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Gregory S Merrick

Publications and source records attributed to Gregory S Merrick.

At least 19 recordsLinked to original sources
PubMed2003

Late rectal function after prostate brachytherapy.

PURPOSE: Using a patient-administered quality of life instrument, to evaluate the effect of permanent prostate brachytherapy on late rectal function. METHODS AND MATERIALS: One hundred eighty-nine prostate brachytherapy patients were mailed the Rectal Function Assessment Score (R-FAS), with a prestamped return envelope. The R-FAS consists of nine questions and a scoring range of 0-27, with higher scores indicative of poorer bowel function. One hundred eighty-seven (98.4%) surveys were returned. The median follow-up was 66.3 months (range 54-92 months). Clinical, treatment, and dosimetric parameters evaluated for bowel dysfunction included patient age, diabetes, hypertension, tobacco consumption, clinical T-stage, elapsed time since implant, prostate ultrasound volume, planning target volume, hormonal status, supplemental external beam radiation therapy (EBRT), isotope, average, median and maximum rectal doses, total implanted seed strength, values of the minimum dose received by 90% of the prostate gland (D(90)), and the percent prostate volume receiving 100%, 150%, and 200% of the minimum prescribed dose (V(100/150/200)). RESULTS: The R-FAS score for the evaluated cohort was 3.92, which represented a slight improvement from the 1999 survey score of 4.15 (p = 0.29). Of the evaluated clinical, treatment, and dosimetric parameters, the number of preimplant bowel movements, a history of tobacco consumption, and the median rectal dose correlated with the R-FAS. Although lower rectal doses were noted with Pd-103, isotope did not predict for bowel function. Only 12% (23/187) of patients reported their bowel function to be worse after implantation. Patient perception of overall rectal quality of life was inversely related to the use of supplemental EBRT (p = 0.007). CONCLUSION: Minor bowel changes are noted following prostate brachytherapy. The vast majority of patients did not report any deterioration in bowel function. In addition, the R-FAS continue to improve with time.

Aged↗
PubMed2003

Long-term urinary quality of life after permanent prostate brachytherapy.

PURPOSE: To evaluate late urinary function after permanent prostate brachytherapy using a validated, patient-administered quality-of-life instrument. METHODS AND MATERIALS: A total of 225 consecutive patients underwent prostate brachytherapy between April 1995 and March 1998. Of the 225 patients, 17 had died and 3 had been institutionalized secondary to Alzheimer's disease. Of the remaining 205 patients, each was mailed a self-administered questionnaire (the urinary function component of the Expanded Prostate Cancer Index [EPIC] and the International Prostate Symptom Score [IPSS]). Of the 205 surveys mailed, 195 (95.1%) were returned. The mean and median follow-up was 66.3 and 64.0 months, respectively. The clinical parameters evaluated included age, pretreatment prostate-specific antigen level, Gleason score, stage, risk group, prostate volume, presence of diabetes and hypertension, and tobacco consumption. The treatment parameters included the ultrasound planning volume, hormonal status, use of supplemental external beam radiotherapy, isotope, and follow-up. The dosimetric parameters included values of the minimal dose received by 90% of the prostate gland and the percentage of prostate volume receiving 100%, 150%, and 200% of the prescribed minimal peripheral dose. Because detailed baseline urinary function was not available, a cross-sectional survey was performed in which 51 newly diagnosed prostate cancer patients of comparable demographics served as controls. RESULTS: When the survey scores for the implant patients were compared with the control group, no significant differences in either the IPSS or function, bother, incontinence, or irritation/obstruction subscales of the urinary EPIC were discernible. In addition, no significant difference was observed between the implant and control groups when the EPIC and IPSS surveys were evaluated by each individual question. Of all the evaluated parameters, the use of tobacco was the best predictive variable for diminished quality of life. CONCLUSION: No significant difference was noted in the overall long-term urinary quality of life when brachytherapy patients were compared with a group of newly diagnosed prostate cancer patients of comparable demographics. Of all parameters evaluated, tobacco consumption was the single strongest predictor of late urinary function.

Aged↗
PubMed2003

Dysuria after permanent prostate brachytherapy.

PURPOSE: Although numerous prostate cancer quality-of-life studies have been reported, a paucity of data exists regarding brachytherapy-related dysuria. In this study, we evaluated the incidence and temporal resolution of dysuria, along with the influence of multiple treatment, clinical, and dosimetric parameters. MATERIALS AND METHODS: Five hundred eighty-one consecutive patients without a preimplant history of transurethral resection of the prostate underwent brachytherapy between January 1998 and December 2001 for clinical T1c-T3a (1997 AJCC) adenocarcinoma of the prostate gland. The evaluated population consisted of the 546 patients who had completed at least two postimplant dysuria evaluations. The median patient follow-up was 26.4 months. In all patients, alpha-blocker therapy was initiated before implantation and continued at least until the International Prostate Symptom Score (IPSS) returned to baseline. The frequency of dysuria was assessed on a 1-5 scale using the IPSS scoring criteria. The dysuria severity was scored on a 1-10 scale. The clinical parameters evaluated included age, T stage, preimplant IPSS, ultrasound volume, and elapsed time since implantation. The treatment parameters included the use of neoadjuvant hormonal manipulation, use of supplemental external beam radiotherapy, isotope, and total implanted seed strength. The dosimetric parameters included values of the minimal dose received by 90% of the prostate, the percentage of prostate volume receiving 100%, 150%, and 200% of the prescribed minimal peripheral dose, and the median and maximal urethral doses. RESULTS: The incidence of dysuria peaked at 52% 1 month after implantation. The median dysuria frequency score was 0 of 5 for all patients and 2 of 5 for those reporting dysuria. The median severity score was 0 of 10 for the entire cohort and 3 of 10 for those reporting dysuria. For the entire group, both the frequency and the severity of dysuria steadily improved with time, with near complete resolution of dysuria at 45 months. For those patients reporting dysuria, neither the frequency nor the severity revealed any durable improvement for approximately 36 months. Patients with dysuria displayed higher postimplant IPSSs. Of the 7 IPSS questions, nocturia and incomplete voiding were the best surrogates for dysuria. The isotope, supplemental external beam radiotherapy, hormonal status, minimal dose received by 90% of the prostate, and urethral dose did not predict for dysuria. CONCLUSIONS: After permanent prostate brachytherapy, dysuria is a relatively common event, but only rarely severe in frequency or intensity. At approximately 45 months after brachytherapy, dysuria appears to resolve in almost all patients.

Aged↗
PubMed2003

Permanent interstitial brachytherapy for the management of carcinoma of the prostate gland.

PURPOSE: We summarize the permanent prostate brachytherapy literature, including biochemical outcomes, quality of life parameters and areas of controversy. MATERIALS AND METHODS: The permanent prostate brachytherapy literature was reviewed using MEDLINE searches to ensure completeness. RESULTS: Using various planning and intraoperative techniques the majority of the brachytherapy literature demonstrates durable biochemical outcomes for patients with low, intermediate and high risk features. For low risk patients there is no advantage to combining supplemental external beam radiation therapy with brachytherapy. In addition, supplemental external beam radiation therapy may not improve biochemical outcomes for patients at intermediate and high risk if the target volume consists of the prostate with a generous periprostatic margin. There is no defined role for adjuvant hormonal manipulation. Although a reliable set of pretreatment criteria to predict implant related morbidity is not available, severe urinary and rectal morbidity is rare. The incidence of brachytherapy induced erectile dysfunction is significantly greater than initially reported but the majority of patients respond favorably to sildenafil. CONCLUSIONS: Continued refinements in brachytherapy planning and implementation techniques, postimplantation evaluation and continued elucidation of the etiology of urinary, bowel and sexual dysfunction should result in further improvements in biochemical and quality of life outcomes.

Brachytherapy↗
PubMed2003

Management of sexual dysfunction after prostate brachytherapy.

Erectile dysfunction is a common sequela following potentially curative local treatment for early-stage carcinoma of the prostate gland. With larger studies and longer follow-up, it is clear that erectile dysfunction following prostate brachytherapy is more common than previously reported, with a myriad of previously unrecognized sexual symptoms. Approximately 50% of patients develop erectile dysfunction within 5 years of implantation. Several factors including preimplant potency, patient age, the use of supplemental external-beam irradiation, radiation dose to the prostate gland, radiation dose to the bulb of the penis, and diabetes mellitus appear to exacerbate brachytherapy-related erectile dysfunction. The majority of patients with brachytherapy-induced erectile dysfunction respond favorably to sildenafil citrate (Viagra). Despite reports questioning the potency-sparing advantage associated with brachytherapy, recent elucidations of brachytherapy-related erectile dysfunction may result in refinement of treatment techniques, an increased likelihood of potency preservation, and ultimately, improved quality of life.

Adult↗
PubMed2002

The importance of radiation doses to the penile bulb vs. crura in the development of postbrachytherapy erectile dysfunction.

PURPOSE: Recent studies have implicated the proximal penis as a potential site-specific structure for radiation-related erectile dysfunction (ED). In this study, we evaluated by means of a validated patient-administered questionnaire whether radiation doses to the bulb of the penis and/or the proximal corporeal bodies were predictive for the development of brachytherapy-induced ED. METHODS AND MATERIALS: Thirty patients who underwent permanent prostate brachytherapy between April 1995 and October 1999 and developed brachytherapy-induced ED were paired with 30 similar men who maintained potency after implantation. None of the 60 patients received supplemental external beam radiation therapy, either before or after implantation. Potency was assessed by patient self-administration of the specific erectile questions of the International Index of Erectile Function. The questionnaire consisted of 5 questions with a maximum score of 25. Postimplant potency was defined as an International Index of Erectile Function score > or =11. Mean and median follow-up was 48.3 +/- 14.4 months and 48.0 months, respectively (range: 26.6-79.3 months). The bulb of the penis and the proximal crura were outlined at 0.5-cm intervals on the Day 0 postimplant CT scan. The radiation dose distribution to the bulb of the penis and adjacent crura was defined in terms of the minimum dose delivered to 25%, 50%, 70%, 75%, 90%, and 95% of the bulb (D(25), D(50), D(70), D(75), D(90), and D(95)). RESULTS: The radiation dose delivered to the bulb of the penis and the proximal crura in men with brachytherapy-induced ED was statistically greater for all evaluated dosimetric parameters (D(25), D(50), D(70), D(75), D(90), and D(95)). Stepwise linear regression analysis indicated that penile bulb dose parameter D(50), the postimplant prostate CT volume, and patient age at implant were predictive of postimplant ED, whereas the crura dose D(25) approached statistical significance. Seventy-five percent of the impotent men had a bulb D(25) >60% of prescribed minimum peripheral dose (mPD), whereas 80% of potent men had a bulb D(25) < or =60% mPD. Using the D(50) bulb parameter, 70% of ED men had a dose >40% mPD, whereas 90% of potent men had a dose < or =40% mPD. Similar cut points for D(25) and D(50) crura doses were 40% and 28% mPD. The crura D(25) cut point was exceeded by 50% of the ED patients and only 7% of the potent patients. CONCLUSION: This is the first study to evaluate potency preservation and radiation doses to the proximal penis by means of a validated patient-administered quality-of-life instrument. Our data confirm prior reports that radiation doses to the proximal penis are predictive of brachytherapy-induced ED. In a stepwise linear regression analysis, the strongest predictors of potency preservation were bulb D(50), postimplant prostate CT volume, and patient age. With Day 0 dosimetric evaluation, the penile bulb D(50) and D(25) should be maintained below 40% and 60% mPD, respectively, whereas the crura D(50) and D(25) should be maintained below 40% and 28% mPD, respectively, to maximize posttreatment potency.

Age Factors↗
PubMed2002

American Brachytherapy Society recommendations for reporting morbidity after prostate brachytherapy.

PURPOSE: To standardize the reporting of brachytherapy-related prostate morbidity to guide ongoing clinical practice and future investigations. METHODS: Members of the American Brachytherapy Society (ABS) with expertise in prostate brachytherapy performed a literature review and, guided by their clinical experience, formulated specific recommendations for reporting on morbidity related to prostate brachytherapy. RESULTS: The ABS recommends using validated, patient-administered health-related quality-of-life instruments for the determination of baseline and follow-up data regarding bowel, urinary, and sexual function. Both actuarial and crude incidences should be reported, along with the temporal resolution of specific complications, and correlated with the doses to the normal tissues. The International Prostate Symptom Score is recommended to assess urinary morbidity, and any dysuria, gross hematuria, urinary retention, incontinence, or medication use should be quantified. Likewise, the "Sexual Health Inventory for Men," which includes the specific erectile questions of the International Index of Erectile Function, is the preferred instrument for reporting sexual function, and the loss of sexual desire, incidence of hematospermia, painful orgasm (orgasmalgia), altered orgasm intensity, decreased ejaculatory volume, use of erectile aids, and use of hormones for androgen deprivation should be quantified. The ABS recommends adoption of the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer acute and late radiation morbidity scoring scheme for reporting rectal morbidity and noting the incidence of rectal steroid, laser, or antidiarrheal use. CONCLUSION: It is important to focus on health-related quality-of-life issues in the treatment of prostate cancer, because the control rates are very similar between appropriate treatment modalities. The ABS recommends using the International Prostate Symptom Score, International Index of Erectile Function, and Radiation Therapy Oncology Group toxicity grading criteria for the determination of urinary, sexual, and bowel function, respectively. Additional parameters for reporting urinary, rectal, and sexual morbidities are presented. These morbidities should be correlated with the doses to the normal tissues. Some of these specific recommendations may be modified if and when new data become available.

Brachytherapy↗
PubMed2002

Prostate-specific antigen spikes after permanent prostate brachytherapy.

PURPOSE: To evaluate whether any clinical, treatment, or dosimetric parameters correlated with the development of a prostate-specific antigen (PSA) spike after permanent prostate brachytherapy. METHODS AND MATERIALS: The evaluated population consisted of 218 hormone-naive patients free of biochemical or clinical failure who underwent permanent prostate brachytherapy with or without supplemental external beam radiotherapy for clinical Stage T1b-T3a adenocarcinoma of the prostate gland (1997 AJCC) between August 1995 and November 1999. No patient underwent pre- or postimplant hormonal manipulation, pretreatment seminal vesicle biopsy, or pathologic lymph node staging. In addition, none of the 218 patients possessed equivocal biochemical results (one or two consecutive PSA rises or a declining PSA >1.0 ng/mL). The median patient follow-up was 46.2 months. A PSA spike was defined as a rise of >or=0.2 ng/mL, followed by a durable decline. The clinical parameters evaluated included patient age, clinical T stage, Gleason score, pretreatment PSA level, prostate volume, brachytherapy planning volume, and patient follow-up in months. The evaluated treatment parameters included isotope and use of supplemental external beam radiotherapy. The dosimetric parameters evaluated included the minimal dose received by 90% of the prostate gland (D(90)), the percentage of the prostate volume receiving 100% (V(100)), 150%, and 200% (V(200)) of the prescribed minimal peripheral dose, and the mean, median, maximal, and minimal urethral doses. Biochemical disease-free survival was defined by the American Society for Therapeutic Radiology and Oncology consensus definition with the additional constraint that the most recent PSA level was 0.2 to 0.5 to 1.0 ng/mL (20%, 50%, and 80%, respectively, p <0.001). In Cox multivariate regression analysis, patient age, clinical stage, first postimplant PSA level, and V(150) were predictive for the development of a PSA spike. A postimplant dosimetric threshold of either <115% of the minimal peripheral dose for D(90) or <55% of the prostate volume for V(150) was strongly predictive of a spike. When the variables only determinable after the occurrence of the PSA spike were included in the multivariate analysis, V(150), preimplant PSA level, and nadir PSA were the significant predictors. CONCLUSION: Of the patients, 23.9% developed a PSA spike with a median time to development of 16.3 months and a median prespike and median postspike PSA of 0.50 ng/mL and 0.90 ng/mL, respectively. In multivariate analysis, patient age, clinical stage, first postimplant PSA level, and V(150) were predictive for the development of a PSA spike. At approximately 66 months after implantation, the PSA curves converged for spike and nonspike patients, with a median PSA level <0.1 ng/mL.

Adenocarcinoma↗
PubMed2002

Penile bulb imaging.

PURPOSE: Because of the apparent relationship between potency loss and radiation doses to the erectile bodies, there is increasing rationale for incorporating penile bulb dosimetry into treatment planning and posttreatment evaluation. Because the location and shape of the penile bulb have not been described in detail on various imaging modalities, we herein describe the anatomic boundaries of the penile bulb on computed tomography (CT), magnetic resonance imaging (MR), and transrectal ultrasound (TRUS), before and after brachytherapy. METHODS AND MATERIALS: Nonenhanced axial CT images were taken on a CTi CT Scanner (General Electric Medical Systems, Milwaukee, WI) with the patient in the supine position. Settings were at 300 ma, 140 kvp, 4-s scan time per slice, and collimation of 3 mm with data obtained at 3-mm intervals. Nonenhanced MR images were obtained with a 1.5 Tesla Signa Horizon LX Scanner using fast spin-echo T1-weighted (TR/TE, 466/20) and T2-weighted (TR/TE, 8000/90) images, with a slice thickness of 2 mm and an interslice gap of 0.5 mm. TRUS images were obtained with a Siemens SONOLINE Prima ultrasound machine at 6.0 MHz and a Winston-Barzell stepper unit. RESULTS: The penile bulb is best visualized on T2-weighted MR images in the axial, sagittal, and coronal planes, appearing as an oval-shaped, hyperintense midline structure. On axial CT imaging, the bulb of the penis is typically readily identifiable, bounded by the paired crura laterally, the corpora spongiosum anteriorly, and the levator ani posteriorly. The penile bulb is typically well visualized on transverse TRUS, but usually only faintly seen on sagittal TRUS. The bulb is partially obscured on postimplant CT and MR images, presumably because of implant-related edema. Bulb volumes vary markedly from patient to patient, ranging from 5.6 to 12.4 cc (median: 8.1 cc). CONCLUSION: Closer attention to penile erectile tissue doses should lead to improved external beam radiation and brachytherapy delivery. It will benefit the radiation oncology community to become familiar with these imaging findings, so that penile bulb dosimetry can be incorporated into our daily practice.

Humans↗
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↗
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

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↗