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Gregory S Merrick

Publications and source records attributed to Gregory S Merrick.

At least 73 records · Page 4Linked to original sources
PubMed2002

Erectile function after permanent prostate brachytherapy.

PURPOSE: To determine the incidence of potency preservation after permanent prostate brachytherapy using a validated patient-administered questionnaire and to evaluate the effect of multiple clinical and treatment parameters on penile erectile function. MATERIALS AND METHODS: Four hundred twenty-five patients underwent permanent prostate brachytherapy from April 1995 to October 1999. Two hundred nine patients who were potent before brachytherapy and who at the time of the survey were not receiving hormonal therapy were mailed the specific erectile questions of the International Index of Erectile Function (IIEF) questionnaire with a self-addressed stamped envelope. The questionnaire consisted of 5 questions, with a maximal score of 25. Of the 209 patients, 181 (87%) completed and returned the questionnaire. The mean and median follow-up was 40.4 +/- 14.9 and 40.6 months, respectively (range 19-75). Preimplant erectile function was assigned using a three-tiered scoring system (2 = erections always or nearly always sufficient for vaginal penetration; 1 = erections sufficient for vaginal penetration but considered suboptimal; 0 = the inability to obtain erections and/or erections inadequate for vaginal penetration). Postimplant potency was defined as an IIEF score >/=11. The clinical parameters evaluated for erectile function included patient age, preimplant potency, clinical T-stage, pretreatment prostate-specific antigen level, Gleason score, elapsed time after implantation, hypertension, diabetes mellitus, and tobacco consumption. Treatment parameters included radiation dose to the prostate gland, use of hormonal manipulation, use of supplemental external beam radiotherapy (EBRT), choice of isotope, prostate volume, and planning volume. The efficacy of sildenafil citrate in brachytherapy-induced erectile dysfunction (ED) was also evaluated. RESULTS: Pretreatment erectile function scores of 2 and 1 were assigned to 125 and 56 patients, respectively. With a 6-year follow-up, 39% of patients maintained potency after prostate brachytherapy, with a plateau on the potency preservation curve. Postimplant preservation of potency (IIEF >/=11) correlated with preimplant erectile function (50.4% vs. 13.2% for preimplant scores of 2 and 1, respectively, p <0.001), patient age (57.4%, 38.2%, and 21.9% for patients <60, 60-69, and >/=70 years old, respectively, p <0.004), use of supplemental EBRT (52.0% vs. 26.4% for patients without and with EBRT, p <0.001), and a history of diabetes mellitus (41.4% vs. 0% for patients without and with diabetes, respectively, p = 0.017). In multivariate analysis, clinical stage, radiation dose to the prostate gland, hormonal manipulation, choice of isotope, history of hypertension, and tobacco consumption had no effect on the ultimate preservation of potency. Only the preimplant potency score, use of supplemental EBRT, and diabetes maintained statistical significance. Sixty-two patients used sildenafil, with 53 (85%) reporting a favorable response. When potent patients were grouped with the ED patients who used sildenafil, the 6-year actuarial rate of potency preservation was 92%. Including the 70 impotent patients who never used sildenafil, the actuarial 6-year rate of potency preservation with and without pharmacologic support was 54% and 39%, respectively. CONCLUSION: Our results suggest that brachytherapy-induced ED is more common than previously reported and may be the result of obtaining patient information by means of a validated quality-of-life instrument by mail and not by personal interview. In multivariate analysis, only pretreatment potency, supplemental EBRT, and diabetes maintained statistical significance. Most patients with brachytherapy-induced ED responded favorably to sildenafil. Although the 6-year actuarial incidence of potency preservation was 39%, 52% of patients not receiving supplemental EBRT maintained potency. In addition, with pharmacologic support, 92% of patients maintained potency.

Adenocarcinoma↗
PubMed2002

Relationship between percent positive biopsies and biochemical outcome after permanent interstitial brachytherapy for clinically organ-confined carcinoma of the prostate gland.

PURPOSE: Recently, the percentage of positive prostate biopsies has been reported to be statistically significant in predicting the biochemical outcome after either radical prostatectomy or 3-dimensional conformal external beam radiotherapy. In this study, we evaluated the impact of the percentage of positive prostate biopsies in predicting the 5-year biochemical outcome for patients with clinically organ-confined prostate cancer undergoing permanent interstitial brachytherapy. METHODS AND MATERIALS: Two hundred sixty-two hormone naive patients underwent transperineal ultrasound-guided permanent prostate brachytherapy with generous periprostatic margins, using either 103Pd or 125I for clinical T1b/T2b NXM0 (1997 AJCC) adenocarcinoma of the prostate gland from April 1995 to October 1999. No patient was lost to follow-up. The actual percentage of positive biopsies (number of positive biopsies/total number of biopsies) was determinable for 255 of the 262 patients. Of the evaluated cases, 133 patients were implanted with 103Pd and 122 patients with 125I. The median patient age was 68 years (range 48-81). The median follow-up was 38.6 months (range 6-73). Follow-up was calculated from the day of implantation. Patients were stratified by the percentage of positive biopsies into the following groups: <34%, 34-50%, and >50%. Additional clinical parameters evaluated included patient age, clinical T-stage, Gleason score, pretreatment prostate specific antigen (PSA), risk group, and prostate volume. Low-risk patients were staged as clinical T1c/T2a, Gleason score < or =6, and pretreatment PSA < or =10 ng/mL, intermediate-risk patients presented with one unfavorable prognostic parameter, and high-risk patients presented with two or more unfavorable prognostic parameters (clinical stage T2b, PSA >10 ng/mL, Gleason score > or =7). Treatment parameters included the use of supplemental external beam radiation and choice of isotope. Biochemical disease-free survival was defined by the American Society of Therapeutic Radiation and Oncology consensus definition. RESULTS: For the 255 evaluated patients, the 5-year actuarial biochemical no evidence of disease survival rate was 92.5%. For patients with low, intermediate, and high-risk disease, 95.8%, 98.1%, and 79.4% of patients were free of biochemical failure, respectively. When each risk group was stratified into the percent positive biopsy categories of <34%, 34-50%, and >50%, no statistical difference was found in biochemical outcome for the biopsy subgroups. In multivariate analysis, none of the clinical or treatment parameters predicted for failure in the low-risk group; only Gleason score was predictive for intermediate-risk patients and only PSA for high-risk patients. In the overall population, PSA and Gleason score were both found to be predictors of biochemical failure, but not risk group, clinical stage, or percentage of positive biopsies. There was no significant dependence between the percent positive biopsy group and the Kaplan-Meier biochemical survival rates for any of the various subgroups of clinical and treatment parameters, except for clinical stage T1c-T2a (p = 0.006). The median postimplant PSA was 0.2 ng/mL for patients with either low-risk disease or <34% positive biopsies and 0.1 ng/mL for all other risk groups or percent positive biopsy subgroups. CONCLUSION: Although a significant trend was found for biochemical failure with increasing percent positive biopsies in the overall population, our results suggest that the percentage of positive biopsies is not statistically significant in predicting the 5-year biochemical disease-free outcome for patients with low, intermediate, and high-risk disease undergoing permanent prostate brachytherapy. Only the Gleason score in intermediate-risk patients and the pretreatment PSA level in high-risk patients was predictive of biochemical failure. We believe this relative lack of significance for the percentage of positive biopsies is a result of dose escalation far exceeding other radiotherapy modalities and the ability to aggressively treat the periprostatic region compared with radical prostatectomy by way of the accurate placement of periprostatic seeds.

Aged↗
PubMed2002

The dosimetry of prostate brachytherapy-induced urethral strictures.

PURPOSE: There is a paucity of data regarding the incidence of urethral strictures after prostate brachytherapy. In this study, we evaluate multiple clinical, treatment, and dosimetric parameters to identify factors associated with the development of brachytherapy-induced urethral strictures. METHODS AND MATERIALS: 425 patients underwent transperineal ultrasound-guided prostate brachytherapy using either (103)Pd or (125)I for clinical T1b/T3a NxM0 (1997, American Joint Committee on Cancer) adenocarcinoma of the prostate gland from April 1995 to October 1999. No patient was lost to follow-up. 221 patients were implanted with (103)Pd and 204 patients with (125)I. The median patient age was 68 years (range 48-81 years). The median follow-up was 35.2 months (range 15-72 months). Follow-up was calculated from the day of implantation. Thirteen patients developed brachytherapy-induced strictures, and all strictures involved the membranous urethra. A control group of 35 patients was rigorously matched to the stricture patients in terms of treatment approach; i.e., choice of isotope, plus or minus radiation therapy, and plus or minus hormonal manipulation. Nine of the 13 stricture patients had detailed Day 0 urethral dosimetry available for review. The apex of the prostate gland and the membranous urethra were defined by CT evaluation. Urethral dosimetry was reported for the prostatic urethra, the apical slice of the prostate gland, and the membranous urethra which was defined as extending 20 mm in length. RESULTS: The 5-year actuarial risk of a urethral stricture was 5.3%, with a median time to development of 26.6 months (range 7.8-44.1 months). Of multiple clinical and treatment parameters evaluated, only the duration of hormonal manipulation (>4 months, p = 0.011) was predictive for the development of a urethral stricture. The radiation dose to the membranous urethra was significantly greater in patients with strictures than those without: 97.6% +/- 20.8% vs. 81.0% +/- 19.8% of prescribed minimum prostate dose, mPD (p = 0.031). The urethral dose 20 mm distal to the prostate apex was 57.6% +/- 23.8% vs. 31.5% +/- 13.9% of mPD for the stricture and control patients, respectively (p = 0.011). In addition, the extent of the 75% mPD and 50% mPD levels beyond the prostatic apex was also significantly greater for stricture patients, 16.6 +/- 5.3 mm vs. 11.9 +/- 4.5 mm (p = 0.010) and 19.0 +/- 3.2 mm vs. 16.0 +/- 3.4 mm (p = 0.021), respectively. Dose to the prostatic urethra was not predictive of stricture, but the magnitude and extent of high-dose regions within the prostate were predictive of stricture. Twelve of the 13 patients who developed urethral strictures were successfully managed by dilatation/transurethral incision. To date, 1 of the 12 patients has required a second dilatation. The remaining patient developed an iatrogenic induced injury and was catheter-dependent for 6 months. CONCLUSIONS: After prostate brachytherapy, the actuarial 5-year incidence of urethral strictures is 5.3% with a median time to development of 26.6 months. All strictures involved the membranous urethra and occurred within the first 44 months after brachytherapy. In most cases, membranous urethral strictures are easily managed with dilatation/incision. Factors predicting for the development of a urethral stricture included the magnitude and extent of high-dose regions within the prostate, the mean membranous urethra dose and the dose 20 mm distal to the prostatic apex, the maximum extent along the membranous urethra of certain dose levels, and the duration of hormonal manipulation.

Aged↗
PubMed2002

Permanent prostate brachytherapy-induced morbidity in patients with grade II and III obesity.

OBJECTIVES: To determine the influence of obesity on the development of urinary, bowel, and sexual dysfunction after brachytherapy by means of patient-administered questionnaires. The effect of obesity on dosimetric quality and biochemical outcome was also evaluated. METHODS: Thirty-two patients with grade II and III obesity underwent brachytherapy from June 1997 through April 2001. Grade II and III obesity was defined as a body mass index of 35.0 to 39.9 and 40.0 kg/m2 or greater, respectively. Serial International Prostate Symptom Score (IPSS) evaluations were obtained at predetermined intervals. Bowel and sexual function were assessed by a rectal function assessment score (R-FAS) and the specific erectile questions of the International Index of Erectile Function (IIEF). The median follow-up was 26.4 months. An alpha-blocker was initiated before implantation and continued at least until the IPSS normalized. Catheter dependency, alpha-blocker dependency, and the incidence of urethral strictures were also evaluated. The efficacy of sildenafil in brachytherapy-induced erectile dysfunction was also evaluated. Dosimetric parameters evaluated included the percentage of the prostate receiving 100%, 150%, and 200% of the prescribed dose (V100, V150, and V200), the minimal dose received by 90% of the prostate (D90), urethral doses, and rectal doses. Biochemical outcome was determined by the ASTRO consensus conference definition. RESULTS: Of the 32 patients, 31 (97%) had the urinary catheter permanently removed on day 0, and no patient required a urinary catheter for longer than 1 day. One patient developed a urethral stricture. No patient required a transurethral resection or developed urinary incontinence. On average, the IPSS peaked 2 weeks after implantation and returned to baseline at a median of 8 weeks (mean 16). The post-treatment R-FAS was 3.6. No patient developed a rectal ulcer or fistula. Of the 22 patients who were potent before implantation, 7 (31.8%) maintained potency. With pharmacologic support, 59.1% maintained erections sufficient for vaginal penetration. Day 0 dosimetry demonstrated a median V100 and D90 of 96.5% and 113.5%. At last follow-up, all patients remained free of biochemical failure, with a median prostate-specific antigen level of 0.1 ng/mL. CONCLUSIONS: No difference in quality-of-life parameters was discerned in patients with grade II and III obesity. In addition, the dosimetric quality of the implants was outstanding, and the short-term biochemical outcome was encouraging.

Adenocarcinoma↗
PubMed2002

Biochemical outcome for hormone-naive patients with Gleason score 3+4 versus 4+3 prostate cancer undergoing permanent prostate brachytherapy.

OBJECTIVES: To determine the effect of the dominant pattern in Gleason score 7 histologic findings on biochemical no evidence of disease survival for hormone-naive patients undergoing permanent prostate brachytherapy. METHODS: A total of 114 hormone-naive patients with Gleason score 7 histologic findings underwent transperineal ultrasound-guided permanent prostate brachytherapy for clinical T1c-T3a NxM0 adenocarcinoma of the prostate gland from April 1995 to October 1999. No patient was lost to follow-up. No patient underwent seminal vesicle biopsy or pathologic lymph node staging. Sixty-four patients were diagnosed with Gleason score 3+4 and 50 with Gleason score 4+3 prostate cancer. Twenty-one patients were implanted with either palladium 103 or iodine 125 monotherapy, and 93 patients received supplemental external beam radiotherapy with a brachytherapy boost. The median patient age was 69 years (range 49 to 79). The median follow-up was 46.4 months (range 20 to 80). The American Society for Therapeutic Radiology and Oncology consensus definition was used to determine the biochemical disease-free survival. RESULTS: The actuarial 5-year biochemical disease-free survival rate was 90.3%. No statistically significant difference in outcome was found when stratified by the dominant pattern in Gleason score 7 histologic features (89.4% versus 91.5% for 3+4 and 4+3, respectively, P = 0.700). The biochemical no evidence of disease survival analysis in terms of the Gleason cohorts revealed no difference in terms of the choice of isotope, use of supplemental external beam radiotherapy, or preimplant prostate-specific antigen level. The median and mean postimplant prostate-specific antigen level was less than 0.1 ng/mL and 0.12 +/- 0.20 ng/mL, respectively, without a significant difference between Gleason score 3+4 and 4+3. CONCLUSIONS: Our results indicate that the 5-year biochemical outcome with a hormone-naive prostate brachytherapy approach that uses multiple periprostatic seeds is not dependent on Gleason score 3+4 versus 4+3 histologic features.

Adenocarcinoma↗
PubMed2002

Prophylactic versus therapeutic alpha-blockers after permanent prostate brachytherapy.

OBJECTIVES: To evaluate the influence of prophylactic versus therapeutic alpha-blockers on urinary morbidity after permanent prostate brachytherapy. Multiple clinical and treatment parameters were evaluated to identify the factors associated with acute urinary morbidity. METHODS: A total of 234 consecutive patients underwent permanent prostate brachytherapy in one of two prospective randomized studies from October 1999 through February 2001 using either palladium-103 or iodine-125 for clinical Stage T1b-T2b (1997 American Joint Commission on Cancer staging system) prostate cancer at either the Schiffler Cancer Center or Puget Sound Health Care System. The mean and median follow-up was 8.8 +/- 4.6 months and 6 months, respectively. In 142 patients, an alpha-blocker was initiated before implantation and continued at least until the International Prostate Symptom Score (IPSS) returned to baseline levels; 92 patients either did not receive an alpha-blocker or received a therapeutic alpha-blocker after implantation because of urinary obstructive symptoms. The clinical and treatment parameters evaluated for urinary morbidity included prophylactic versus therapeutic alpha-blockers, age, preimplant IPSS, ultrasound volume, use of neoadjuvant hormones, use of supplemental external beam radiotherapy, isotope, urethral dose, and multiple dosimetric quality indicators (minimal dose received by 90% of the prostate gland and percentage of prostate volume receiving 100% or 200% of the prescribed minimal peripheral dose). Catheter dependency and the duration of alpha-blocker dependency were also evaluated. RESULTS: In both the prophylactic and the therapeutic cohorts, the IPSS peaked 1 month after implantation. Patients receiving a prophylactic alpha-blocker returned to baseline at a mean of 4 months and a median of 3 months postoperatively. For those patients not receiving prophylactic alpha-blockers, the IPSS returned to the antecedent value at a mean and median of 10 months and 6 months, respectively. Of the 125 patients receiving prophylactic alpha-blockers, 102 (81.2%) remained medication dependent at the conclusion of the study, and 140 (78.2%) of 179 patients receiving alpha-blockers other than for hypertensive purposes did so. The incidence of prolonged urinary catheter dependency (greater than 3 days) and the need for postimplant transuretheral incision of the prostate/transurethral resection of the prostate were not affected by alpha-blocker use. Cox regression analysis revealed that only the prophylactic use of alpha-blockers and the difference between the preimplant IPSS and the 1-month IPSS were predictive of the time to return to the referent zone. CONCLUSIONS: Prophylactic use of alpha-blockers results in significantly less urinary morbidity than either the absence or therapeutic use of alpha-blockers. In patients receiving prophylactic alpha-blockers, the IPSS normalized significantly faster but had no impact on urinary retention or the ultimate need for postimplant surgical intervention.

Adenocarcinoma↗
PubMed2002

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

PURPOSE: To report the 6-year biochemical disease-free outcome for hormone-naïve patients with intermediate-risk disease (Gleason score > or =7, prostate-specific antigen (PSA) > or =10 ng/ml, or clinical stage > or =T2b [1997 American Joint Committee on Cancer]) undergoing brachytherapy with supplemental external beam radiation (XRT). METHODS AND MATERIALS: Seventy-seven consecutive hormone-naïve intermediate-risk prostate cancer patients received supplemental XRT followed by a brachytherapy boost. No patient underwent pathologic lymph node staging. The median patient age was 69 years and the median follow-up was 52 months. Biochemical disease-free survival was defined by the American Society of Therapeutic Radiology and Oncology consensus definition. Clinical and treatment parameters evaluated included patient age, clinical stage, Gleason score, pretreatment PSA, and isotope. RESULTS: The 6-year actuarial biochemical no-evidence-of-disease survival rate was 97.4%. None of the evaluated clinical or treatment parameters, except for a Gleason score > or =8, predicted for failure. The mean and median posttreatment PSA was 0.08 +/- 0.19 ng/ml and <0.1 ng/ml, respectively. When stratified by isotope, the mean posttreatment PSA was not significantly different (0.07 +/- 0.11 ng/ml for 103Pd vs. 0.14 +/- 0.32 ng/ml for 125I; p=0.397). CONCLUSIONS: Hormone-naïve intermediate-risk prostate cancer patients undergoing brachytherapy with supplemental XRT have a high probability of 6-year biochemical disease-free survival. None of the evaluated clinical or treatment parameters, except Gleason score > or =8, predicted for treatment failure.

Aged↗
PubMedDate not supplied

Statins and cholesterol lowering after a cancer diagnosis: why not?

The pleiotropic effects of statins continue to garner attention. One area of interest that requires more attention is their potential, or that of another heart healthy agent, to impact favorably or inhibit the progression of numerous cancers, especially prostate cancer. Statins have accumulated a plethora of data in the area of general cancer cell line inhibition, and the potential to have a synergistic impact in patients receiving a variety of conventional treatments for a diversity of cancers is endorsed at least by laboratory and some preliminary small clinical studies. However, prostate cancer is unique compared to other cancers because, despite a high prevalence, some men choose watchful waiting or no treatment, especially if they are older and/or have a well-differentiated tumor. Thus, prostate cancer is a good candidate for the potential investigation of statins after diagnosis, with or without standard therapy. Regardless, because the number 1 or 2 cause of death in men with prostate cancer is cardiovascular disease than even in the worst-case scenario, these agents appear attractive for more immediate clinical study because they could impact a major cause of morbidity and mortality in these men. It is time to see the forest over the tree, and statins seem to have an argument as good as many other agents for allocating more money and time to test their ability as adjuvant therapy in a randomized trial or, in some cases, of nonaggressive disease as a potential monotherapy.

Anticarcinogenic Agents↗
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.

Aged↗
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.

Aged↗
PubMedDate not supplied

The impact of primary Gleason grade on biochemical outcome following brachytherapy for hormone-naive Gleason score 7 prostate cancer.

PURPOSE: Although the perception exists that biochemical outcome in patients with a Gleason score of 7 with dominant pattern 4 histology is inferior to that of patients with a Gleason score of 7 with a primary Gleason grade of 3, conflicting conclusions have been reported for radical prostatectomy and brachytherapy. In this study, we evaluate the effect of the dominant histologic pattern in Gleason score 7 prostate cancer on biochemical progression-free survival after brachytherapy. MATERIAL AND METHODS: Between April 1995 and October 2001, 273 consecutive patients underwent permanent interstitial brachytherapy without androgen deprivation therapy for clinical T1c-T3a NxM0 (2002 American Joint Committee on Cancer) prostate cancer. No patient underwent seminal vesicle biopsy or pathological lymph node staging. All patients underwent brachytherapy more than 3 years before analysis. Biochemical progression-free survival was defined by a prostate specific antigen (PSA) cut point < or = 0.4 ng/mL after nadir or by the American Society for Therapeutic Radiology and Oncology (ASTRO) consensus definition. The median follow-up was 4.7 years. Clinical, treatment, and dosimetric parameters evaluated for biochemical progression-free survival included primary Gleason grade; clinical T stage; pretreatment PSA level; risk group; percent positive biopsy results; perineural invasion; patient age; isotope; supplemental external-beam radiation therapy; prostate volume; brachytherapy planning volume; percent of the target volume receiving 100%, 150%, and 200% of the prescribed dose (V100/150/200); minimum percent of the prescribed dose covering 90% of the target volume (D90); tobacco consumption; hypertension; and diabetes. RESULTS: For the entire cohort, the actuarial 8-year biochemical progression-free survival rate was 94.5% and 94.8% using a PSA cut point < or = 0.4 ng/mL after nadir and the ASTRO consensus definition, respectively. For biochemically disease free patients, the median posttreatment PSA level was < 0.1 ng/mL. When the group was stratified by the dominant histologic pattern, no statistical difference in outcome was noted for any of the evaluated parameters. In forward conditional Cox regression analysis, pretreatment PSA level and percent positive biopsy results were statistically significant predictors of biochemical outcome. CONCLUSIONS: In hormone-naive patients with a Gleason score of 7, prostate brachytherapy results in a high probability of 8-year biochemical progression-free survival and is independent of Gleason 3 + 4 versus 4 + 3 histology.

Aged↗
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.

Aged↗
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↗
PubMedDate not supplied

Enzymatic prostatic acid phosphatase in the clinical staging of patients diagnosed with prostate cancer.

From October 1999 to July 2002, 821 newly diagnosed untreated prostate cancer patients at Schiffler Cancer Center at Wheeling Hospital in Wheeling, W. Va., who had pretreatment enzymatic prostatic acid phosphatase (PAP) determinations, were evaluated to determine if PAP could refine the subset of those requiring radiographic staging. PAP was obtained using a microparticle enzyme immunoassay (MEIA). A multivariate logistic regression model was constructed using pretreatment variables to determine whether PAP represented an independent predictor of positive bone and/or CT scans. A linear regression evaluated the predictive value of age, PSA, prostate volume, PAP and percent positive biopsies with the subsequent radiographic work-up. Enzymatic PAP proved useful in the clinical staging of newly diagnosed, untreated prostate cancer Using cutpoints of 15 ng/mL for PAP and 50 ng/mL for PSA, the negative predictive value for radiographically detected metastases was 99.8%.

Acid Phosphatase↗