The purpose of this study was to compare the performance of 14- and 12-gauge needles for obtaining biopsy specimens under stereotactic guidance. The authors compared the biopsies of nonpalpable breast lesions using these different size needles, regarding the length of the fragments obtained and the types of diagnosed lesions. A total of 1,009 samples were obtained using 14-gauge (900 samples) and 12-gauge (109 samples) needles. The size of the samples was evaluated on the first 700 consecutive biopsies using 14-gauge needles. The use of 12-gauge needles consistently provided larger size specimens than 14-gauge needles (p < 0.001); a reduction in the prevalence of benign nonneoplastic lesions (p = 0.03) and a higher frequency of in situ and invasive carcinomas (p < 0.001) were also observed. These findings may suggest a higher diagnostic accuracy of biopsies performed with 12-gauge needles due to the larger samples obtained and/or due to a better radiological selection of those lesions, which were detected by digital mammography and biopsied under digital stereotactic guidance.

Keywords: Stereotactic core needle biopsy, Breast cancer, 14-gauge needle, 12-gauge needle

Occlusion of the iliac arteries is a common disease. Several surgical options are available to treat them, such as aorto-bifemoral bypass graft, cross femoro-femoral bypass, endoprosthesis implants and others. Aorto-bifemoral bypass graft is considered the treatment that provides the best results. Endovascular treatment for occlusion of the iliac arteries provides high success rates and low incidence of complications. Twenty-four patients, aged between 39 and 82 years (mean 61 years), were submitted to this treatment. Intermittent claudication and critical ischemia were the indications in 19 and 5 patients, respectively. The most common risk factor was smoking (19 patients). The technical success rate of iliac artery recanalization was 91.7% and the patency rate after one year was 71%. The good results achieved with percutaneous recanalization and stenting of occluded iliac arteries, which presents low morbidity and mortality rates, suggest that this procedure should be included among the therapeutic options for the treatment of iliac arteries occlusion.

Keywords: Iliac arteries, Recanalization, Endoprosthesis

Dynamic renal scintigraphy allows the diagnosis of complications in patients submitted to organ transplantation, such as perfusion abnormalities, acute tubular necrosis and rejection. In this study we employed 99mTc-DTPA scintigraphy to study patients submitted to kidney transplantation. The results obtained and the clinical findings were conjunctly analyzed in order to detect graft rejection or other complications. The type of immunosuppressive scheme used was also correlated with the observed complications. Fifty-five patients submitted to kidney transplantation from 1989 to 1999 were evaluated. All patients with nephrotoxicity received a 3-drug immunosuppressive scheme. In this study, acute rejection was the most frequent complication (40.4%) observed following transplantation. Thirteen of 15 recipients of cadaveric kidney grafts presented acute tubular necrosis. Only one false-positive case was observed when scintigraphy and clinical findings were not concordant. We suggest carrying out renal scintigraphy to follow-up post-transplantation patients.

Keywords: Dynamic renal scintigraphy, 99mTc-DTPA, Kidney transplantation, Immunosuppression

A quality assurance program is a mandatory prerequisite for obtaining the high level of accuracy required for radiotherapy. This paper reports the results of part of the routine quality control tests for linear accelerators at the National Cancer Institute, Brazil, performed monthly over a period of two years. These tests included dose output and beam quality indicator. The results were compared with the guidelines of the AAPM TG-40 protocol. The results for the photon beams have shown dose output variations of up to 12%; for electron beams, the largest deviation found was 10%. The fluctuations observed in the beam quality indicator for the electron beams were greater than for the photon beams. These results strongly emphasize the importance of a quality assurance program in radiotherapy services in order to allow prompt corrections of the dose delivered to the patient.

Keywords: Quality control, Dose output, Beam quality indicator, Linear accelerator

This paper describes the operational characteristics of the final process of implementation of a quality control program using routine mechanical and radiation tests. The quality control program was performed during 35 months and demonstrated the excellent stability of this accelerator.

Keywords: Linear accelerator, Quality control, Photon radiation

Several technological developments are contributing to increase the use of imaging techniques in biomedical research and clinical medicine. Many investigators have attempted to develop computerized routines for automated detection and quantitative analysis of abnormalities in radiological images. These routines have been referred to as computer-aided diagnosis. In this paper we discuss the basic concepts of computer-aided diagnosis and review the literature.

Keywords: Computer-aided diagnosis, Digital radiography, Image processing, Computer vision, Artificial intelligence

The authors present a case of a patient with primary pancreatic leiomyosarcoma and describe the ultrasound findings during intraoperative ultrasonography. Although ultrasound, computed tomography and magnetic resonance features of primary pancreatic leiomyosarcomas have been previously described, there is no report on the ultrasonographic appearance of these tumors during intraoperative ultrasonography. The authors also stress the importance of intraoperative ultrasonography in establishing vascular invasion by the tumor.

Keywords: Intraoperative ultrasonography, Pancreas, Pancreatic tumors, Pancreatic leiomyosarcoma

The authors report a case of intraabdominal desmoplastic small round cell tumor in a 21-year-old male patient who presented with abdominal pain, right lower limb thrombosis and obstructive loss of renal function. Initial investigation showed a large lobulated intraabdominal soft tissue mass with internal cystic cavities, located posteriorly to the bladder and causing obstruction of ureteral flow, compression of the right iliac vein and partial occlusion of the rectum. Involvement of intraperitoneal and retroperitoneal nodes was also seen. Ultrasound, computed tomography and magnetic resonance imaging findings, as well as surgical and histopathology macroscopical, microscopical and immunohistochemistry findings are described.

Keywords: Desmoplastic small cell tumor, Desmoplastic tumor

Undifferentiated embryonal sarcoma of the liver is a rare disease that affects predominantly children over five years of age. The most common macroscopic finding is a large hepatic mass with a greater solid component and smaller cystic areas. However, computed tomography tends to overestimate the cystic components of the lesion and consequently ultrasonography is considered a more reliable technique for evaluating the texture of the tumor. Imaging methods can help to rule out nonneoplastic diseases such as liver abscesses and hematomas, and to establish the extent of the lesions. The diagnosis of undifferentiated embryonal sarcoma can be correctly inferred when imaging findings, the age of the patient and serum alpha protein levels are concurrently analyzed. The authors report a case of undifferentiated embryonal sarcoma in a 10-year-old girl and discuss the imaging findings features and differential diagnosis.

Keywords: Sarcoma, Tumor, Liver

The authors report a case of a patient with an extensive angiosarcoma of the scalp that was submitted only to radiotherapy with a combination of orthovoltage roentgentherapy and high-dose rate brachytherapy, using a mould. The clinical and technical features as well as the therapeutic outcome are presented, and the usefulness and peculiarities of high-dose rate brachytherapy for this particular indication is discussed. A comparative analysis of the difficulties and limitations of employing low-dose rate brachytherapy is also presented. The authors concluded that high-dose rate brachytherapy might be an useful, practical and safe option to treat neoplastic lesions of the scalp, and an alternative treatment to electrontherapy.

Keywords: High-dose rate brachytherapy, Mould, Scalp angiosarcoma