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Biomedical subjects

E E Martin

Publications and source records attributed to E E Martin.

7 recordsLinked to original sources
PubMed1995

A heuristic approach to edge detection in on-line portal imaging.

PURPOSE: Portal field edge detection is an essential component of several postprocessing techniques used in on-line portal imaging, including field shape verification, selective contrast enhancement, and treatment setup error detection. Currently edge detection of successive fractions in a multifraction portal image series involves the repetitive application of the same algorithm. As the number of changes in the field is small compared to the total number of fractions, standard edge detection algorithms essentially recalculate the same field shape numerous times. A heuristic approach to portal edge detection has been developed that takes advantage of the relatively few changes in the portal field shape throughout a fractionation series. METHODS AND MATERIALS: The routine applies a standard edge detection routine to calculate an initial field edge and saves the edge information. Subsequent fractions are processed by applying an edge detection operator over a small region about each point of the previously defined contour, to determine any shifts in the field shape in the new image. Failure of this edge check indicates that a significant change in the field edge has occurred, and the original edge detection routine is applied to the image. Otherwise the modified edge contour is used to define the new edge. RESULTS: Two hundred and eighty-one portal images collected from an electronic portal imaging device were processed by the edge detection routine. The algorithm accurately calculated each portal field edge, as well as reducing processing time in subsequent fractions of an individual portal field by a factor of up to 14. CONCLUSIONS: The heuristic edge detection routine is an accurate and fast method for calculating portal field edges and determining field edge setup errors.

Breast Neoplasms↗
PubMed1995

Picture archiving and communications systems in radiation oncology (PACSRO): tools for a physician-based digital image review system.

Digital imaging is becoming more and more important in the diagnosis, staging, and treatment of patients in radiation oncology. In order to facilitate the most efficient interface of this technology to physicians and other users of this information, a medical image display system (MID) has been developed at the Fox Chase Cancer Center (FCCC). The system runs on 20 personal computers situated in physicians offices as well as a modified system located in the radiation oncology conference room. Access to CT, MRI, and EPID information is achieved through an Ethernet connection to the hospital picture archiving and communications system (PACS). Over a 1-year period a total of 503 patients and 3845 images have been stored on the system. Physician approval using the MID system (without conventional films) was performed on 106 patients. Of these, 22%, 16%, 11%, 10%, and 9% consisted of breast, prostate, pelvic, lung, and head and neck patients, respectively. Digital images sent from a variety of image sources to the MID system take up to 15 s to process and format while image access and display can take 2-5 s, dependent upon image size and speed of the host computer.

Adult↗
PubMed1993

Swallowing function in patients with esophageal cancer treated with concurrent radiation and chemotherapy.

BACKGROUND: Major goals of concurrent radiation and chemotherapy in the treatment of esophageal cancer are the early restoration and long-term maintenance of swallowing function. The purpose of this study was to determine the impact of concurrent radiation and chemotherapy on swallowing function. METHODS: Between September 1980 and September 1990, 120 patients with esophageal cancer were treated at the Fox Chase Cancer Center on the basis of one of three prospective nonrandomized protocols using concurrent chemotherapy and radiation. Swallowing function was retrospectively assessed in these patients by use of a swallowing-function scoring system. In addition, patients who had long-term control of their esophageal cancer underwent a more detailed analysis of swallowing function. RESULTS: Initial improvement in dysphagia occurred in 88% of the 102 assessable patients, with a median time to improvement of 2 weeks. There was no difference in overall percentage of initial improvement for patients with adenocarcinoma versus squamous cell carcinoma. Patients with distal tumors, however, showed both earlier and higher frequency of initial improvement than did patients with tumors in the upper two-thirds of the thoracic esophagus (95% versus 79%). Local relapse-free survival of definitively treated patients at 3 years was 60% and was significantly better for patients with Stage I (76%) versus Stage II cancers (55%) (P < 0.05). All 25 patients treated with curative intent who survived for more than 1 year without evidence of disease were able to eat soft or solid foods and had a benign stricture rate of only 12%. Even in patients with advanced disease who were treated with palliative intent, 91% had an initial improvement in swallowing function and 67% had improvement in swallowing function that lasted until death. CONCLUSIONS: High-dose concurrent radiation and chemotherapy provides rapid improvement in dysphagia, and this improvement results in normal or near-normal swallowing function of long duration.

Combined Modality Therapy↗
PubMed1991

Digital imaging in the radiation oncology environment: a personal computer local area network solution.

Personal computer (PC) driven digital imaging devices are now becoming available in the market place for use in radiation oncology to produce what are known as real time portal images. These limited contrast images are used to verify the patient anatomy under treatment by megavoltage x-rays and are a vital part of the patient treatment. The current generation of devices can produce both single and movie loop images in real time for physician review and approval. To disseminate these images and other digital images used in the planning and delivery of radiation therapy, a PC-based picture archiving and communications system has been developed that is tailored to the special needs of radiation oncology.

Humans↗
PubMed1986

Human T helper cells specific for antigens of typhus group rickettsiae enhance natural killer cell activity in vitro.

The peripheral blood mononuclear cells (PBMC) from 5 individuals immune to typhus group rickettsiae and from 13 nonimmune individuals were stimulated in vitro for 7 days with typhus group rickettsial antigen (TGRA). At the end of day 7, lysis of the natural killer (NK)-susceptible target K562 by these PBMC was determined. As controls, PBMC from both groups of donors were cultured in vitro for 7 days without antigen or were freshly isolated, and lysis of the K562 target was determined. There was no significant difference between the level of NK activity in freshly isolated PBMC from immune and nonimmune donors. PBMC from immune donors which were stimulated with antigen for 7 days exhibited significantly greater NK activity than did the control population, which was cultured for 7 days without antigen. PBMC from immune donors which were stimulated with TGRA demonstrated significantly higher NK activity than the same PBMC stimulated with antigen derived from an antigenically unrelated rickettsia, Coxiella burnetii. There was no significant difference, however, in the level of NK activity of nonimmune antigen-stimulated PBMC compared with that of the same PBMC population cultured without antigen. Most of the antigen-stimulated NK activity was mediated by Leu-11-positive cells as determined by electronic cell sorting. The ability of TGRA to sustain the NK activity of PBMC from immune donors was abolished when the T4/Leu-3-positive population of lymphocytes was eliminated by positive or negative selection prior to antigen stimulation. The ability of TGRA to sustain the NK activity of PBMC from immune donors was also significantly decreased in the presence of antibodies against human interleukin-2. The results suggest that the activity of human NK cells can be sustained in vitro by antigen-specific T helper cells and that the effect of the T helper cell is mediated, at least in part, by interleukin-2.

Antibodies, Monoclonal↗