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Biomedical subjects

R S Bush

Publications and source records attributed to R S Bush.

At least 37 records · Page 2Linked to original sources
PubMed1984

Ovarian cancer: contribution of radiation therapy to patient management. Erskine memorial lecture, 1983.

Ovarian cancer may be treated with radiation therapy, surgery, chemotherapy, or a combination. To evaluate the contribution of radiation therapy to patient management the cure rate must be estimated; data are presented suggesting that the 5-year survival rate provides a reasonable estimate of the cure rate. Multiple prognostic factors have been shown to affect outcome. A study of patients treated since 1971 showed that stage and postoperative residuum could be used to divide patients into two subgroups, a "poor prognosis" group and a "good prognosis" group; a multifactorial grouping of patients in the good prognosis group who were treated postoperatively with radiation therapy only was further able to divide patients into low-risk, intermediate-risk, and high-risk groups. Studies of radiation therapy for different subgroups are discussed; abdominopelvic irradiation has been shown to improve survival for approximately one-third of patients with cancer of the ovary.

Female↗
PubMed1984

Quality assurance in radiation therapy: clinical and physical aspects. Future plans: clinical.

On a national scale in Canada, the members of the Canadian Association of Radiologists, Section of Radiation Oncology, plan to continue their outcome analyses. Nevertheless, there is considerable activity within many of the cancer centers in establishing quality assurance for all aspects of clinical practice, not just related to the technique of radiation therapy. Studies from the Princess Margaret Hospital will be used as examples to illustrate the need for quality assurance in: (a) diagnosis and evaluation of patients; (b) decision making with respect to treatment; (c) technical components of radiation therapy; and (d) outcome analysis, particularly an analysis of failures. For the future, there are two major objectives related to quality assurance. One is related to those patients with cancers who have a high probability of being cured. In this situation, achieving optimal treatment must be the objective and quality assurance must be directed at determining what is optimal treatment. For those patients in whom cure is still not commonly reached, the objective will be to determine why failures are occurring and whether radiation therapy technique can decrease the relapse rate.

Canada↗
PubMed1983

Ovarian irradiation and prednisone following surgery and radiotherapy for carcinoma of the breast.

Following mastectomy, patients with operable breast cancer underwent postoperative irradiation of the chest wall and regional lymph nodes. They were then assigned at random to receive no further therapy, ovarian irradiation (2000 rad in five days) or ovarian irradiation in the same dosage plus prednisone, 7.5 mg daily. A total of 705 patients received the randomly assigned treatment and were followed for up to 15 years. In premenopausal patients who received ovarian irradiation, the recurrence of breast cancer was delayed and survival prolonged, but not significantly. In premenopausal women aged 45 years or more, ovarian irradiation plus prednisone therapy significantly delayed the recurrence of breast cancer (p = 0.04) and prolonged survival (p = 0.02). No value was demonstrated for ovarian irradiation with or without prednisone therapy in postmenopausal patients.

Adult↗
PubMed1983

Chordoma: the results of megavoltage radiation therapy.

Twenty-four patients with chordoma who received one or more courses of megavoltage radiation therapy following biopsy or incomplete resection were reviewed. The uncorrected survival rate at five years was 62%, and at 10 years was 28%, but most patients had clinically detectable residual chordoma present at the time of death or last follow-up. The duration of symptomatic improvement following irradiation ranged from a few months to 18 years, median 3.5 years. Detailed dose-time and symptomatic response data for 56 patients from this series and from the literature who were treated by conventional daily fractionated megavoltage irradiation show no convincing evidence that symptomatic relief is more likely after high doses than after total doses of only 4000 to 5500 cGy. Patients are rarely cured of chordoma by partial tumor resection and conventional radiation. Four patients received multiple fractions of 100 cGy each day either as retreatment for recurrence, or as initial treatment. Symptomatic responses, and decreases in the size of tumor masses, were seen following total doses ranging from 2000 cGy/20 fractions/5 days/4 X 3 hourly fractions each day to 4000 cGy/40 fractions/12 days/4 X 3 hourly fractions each day. The short duration of follow-up in these patients prevents comparison with conventional fractionation. However, this technique presents one possible new approach for the treatment of chordoma.

Adult↗
PubMed1983

Radiation therapy for patients with ovarian cancer.

Evidence for an overall improvement in survival for patients with cancer of the ovary is presented. This improvement is from approximately 30% to 40% with a long term survival compatible with cure. The discussion then focuses on how treatment has contributed to that improvement, and in particular the use of radiation therapeutically. The results of the prospective randomized clinical trials at The Princess Margaret Hospital, Toronto, indicate that the use of pelvic and abdominopelvic irradiation for patients other than Stage IA, well differentiated, who have no or small residuum following surgery is curative for a large proportion and is the reason for the improvement in overall survival. Comparison of these results with others in the literature is done and shown not to disprove the findings of the PMH study. Mention is made of newer developments in multifactorial analysis to better define the patients for whom radiation is the treatment of choice currently.

Carcinoma↗
PubMed1982

Internal mammary lymphoscintigraphy in the assessment of patients with ovarian carcinoma.

Radiocolloid internal mammary lymphoscintigraphy (IML) was evaluated in 364 patients with ovarian carcinoma to determine the frequency of abnormalities in post-operative patients, the association between the results of the lymphoscintigram and known clinical prognostic variables, and to establish whether IML yielded predictive information independent of these variables. Results of IML showed a correlation with established clinical prognostic features and yielded independent prognostic information. The sensitivity and specificity of IML in predicting relapse are 51% and 71% respectively, indicating that a single post-operative IML does not predict relapse or freedom from relapse with sufficient accuracy to make it a clinically useful test even though it provides an independent prediction of relapse.

Adenocarcinoma, Mucinous↗
PubMed1982

A phase I study of misonidazole and pelvic irradiation in patients with carcinoma of cervix.

A Phase I study of oral daily misonidazole (MISO) with conventional pelvic irradiation, has been conducted in patients with carcinoma of the cervix Stages IB, IIB, IIIB and IVA. MISO was administered in daily dosages to sequential groups of patients at doses of 0.15 g/m2, 0.30 g/m2 or 0.45 g/m2 for 22 days over 5 weeks. Sixteen patients were assigned to each dose level. Using a double-blind randomization, they received either placebo (3/16) or MISO (13/16). The major dose-limiting toxicity was peripheral neuropathy (PN). None of the 13 patients receiving 0.15 g/m2 or the 13 receiving 0.3 g/m2 developed PN. However, 6/13 at the 0.45 g/m2 level (total dose less than or equal to 9.9 g/m2) developed PN. Additional patients were entered at this level and a total of 13/26 developed PN, which was considered of clinically significant severity in 9. Symptoms of PN have persisted from 1 week to 10 months, and have been completely reversed in 9/13 patients. Pharmacological parameters were examined for correlation with clinically evident toxicities. Although peak plasma MISO levels and half-lives did not correlate significantly with PN, there was a significant correlation between the calculated "area under the curve" (AUC) and PN. No correlation exists between PN and total urinary excretion of MISO or the O-demethylation product. A daily dose of 0.45 g/m2; MISO (total dose less than or equal to 9.9 g/m2) is considered to produce an acceptable level of toxicity for this patient population.

Double-Blind Method↗
PubMed1982

Non-Hodgkin lymphoma of the testis.

Sixteen patients (median age 67 yrs.) with non-Hodgkin lymphoma of the testis were studied. Twelve of these patients had disease that was classified as local (Stages IE and IIE). Eight patients had diffuse histiocytic lymphoma, 6 had diffuse poorly differentiated lymphocytic lymphoma, 1 had both lymphoma and seminoma, and 1 had nodular poorly differentiated lymphocytic lymphoma. The overall median survival was 9.5 months. Para-aortic nodal involvement was the factor that had the strongest prognostic influence with the management methods used. Median survival without para-aortic nodal involvement was 57+ months, but with such involvement it was 6 months (p = 0.002). There is a high probability of generalized disease if lymphoma can be detected in the para-aortic nodes. For patients with Stages IE and IIE disease, radical radiation therapy is the preferred treatment. For those with disseminated disease, chemotherapy, with irradiation reserved for symptomatic and bulky localized deposits, is the recommended method of management.

Adult↗
PubMed1982

Results of treating Hodgkin's disease without a policy of laparotomy staging.

Results of the treatment of 780 primary patients with Hodgkin's disease at the Princess Margaret Hospital (PMH) between 1968 and 1977 are analyzed. Treatment decisions were based on the evaluation of the extent of disease by clinical methods. A marked improvement in relapse-free survival and overall survival was observed for 1973-1977 as compared to 1968-1972. This improvement did not result from differences in the distribution of important prognostic attributes (clinical stage, pathology, and age) between the two periods, and there was no improvement in our ability to rescue relapsed patients. Improved relapse-free and overall survival during the second period was observed for all stages in patients less than 50 years of age, but not in the older group. The improved survival of patients treated between 1973 and 1977 is attributed to more effective initial therapy, which reduced the fraction of patients who relapsed. These observations provide indirect evidence that relapse has a negative effect on prognosis, and that the initial treatment of patients with Hodgkin's disease should be designed to reduce the risk of relapse to a minimum without causing an unacceptable increase in late complications. The observed/expected incidence of acute leukemia and non-Hodgkin's lymphoma in the PMH series was increased to 41.9 and 13.9 respectively. The question of whether a policy of doing routine staging laparotomies improves the results of treatment of patients with Hodgkin's disease is considered only in general terms by comparing the total PMH series with the total Stanford Medical Center series of patients treated between 1968 and 1977. Relapse-free survival at 10 years is 48.9% and 66.8% respectively, at the two institutions, while overall survival at 10 years is identified.

Adult↗
PubMed1982

Clinico-pathological correlates in ovarian cancer.

Multivariate analysis was performed on prognostic data derived from 810 patients with invasive ovarian cancer treated between 1971 and 1978. An examination of the prognostic significance of grade and pathologic subtype revealed that grade was strongly prognostic for serous tumors. In mucinous and endometrioid tumors however, the effect of grade was quite weak; furthermore, the prognostic significance of mucinous and endometrioid tumors did not differ from each other and was intermediate between well and poorly (or moderately) differentiated serous tumors. The compound pathology-grade classification derived from this analysis as well as the amount of macroscopic tumor residuum and the anatomic stage, were shown to exert a powerful prognostic effect independent of each other. Combining the information derived from all of these variables permits enhanced treatment selection to a degree which is not possible when each factor is considered on its own.

Adult↗
PubMed1981

An approach to classifying prognostic factors related to survival experience for non-Hodgkin's lymphoma patients: based on a series of 982 patients: 1967-1975.

The survival experience of 982 non-Hodgkin's lymphoma patients registered at Princess Margaret Hospital, Toronto, between 1967 and 1975, was studied. Prognostic groups were obtained by means of a classification procedure based on standard statistical techniques; the variables utilized in the classification were ones of known reproducibility which could be measured with little inconvenience to the patient. The results show that these prognostic groups give better information than the Ann Arbor staging classification in the sense that the survival curves are clearly separated and "good prognosis" and "poor prognosis" groups are clearly identified. Implications for therapy planning are briefly discussed.

Aged↗
PubMed1981

Effect of fermentation and formalin preservation on the protein component of bovine colostrum.

Colostrum was inoculated with Streptococcus lactis or yogurt culture or preserved with .1% (vol/vol) formalin in two separate experiments. All preparations then were stored at ambient temperature for 24 days. With increasing storage time, a larger proportion of the total colostrum nitrogen was not precipitated in 10% (wt/vol) trichloroacetic acid. By day 24, this represented 30 to 35% for the fermented samples and 10 to 15% for the formalin preserved samples. The majority of this nonprecipitable nitrogen was amino acids and small peptides. Most of the nitrogen in colostrum even after 24 days of storage should be nutritionally useful to the calf because even the nonprecipitable portion is amino acids and peptides.

Animals↗
PubMed1980

Alkali-resistant hemoglobin (HbF) in cancer patients.

Elevated levels of alkali-resistant (fetal) hemoglobin were found in patients with cancer, in the absence of any overt hematologic disorders. This phenomenon was observed most frequently in patients with gonadal tumors and appears to reflect tumor burden and activity of disease.

Female↗