Perfused lung volume to thoracic gas volume ratio (perfused lung fraction) in patients with COPD and in controls.

BACKGROUND: The deterioration of the ventilation-to-perfusion distribution in patients with chronic obstructive pulmonary disease (COPD) reflects structural changes affecting both the airways and the blood vessels. These changes result in lung perfusion abnormalities that may be quantified by lung perfusion single photon emission computed tomography (SPECT). OBJECTIVE: To compare the perfused lung fraction (PLF) in patients with airflow obstruction and controls. METHODS: Fourteen patients with COPD and 21 controls underwent spirometry, whole-body plethysmography, and lung perfusion SPECT. PLF was derived from the ratio of perfused lung volume (measured by SPECT) to thoracic gas volume (measured by whole-body plethysmography). RESULTS: In the whole study sample, there were 18 (51%) women and 17 (49%) men, mean age was 46.2 (±20.3) years, range: 18-80 years). In the COPD group, PLF was 0.74 (±0.08), whereas in the control group PLF was 0.99 (±0.18) (P<0.001). PLF correlated directly with forced expiratory volume in 1 s to forced vital capacity (r=0.597, P<0.001). Perfused lung volume was 3.66 (±0.64) l in the COPD group compared with 2.71 (±0.70) l in the control group (P<0.001). CONCLUSION: The fraction of lung volume receiving blood from the pulmonary artery is reduced in patients with COPD. The degree of underperfusion seems to correlate with the degree of airflow limitation.

Scintigraphic sentinel node detection in breast cancer patients: paired and blinded comparison of 99mTc dextran 500 and 99mTc phytate.

BACKGROUND: Breast cancer surgery has evolved towards minimizing morbidity, maximizing cure rates and stratifying treatments according to disease stage. Sentinel lymph node biopsy is becoming standard practice in most centres. However, no standard radiopharmaceutical exists. OBJECTIVES: To blindly compare 99mTc dextran 500 and 99mTc phytate in the scintigraphic detection of sentinel lymph nodes. Endpoints were the detection of axillary or internal mammary lymph nodes, number of lymph nodes detected, detectability in the first versus the second hour of evaluation and the relationship between rate of detection and age or body mass index. METHODS: Forty-six patients with histological diagnosis of early breast cancer, without previous surgical treatment, were enrolled in our study. Each patient underwent lymphoscintigraphy twice: on one day with 99mTc dextran 500 and on another day with 99mTc phytate. Images were acquired 1 h and 2 h after tracer administration. RESULTS: Eighty-eight lymphoscintigraphic studies were performed in 44 patients. On the first image (taken at 1 h), 34 patients from the 99mTc dextran group showed sentinel nodes compared with 28 positive examinations using 99mTc phytate (P = 0.113). On the second image (taken at 2 h) 39 patients from the 99mTc dextran group showed positive results compared to 30 positive examinations using 99mTc phytate (P = 0.036). There was no statistically significant correlation between the body mass index or age and the result of the lymphoscintigraphy. CONCLUSION: 99mTc dextran 500 is better than 99mTc phytate for use in a 2 h interval scintigraphic protocol because it demonstrates the sentinel node in a significantly higher number of patients and also showed more lymph nodes suitable for pathological examination.

Sentinel lymph node procedure in patients with epidermoid carcinoma of the anal canal: early experience.

PURPOSE: This study was conducted to assess the feasibility of the sentinel lymph node procedure in patients with epidermoid carcinoma of the anal canal. METHODS: Between February 2001 and November 2002, 14 patients with epidermoid carcinoma of the anal canal and no clinical evidence of inguinal involvement were prospectively enrolled in the study. The sentinel lymph node procedure consisted of a combination of preoperative lymphoscintigraphy with technetium 99m dextran 500 injected around the tumor and intraoperative detection of the sentinel node with a gamma probe. Patent blue V dye was also injected at the periphery of the tumor to facilitate direct identification of the blue-stained lymph node. After removal, the sentinel node was studied by hematoxylin and eosin staining and immunohistochemistry for pancytokeratins (antigen A1 and A3). RESULTS: Detection and removal of sentinel lymph nodes was possible in all patients. There was no correlation between tumor size and pattern of lymphatic drainage to the groin. Tumors located in the midline of the anal canal gave rise to bilateral sentinel nodes in eight of nine cases. In total, 23 sentinel lymph nodes were removed. One patient (7.1 percent) had a node identified as positive for metastatic carcinoma on immunohistochemical staining. Surgical complications were minimal. CONCLUSIONS: The standardized technique was safe and highly effective in sampling inguinal sentinel lymph nodes in carcinoma of the anal canal. It also proved to be useful as an instrument to detect micrometastatic deposits in clinically normal nodes. Our early results suggest the sentinel lymph node procedure may have a role in guiding a more selective approach for patients with anal cancer. Additional studies in a larger patient population to determine the sensitivity and specificity of this method are warranted.

Detecção do linfonodo sentinela em câncer da mama: comparação entre métodos / Sentinel lymph node detection in breast cancer: comparison between methods

Objetivos: avaliar a eficiência da cintilografia mamária, do detector manual de raios gama (probe) e do corante azul vital para a localização do linfonodo sentinela (LNS), estabelecendo a sensibilidade, o valor preditivo negativo (VPN) e a acurácia do mapeamento do LNS. Métodos: neste estudo estão incluídas 88 pacientes com câncer de mama atendidas consecutivamente e com axila clinicamente negativa. Foi utilizado o radiofármaco tecnécio ligado ao colóide dextran 500 (Dextran 99mTc), para cintilografia pré-operatória, realizada em 58 pacientes, e detecção transoperatória com o probe em 53 pacientes. Destas, 47 tiveram as contagens de irradiação gama anotadas e também o intervalo de tempo decorrido entre a injeção e a cirurgia. Foram empregados 2 mL do corante vital Bleu Patente V, injetado em torno do tumor, 5 minutos antes da incisão cirúrgica na axila em todos os casos. O LNS foi avaliado por congelação em 77 casos e todos pela coloração por hematoxilina e eosina. Resultados: a linfocintilografia, realizada em 58 casos, foi útil em 62,1 por cento, sendo que em nove ocorreu mapeamento de dois linfonodos, e com o probe foram confirmados 45 casos (84,9 por cento) dos 53 avaliados. Das 47 com anotação de contagens de raios gama e do tempo decorrido da injeção do radiofármaco até a cirurgia, constituíram-se dois grupos para análise, o grupo dia (27 casos) e o grupo outro dia (20 casos), que se mostraram diferentes, com significância estatística, tanto no tempo decorrido quanto nas contagens de raios gama, porém sem interferência nos resultados de detecção do LNS. A associação do probe e do corante azul resultou em sucesso nos 53 casos avaliados, assim como em 32 dos 35 casos em que só o corante foi usado. A média de idade das pacientes foi 58 anos. Quarenta e uma pacientes tiveram linfonodos axilares com metástase e apenas duas com LNS falsamente negativo, dando sensibilidade de 95,3 por cento, VPN de 95,5 por cento e acurácia de 97,6. Conclusões: o mapeamento do LNS é factível tanto com o uso do tecnécio, aplicado com intervalo variável de 3:00 a 17:00 horas, quanto com o azul vital. Com a associação dos métodos a eficácia foi de 100 por cento. A confirmação histopatológica, em 97,6 por cento dos LNS negativos, torna real a possibilidade de evitar a linfadenectomia nestes casos

Diagnóstico cintilográfico de antro gástrico retido: relato de um caso / Scintigraphic diagnosis of retained gastric antrum: report of a case

Descreve-se um caso de antro gástrico retido, o qual após múltiplas cirurgias foi diagnosticado pela cintilografia abdominal com pertecnetato (99mTcO4-). A especificidade do acúmulo desse radionuclídeo ao nível da mucosa gástrica, permite um diagnóstico preciso na investigaçäo de casos de mucosa gástrica ectópica ou de mucosa antral retida após gastrectomia à BII. O interesse do método encontra justificativa no fato da boa tolerância pelo paciente e da presteza de seus resultados, decisivos para o encaminhamento da conduta terapêutica e conseqüente reduçäo da morbidade e mortalidade em pacientes de alto risco