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Biomedical subjects

S A Feig

Publications and source records attributed to S A Feig.

At least 127 records · Page 7Linked to original sources
PubMed1987

Mammography equipment: principles, features, selection.

1. Three-phase and constant potential generators may offer advantages over single-phase generators. These include shorter exposure times with less chance for motion unsharpenss, more adequate exposure and possible lower dose, and longer tube life. 2. Control of tube voltage in increments of 1 kVp are desirable for screen-film mammography and 2 kVp for xeromammography. 3. Tube loading limitations should be capable of allowing an adequate mA and mAs output. A mammography unit with a lower mA output may require longer exposure times with consequent motion unsharpness and/or higher dose. The maximum mA output is limited by the power rating of the tube and not by the power rating of the generator, which is usually much higher. Thus, tube rating charts rather than generator power rating should be used to compare the mA output of different mammography units. 4. Phototimer capability can reduce exam time, facilitate proper exposure, and reduce radiation dose. Units with a greater number of density steps and three or more photocell locations, one of which is near the edge of the film holder, provide better phototimer results. 5. A molybdenum target, beryllium window tube with 0.03 mm molybdenum added filtration is presently preferred for screen-film mammography. A tungsten target tube with 1 to 2 mm added aluminum filtration is advised for xeromammography. 6. Effective local spot size for contact mammography should be in the range of 0.2 to 0.5 mm. However, high resolution also requires sufficiently long source-to-image-receptor distances. Using measured focal spot size and source-to-image-receptor distance, it has been shown that some mammography units do not fully utilize the resolution capabilities of some available screen-film systems. On the other hand, a focal spot that is too small may limit the field size and lead to uneven energy distribution in the x-ray field. 7. In order to perform standard and supplementary mammographic projections, the C arm assembly must be capable of being located at multiple positions within a 180 degrees rotation. Greater degrees of rotation are not required. 8. The heat dissipation capability should be adequate to accommodate the anticipated work-load in terms of number of patients and patient scheduling. A mammographic unit with an anode heat capacity of 90,000 heat units or more should be adequate for most practices. A mammography unit with a heat capacity of 20,000 heat units or less may require waiting time between exposures or studies in a high-volume mammography practice. 9. The compression plate should be made of plastic, usually 1 to 4 mm thick.(ABSTRACT TRUNCATED AT 400 WORDS)

Female↗
PubMed1987

Bone marrow transplantation for acute non-lymphocytic leukemia: a report from the Childrens Cancer Study Group of sixty-seven children transplanted in first remission.

Sixty-seven children with acute non-lymphocytic leukemia (ANLL) in first remission underwent HLA-identical sibling bone marrow transplants as part of a cooperative study by the Childrens Cancer Study Group. Three patients died of sepsis before marrow recovery. Sixty-four patients recovered marrow function and have been followed for a median of greater than 1300 days. Two-year actuarial survival is 59% (95% confidence interval (CI): 47-71%). The risk of relapse by 2 years is 16% (95% CI: 6-26). All relapses occurred among patients with single-dose irradiation (p = 0.07), but these patients also experienced a diminished risk of acute graft-versus-host disease (AGVHD) (p = 0.12) compared to patients conditioned with fractionated irradiation. Radiation technique (single-dose vs fractionated) did not affect survival or the risk of development of interstitial pneumonia. Significant AGVHD (greater than or equal to grade II) occurred in 27 patients (40%). Patients with AGVHD were at increased risk of death due to sepsis or interstitial pneumonia during the first year after transplant, but disease-free survival was unaffected by AGVHD, because all 10 relapses occurred in patients without significant AGVHD. Neither survival nor relapse risk were affected by patient age, sex, white cell count at diagnosis, or FAB classification. This collaborative transplant study has resulted in survival data comparable to those of single institutions and the best reported outcomes of conventional chemotherapy.

Age Factors↗
PubMed1987

Imaging techniques and guidelines for evaluation and follow-up of breast cancer patients.

The use of imaging procedures for breast cancer staging and follow-up should be based on the natural history of the disease as well as the accuracy, cost, and availability of the studies themselves. Early detection of metastases may provide palliation but probably does not affect survival. For staging, chest X-ray and mammogram are both recommended on all patients; radionuclide bone scan is advised in the presence of either an elevated alkaline phosphatase, axillary metastases, or a primary tumor measuring more than 2 cm; abdominal CT should be performed if liver chemistries are abnormal; CT brain scan is the procedure of choice for neurological symptoms. Chest CT should be reserved for selected patients with an abnormal chest X-ray. Follow-up recommendations include annual chest X-rays and mammogram, bone scans every 5 years when a staging scan was indicated, and CT of the liver and/or brain in the presence of appropriate symptoms or laboratory values.

Bone Neoplasms↗
PubMed1986

Magnetic resonance imaging of Wilms tumor.

Magnetic resonance imaging (MRI) in 4 children with Wilms tumor suggests the usefulness of this newer imaging modality in evaluating the organ of origin and defining the extent of Wilms tumor. Coronal T1-weighted images were the most useful pulsing sequence for evaluating these children.

Child, Preschool↗
PubMed1986

Marrow transplantation for thalassemia.

Ten patients with homozygous beta thalassemia, aged from 1 year 7 months to 13 years, underwent bone marrow transplantation from siblings or parents. The first case received 12 mg/kg busulfan, 120 mg/kg cyclophosphamide, and 300 cGy total body irradiation before transplantation; he survives, with a graft, more than 680 days after transplantation. The other nine patients received 16 mg/kg busulfan and 200 mg/kg cyclophosphamide. Two died of transplantation-related complications on days 30 and 55. Seven survive 170 to 580 days after transplantation. Three of the seven surviving patients have durable engraftment (greater than 230 to greater than 550 days) while four patients have autologous hematopoietic recovery. Four of five patients who had less than 50 prior transfusions achieved engraftment. Only one of five patients who had more than 50 prior transfusions achieved engraftment (P less than 0.05). The six-month actuarial survival was 80%; six-month actuarial disease-free survival was 40%. These data demonstrate that bone marrow transplantation may cure thalassemia, but engraftment may be jeopardized among patients who have been heavily transfused or have received marrow from a donor who is not HLA-identical.

Actuarial Analysis↗
PubMed1985

Bone-marrow transplantation for metachromatic leucodystrophy.

An 11-month-old boy with late infantile metachromatic leucodystrophy was given a bone-marrow transplant (BMT) from an HLA-identical sister; 6 months later his cerebrospinal fluid leucocytes were exclusively of donor origin. Coupled with the patient's continued developmental progress, as assessed 33 months after the procedure, the findings suggest that BMT may be an effective treatment for some congenital metabolic disorders which affect the central nervous system.

Adolescent↗
PubMed1985

Treatment of acute myelogenous leukemia. A prospective controlled trial of bone marrow transplantation versus consolidation chemotherapy.

In a prospective controlled trial, the relative effectiveness of allogeneic bone marrow transplantation and postremission chemotherapy was assessed for adult patients with acute myelogenous leukemia in first complete remission. Twenty-three patients, 15 to 45 years of age, who had an HLA-identical sibling donor were designated to receive bone marrow transplantation. Forty-four patients who either lacked an HLA-identical sibling or were over 45 years of age were designated to receive intensive consolidation chemotherapy. The actuarial rate of leukemia relapse was significantly lower in the transplantation group than in the chemotherapy group (40 +/- 25% [95% confidence interval] compared with 71 +/- 14%, p = 0.01). Actuarial survival at greater than 4 years was not significantly different (40 +/- 21% compared with 27 +/- 14%, p greater than 0.4). These data show that bone marrow transplantation is more effective than consolidation chemotherapy in preventing leukemia relapse, but overall survival was not improved in this study.

Adolescent↗
PubMed1985

Do androgens enhance the response to antithymocyte globulin in patients with aplastic anemia? A prospective randomized trial.

We analyzed the effect of antithymocyte globulin (ATG) with or without androgens in 121 patients with aplastic anemia. Fifty-three patients with moderate to severe aplastic anemia were prospectively randomized to receive ATG with or without oral androgens. Eleven of 26 patients (42%) receiving ATG plus androgen responded, including three complete and eight partial responses. Twelve of 27 patients (44%) receiving ATG plus placebo responded, including five complete and seven partial responses. The difference in response rates was not significant (P greater than .9). Survival was also comparable in the two groups; for patients with severe aplastic anemia, actuarial survival at two years was 55% +/- 24% (95% confidence interval) in patients receiving ATG plus androgen compared with 50% +/- 24% in the ATG plus placebo group (P = .65). Furthermore, results in both groups were indistinguishable from those obtained in 68 historical controls receiving ATG without androgens. These data indicate that androgens are not required in order to respond to antithymocyte globulin and the addition of androgens, as used in this trial, did not significantly improve response rates to ATG treatment.

Adolescent↗
PubMed1984

Staging and treatment of clinically occult breast cancer.

Five hundred fifty-seven biopsies were performed for clinically occult mammary lesions, detected by mammography as clustered calcifications or nonpalpable masses within the breast. One hundred seventy-five cancers were demonstrated within this group, including 106 invasive carcinomas, 10 microinvasive carcinomas, 45 in situ ductal carcinomas, and 14 lobular carcinomas in situ (lobular neoplasia). No patient with in situ or microinvasive carcinoma had evidence of axillary node metastases in 33 specimens studied. However, a disturbingly high proportion of those patients with invasive carcinomas, approximately 35%, had histologically confirmed axillary node metastases, despite the small size of the primary tumors. These observations suggest that the use of the term "minimal" cancer is misleading when applied to invasive carcinoma. Staging systems for breast cancer have been imprecise when referring to nonpalpable lesions. Cancers detected as clustered calcifications only or as areas of parenchymal distortion without an accompanying mass are properly considered as T-0 cancers, with a suggested T-0(m) to indicate that the lesion was detected by mammography. However, when the mammogram indicates the presence of a mass that proves to be malignant, although the clinical examination may have been negative, the cancer should be staged according to the size of the mass on the mammogram, with the notation that it was detected by mammography, e.g., T-1(m), T-2(m), etc. The incidence of axillary node metastases even in these so-called occult cancers is significant, so that recommendations for treatment for any invasive cancer, regardless of its size, must take these observations into account. Similarly, the incidence of multifocal sites of cancer within the breast, even in the noninvasive cancers encountered, must be remembered when treatment is suggested.

Adult↗
PubMed1984

Hypothetical breast cancer risk from mammography.

The existence of low-dose risk has neither been proven nor disproven. If there is a risk from the low doses used in current mammographic techniques, it is immeasurably small, especially when compared to the overwhelmingly large incidence of naturally occurring breast cancers, many of which could be detected by mammography at an early curable stage. The risk, if it does exist, would be lowest among women exposed over 30 years of age, a fortunate circumstance since this group would benefit most from mammography.

Adolescent↗
PubMed1984

Localization and significance of clinically occult breast lesions: experience with 469 needle-guided biopsies.

Experience with 469 clinically occult breast lesions is presented. The overall incidence of malignancy observed was 32%, just about one in three. The technique of needle-guided biopsy is described, insuring precise localization and excision of minute radiographic findings, yet without leaving a conspicuous scar to remind the patient of her experience. Although it is too early to speculate about a possible increase in survival of these "earliest" breast cancers, the observed decreased incidence of axillary node metastasis implies a lowered death rate from breast cancer in these patients. It is not unreasonable to extrapolate the extent of patient salvage from axillary node status. Many of these cancers were uncovered in the course of screening asymptomatic patients, and this further implies the efficacy of such screening programs in the early detection of breast cancer. The surprisingly high incidence of multicentricity in these tiny cancers must not be ignored when recommending adequate and appropriate therapy for these impalpable malignancies.

Adult↗