Biomedical subjects

Wayne M Butler

Publications and source records attributed to Wayne M Butler.

43 records · Page 3Linked to original sources

PubMedDate not supplied

Biochemical outcome for hormone-naïve patients with high-risk prostate cancer managed with permanent interstitial brachytherapy and supplemental external-beam radiation.

PURPOSE: The purpose of this article is to report the 5-year biochemical disease-free outcome for hormone-naive patients with high-risk disease who underwent permanent prostate brachytherapy. Multiple clinical and treatment parameters were also evaluated to determine whether any of these influence biochemical outcome. MATERIALS AND METHODS: Sixty-six hormone-naïve patients underwent transperineal ultrasound-guided permanent prostate brachytherapy with generous periprostatic margins by use of either 103Pd or 125I for high-risk prostate cancer from April 1995 to October 1999. High-risk patients presented with two or three of the following risk factors: Gleason score > or = 7, prostate-specific antigen > or = 10 ng/mL, and clinical stage > or = T2b, 1997 AJCC. No patient underwent pathological lymph node staging. Only one patient was implanted with monotherapy, whereas 65 patients received supplemental external-beam radiation therapy before a prostate brachytherapy boost. The median patient age was 69 years (range, 50-81 years). No patient was lost to follow-up. The mean follow-up and median follow-up were 53.2 +/- 14.9 months and 53.7 months, respectively (range, 19.8-79.7 months). Follow-up was calculated from the day of implantation. Biochemical disease-free survival was defined by the American Society of Therapeutic Radiology and Oncology consensus definition. Clinical parameters evaluated for biochemical disease-free survival included patient age, clinical stage, Gleason score, and pretreatment prostate-specific antigen. Treatment parameters included use of supplemental external-beam radiation therapy and choice of isotope. RESULTS: The 5-year actuarial biochemical disease-free survival rate was 79.9%. In multivariate analysis, preimplantation prostate-specific antigen (P = 0.008) was the only clinical or treatment parameter that predicted for biochemical failure. The mean and median posttreatment prostate-specific antigen levels were 0.13 +/- 0.22 ng/mL and < 0.1 ng/mL, respectively. DISCUSSION: At a median follow-up of 53.7 months, hormone-naive patients with high-risk disease who undergo permanent prostate brachytherapy have a high probability of 5-year biochemical disease-free survival and an apparent plateau on the biochemical disease-free survival curve.

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PubMedDate not supplied

Prognostic significance of percent positive biopsies in clinically organ-confined prostate cancer treated with permanent prostate brachytherapy with or without supplemental external-beam radiation.

PURPOSE: The purpose of this paper was to evaluate the relationship between the percentage of positive biopsies and the biochemical outcome in hormone-naive patients undergoing permanent prostate brachytherapy with or without supplemental external-beam radiation therapy. MATERIALS AND METHODS: Four hundred thirteen hormone-naive patients underwent prostate brachytherapy for clinical T1c-T2b NxM0 (1997 American Joint Committee on Cancer classification) adenocarcinoma of the prostate gland from April 1995 through June 2001. The median patient age was 66.9 years, and the median pretreatment prostate-specific antigen value was 6.8 ng/mL. The median follow-up was 52 months. Patients were stratified by percentage of positive biopsy results into the following cohorts: < 34%, 34%-50%, and > 50%. The influences of percentage of positive biopsy results, patient age, clinical T stage, Gleason score, pretreatment prostate-specific antigen value, risk group, prostate volume, supplemental external-beam radiation therapy, isotope, percentage of prescribed dose covering 90% of the target volume (D90), and volume receiving 100%, 150%, and 200% of the prescribed dose (V100/150/200) were evaluated. Biochemical disease-free survival was defined by the American Society of Therapeutic Radiology and Oncology consensus definition. RESULTS: For all 413 patients, the 7-year actuarial freedom from biochemical progression rate was 99.4%, 94.3%, and 89.2% when stratified by percentage of positive biopsy results in the < 34%, 34%-50%, and > 50% groups, respectively. When low-, intermediate-, and high-risk patients were stratified by percentage of positive biopsy results, a nonsignificant trend for increased biochemical progression was noted with increasing positive biopsy results. In multivariate analysis, percentage of positive biopsy results and pretreatment prostate-specific antigen value were the only significant predictors of biochemical outcome. The median postimplantation prostate-specific antigen value for all biochemically disease-free patients was < 0.1 ng/mL, regardless of risk group or percentage of positive biopsy results cohort. DISCUSSION: Multivariate analysis demonstrated that percentage of positive biopsy results and pretreatment prostate-specific antigen value were statistically significant predictors of 7-year biochemical progression-free survival. However, the relatively small absolute differences in biochemical outcome based on percentage of positive biopsy results may be a result of radiation dose escalation with the utilization of generous periprostatic treatment margins.

Adenocarcinoma↗

PubMedDate not supplied

Treatment margins predict biochemical outcomes after prostate brachytherapy.

PURPOSE: Due to the theoretical role of treatment margins (TMs) in cancer, we have correlated biochemical outcomes with post-implant TMs in patients treated with brachytherapy for early stage prostate cancer. METHODS: From November 1998 through September 2003, 492 of a planned total of 600 patients with 1997 AJC clinical stage T1c-T2a prostatic carcinoma (Gleason score 5 or 6, PSA 4 to 10 ng/mL) have been randomized to implantation with (125)I (144 Gy, TG-43) versus (103)Pd (125 Gy, NIST-99). This preliminary analysis included only the first 122 analyzable patients, while accrual to the trial finishes. Isotope implantation was performed by standard techniques, using a modified peripheral loading pattern. Axial CT images at 3 mm intervals were acquired within four hours postoperatively for post-implant dosimetry. The contoured images and sources were entered into Varian Variseed system 7.1 (Charlottesville, VA). After completion of standard dosimetric calculations, the 100% prescription dose TMs were measured and tabulated around the prostate periphery at the 0.0, 1.0, 2.0 and 3.0 cm planes, going distal from the bladder-prostate interface. Measurements were limited to the transverse planes. Freedom from biochemical failure was defined as a serum PSA < or = 0.5 ng/mL at last follow-up. Patients were censored at last follow-up if their serum PSA was still decreasing. Patients whose serum PSA nadired at a value >0.5 ng/mL were scored as failures at the time at which their PSA nadired. The follow-up period for non-failing patients ranged from 2.1-5.0 years (median: 3.3 years). RESULTS: The average 100% prescription dose treatment margin (for individual patients) ranged from -5.0 to 8.7 mm, with an overall average of 2.6 mm (+/-3.1). In univariate analysis, the D(90) was the best predictor of biochemical control for (125)I, while the average TM was the best predictor for (103)Pd. Similarly, in multivariate analysis using the D(90), V(100), and average TM as the independent variables and biochemical control as the dependent variable, the D(90) was most closely related to biochemical control for (125)I patients, while average TM was most closely related for (103)Pd patients. In separate analysis of TM by site, the anterior TMs were the best predictors of biochemical outcomes. CONCLUSION: V(100), D(90), and TMs all appear to have a bearing on biochemical freedom from relapse after prostate brachytherapy. Efforts to better identify and test geographic dosimetric parameters are theoretically appealing, and supported by the clinical data summarized here.

Brachytherapy↗

PubMedDate not supplied

The impact of prostate volume and neoadjuvant androgen-deprivation therapy on urinary function following prostate brachytherapy.

PURPOSE: The purpose of this article is to evaluate the impact of prostate size and the magnitude of cytoreduction after neoadjuvant androgen-deprivation therapy (ADT) on catheter dependency, urinary symptomatology, and need for postbrachytherapy surgical intervention. MATERIALS AND METHODS: From February 1998 to August 2002, 186 consecutive patients under went monotherapeutic brachytherapy (no supplemental external-beam radiotherapy or ADT), and 101 consecutive patients received < or = 6 months of ADT (a luteinizing hormone-releasing hormone agonist and an anti-androgen) in conjunction with brachytherapy without supplemental external-beam radiotherapy for clinical Tlc-T2b (2002 American Joint Committee on Cancer) prostate cancer. ADT was initiated approximately 3 months before brachytherapy. The median follow-up was 38.6 months. An alpha-blocker was initiated before implantation and continued at least until the International Prostate Symptom Score (IPSS) returned to baseline levels. Evaluated parameters included patient age, pretreatment prostate-specific antigen, Gleason score, clinical T stage, preimplantation IPSS, ultrasound volume, hormonal status, isotope, D(90), V(100/150/200), and urethral dose (average and maximum). RESULTS: Patients receiving neoadjuvant ADT were statistically older, presented with higher preimplantation IPSS scores, and larger prostate volumes. Patients receiving ADT were likelier to require a urinary catheter for the first 3 days after implantation; however, by day 4, no statistical difference in catheter dependency could be discerned between the two cohorts. Hormonal status did not predict for postbrachytherapy surgical intervention. IPSS returned to baseline at a mean of 1.8 and 1.7 months in hormone-naive and ADT patients, respectively. In multivariate Cox regression analysis, the preimplantation IPSS and the maximum postimplantation IPSS predicted for IPSS normalization overall and in both cohorts. Ultrasound prostate volume did not predict for IPSS normalization, catheter dependency, or need for postimplantation surgical intervention. CONCLUSION: Although patients receiving ADT were likelier to require a urinary catheter for the first three days after implantation, hormonal manipulation did not affect IPSS normalization, prolonged catheter dependency, or need for postbrachytherapy surgical intervention in these patients treated with brachytherapy without supplemental external-beam radiotherapy.

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PubMedDate not supplied

Treatment outcomes and quality-of-life issues for patients treated with prostate brachytherapy.

The increasing popularity of brachytherapy for treatment of early-stage prostate cancer requires oncology nurses to have a comprehensive knowledge of the disease, its treatment, and management of side effects. Because quality-of-life (QOL) issues have become an important consideration in treatment selection for many patients, oncology nurses must have a thorough understanding of these QOL issues and their management. Armed with knowledge about prostate brachytherapy and its effect on QOL, oncology nurses can offer accurate information and evidence-based symptom management techniques to patients undergoing brachytherapy for prostate cancer.

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PubMedDate not supplied

Nursing assessment of sexual function following permanent prostate brachytherapy for patients with early-stage prostate cancer.

Assessment of sexual function following potentially curative local treatment for carcinoma of the prostate gland has resulted in wide ranges of potency preservation rates, which may be because of differences in the evaluated patient populations, mode of data collection, and length of patient follow-up. Quality-of-life data are most reliable when obtained by patient-administered and validated quality-of-life instruments. In the Schiffler Cancer Center's prostate brachytherapy unit, healthcare professionals utilize the specific erectile questions of the International Index of Erectile Function to ascertain pre- and post-treatment erectile function. Documentation of sexual function following all local treatments, including prostate brachytherapy, may help to clarify the etiology of treatment-induced erectile dysfunction (ED), improve treatment for ED, and, ultimately, improve quality-of-life outcomes. Fortunately, the majority of patients with brachytherapy-induced ED respond favorably to sildenafil citrate.

Adenocarcinoma↗

PubMedDate not supplied

Rectal function following permanent prostate brachytherapy.

The purpose of this study was to review the clinical presentation, dosimetry, quality of life assessment, and management of proctitis following permanent prostate brachytherapy. The permanent prostate brachytherapy literature was reviewed using MEDLINE searches to ensure completeness. Rectal complications primarily consist of mild, self-limited proctitis. Rectal bleeding has been correlated with rectal dose. Dose response analysis has demonstrated that the risk of proctitis strongly correlates with the volume of rectal tissue exposed to a given dose. The reported incidence of rectal ulceration/fistula formation is < or = 1%. Constipation significantly increases the radiation dose to the rectum and potentially may contribute to brachytherapy-related morbidity. Quality of life assessments obtained via patient-administered instruments and by physician interview have illustrated that long-term bowel dysfunction is relatively uncommon. Significant bowel dysfunction following prostate brachytherapy is relatively rare, but rectal bleeding has been correlated with radiation dose. Routine post-brachytherapy biopsies of the anterior rectal wall are strongly contraindicated. The continued elucidation of the etiology of bowel dysfunction should result in refinements in implant technique and decreased brachytherapy-related morbidity.

Brachytherapy↗