摘要:

AbstractThe substituted benzaldehyde BW12C has previously been shown to decrease tumor oxygenation. This, in turn, was linked to the drug's ability to alter the affinity of hemoglobin for oxygen and/or to change tumor blood flow. In the present study, the ability of BW12C to modify oxygen‐hemoglobin binding affinity, tumor blood flow, and tumor radiosensitivity was investigated using BALB/c mice with a 3‐methylcholanthrene‐induced rhabdomyosarcoma and WHT mice with a Fib/T tumor. Results for BALB/c mice indicated that BW12C caused an initial decrease in the P50 and in tumor blood flow, which was accompanied by a decrease in the radiosensitivity of the chemically induced rhabdomyosarcoma. When the P50 and tumor blood flow levels returned to normal again, tumor radiosensitivity increased and exceeded that of mice that were not given BW12C. Although BW12C caused a similar pattern of change in WHT mice with respect to oxygen‐hemoglobin binding affinity, the drug had no effect on Fib/T tumor blood flow or radiosensitivity. © 1995 Wiley

ISSN:1065-7541    

DOI:10.1002/roi.2970030402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractIntestinal dysmotility is a prominent feature of chronic radiation enteropathy. This study addressed the question whether localized radiation enteropathy without anatomical obstruction influences stomach to cecum transit time. Male rats were orchiectomized and a loop of ileum was sutured to the inside of the scrotum. After 3 weeks postoperative recovery, the “scrotal hernia” containing the transposed intestine was irradiated with 18 twice‐daily fractions of 2.8 Gy, or 9 daily fractions of 5.6 Gy orthovoltage X‐rays. Control animals were operated and sham‐irradiated. Stomach to cecum transit time was assessed 26 weeks after irradiation. A 1‐ml bolus of barium suspension was administered by gavage and diagnostic X‐ray films were obtained at 0,1, 2,2.5, 3, 3.5, and 4 hr. Transit time was defined as the time to the first X‐ray that showed unequivocal contrast filling of the cecum. Normal range and day‐to‐day variability were assessed in normal, unoperated control rats. After completion of transit studies, the rats were euthanized, samples from shielded and irradiated intestine were procured, and radiation injury was assessed with a histopathological scoring system. Median stomach to cecum transit time in unoperated controls was 2.25 hr. The surgical procedure and aging did not significantly affect transit time. Transit time was significantly prolonged both in the 2.8 Gy × 18 group (P= 0.02) and in the 5.6 Gy × 9 group (P =0.0001). The association between histopathologic radiation injury and transit time did not reach statistical significance. We conclude that non‐obstructing radiation injury in the distal ileum significantly prolongs intestinal transit time and that small bowel follow‐through with barium contrast may be used to assess radiation enteropathy in this animal mode

ISSN:1065-7541    

DOI:10.1002/roi.2970030403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractSeven patients with a diagnosis of polycythemia vera (PCV) with symptomatic splenomegaly received 10 courses of splenic irradiation. Patients received a total dose of 250–1,425 cGy to the whole spleen with twice‐weekly fractionation beginning with 25 cGy per fraction, gradually escalating to no more than 100 cGy per fraction. All 10 courses resulted in palliation of the symptoms of abdominal discomfort and early satiety. Greater than 50% reduction in spleen size was observed in 7 of 10 courses. The primary toxicity was a transient decrease in circulating platelets though two patients with thrombocytopenia at presentation had improvement in their platelet counts corresponding with a decrease in spleen size. These results demonstrate that splenic irradiation with low dose, twice‐weekly irradiation is an effective way to reduce spleen size and palliate symptoms in patients with PCV. © 1995 Wiley‐L

ISSN:1065-7541    

DOI:10.1002/roi.2970030404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThe purpose of this study was to investigate the patterns of care in women over the age of 65 years presenting with breast cancer. Tumor registry data from three different sized and geographically located hospitals in northwest Ohio were reviewed and analyzed. Three hundred forty‐five patients were eligible for analysis. An age difference was noted between those patients receiving lumpectomy only compared to those patients receiving mastectomy or lumpectomy and radiation. The majority of patients with regional disease received hormonal therapy. Only two of six patients with positive lumpectomy margins experienced a local recurrence. The tumor volume was statistically significantly higher in patients who experienced a local recurrence. In conclusion, treatment for elderly patients with breast cancer should be based on physiologic not chronologic age. © 1995 Wiley‐Liss,

ISSN:1065-7541    

DOI:10.1002/roi.2970030405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractSerum prostate specific antigen (PSA) values decrease after external beam radiation (EBRT) for clinically localized prostate cancer, reaching their nadir 6–12 months after treatment. The nadir PSA value is predictive of disease‐free survival. This prospective study was initiated to evaluate whether the early response of PSA as measured by 1) the rate of PSA decrease during treatment (PSA slope) and 2) the immediate (within 1 month) post‐treatment PSA would predict the PSA nadir.Thirty patients treated with EBRT for clinical stages A2‐C2 (T1c‐T3c) adenocarcinoma of the prostate were enrolled in this prospective study. Nine patients were subsequently excluded because they were lost to follow‐up after less than 1 year (n = 6) or their pretreatment PSA was measured by a method other than Hybritech (n = 3). Serum PSA measurements were obtained at weeks 2, 4, and 6 of treatment (n = 21) as well as immediate post‐treatment PSA at the first follow‐up 2–4 weeks after treatment (n = 17). The end‐point analyzed was whether or not the PSA nadir was ≦ 1.5 ng/ml. A linear regression model of log(PSA) vs. time (treatment week) was fit for each patient's data. The rate of decrease of PSA (PSA slope) was estimated from this regression. The PSA slope, pretreatment PSA, immediate post‐treatment PSA, stage, and grade were studied by Cox life table regression analysis to determine predictors of PSA nadir. In the Cox model, time was measured from the start of radiotherapy until PSA ≦ 1.5 ng/ml or until the last measurement for those who did not reach this level. Models combining the significant individual factors were then constructed. The minimum follow‐up is 52 weeks and the median is 66 weeks.The PSA slope (P= 0.05) and the immediate post‐treatment PSA (P =0.02) predicted a PSA nadir ≦ 1.5 ng/ml. Pretreatment PSA approached significance (P =0.09). A model which combined pretreatment PSA and PSA slope predicted PSA nadir ≦ 1.5 ng/ml (P= 0.05) as did PSA slope combined with immediate post‐treatment PSA (P = 0.01). Within each model, PSA slope was the stronger predictor.In conclusion, the early response of serum PSA as measured by the PSA slope and the immediate post‐treatment PSA appears to be predictive of PSA nadir in patients treated with EBRT. More patients and longer follow‐up are needed to confirm this finding and determine whether the early response predicts diseas

ISSN:1065-7541    

DOI:10.1002/roi.2970030406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractImprovements in prostate volume measurements and in dose distribution have led to an increase in the use of brachytherapy for prostate cancer. The addition of interactive ultrasound and three‐dimensional dosimetry has also enhanced the treatment plan. We investigated the effect of these changes on implant outcome in patients with localized carcinoma of the prostate who were treated with these new techniques. Two hundred twenty‐one men with an elevated prostate specific antigen (PSA) or abnormal digital rectal examination (DRE) had transrectal ultrasound evaluation and needle biopsy of the prostate. Prostate volume was determined by ellipsoid and planimetry techniques. Differences of at least 5%, 10%, 15%, 25%, and 50% between the two techniques were found in 170 (77%), 130 (59%), 102 (46%), 53 (24%), and 11 (5%), respectively. In addition, the ellipsoid measurements, which approximate the caliper measurements of the open retropubic implants, were found to underestimate gland volume by 10% in 47 patients (21%), 15% in 39 (18%), 25% in 28 (13%), and 50% in 8 (4%). In 75 patients who had125I implant the dose to 90% (D90) of the gland increased from 7,619 to 15,806 cGy (P<0.02) by distributing the majority (70%) of the activity in the periphery and by increasing the total implanted activity by 35%. Despite this peripheral dose placement and increased activity, there was no increase in dose to the anterior rectal wall. We conclude that accurate prostate gland determinations (by planimetry), a peripheral activity distribution, and a 35% increase in implanted activity are necessary in order to ensure adequate dose coverage to the prostate gland when implanting125I. These changes also may be accomplished without an increase in rectal dose and subsequent radiation proctitis. © 1995 Wiley‐Lis

ISSN:1065-7541    

DOI:10.1002/roi.2970030407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThe purpose of this study was to establish the efficacy of standardized treatment planning for high dose rate (HDR) vaginal cuff brachytherapy in order to simplify and shorten the brachytherapy procedure. Two separate but related studies are presented. The first examined the reproducibility of treatment planning by assessing interoperator variability. This provided a baseline assessment of variability to evaluate standardized treatment planning in the second study. The second study examined interpatient variability in which the treatment plans of 20 patients were investigated by two different treatment methods. The first method used the dosimetry of the first insertion for the next insertion, while the other method utilized a standardized plan for all insertions dependent upon ovoid size. The dose was prescribed to the vaginal surface using either applicator points or dose points. Based on multiple calculations, a graph of distance vs. dose was generated to determine the dose to the bladder and rectum for a given implant. In the first study, interoperator variability was acceptable with a standard deviation of 0.4% of the prescribed dose using dose points for the worst case. Applicator points were less reproducible with a worst‐case standard deviation of 2.1% of the prescribed dose. In the second study, implementing initial dosimetric plans for the second implant for an individual patient yielded a worst‐case standard deviation of 2.4% of the prescribed dose. The use of standardized treatment plans for all implants was also efficacious with a worst‐case standard deviation of 1.7% of the prescribed dose. Treatment plans were always more reproducible when calculated to dose points rather than applicator points. Analysis of maximum bladder and rectal doses provided acceptable late tissue doses as predicted by the linear quadratic model. In conclusion, standardized dosimetry plans for vaginal cuff insertion are feasible and reliable in producing precise delivery of vaginal surface doses. The use of dose vs. distance curves facilitates rapid planning by providing a close approximation of the maximum bladder and rectal doses. © 1995 Wiley‐L

ISSN:1065-7541    

DOI:10.1002/roi.2970030408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

ISSN:1065-7541    

DOI:10.1002/roi.2970030401

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY