal volunteers. These results show that dual photon densitometry is a simple, sensitive and non-invasible method for early diagnosis and therapeutic follow-up of osteoporotical patients.

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