316 research outputs found

    Individualized predictions of disease progression following radiation therapy for prostate cancer.

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    Background: Following treatment for localized prostate cancer, men are monitored with serial PSA measurements. Refining the predictive value of post-treatment PSA determinations may add to clinical management and we have developed a model that predicts for an individual patient future PSA values and estimates the time to future clinical recurrence. Methods: Data from 934 patients treated for prostate cancer between 1987 and 2000 were used to develop a comprehensive statistical model to fit the clinical recurrence events and pattern of PSA data. A logistic regression model was used for the probability of cure, non-linear hierarchical mixed models were used for serial PSA measurements and a time-dependent proportional hazards model was used for recurrences. Data available up to February 2001 and September 2003 was used to assess the performance of the model. Results: The model suggests that T-stage, baseline PSA, and radiotherapy dosage are all associated with probability of cure. The risk of clinical recurrence in those not cured by radiotherapy is most strongly affected by the slope of the long-transformed PSA values. We show how the model can be used for individual monitoring of a patient’s disease progression. For each patient the model predicts, based upon his baseline and all post-treatment PSA values, the probability of future clinical recurrence in the validation dataset and of 406 PSA measurements obtained 1-2 years after February 2001, 92.8% were within 95% prediction limits from the model. Conclusions: This statistical model presented accurately predicts future PSA values and risk of clinical relapse. This predictive information for each individual patient, which can be updated with each additional PSA value, may prove useful to patents and physicians in determining what post-treatment salvage should be employed

    Management preferences following radical inguinal orchidectomy for Stage I testicular seminoma in Australasia

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    A survey to evaluate the preferred patterns of management of Stage I seminoma was conducted during March 2001. The questionnaire was distributed by the Royal Australian and New Zealand College of Radiologists to all qualified radiation oncologists, 74 out of 170 responded. All performed a staging CT scan of the abdomen and pelvis. Thoracic imaging consisted of either chest X-ray (29%) or chest CT (38%) while 33% performed both. Fifty-four percent of radiation oncologists discussed surveillance with their patients but estimated that 5% or less would choose this option. The most commonly prescribed dose was 25 Gy in 15 or 20 fractions (79%). Sixty-five percent of respondents treated the para-aortic (PA) nodes alone. Forty-two of 48 clinicians treating the PA field reported a change in practice after publication of the Medical Research Council study in 1999. Of these, 40 and 23% perform CT scans of the pelvis annually and every 6 months. Thirty-one percent did no follow-up CT scan. Compared to a similar survey from North America, we are more likely to use PA fields and less likely to discuss surveillance. As in the USA, and in contrast to Canada, few patients choose surveillance. There is no consensus regarding the frequency of follow-up scans in either North America or Australasia.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75636/1/j.1440-1673.2002.01060.x.pd

    Latino Parents\u27 Motivations for Involvement in Their Children\u27s Schooling: An Exploratory Study

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    This study examines the ability of a theoretical model of the parental involvement process to predict Latino parents\u27 involvement in their children\u27s schooling. A sample of Latino parents (N = 147) of grade 1 through 6 children in a large urban public school district in the southeastern United States responded to surveys assessing model-based predictors of involvement (personal psychological beliefs, contextual motivators of involvement, perceived life-context variables), as well as levels of home- and school-based involvement. Home-based involvement was predicted by partnership-focused role construction (a personal psychological belief) and by specific invitations from the student (a contextual motivator of involvement). School-based involvement was predicted by specific invitations from the teacher (a contextual motivator) and by perceptions of time and energy for involvement (a life-context variable). Results are discussed with reference to research on Latino parents\u27 involvemen

    Stereotactic Radiosurgery of a Patient with Severe Kyphosis

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    A patient with a severe kyphotic deformity presented for stereotactic radiosurgery. In the supine position with the apex of the patient's kyphosis on the treatment couch, his head and buttocks were found to be approximately 30 cm from the table. Pretreatment consultation with the physicist and engineer was arranged. By creating a modified table mount for the head ring and a custom-molded Styrofoam cradle for the patient's pelvis, radiosurgery in the supine position was carried out without difficulty or patient discomfort. We describe the technical aspects of the treatment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45113/1/10941_2004_Article_421636.pd

    Unification of favourable intermediate‐, unfavourable intermediate‐, and very high‐risk stratification criteria for prostate cancer

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139069/1/bju13903.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139069/2/bju13903_am.pd

    Late toxicity and biochemical recurrence after external-beam radiotherapy combined with permanent-source prostate brachytherapy

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    BACKGROUND The combination of external-beam radiotherapy and brachytherapy is used commonly to treat men with prostate cancer. In this analysis, the authors examined the rate of biochemical recurrence (BR) and late grade ≥3 genitourinary (GU) and gastrointestinal (GI) toxicity after treatment with external-beam radiotherapy and brachytherapy in a multiinstitutional, cooperative group setting. METHODS All eligible patients received external-beam radiotherapy (45 Gray [Gy] in 25 fractions) followed 2 to 6 weeks later by an interstitial implant using iodine-125 to deliver an additional 108 Gy. BR was defined in 2 ways: according to the American Society for Therapeutic Radiology and Oncology (ASTRO) Consensus Definition (ACD) and according to the Phoenix definition (PD) (prostate-specific antigen nadir +2 ng/mL). The Radiation Therapy Oncology Group(RTOG)/European Organization for Research and Treatment of Cancer late radiation morbidity scoring system was used to grade all toxicity. RESULTS One hundred thirty-eight patients were enrolled, and 130 were eligible for the current analysis. The median follow-up for surviving patients was 49 months (range, 20–60 months). The 48-month estimate of late grade ≥3 GU/GI toxicity was 15% (95% confidence interval [95% CI], 8–21%), and the 48-month estimate of BR was 19% (95% CI, 12–26%) and 14% (95% CI, 8–20%) according to the ACD and PD, respectively. CONCLUSIONS The morbidity observed in this multiinstitutional, cooperative group study was slightly higher than that reported in recent RTOG studies using brachytherapy alone or high-dose external-beam radiotherapy. The BR rate observed in this report was similar to that observed with high-dose external-beam radiotherapy alone in similar patients. Cancer 2007. © 2007 American Cancer Society.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55987/1/22560_ftp.pd
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