Biomedical subjects

Zachariah A Allen

Publications and source records attributed to Zachariah A Allen.

15 recordsLinked to original sources

PubMed2006

Temporal relationship between prostate brachytherapy and the diagnosis of colorectal cancer.

PURPOSE: To identify the location of pretreatment and posttreatment colorectal malignancies and posttreatment colorectal polyps in patients with clinically localized prostate cancer managed with brachytherapy. METHODS AND MATERIALS: From April 1995 through July 2004, 1,351 consecutive patients underwent brachytherapy for clinical stage T1b-T3a (American Joint Committee on Cancer, 2002) prostate cancer. Supplemental external beam radiotherapy (XRT) was administered to 699 patients. The median follow-up was 4.6 years. Operative and pathology reports were reviewed for all patients with pretreatment and posttreatment colorectal cancer and posttreatment colorectal polyps. Multiple parameters were evaluated for the development of colorectal cancer or colorectal polyps. RESULTS: Colorectal cancer was diagnosed in 23 and 25 patients before and after prostate brachytherapy, respectively. No differences were identified in the distribution of colorectal cancers either before or after treatment (3 and 4 rectal cancers in the pre- and postbrachytherapy cohorts). Thirty-five of the 48 colorectal cancers (73%) were diagnosed within 5 years of brachytherapy with a peak incidence 1 year after brachytherapy. One hundred ninety-two colorectal polyps were diagnosed after brachytherapy, 160 (83%) occurred within 4 years of brachytherapy, and only 27 (14%) were located in the rectum. In multivariate Cox regression analysis, prostate D(90) (minimum percentage of the dose covering 90% of the target volume) predicted for posttreatment colorectal cancer. Rectal polyps were most closely related to patient age and percent positive biopsies, whereas sigmoid/colon polyps were best predicted by patient age, planning volume, and supplemental XRT. CONCLUSIONS: Colorectal cancer was diagnosed with equal frequency before and after brachytherapy with comparable geographic distributions. In addition, the vast majority of postbrachytherapy colorectal polyps were located beyond the confines of the rectum.

Age Factors↗

PubMed2006

Androgen-deprivation therapy does not impact cause-specific or overall survival after permanent prostate brachytherapy.

PURPOSE: To determine if androgen-deprivation therapy (ADT) has an impact on cause-specific, biochemical progression-free, or overall survival after prostate brachytherapy. METHODS AND MATERIALS: From April 1995 through June 2002, 938 consecutive patients underwent brachytherapy for clinical Stage T1b to T3a (2002 AJCC) prostate cancer. All patients underwent brachytherapy more than 3 years before analysis. A total of 382 patients (40.7%) received ADT with a duration of 6 months or less in 277 and more than 6 months in 105. The median follow-up was 5.4 years. Multiple clinical, treatment, and dosimetric parameters were evaluated as predictors of cause-specific, biochemical progression-free, and overall survival. RESULTS: The 10-year cause-specific, biochemical progression-free, and overall survival rates for the entire cohort were 96.4%, 95.9%, and 78.1%, respectively. Except for biochemical progression-free survival in high-risk patients, ADT did not statistically impact any of the three survival categories. A Cox linear-regression analysis demonstrated that Gleason score was the best predictor of cause-specific survival, whereas percent-positive biopsies, prostate volume, and risk group predicted for biochemical progression-free survival. Patient age and tobacco use were the strongest predictors of overall survival. One hundred two patients have died, with 80 of the deaths a result of cardiovascular disease (54) and second malignancies (26). To date, only 12 patients have died of metastatic prostate cancer. CONCLUSIONS: After brachytherapy, androgen-deprivation therapy did not have an impact on cause-specific or overall survival for any risk group; however, ADT had a beneficial effect on biochemical progression-free survival in high-risk patients. Cardiovascular disease and second malignancies far outweighed prostate cancer as competing causes of death.

Age Factors↗

PubMed2006

Efficacy of neoadjuvant bicalutamide and dutasteride as a cytoreductive regimen before prostate brachytherapy.

OBJECTIVES: To evaluate the cytoreductive effectiveness of combined neoadjuvant bicalutamide and dutasteride before prostate brachytherapy for clinically localized prostate cancer. METHODS: From April 2003 to May 2005, 31 patients opted for cytoreduction with bicalutamide (50 mg daily) and dutasteride (0.5 mg daily). Before, and at 3 months (90 +/- 5 days) after, the initiation of medical therapy, all patients underwent a transrectal ultrasound volumetric study of the prostate gland, with ellipsoid volume determination of the prostate gland and transition zone. The variables analyzed included pretreatment and posttreatment prostate and transition zone volumes and changes in width, height, and length of the prostate gland and transition zone. A multivariate analysis was performed to identify predictors for prostate gland and transition zone volume reduction. RESULTS: Before the initiation of bicalutamide and dutasteride, the mean prostate volume was 54.3 cm3 by planimetric summation and 49.7 cm3 by ellipsoid volume calculation. After a 3-month course of combination medical therapy, the average prostate volume was 36.1 cm3 (33.6% reduction) and 32.5 cm3 (34.6% reduction) using the volumetric and ellipsoid volume determinations, respectively. Bicalutamide and dutasteride resulted in a 39.8% reduction in transition zone volume (20.8 cm3 versus 12.4 cm3). The prostate gland and transition zone dimensions (width, height, and length) decreased about 11.4% to 19.9%. CONCLUSIONS: The prostate gland and transition zone volume reductions after a 3-month course of neoadjuvant bicalutamide and dutasteride are comparable to previous reports of volume reduction using a luteinizing hormone-releasing hormone agonist with or without an antiandrogen.

5-alpha Reductase Inhibitors↗

PubMed2006

Risk factors for the development of prostate brachytherapy related urethral strictures.

PURPOSE: We identified clinical, treatment and dosimetric parameters associated with the development of urethral strictures following permanent prostate brachytherapy. MATERIALS AND METHODS: From April 1995 through April 2003, 1,186 consecutive patients underwent prostate brachytherapy for clinical stage T1b-T3a NxM0 (2002 American Joint Committee on Cancer) prostate cancer. The treatment plan included supplemental XRT in 625 patients (52.7%) and androgen deprivation therapy in 465 (39.2%). Median followup was 4.3 years. Multiple clinical, treatment and dosimetric parameters were evaluated in univariate and multivariate analyses to identify independent predictors for urethral stricture disease. RESULTS: A total of 29 patients had brachytherapy related urethral strictures. All strictures involved the BM urethra with a 9-year actuarial risk of 3.6% and a median time to development of 2.4 years. The mean radiation dose to the BM urethra was significantly greater in patients with vs without stricture (p = 0.002). On multivariate analysis the BM urethral dose and supplemental XRT predicted urethral stricture. All except 3 patients were successfully treated with urethral dilation or internal optical urethrotomy. CONCLUSIONS: Brachytherapy related urethral stricture disease correlates highly with the radiation dose to the BM urethra. Careful attention to brachytherapy preplanning and intraoperative execution along with the judicious use of supplemental XRT is essential to minimize the incidence of stricture disease.

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PubMed2006

Brachytherapy in men aged < or = 54 years with clinically localized prostate cancer.

OBJECTIVE: To report the biochemical progression-free survival (BPFS) in hormone-naive men aged < or = 54 years who underwent brachytherapy with or without supplemental external beam radiation therapy (EBRT), as despite favourable biochemical control rates with brachytherapy, there remains a reluctance to recommend non-extirpative approaches for young men with clinically localized prostate cancer. PATIENTS AND METHODS: From April 1995 to October 2002, 108 hormone-naive patients aged < or = 54 years (median 52 years, range 45-54) had permanent interstitial brachytherapy for clinical stage T1c-T2c NXM0 (2002 American Joint Committee on Cancer staging) prostate cancer. No patient had a seminal vesicle biopsy or pathological lymph node staging. The mean (sd, median) follow-up was 5.3 (1.8, 4.8) years. BPFS was defined by a prostate-specific antigen (PSA) level of < or = 0.40 ng/mL after the nadir. Risk groups were assigned using the Memorial Sloan-Kettering Cancer Center criteria. Several clinical, treatment and dosimetric variables were evaluated for their effect on BPFS. RESULTS: For the entire group, the actuarial 8-year BPFS was 96%; for low- (57 men), intermediate- (47) and high- (four) risk patients, the BPFS rates were 96%, 100% and three of four, respectively. For biochemically disease-free patients, the median PSA level after treatment was 0.05 ng/mL. In a multivariate analysis, only pretreatment PSA level predicted biochemical control, while dosimetry variables after treatment were almost statistically significant. CONCLUSIONS: Hormone-naive patients aged < or = 54 years have a high probability of a good 8-year BPFS after permanent interstitial brachytherapy with or without supplemental EBRT.

Brachytherapy↗

PubMed2006

Statins, especially atorvastatin, may improve survival following brachytherapy for clinically localized prostate cancer.

This is the largest and longest clinical study to date to examine statin usage and overall patient survival following clinically localized prostate cancer. In a retrospective examination of 938 consecutive patients with early-stage prostate cancer treated with brachytherapy, 191 patients were documented to be taking statin medications. The patients taking statin medications had significantly lower prostate-specific antigen values, percent positive biopsies, and prostate volume than those patients not taking statin medications. Statin usage resulted in a nonstatistical improvement in all survival parameters with the results most pronounced for atorvastatin. Improving prostate cancer survival with statins could have important treatment implications and could potentially limit or even improve the role of supplemental therapies. A prospective trial of statin medications in conjunction with definitive local treatment for prostate cancer is recommended.

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PubMed2005

The influence of isotope and prostate volume on urinary morbidity after prostate brachytherapy.

PURPOSE: To evaluate the influence of isotope and prostate size on International Prostate Symptom Score (IPSS) normalization, catheter dependency, and the need for surgical intervention secondary to bladder outlet obstruction after prostate brachytherapy. METHODS AND MATERIALS: Between January 1998 and June 2003, 976 consecutive patients underwent brachytherapy for clinical stage T1b-T3a (2002 American Joint Committee on Cancer) prostate cancer. Seven hundred eighty-nine (80.8%) were implanted with 103Pd and 187 (19.2%) with 125I. The median follow-up was 41.2 months. Patients were stratified into size cohorts < or = 25 cm3, 25.1-35 cm3, 35.1-45 cm3, and >45 cm3. Four hundred eighteen patients (42.8%) received androgen deprivation therapy (ADT). Four hundred eighty-six patients (49.7%) received supplemental external-beam radiation therapy (XRT). In all patients, an alpha blocker was initiated before implantation and continued at least until the IPSS returned to baseline. IPSS resolution was defined as a return to within one point of baseline. The median number of IPSS determinations per patient was 21. Clinical, treatment, and dosimetric parameters evaluated included patient age, pretreatment PSA, Gleason score, clinical T stage, percent positive biopsies, preimplant IPSS, ultrasound volume, planning volume, isotope, V(100/150/200), D(90), urethral dose (average and maximum), supplemental XRT, ADT, and the duration of ADT (< or = 6 months vs. >6 months). Catheter dependency and the need for postsurgical intervention were also evaluated. RESULTS: For both isotopes and all prostate size cohorts, IPSS peaked 1 month after implantation and returned to baseline at a mean of 1.9 months. Stratification of prostate size cohorts by isotope demonstrated no significant differences in prolonged catheter dependency (> or = 5 days), IPSS resolution, or postimplant surgical intervention. In Cox regression analysis, IPSS normalization was best predicted by preimplant IPSS, XRT, and any need for a catheter after brachytherapy. Catheter dependency correlated with prostate size and ADT, whereas the need for surgical intervention was most closely related to any catheter dependency, maximum urethral dose, ADT, and maximum IPSS increase. CONCLUSIONS: Regardless of prostate size, isotope did not impact IPSS resolution, catheter dependency, or the need for postbrachytherapy surgical intervention. Although prostate size did predict for short-term (<5 days) catheter dependency, it did not influence IPSS resolution or the need for surgical intervention.

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PubMed2005

Detailed urethral dosimetry in the evaluation of prostate brachytherapy-related urinary morbidity.

PURPOSE: To evaluate the relationship between urinary morbidity after prostate brachytherapy and urethral doses calculated at the base, midprostate, apex, and urogenital diaphragm. METHODS AND MATERIALS: From February 1998 through July 2002, 186 consecutive patients without a prior history of a transurethral resection underwent monotherapeutic brachytherapy (no supplemental external beam radiation therapy or androgen deprivation therapy) with urethral-sparing techniques (average urethral dose 100%-140% minimum peripheral dose) for clinical T1c-T2b (2002 AJCC) prostate cancer. The median follow-up was 45.5 months. Urinary morbidity was defined by time to International Prostate Symptom Score (IPSS) resolution, maximum increase in IPSS, catheter dependency, and the need for postimplant surgical intervention. An alpha blocker was initiated approximately 2 weeks before implantation and continued at least until the IPSS returned to baseline. Evaluated parameters included overall urethral dose (average and maximum), doses to the base, midprostate, apex, and urogenital diaphragm, patient age, clinical T stage, preimplant IPSS, ultrasound volume, isotope, and D90 and V100/150/200. RESULTS: Of the 186 patients, 176 (94.6%) had the urinary catheter permanently removed on the day of implantation with only 1 patient requiring a urinary catheter >5 days. No patient had a urethral stricture and only 2 patients (1.1%) required a postbrachytherapy transurethral resection of the prostate (TURP). For the entire cohort, IPSS on average peaked 2 weeks after implantation with a mean and median time to IPSS resolution of 14 and 3 weeks, respectively. For the entire cohort, only isotope predicted for IPSS resolution, while neither overall average prostatic urethra nor segmental urethral dose predicted for IPSS resolution. The maximum postimplant IPSS increase was best predicted by preimplant IPSS and the maximum apical urethral dose. CONCLUSIONS: With the routine use of prophylactic alpha blockers and strict adherence to urethral-sparing techniques, detailed urethral dosimetry did not substantially improve the ability to predict urinary morbidity. Neither the average dose to the prostatic urethra nor urethral doses stratified into base, midprostate, apex, or urogenital diaphragm segments predicted for IPSS normalization. Radiation doses of 100%-140% minimum peripheral dose are well tolerated by all segments of the prostatic urethra with resultant tumoricidal doses to foci of periurethral cancer.

Adrenergic alpha-Antagonists↗

PubMed2005

Erectile function after prostate brachytherapy.

PURPOSE: To evaluate erectile function after permanent prostate brachytherapy using a validated patient-administered questionnaire and to determine the effect of multiple clinical, treatment, and dosimetric parameters on penile erectile function. METHODS AND MATERIALS: A total of 226 patients with preimplant erectile function determined by the International Index of Erectile Function (IIEF) questionnaire underwent permanent prostate brachytherapy in two prospective randomized trials between February 2001 and January 2003 for clinical Stage T1c-T2c (2002 American Joint Committee on Cancer) prostate cancer. Of the 226 patients, 132 were potent before treatment and, of those, 128 (97%) completed and returned the IIEF questionnaire after brachytherapy. The median follow-up was 29.1 months. Potency was defined as an IIEF score of > or =13. The clinical, treatment, and dosimetric parameters evaluated included patient age; preimplant IIEF score; clinical T stage; pretreatment prostate-specific antigen level; Gleason score; elapsed time after implantation; preimplant nocturnal erections; body mass index; presence of hypertension or diabetes mellitus; tobacco consumption; the volume of the prostate gland receiving 100%, 150%, and 200% of the prescribed dose (V(100/150/200)); the dose delivered to 90% of the prostate gland (D(90)); androgen deprivation therapy; supplemental external beam radiotherapy (EBRT); isotope; prostate volume; planning volume; and radiation dose to the proximal penis. RESULTS: The 3-year actuarial rate of potency preservation was 50.5%. For patients who maintained adequate posttreatment erectile function, the preimplant IIEF score was 29, and in patients with brachytherapy-related ED, the preimplant IIEF score was 25. The median time to the onset of ED was 5.4 months. After brachytherapy, the median IIEF score was 20 in potent patients and 3 in impotent patients. On univariate analysis, the preimplant IIEF score, patient age, presence of nocturnal erections, and dose to the proximal penis predicted for postimplant erectile function. However, in multivariate analysis, only the preimplant IIEF score and the D(50) to the proximal crura were statistically significant predictors of brachytherapy-related erectile function. CONCLUSIONS: Using a patient-administered validated quality-of-life instrument, brachytherapy-induced ED occurred in 50% of patients at 3 years. On multivariate analysis, preimplant erectile function and the D(50) to the proximal crura were the best predictors of brachytherapy-related erectile function. Because the proximal penis is the most significant treatment-related predictor of brachytherapy-related ED, techniques to minimize the radiation dose to the proximal penis may result in improved rates of potency preservation.

Age Factors↗

PubMed2005

The impact of radiation dose to the urethra on brachytherapy-related dysuria.

PURPOSE: To determine the effect of urethral dose on dysuria after permanent prostate brachytherapy. METHODS AND MATERIALS: One hundred eight patients without a preimplant history of a transurethral resection underwent brachytherapy on one of two prospective randomized trials for clinical T1c-T2c (2002 AJCC) prostate cancer. Urethral dose was stratified into cohorts of <150% and 150% minimum peripheral dose (mPD) respectively. No patient received prophylactic alpha blockers. The median follow-up was 27.4 months. Dysuria was defined as pain and/or burning on urination and was evaluated on a 0-10 scale. Normalization of dysuria was defined as a return to within 1 point of baseline. Dysuria surveys were obtained before brachytherapy and at 1, 3, 6, and 12 months after implantation. Clinical, treatment, and dosimetric parameters evaluated included urethral dose, age, preimplant International Prostate Symptom Score (I-PSS), ultrasound volume, hormonal status, supplemental XRT, isotope, V(100/200), D(90), the maximum post-implant I-PSS, and the time to I-PSS resolution. RESULTS: The incidence of dysuria peaked at 85% one month after brachytherapy with subsequent resolution over time. Radiation dose to the urethra (stratified into cohorts of <150%, and 150% mPD) was not a significant predictor of prevalence, severity, or resolution of dysuria. In a multivariate analysis, isotope predicted for dysuria normalization while preimplant I-PSS and D(90) predicted for maximum dysuria; however, the area under the ROC curve and the Pearson correlation coefficient revealed weak correlations. CONCLUSIONS: Dysuria is common after brachytherapy, but typically minimal in severity. Urethral doses did not predict for either dysuria severity or normalization. Although preimplant I-PSS was the strongest predictor of maximum dysuria and isotope the best predictor for dysuria normalization, robust predictors for brachytherapy-related dysuria were not identified.

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PubMed2005

Variability of prostate brachytherapy pre-implant dosimetry: a multi-institutional analysis.

PURPOSE: To conduct a multi-institutional comparison of prostate brachytherapy pre-implant dosimetry of Pd-103 and I-125. METHODS AND MATERIALS: Eight experienced brachytherapists submitted Pd-103 and I-125 monotherapeutic and boost pre-implant dosimetry plans for central review. All 32 plans were calculated using the same transrectal ultrasound volumetric study. Seeds of any strength were acceptable, but were restricted to Theraseed Model 200 (Theragenics Inc., Buford, GA) and Oncura Oncoseed Model 6711 (Oncura, Plymouth Meeting, PA). The dosimetric analysis included evaluation of target volume, target to prostate ratio, target length, number of needles, seed activity, number of seeds, total activity, total activity divided by treatment planning volume, the use of extracapsular seeds, and average treatment margins (defined as the perpendicular distance between the prostate capsule and the 100% isodose line). Prostate coverage was defined in terms of V(100)/V(150)/V(200)/V(300) and D(100)/D(90)/D(50), whereas urethral dosimetry consisted of UV(100)/UV(150)/UV(200) and UD(90)/UD(50). RESULTS: The mean planning target volume to prostate volume ratio varied dramatically (mean 1.29, range 0.99-1.76) with the target length ranging from 3.5 to 4.5 cm. Although the prostate V(100) was >95% in all cases, the V(150) ranged from 29.9% to 92.1% and the V(200) from 6.72% to 52.5%. The urethral V(100) was 100% in all cases with six of the eight brachytherapists limiting the UV(150) to <3%. However, the median urethral dose varied by up to 50%. Treatment margins also varied significantly (average 3.98 mm, range 0.32-7.68 mm). All brachytherapists used extracapsular seeds with five implanting >25% of the seeds in extracapsular locations (range 6.4-58.2%). In addition, significant variability existed in the number of needles, number of seeds, and seed strength. CONCLUSIONS: This study highlights the substantial variability that exists regarding target volume, seed strength, dose homogeneity, treatment margins, and extracapsular seed placement, although prostate brachytherapy prescription doses are uniform. The standardization of pre-implant dosimetry is essential for meaningful multi-institutional comparisons of biochemical outcomes and morbidity.

Brachytherapy↗

PubMed2005

Prognostic significance of perineural invasion on biochemical progression-free survival after prostate brachytherapy.

OBJECTIVES: To evaluate the influence of perineural invasion (PNI) in the biopsy specimen on biochemical progression-free survival in hormone-naive patients with prostate cancer undergoing brachytherapy. METHODS: A total of 512 consecutive hormone-naive patients (173 low risk, 212 intermediate risk, and 127 high risk) underwent brachytherapy for clinical Stage T1b-T2cNxM0 (2002 American Joint Committee on Cancer staging system) prostate cancer. No patient underwent seminal vesicle or pathologic lymph node staging. All patients had undergone brachytherapy at least 3 years before analysis. The median follow-up was 5.3 years. Biochemical progression-free survival was defined by a prostate-specific antigen (PSA) cutpoint of 0.4 ng/mL or less after nadir and by the American Society for Therapeutic Radiology and Oncology consensus definition. PNI was defined as carcinoma tracking along, or around, a nerve within the perineural space. RESULTS: PNI was documented in 133 patients (26.0%). For both biochemical progression-free definitions, 94.0% and 94.9% of patients with and without PNI, respectively, remained free of biochemical progression. The median time to failure in patients with and without PNI was 17.2 and 17.9 months, respectively. For the biochemically disease-free cohort, the median posttreatment PSA level was less than 0.1 ng/mL. On univariate Cox regression analysis, the pretreatment PSA level, percentage of positive biopsies, prostate volume, and Gleason score predicted for biochemical outcome. PNI did not approach statistical significance (P = 0.671). On multivariate analysis, only pretreatment PSA (P < 0.001) and the percentage of positive biopsies (P < 0.001) maintained statistical significance. CONCLUSIONS: In hormone-naive brachytherapy patients implanted with generous periprostatic treatment margins, the presence of PNI in the biopsy specimen did not adversely affect 8-year biochemical progression-free survival.

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PubMed2005

Selecting patients with pretreatment postvoid residual urine volume less than 100 mL may favorably influence brachytherapy-related urinary morbidity.

OBJECTIVES: To evaluate the relationship between pretreatment postvoid residual urine (PVR) less than 100 mL and brachytherapy-related urinary morbidity. METHODS: A total of 204 patients with a pretreatment PVR measurement underwent permanent prostate brachytherapy with urethral-sparing techniques (100% to 140% minimal peripheral dose) for clinical Stage T1b-T2c (2002 American Joint Committee on Cancer staging system) prostate cancer. The median follow-up was 11.7 months. Evaluation of urinary morbidity consisted of the time to International Prostate Symptom Score (IPSS) resolution, length of catheter dependency, and the need for postimplant surgical intervention. IPSS resolution was defined as a return to within 1 point of the score at baseline. In all patients, an alpha-blocker was initiated before implantation and continued at least until the IPSS returned to baseline. Statistically significant predictors of urinary morbidity were determined using Cox regression analysis of multiple clinical, treatment, and dosimetric parameters. RESULTS: For the entire cohort, the mean time to IPSS resolution was 2.5 months. The urinary catheter was removed on the day of implantation in 171 patients (83.8%), with no patient remaining catheter dependent for more than 3 days. To date, no patient has required postimplant surgical intervention. On multivariate analysis, pretreatment PVR predicted for clinically irrelevant differences in IPSS resolution and did not influence catheter dependency. CONCLUSIONS: The selection of patients with a pretreatment PVR of less than 100 mL was associated with rapid IPSS resolution, the absence of prolonged (more than 3 days) catheter dependency, and the elimination of postbrachytherapy surgical intervention for bladder outlet obstruction.

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

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.

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