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Biomedical subjects

W Powlis

Publications and source records attributed to W Powlis.

6 recordsLinked to original sources
PubMed1996

4-Hydroperoxycyclophosphamide purged autologous bone marrow transplantation in non-Hodgkin's lymphoma patients at high risk of bone marrow involvement.

Between June 1990 and January 1994, 19 patients with non-Hodgkin's lymphoma (NHL) at high risk for bone marrow involvement underwent 4-hydroperoxycyclophosphamide (4-HC) purged bone marrow transplantation. Eleven patients had low grade, seven intermediate grade and one high grade NHL and 7/19 patients had received three or more previous chemotherapeutic regimens. Four patients were transplanted in first partial remission (PR) and the remainder in responsive relapse. Fourteen patients had bone marrow (BM) involvement at diagnosis and/or at relapse. The median times to granulocyte and platelet recovery were 26 and 29 days, respectively. There were two toxic deaths and one complete responder developed secondary AML at 31 months post-BMT. Seventeen of 18 evaluable patients achieved a complete remission (CR) and one patient a PR. Fourteen patients (74%) are progression-free at a median follow-up of survivors of 34 months (range 29-55). The 3 year event-free (EFS) and overall survival (OS) probabilities are both 67%. No statistically significant difference was seen between EFS or OS and BM involvement or histologic grade at diagnosis. At 29 months, 4/7 patients with a morphologically involved BM harvest had relapsed or died compared to 1/12 patients with negative BM (P = 0.03). These results are encouraging and warrant further investigation of 4-HC purging in NHL.

Adult↗
PubMed1993

A new technique for positioning tangential fields.

PURPOSE: A technique that eliminates the use of a mechanical "breast-bridge" for positioning tangential fields for treatment of the intact breast or chest wall has been developed. METHODS AND MATERIALS: Treatment set-up parameters are determined using measuring capabilities (gantry angles and source-skin distances) available on a standard simulator unit. A programmable scientific calculator is used to determine field geometry from polar coordinates for various points on the patient's skin. The calculator program determines the field size, a depth and lateral shift from a skin reference point to the isocenter for the tangential fields, and the gantry angles. The program provides additional information which facilitates the simulation process: First, the coordinates of the isocenter for the tangential fields are expressed relative to couch coordinates for an initial arbitrary isocenter so that the "auto go to" capability available on some simulators can be used. Second, the coordinates of the medial and lateral entry points can be edited when the first set of tangents are not accepted. This part of the program allows quick and efficient adjustment of the fields to obtain adequate treatment volume coverage and a minimum of irradiated lung or heart. RESULTS: Simulation of more than 300 patients has shown the technique to be a practical and efficient method for positioning tangential fields for breast or chest wall irradiation. CONCLUSION: The technique described here takes full advantage of the capabilities of the new generation of computer controlled simulators, and offers an alternative to previous methods employing a mechanical "breast-bridge."

Breast Neoplasms↗
PubMed1992

Clinical implications of learned food aversions in patients with cancer treated with chemotherapy or radiation therapy.

BACKGROUND: The nutritional implications of learned food aversions were evaluated in patients with newly diagnosed cancer receiving either chemotherapy (n = 53) or radiation therapy (n = 49). METHODS: Aversion incidence was determined by questionnaires and a food challenge. Measures of dietary and nutritional status included ratings of appetite and chemosensory function; reported shifts of food selection and measured body weight; lymphocyte count; hematocrit; and plasma albumin, transferrin, and hemoglobin levels. Quality of life was assessed by self-ratings of mood and well-being. RESULTS: Subsequent to the initiation of treatments, aversions formed in 56% and 62% of patients receiving chemotherapy and radiation therapy, respectively. The aversions were specific (two to four items per afflicted patient) and transient (mean duration, 0.25-2 months). All types of foods and beverages were targeted. No significant association was observed between food aversion incidence and any measure of dietary complications, nutritional status, or quality of life. CONCLUSIONS: Although food aversions are a common sequela of chemotherapy and radiation therapy, they generally have limited clinical significance.

Adult↗
PubMed1991

A descriptive study of learned food aversions in radiotherapy patients.

While animal studies have documented the efficacy of ionizing radiation as a conditioning stimulus for food aversion learning, little is known about the incidence or nature of aversions that form in cancer patients administered radiation therapy. Forty-nine newly diagnosed patients with a variety of cancer types were monitored for the duration of their treatment or up to six months. Aversions were identified by questionnaires and responses to an experimental food administered at stipulated time points. Fifty-nine percent of patients formed new aversions after initiating treatment and for 53% of patients, this involved items in their customary diet. A wide array of items were targeted, but there was direct relationship between exposure frequency and aversion formation. The aversions were highly specific (median = 2.5 items/afflicted patient). The onset time was approximately 1-2 weeks, and they were transient, generally lasting 1-3 weeks. There was no evidence of a discrepant incidence among patients treated in different sites. Aversion incidence was not significantly associated with age, gender or other selected patient characteristics.

Abdomen↗
PubMedDate not supplied

Radiation therapy of canine brain masses.

This article evaluates the responses of 14 dogs with brain masses using orthovoltage irradiation for definitive treatment. Dogs were anesthetized for computed tomography (CT) examination, formation of head immobilization and positioning devices, radiation treatment simulation, and treatments. Total doses of 39 Gy (9 dogs) or 45 Gy (5 dogs) to the tumor were administered over 25 to 41 days. Two or three portals (parallel opposed lateral with or without a dorsal field) were used. Treatment volumes included the tumor and peritumoral edema, as determined by CT scan, and a 1-cm margin. Histopathologic diagnoses were available in 9 of 14 dogs. There were 4 meningiomas, 1 lymphosarcoma, 1 pituitary adenoma, 1 metastatic anaplastic carcinoma, 1 anaplastic oligodendroglioma and 1 dog with granulomatous meningoencephalitis. At the end of radiation therapy, 10 dogs could be evaluated for progression of clinical signs: 3 dogs deteriorated or failed to improve, and 7 dogs improved. At the time of analysis, all dogs were dead. Mean and median survival times, measured from the beginning of radiation, were 345 and 489 days, respectively. This was compared with mean survival times of 30 to 81 days reported in the literature for dogs with brain tumors that did not receive treatment. The median survival time of 9 dogs treated with 39 Gy was 153 days, versus 519 days for 5 dogs that received 45 Gy. It appears that radiation therapy prolongs survival times for dogs with brain masses. Although megavoltage therapy would be optimal, orthovoltage radiation can be applied in total doses of 45 Gy in 3.75 Gy fractions over 28 days without adverse effects.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗