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Biomedical subjects

S M Hubbard

Publications and source records attributed to S M Hubbard.

At least 37 records · Page 2Linked to original sources
PubMed1990

Treatment of Hodgkin's disease.

The available data support the hypothesis proposed by Smithers that Hodgkin's disease appears to be a systemic disorder of the lymphatic system. Standard treatments have been developed that cure approximately 70% of all patients who present to most institutions. Physicians should know the treatment approaches before proceeding with staging, because intelligent use of the best available treatment often obviates the need for staging laparotomy. At present, it is best that either chemotherapy or radiotherapy be used alone, except in patients who have massive mediastinal disease and for whom combinations of radiotherapy and combination chemotherapy are superior. Despite the long series of clinical trials conducted over the past two decades, no combination of four drugs has improved the results obtained with the original mechlorethamine-vincristine-procarbazine-prednisone program, when it is given in sufficient doses. It has been assumed that drug resistance of a specific type was the major reason for treatment failure. Attempts by physicians to overcome drug resistance, using alternating cyclical non-cross-resistant combination chemotherapy, have thus far not proved this approach to be superior to the use of a four-drug combination in full doses, and call into question this approach to testing the Goldie-Coldman hypothesis. Dose intensity has been a poorly controlled variable in virtually all clinical trials in Hodgkin's disease, and inadequate dosing may be the prime reason for treatment failure. This point has been highlighted by recent excellent results with marrow-ablative, high-dose chemotherapy and autologous bone marrow transplantation support for patients with very advanced "drug-resistant" disease. Investigators are now attempting to improve dose intensity by using more concentrated versions of standard drug combinations with colony-stimulating factors for support.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1989

NCI's breast cancer clinical alert: rationale and results.

In the U.S. alone, of the 60,000 women diagnosed with node-negative breast cancer each year, between 2,000 and 5,000 would be candidates for postoperative adjuvant therapy each month. Thousands of women had a chance to benefit from data contained in the National Cancer Institute's Clinical Alert and the announcements of the trial's results in the lay press.

Breast Neoplasms↗
PubMed1989

Treatment of localized aggressive lymphomas with combination chemotherapy followed by involved-field radiation therapy.

Localized lymphomas of diffuse and aggressive histology sometimes undergo early hematogenous dissemination such that local therapies (surgery alone or followed by radiation therapy) are not curative in 100% of cases. We have treated 47 clinical stage I or IE patients with aggressive lymphoma histologies (diffuse large-cell, diffuse mixed, diffuse immunoblastic, follicular large-cell, diffuse small-non-cleaved cell) with four monthly cycles of an eight-drug combination chemotherapy program consisting of cyclophosphamide, etoposide, doxorubicin, nitrogen mustard (mechlorethamine), procarbazine, high-dose methotrexate with leucovorin rescue, and prednisone (Pro-MACE-MOPP) administered systemically followed by 40 Gy involved-field radiation therapy. Forty-five (96%) patients achieved a complete remission and no patient has relapsed with a median follow-up time of 42 months (range, 8 to 90). Both patients failing to achieve a complete remission died of lymphoma, and one patient died free of lymphoma 45 months after diagnosis during coronary artery bypass surgery unrelated to lymphoma or its treatment. Hospital admissions were necessary to manage complications on nine of 188 (5%) cycles of treatment. There were no treatment-related deaths. ProMACE-MOPP plus involved-field radiation therapy is safe and effective treatment for localized aggressive lymphoma.

Adult↗
PubMed1988

PDQ--a database of clinical trials and cancer treatment information.

The National Cancer Institute has developed an online clinical information system known as PDQ (Physician Data Query) to provide physicians with up-to-date information on cancer treatment and to facilitate participation in cancer clinical trials. PDQ is a major component in the National Cancer Institute's goal of reducing cancer mortality 50% by the year 2000.

Clinical Trials as Topic↗
PubMed1988

Angle independent ultrasonic blood flow detection by frame-to-frame correlation of B-mode images.

We have previously reported initial clinical results of a novel blood velocity imaging technique utilizing a two-dimensional correlation search applied to consecutively acquired echoes. In this paper, we describe both the physical principles underlying this technique and test tank experiments which define its performance under a variety of conditions. The results indicate that, unlike Doppler flow imaging systems, this technique defines the flow velocity vector in two dimensions and is not subject to aliasing.

Blood Flow Velocity↗
PubMed1988

Properties of acoustical speckle in the presence of phase aberration. Part II: Correlation lengths.

In recent years, analysis of the second order statistics of ultrasound speckle has led to accurate prediction and measurements of the average speckle size in the transducer focal zone. In this paper, that work has been extended to the average speckle size as determined by the normalized autocovariance in the presence of transducer phase aberrations. In general, a phase aberration causes a narrowing of the main lobe of the normalized autocovariance in the lateral direction. However, the lateral speckle autocovariance also showed significant side lobes in the presence of phase aberrations, indicating that individual speckles in a region of interest are not independent but are correlated so that less information is present for the task of signal detection when a transducer phase aberration exists. The same evidence of correlated speckle was found in the near field of a transducer in the region of fine speckle texture. This explanation satisfies the quandary of poor detectability in the near field region where the speckle is fine but the lateral resolution is quite degraded. The axial speckle in the presence of phase aberrations showed a small increase in main lobe widths and no evidence of side lobes. Beginning in 1978, the analysis of the second order statistics of speckle images for the purpose of spatial compounding led to accurate measurement and prediction of the cross-correlation curve as a function of transducer aperture translation for purposes of spatial compounding. In this paper, that work has been extended to the presence of transducer phase aberrations. The existence of transducer phase aberrations causes significant increases in the rate of decorrelation of speckle interference patterns as a transducer is translated. This indicates that spatial compounding will result in quite significant improvements in area-wise SNR and low contrast lesion detection for the case of severe random aberrators or focal point errors.

Humans↗
PubMed1988

Keeping up with the cancer literature--PDQ ACCESS.

Physician Data Query (PDQ) (National Cancer Institute [NCI], Bethesda, MD) and CANCERLIT (NCI, Bethesda, MD) are two online cancer information databases. PDQ summarizes current cancer therapy literature into specific treatment recommendations. CANCERLIT is a bibliographic system similar to MEDLINE (National Library of Medicine [NLM], Bethesda, MD) that provides a comprehensive source of literature citations for the field of cancer. In this report, we discuss linking PDQ and CANCERLIT with PDQ ACCESS (NCI, Bethesda, MD)--a custom software package that makes searching the cancer literature easy for the practicing physician unfamiliar with database searching.

Humans↗
PubMed1988

Residual abdominal masses in aggressive non-Hodgkin's lymphoma after combination chemotherapy: significance and management.

When patients with aggressive lymphoma present with intraabdominal disease, a stable residual mass is frequently detected radiographically at the time of the clinical complete remission. To discern the optimal management for this clinical problem, we reviewed 241 patients with aggressive lymphoma treated at the National Cancer Institute (NCI) from 1977 to 1986. Seventy-two/241 patients (30%) had an abdominal mass at diagnosis and 29/72 (40%) were left with a radiographically detectable residual mass at clinical complete remission. The likelihood of a residual mass was much higher for patients with bulky disease (P2 less than .0003) (two-tailed test [P2]). Twenty-nine patients had radiologically stable residual masses after therapy, and of 22 (76%) with pathologic evaluations, 21 had negative specimens (95%) and one was positive (5%). None of the patients with negative pathologic evaluation has relapsed in the abdominal site (median follow-up, 31 months). Seven patients were observed clinically without laparotomy: five are alive, without evidence of disease, at 2 to 9 years; two relapsed with disseminated disease within 2 months of chemotherapy. Initial tumor size and size of the residual mass did not correlate with residual disease, since residual masses identified by radiographic examination did not usually harbor viable lymphoma cells. Aspiration cytology was negative for residual tumor in 15/16 cases. One negative result was not confirmed at laparotomy, presumably due to sampling error. The one positive aspiration was followed by a negative laparotomy, possibly due to subsequent tumor necrosis. Restaging laparotomy has a low yield. In most patients with aggressive lymphoma who have otherwise completely responded to carefully administered full-dose combination chemotherapy, stable residual abdominal masses can be closely followed clinically without surgical exploration.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1988

The PDQ database: what the primary care physician needs to know about current treatments for cancer and AIDS.

The National Cancer Institute's PDQ database is the most current source of peer-reviewed information available today on state-of-the-art treatment of cancer and AIDS. It can serve the primary care physician as a principal reference point for decisions regarding consultation, referral, and patient care, and it is relatively simple and inexpensive to use. The new PDQ ACCESS microcomputer soft-ware enables untrained searchers automatically to execute current literature searches of the CANCERLIT database, as an adjunct to searching PDQ.

Acquired Immunodeficiency Syndrome↗
PubMed1988

The role of chemotherapy in diffuse aggressive lymphomas.

Diffuse aggressive lymphomas are curable by combination chemotherapy in advanced stages, with 30% to 60% of all treated patients alive and disease free 2 to 5 years from the end of treatment, depending on the program used. The fact that combination chemotherapy can cure this disease has led, since 1975, to several new directions in therapy such as (1) the development of a variety of new combination chemotherapy programs, using older drugs more aggressively, adding additional drugs to each program, or manipulating the scheduling of drugs; (2) the close scrutiny of study results to identify risk factors that influence the ability to attain a durable complete remission; and (3) the use of combination chemotherapy in early stage disease instead of, or with, radiotherapy (RT). The recently developed aggressive programs have been reported to produce results superior to the original studies, but because important prognostic factors have only recently been identified, there remains some uncertainty about the significance of the reported differences between studies. Also, dose intensity, a poorly controlled treatment variable in all studies, has recently been identified as a significant factor affecting outcome. Schedule variation, while reported to exert some independent effect on outcome, appears to influence results by its effect on dose intensity. Regardless of the uncertainty over the ideal program for patients with advanced diffuse aggressive lymphoma, the results in early-stage disease have uniformly favored the use of combination chemotherapy as the primary treatment, with or without subsequent RT, depending on the quality of the response to drugs, reaffirming the invariable inverse relationship between cell number and curability by chemotherapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Decreasing risk of leukemia with prolonged follow-up after chemotherapy and radiotherapy for Hodgkin's disease.

Acute nonlymphocytic leukemia is a recognized complication of combined chemotherapy and radiation treatment of patients with Hodgkin's disease. Previous studies have suggested that the risk of leukemia in these patients increases with time after treatment. We analyzed the occurrence of second neoplasms among 192 patients with Hodgkin's disease who were followed for a median of over 15 years. We originally planned to identify prospectively the morphologic changes in bone marrow that precede the development of acute leukemia. All 63 patients consenting to bone marrow aspiration had normal marrow morphology, and no case of acute leukemia occurred more than 11 years after treatment. Actuarial analysis revealed that the peak onset of leukemia-related complications was between three and nine years after first treatment. We conclude that there appears to be a period of increased risk in patients treated with chemotherapy and radiation, after which the risk of secondary leukemia decreases. Patients surviving for more than 11 years after treatment appear to be at no increased risk of acute leukemia.

Adult↗
PubMed1987

A computer data base for information on cancer treatment.

The Physician Data Query (PDQ) system is a clinically oriented computer data base developed to make recent information on cancer treatment widely available to the medical community. It represents an effort by the National Cancer Institute to promote diffusion of information about the treatment of cancer throughout the country, facilitate access to clinical trials, and accelerate the practical application of advances in research. The computer system provides information about state-of-the-art cancer treatment, which is updated monthly by an editorial board. It also includes a file of active cancer-research protocols and a directory of physicians and organizations providing cancer care to which physicians can gain access by geographic location as well as other features. PDQ was designed for physicians who may not be familiar with computers, to permit them to search for and display information without learning a specialized search language. PDQ uses a computer mainframe, which allows a large amount of data to be stored and made available to physicians rapidly and accurately. Transmission of information about cancer over commercial telecommunication networks gives health professionals access to PDQ by means of a computer terminal and local telephone lines.

Directories as Topic↗
PubMed1987

Technical information programs of the National Cancer Institute.

Since its founding in 1937, the National Cancer Institute (NCI) has supported a substantial program of information dissemination. Two peer-reviewed journals, begun in 1940 and 1959, are supplemented by a congressionally mandated International Cancer Research Data Bank (ICRDB), established in 1972. The NCI has made available online databases of published cancer literature and cancer research in progress for the past decade, using the National Library of Medicine (NLM) MEDLARS system. Recently, a clinical-practice-oriented cancer-information system called Physician Data Query (PDQ) has been developed for access at the NLM, as well as through commercial database vendors. The impact of the NCI information programs is currently under prospective evaluation.

Humans↗